diff --git a/.github/workflows/tarballs.yml b/.github/workflows/tarballs.yml
index 08bd6c806..9f8456cf6 100644
--- a/.github/workflows/tarballs.yml
+++ b/.github/workflows/tarballs.yml
@@ -23,13 +23,12 @@ jobs:
           name: ${{ secrets.CACHIX_NAME }}
           authToken: ${{ secrets.CACHIX_AUTH_TOKEN }}
 
-      - uses: google-github-actions/auth@v1
-        with:
-          credentials_json: ${{ secrets.GCP_CREDENTIALS }}
-
-      - uses: google-github-actions/setup-gcloud@v1
+      - uses: google-github-actions/setup-gcloud@v0.2.0
         with:
+          version: '290.0.1'
+          service_account_key: ${{ secrets.GCS_SERVICE_ACCOUNT_KEY }}
           project_id: ${{ secrets.GCS_PROJECT }}
+          export_default_credentials: true
 
       - run: nix-build -A tarball --arg enableStatic true
 
diff --git a/.github/workflows/vere.yml b/.github/workflows/vere.yml
index 262bed278..eb94e8ea9 100644
--- a/.github/workflows/vere.yml
+++ b/.github/workflows/vere.yml
@@ -125,14 +125,13 @@ jobs:
           echo -n "$version" > ./version-string
 
       - name: upload version string artifact
-        if: inputs.upload && matrix.type == 'linux'
+        if: matrix.type == 'linux'
         uses: actions/upload-artifact@v3
         with:
           name: version-string
           path: version-string
 
       - uses: google-github-actions/auth@v1
-        if: inputs.upload
         with:
           credentials_json: ${{ secrets.GCP_CREDENTIALS }}
 
@@ -245,13 +244,12 @@ jobs:
     needs: [urbit, mingw]
     if: inputs.upload
     steps:
-      - uses: google-github-actions/auth@v1
-        with:
-          credentials_json: ${{ secrets.GCP_CREDENTIALS }}
-
-      - uses: google-github-actions/setup-gcloud@v1
+      - uses: google-github-actions/setup-gcloud@v0.2.0
         with:
+          version: '290.0.1'
+          service_account_key: ${{ secrets.GCS_SERVICE_ACCOUNT_KEY }}
           project_id: ${{ secrets.GCS_PROJECT }}
+          export_default_credentials: true
 
       - name: download version-string
         uses: actions/download-artifact@v3
diff --git a/pkg/urbit/Makefile b/pkg/urbit/Makefile
index f86731275..6b934bc79 100644
--- a/pkg/urbit/Makefile
+++ b/pkg/urbit/Makefile
@@ -2,7 +2,6 @@ include config.mk
 compat_mks := $(foreach dir,$(compat),$(wildcard compat/$(dir)/*.mk))
 include $(compat_mks)
 
-c    = $(wildcard c/*.c)
 jets = jets/tree.c $(wildcard jets/*/*.c)
 noun = $(wildcard noun/*.c)
 ur   = $(wildcard ur/*.c)
@@ -14,7 +13,7 @@ bench  = $(wildcard bench/*.c)
 
 compat := $(foreach dir,$(compat),$(wildcard compat/$(dir)/*.c))
 
-common  = $(c) $(jets) $(noun) $(ur) $(vere) $(compat)
+common  = $(jets) $(noun) $(ur) $(vere) $(compat)
 headers = $(shell find include -type f)
 
 common_objs = $(shell echo $(common) | sed 's/\.c/.o/g')
diff --git a/pkg/urbit/bench/ur_bench.c b/pkg/urbit/bench/ur_bench.c
index 91f04bbbf..4c0151357 100644
--- a/pkg/urbit/bench/ur_bench.c
+++ b/pkg/urbit/bench/ur_bench.c
@@ -7,7 +7,9 @@
 static void
 _setup(void)
 {
-  u3m_boot_lite(1 << 24);
+  u3m_init(1 << 24);
+  u3m_pave(c3y);
+  u3e_init();
 }
 
 /* _ames_writ_ex(): |hi packet from fake ~zod to fake ~nec
diff --git a/pkg/urbit/c/defs.c b/pkg/urbit/c/defs.c
deleted file mode 100644
index 93a1d9b89..000000000
--- a/pkg/urbit/c/defs.c
+++ /dev/null
@@ -1,96 +0,0 @@
-/// @file defs.c
-
-#include "c/defs.h"
-
-/* c3_pread(): full positioned read(), up to eof, retrying errors.
-*/
-ssize_t
-c3_pread(c3_i fid_i, void* buf_v, size_t len_i, off_t off_i)
-{
-  c3_w    max_w = 128;
-  c3_w    try_w = 0;
-  size_t  rem_i = len_i;
-  ssize_t ret_i;
-
-  do {
-    if (  (0 > (ret_i = pread(fid_i, buf_v, rem_i, off_i)))
-       && (  (++try_w == max_w)
-          || (  (EINTR       != errno)
-             && (EAGAIN      != errno)
-             && (EWOULDBLOCK != errno) )))
-    {
-      return -1;
-    }
-    else if ( 0 == ret_i ) {
-      break;
-    }
-    else {
-      buf_v  = (void*)((c3_c*)buf_v + ret_i);
-      rem_i -= ret_i;
-      off_i += ret_i;
-    }
-
-  }
-  while ( rem_i );
-
-  return len_i - rem_i;
-}
-
-/* c3_pwrite(): full positioned write(), retrying errors.
-*/
-ssize_t
-c3_pwrite(c3_i fid_i, const void* buf_v, size_t len_i, off_t off_i)
-{
-  c3_w    max_w = 128;
-  c3_w    try_w = 0;
-  size_t  rem_i = len_i;
-  ssize_t ret_i;
-
-  do {
-    if (  (0 > (ret_i = pwrite(fid_i, buf_v, rem_i, off_i)))
-       && (  (++try_w == max_w)
-          || (  (EINTR       != errno)
-             && (EAGAIN      != errno)
-             && (EWOULDBLOCK != errno) )))
-    {
-      return -1;
-    }
-    else {
-      buf_v  = (void*)((c3_c*)buf_v + ret_i);
-      rem_i -= ret_i;
-      off_i += ret_i;
-    }
-  }
-  while ( rem_i );
-
-  return len_i;
-}
-
-/* c3_write(): full write(), retrying errors.
-*/
-ssize_t
-c3_write(c3_i fid_i, const void* buf_v, size_t len_i)
-{
-  c3_w    max_w = 128;
-  c3_w    try_w = 0;
-  size_t  rem_i = len_i;
-  ssize_t ret_i;
-
-  do {
-    if (  (0 > (ret_i = write(fid_i, buf_v, rem_i)))
-       && (  (++try_w == max_w)
-          || (  (EINTR       != errno)
-             && (EAGAIN      != errno)
-             && (EWOULDBLOCK != errno) )))
-    {
-      return -1;
-    }
-    else {
-      buf_v  = (void*)((c3_c*)buf_v + ret_i);
-      rem_i -= ret_i;
-    }
-  }
-  while ( rem_i );
-
-  return len_i;
-}
diff --git a/pkg/urbit/compat/mingw/compat.c b/pkg/urbit/compat/mingw/compat.c
index 1bd142128..ebef5041f 100644
--- a/pkg/urbit/compat/mingw/compat.c
+++ b/pkg/urbit/compat/mingw/compat.c
@@ -144,63 +144,6 @@ int link(const char *path1, const char *path2)
   return -1;
 }
 
-ssize_t pread(int fd, void *buf, size_t count, off_t offset)
-{
-  DWORD len = 0;
-
-  OVERLAPPED overlapped = {0};
-
-  overlapped.OffsetHigh = (sizeof(off_t) <= sizeof(DWORD)) ?
-                          (DWORD)0 : (DWORD)((offset >> 32) & 0xFFFFFFFFL);
-  overlapped.Offset     = (sizeof(off_t) <= sizeof(DWORD)) ?
-                          (DWORD)offset : (DWORD)(offset & 0xFFFFFFFFL);
-
-  HANDLE h = (HANDLE)_get_osfhandle(fd);
-
-  if ( INVALID_HANDLE_VALUE == h ) {
-    errno = EBADF;
-    return -1;
-  }
-
-  if ( !ReadFile(h, buf, count, &len, &overlapped) ) {
-    DWORD err = GetLastError();
-
-    if ( ERROR_HANDLE_EOF != err ) {
-      errno = err_win_to_posix(err);
-      return -1;
-    }
-  }
-
-  return (ssize_t)len;
-}
-
-ssize_t pwrite(int fd, const void *buf, size_t count, off_t offset)
-{
-  DWORD len = 0;
-
-  OVERLAPPED overlapped = {0};
-
-  overlapped.OffsetHigh = (sizeof(off_t) <= sizeof(DWORD)) ?
-                          (DWORD)0 : (DWORD)((offset >> 32) & 0xFFFFFFFFL);
-  overlapped.Offset     = (sizeof(off_t) <= sizeof(DWORD)) ?
-                          (DWORD)offset : (DWORD)(offset & 0xFFFFFFFFL);
-
-  HANDLE h = (HANDLE)_get_osfhandle(fd);
-
-  if ( INVALID_HANDLE_VALUE == h ) {
-    errno = EBADF;
-    return -1;
-  }
-
-  if ( !WriteFile(h, buf, count, &len, &overlapped) ) {
-    errno = err_win_to_posix(GetLastError());
-    return -1;
-  }
-
-  return (ssize_t)len;
-}
-
-
 // from msys2 mingw-packages-dev patches
 // -----------------------------------------------------------------------
 
diff --git a/pkg/urbit/compat/mingw/compat.h b/pkg/urbit/compat/mingw/compat.h
index 80809f54b..56c35e90a 100644
--- a/pkg/urbit/compat/mingw/compat.h
+++ b/pkg/urbit/compat/mingw/compat.h
@@ -4,8 +4,6 @@
 #define mkdir(A, B) mkdir(A)
 
 int link(const char *path1, const char *path2);
-ssize_t pread(int fd, void *buf, size_t count, off_t offset);
-ssize_t pwrite(int fd, const void *buf, size_t count, off_t offset);
 char *realpath(const char *path, char *resolved_path);
 int fdatasync(int fd);
 int utimes(const char *path, const struct timeval times[2]);
diff --git a/pkg/urbit/compat/mingw/seh_handler.c b/pkg/urbit/compat/mingw/seh_handler.c
index 6730435e4..ecf59f0a4 100644
--- a/pkg/urbit/compat/mingw/seh_handler.c
+++ b/pkg/urbit/compat/mingw/seh_handler.c
@@ -12,7 +12,7 @@ EXCEPTION_DISPOSITION _mingw_exception_filter(
 {
     if (ExceptionRecord->ExceptionCode == EXCEPTION_ACCESS_VIOLATION &&
         ExceptionRecord->ExceptionInformation[0] == 1 &&
-        u3m_fault((void*)ExceptionRecord->ExceptionInformation[1], 1))
+        u3e_fault((void*)ExceptionRecord->ExceptionInformation[1], 1))
     {
         return ExceptionContinueExecution;
     }
diff --git a/pkg/urbit/daemon/main.c b/pkg/urbit/daemon/main.c
index d29da9824..1853ed871 100644
--- a/pkg/urbit/daemon/main.c
+++ b/pkg/urbit/daemon/main.c
@@ -9,8 +9,6 @@
 #include "rsignal.h"
 #include <vere/serf.h>
 #include "vere/vere.h"
-#include "vere/mars.h"
-#include "noun/events.h"
 #if !defined(U3_OS_mingw)
 #include <sigsegv.h>
 #endif
@@ -155,15 +153,6 @@ _main_init(void)
   //
   u3_Host.ops_u.has = c3y;
 
-  //  demand paging (ie, file-backed mapping for the loom)
-  //  is not yet supported on windows
-  //
-#ifdef U3_OS_mingw
-  u3_Host.ops_u.map = c3n;
-#else
-  u3_Host.ops_u.map = c3y;
-#endif
-
   u3_Host.ops_u.net = c3y;
   u3_Host.ops_u.lit = c3n;
   u3_Host.ops_u.nuu = c3n;
@@ -257,7 +246,6 @@ _main_getopt(c3_i argc, c3_c** argv)
     { "scry-format",         required_argument, NULL, 'Z' },
     //
     { "urth-loom",           required_argument, NULL, 5 },
-    { "no-demand",           no_argument,       NULL, 6 },
     //
     { NULL, 0, NULL, 0 },
   };
@@ -278,10 +266,6 @@ _main_getopt(c3_i argc, c3_c** argv)
         u3_Host.ops_u.lut_y = lut_w;
         break;
       }
-      case 6: {  //  no-demand
-        u3_Host.ops_u.map = c3n;
-        break;
-      }
       case 'X': {
         u3_Host.ops_u.pek_c = strdup(optarg);
         break;
@@ -646,17 +630,14 @@ _cw_usage(c3_c* bin_c)
     "utilities:\n",
     "  %s cram %.*s              jam state:\n",
     "  %s dock %.*s              copy binary:\n",
-    "  %s eval %.*s              eval hoon:\n",
     "  %s grab %.*s              measure memory usage:\n",
     "  %s info %.*s              print pier info:\n",
     "  %s meld %.*s              deduplicate snapshot:\n",
     "  %s pack %.*s              defragment snapshot:\n",
-    "  %s play %.*s              recompute events:\n",
     "  %s prep %.*s              prepare for upgrade:\n",
     "  %s next %.*s              request upgrade:\n",
     "  %s queu %.*s<at-event>    cue state:\n",
     "  %s vere ARGS <output dir>    download binary:\n",
-    "  %s vile %.*s              print keyfile:\n",
     "\n  run as a 'serf':\n",
     "    %s serf <pier> <key> <flags> <cache-size> <at-event>"
 #ifdef U3_OS_mingw
@@ -1391,8 +1372,7 @@ _cw_cram(c3_i argc, c3_c* argv[])
   c3_w arg_w;
 
   static struct option lop_u[] = {
-    { "loom",      required_argument, NULL, c3__loom },
-    { "no-demand", no_argument,       NULL, 6 },
+    { "loom", required_argument, NULL, c3__loom },
     { NULL, 0, NULL, 0 }
   };
 
@@ -1400,11 +1380,6 @@ _cw_cram(c3_i argc, c3_c* argv[])
 
   while ( -1 != (ch_i=getopt_long(argc, argv, "", lop_u, &lid_i)) ) {
     switch ( ch_i ) {
-      case 6: {  //  no-demand
-        u3_Host.ops_u.map = c3n;
-        u3C.wag_w |= u3o_no_demand;
-      } break;
-
       case c3__loom: {
         c3_w lom_w;
         c3_o res_o = _main_readw(optarg, u3a_bits + 3, &lom_w);
@@ -1457,7 +1432,7 @@ _cw_cram(c3_i argc, c3_c* argv[])
 
   //  save even on failure, as we just did all the work of deduplication
   //
-  u3m_save();
+  u3e_save();
   u3_disk_exit(log_u);
 
   if ( c3n == ret_o ) {
@@ -1472,26 +1447,18 @@ _cw_cram(c3_i argc, c3_c* argv[])
 static void
 _cw_queu(c3_i argc, c3_c* argv[])
 {
-  c3_i   ch_i, lid_i;
-  c3_w  arg_w;
-  c3_c* roc_c = 0;
+  c3_i ch_i, lid_i;
+  c3_w arg_w;
 
   static struct option lop_u[] = {
-    { "loom",        required_argument, NULL, c3__loom },
-    { "no-demand",   no_argument,       NULL, 6 },
-    { "replay-from", required_argument, NULL, 'r' },
+    { "loom", required_argument, NULL, c3__loom },
     { NULL, 0, NULL, 0 }
   };
 
   u3_Host.dir_c = _main_pier_run(argv[0]);
 
-  while ( -1 != (ch_i=getopt_long(argc, argv, "r:", lop_u, &lid_i)) ) {
+  while ( -1 != (ch_i=getopt_long(argc, argv, "", lop_u, &lid_i)) ) {
     switch ( ch_i ) {
-      case 6: {  //  no-demand
-        u3_Host.ops_u.map = c3n;
-        u3C.wag_w |= u3o_no_demand;
-      } break;
-
       case c3__loom: {
         c3_w lom_w;
         c3_o res_o = _main_readw(optarg, u3a_bits + 3, &lom_w);
@@ -1502,10 +1469,6 @@ _cw_queu(c3_i argc, c3_c* argv[])
         u3_Host.ops_u.lom_y = lom_w;
       } break;
 
-      case 'r': {
-        roc_c = strdup(optarg);
-      } break;
-
       case '?': {
         fprintf(stderr, "invalid argument\r\n");
         exit(1);
@@ -1513,13 +1476,9 @@ _cw_queu(c3_i argc, c3_c* argv[])
     }
   }
 
-  if ( !roc_c ) {
-    fprintf(stderr, "invalid command, -r $EVENT required\r\n");
-    exit(1);
-  }
-
   //  argv[optind] is always "queu"
   //
+
   if ( !u3_Host.dir_c ) {
     if ( optind + 1 < argc ) {
       u3_Host.dir_c = argv[optind + 1];
@@ -1537,10 +1496,11 @@ _cw_queu(c3_i argc, c3_c* argv[])
     exit(1);
   }
 
-  c3_d eve_d;
+  c3_c* eve_c;
+  c3_d  eve_d;
 
-  if ( 1 != sscanf(roc_c, "%" PRIu64 "", &eve_d) ) {
-    fprintf(stderr, "urbit: queu: invalid number '%s'\r\n", roc_c);
+  if ( 1 != sscanf(eve_c, "%" PRIu64 "", &eve_d) ) {
+    fprintf(stderr, "urbit: queu: invalid number '%s'\r\n", eve_c);
     exit(1);
   }
   else {
@@ -1559,7 +1519,7 @@ _cw_queu(c3_i argc, c3_c* argv[])
       exit(1);
     }
 
-    u3m_save();
+    u3e_save();
     u3_disk_exit(log_u);
 
     fprintf(stderr, "urbit: queu: rock loaded at event %" PRIu64 "\r\n", eve_d);
@@ -1576,8 +1536,7 @@ _cw_meld(c3_i argc, c3_c* argv[])
   c3_w arg_w;
 
   static struct option lop_u[] = {
-    { "loom",      required_argument, NULL, c3__loom },
-    { "no-demand", no_argument,       NULL, 6 },
+    { "loom", required_argument, NULL, c3__loom },
     { NULL, 0, NULL, 0 }
   };
 
@@ -1585,11 +1544,6 @@ _cw_meld(c3_i argc, c3_c* argv[])
 
   while ( -1 != (ch_i=getopt_long(argc, argv, "", lop_u, &lid_i)) ) {
     switch ( ch_i ) {
-      case 6: {  //  no-demand
-        u3_Host.ops_u.map = c3n;
-        u3C.wag_w |= u3o_no_demand;
-      } break;
-
       case c3__loom: {
         c3_w lom_w;
         c3_o res_o = _main_readw(optarg, u3a_bits + 3, &lom_w);
@@ -1633,9 +1587,11 @@ _cw_meld(c3_i argc, c3_c* argv[])
   u3C.wag_w |= u3o_hashless;
   u3m_boot(u3_Host.dir_c, (size_t)1 << u3_Host.ops_u.lom_y);
 
-  u3a_print_memory(stderr, "urbit: meld: gained", u3u_meld());
+  pre_w = u3a_open(u3R);
+  u3u_meld();
+  u3a_print_memory(stderr, "urbit: meld: gained", (u3a_open(u3R) - pre_w));
 
-  u3m_save();
+  u3e_save();
   u3_disk_exit(log_u);
   u3m_stop();
 }
@@ -1649,9 +1605,8 @@ _cw_next(c3_i argc, c3_c* argv[])
   c3_w arg_w;
 
   static struct option lop_u[] = {
-    { "arch",      required_argument, NULL, 'a' },
-    { "loom",      required_argument, NULL, c3__loom },
-    { "no-demand", no_argument,       NULL, 6 },
+    { "arch", required_argument, NULL, 'a' },
+    { "loom", required_argument, NULL, c3__loom },
     { NULL, 0, NULL, 0 }
   };
 
@@ -1663,11 +1618,6 @@ _cw_next(c3_i argc, c3_c* argv[])
         u3_Host.arc_c = strdup(optarg);
       } break;
 
-      case 6: {  //  no-demand
-        u3_Host.ops_u.map = c3n;
-        u3C.wag_w |= u3o_no_demand;
-      } break;
-
       case c3__loom: {
         c3_w lom_w;
         c3_o res_o = _main_readw(optarg, u3a_bits + 3, &lom_w);
@@ -1719,8 +1669,7 @@ _cw_pack(c3_i argc, c3_c* argv[])
   c3_w arg_w;
 
   static struct option lop_u[] = {
-    { "loom",      required_argument, NULL, c3__loom },
-    { "no-demand", no_argument,       NULL, 6 },
+    { "loom", required_argument, NULL, c3__loom },
     { NULL, 0, NULL, 0 }
   };
 
@@ -1728,11 +1677,6 @@ _cw_pack(c3_i argc, c3_c* argv[])
 
   while ( -1 != (ch_i=getopt_long(argc, argv, "", lop_u, &lid_i)) ) {
     switch ( ch_i ) {
-      case 6: {  //  no-demand
-        u3_Host.ops_u.map = c3n;
-        u3C.wag_w |= u3o_no_demand;
-      } break;
-
       case c3__loom: {
         c3_w lom_w;
         c3_o res_o = _main_readw(optarg, u3a_bits + 3, &lom_w);
@@ -1775,161 +1719,7 @@ _cw_pack(c3_i argc, c3_c* argv[])
   u3m_boot(u3_Host.dir_c, (size_t)1 << u3_Host.ops_u.lom_y);
   u3a_print_memory(stderr, "urbit: pack: gained", u3m_pack());
 
-  u3m_save();
-  u3_disk_exit(log_u);
-  u3m_stop();
-}
-
-/* _cw_play_slog(): print during replay.
-*/
-static void
-_cw_play_slog(u3_noun hod)
-{
-  u3_pier_tank(0, 0, u3k(u3t(hod)));
-  u3z(hod);
-}
-
-/* _cw_play_exit(): exit immediately.
-*/
-static void
-_cw_play_exit(c3_i int_i)
-{
-  //  explicit fprintf to avoid allocation in u3l_log
-  //
-  fprintf(stderr, "\r\n[received keyboard stop signal, exiting]\r\n");
-  raise(SIGINT);
-}
-
-/* _cw_play(): replay events, but better.
-*/
-static void
-_cw_play(c3_i argc, c3_c* argv[])
-{
-  c3_i ch_i, lid_i;
-  c3_w arg_w;
-  c3_o ful_o = c3n;
-  c3_o mel_o = c3n;
-
-  static struct option lop_u[] = {
-    { "loom",      required_argument, NULL, c3__loom },
-    { "auto-meld", no_argument,       NULL, 4 },
-    { "no-demand", no_argument,       NULL, 6 },
-    { "full",      required_argument, NULL, 'f' },
-    { "replay-to", no_argument,       NULL, 'n' },
-    { NULL, 0, NULL, 0 }
-  };
-
-  u3_Host.dir_c = _main_pier_run(argv[0]);
-
-  while ( -1 != (ch_i=getopt_long(argc, argv, "fn:", lop_u, &lid_i)) ) {
-    switch ( ch_i ) {
-      case 4: {  //  auto-meld
-        mel_o = c3y;
-      } break;
-
-      case 6: {  //  no-demand
-        u3_Host.ops_u.map = c3n;
-        u3C.wag_w |= u3o_no_demand;
-      } break;
-
-      case c3__loom: {
-        c3_w lom_w;
-        c3_o res_o = _main_readw(optarg, u3a_bits + 3, &lom_w);
-        if ( (c3n == res_o) || (lom_w < 20) ) {
-          fprintf(stderr, "error: --loom must be >= 20 and <= %u\r\n", u3a_bits + 2);
-          exit(1);
-        }
-        u3_Host.ops_u.lom_y = lom_w;
-      } break;
-
-      case 'f': {
-        ful_o = c3y;
-        break;
-      }
-
-      case 'n': {
-        u3_Host.ops_u.til_c = strdup(optarg);
-        break;
-      }
-
-      case '?': {
-        fprintf(stderr, "invalid argument\r\n");
-        exit(1);
-      } break;
-    }
-  }
-
-  //  argv[optind] is always "play"
-  //
-
-  if ( !u3_Host.dir_c ) {
-    if ( optind + 1 < argc ) {
-      u3_Host.dir_c = argv[optind + 1];
-    }
-    else {
-      fprintf(stderr, "invalid command, pier required\r\n");
-      exit(1);
-    }
-
-    optind++;
-  }
-
-  if ( optind + 1 != argc ) {
-    fprintf(stderr, "invalid command\r\n");
-    exit(1);
-  }
-
-  u3_disk* log_u = _cw_disk_init(u3_Host.dir_c); // XX s/b try_aquire lock
-
-#if !defined(U3_OS_mingw)
-  //  Handle SIGTSTP as if it was SIGINT.
-  //
-  //    Configured here using signal() so as to be immediately available.
-  //
-  signal(SIGTSTP, _cw_play_exit);
-#endif
-
-  if ( c3y == mel_o ) {
-    u3C.wag_w |= u3o_auto_meld;
-  }
-
-  u3C.wag_w |= u3o_hashless;
-
-  if ( c3y == ful_o ) {
-    u3l_log("mars: preparing for full replay\r\n");
-    u3m_init((size_t)1 << u3_Host.ops_u.lom_y);
-    u3e_live(u3m_pier(u3_Host.dir_c));
-    u3e_yolo();
-    u3m_pave(c3y);
-    u3j_boot(c3y);
-    u3A->eve_d = 0;
-  }
-  else {
-    u3m_boot(u3_Host.dir_c, (size_t)1 << u3_Host.ops_u.lom_y);
-  }
-
-  u3C.slog_f = _cw_play_slog;
-
-  {
-    u3_mars mar_u = {
-      .log_u = log_u,
-      .dir_c = u3_Host.dir_c,
-      .sen_d = u3A->eve_d,
-      .dun_d = u3A->eve_d,
-      .mug_l = u3r_mug(u3A->roc)
-    };
-    c3_d    eve_d = 0;
-    c3_c*   eve_c = u3_Host.ops_u.til_c;
-
-    if ( u3_Host.ops_u.til_c ) {
-      if ( 1 != sscanf(eve_c, "%" PRIu64 "", &eve_d) ) {
-        fprintf(stderr, "mars: replay-to invalid: '%s'\r\n", eve_c);
-      }
-    }
-
-    u3_mars_play(&mar_u, eve_d);
-  }
-
+  u3e_save();
   u3_disk_exit(log_u);
   u3m_stop();
 }
@@ -1943,8 +1733,7 @@ _cw_prep(c3_i argc, c3_c* argv[])
   c3_w arg_w;
 
   static struct option lop_u[] = {
-    { "loom",      required_argument, NULL, c3__loom },
-    { "no-demand", no_argument,       NULL, 6 },
+    { "loom", required_argument, NULL, c3__loom },
     { NULL, 0, NULL, 0 }
   };
 
@@ -1952,11 +1741,6 @@ _cw_prep(c3_i argc, c3_c* argv[])
 
   while ( -1 != (ch_i=getopt_long(argc, argv, "", lop_u, &lid_i)) ) {
     switch ( ch_i ) {
-      case 6: {  //  no-demand
-        u3_Host.ops_u.map = c3n;
-        u3C.wag_w |= u3o_no_demand;
-      } break;
-
       case c3__loom: {
         c3_w lom_w;
         c3_o res_o = _main_readw(optarg, u3a_bits + 3, &lom_w);
@@ -2120,8 +1904,7 @@ _cw_vile(c3_i argc, c3_c* argv[])
   c3_w arg_w;
 
   static struct option lop_u[] = {
-    { "loom",      required_argument, NULL, c3__loom },
-    { "no-demand", no_argument,       NULL, 6 },
+    { "loom", required_argument, NULL, c3__loom },
     { NULL, 0, NULL, 0 }
   };
 
@@ -2129,11 +1912,6 @@ _cw_vile(c3_i argc, c3_c* argv[])
 
   while ( -1 != (ch_i=getopt_long(argc, argv, "", lop_u, &lid_i)) ) {
     switch ( ch_i ) {
-      case 6: {  //  no-demand
-        u3_Host.ops_u.map = c3n;
-        u3C.wag_w |= u3o_no_demand;
-      } break;
-
       case c3__loom: {
         c3_w lom_w;
         c3_o res_o = _main_readw(optarg, u3a_bits + 3, &lom_w);
@@ -2221,13 +1999,11 @@ _cw_utils(c3_i argc, c3_c* argv[])
   //    $@  ~                                             ::  usage
   //    $%  [%cram dir=@t]                                ::  jam state
   //        [%dock dir=@t]                                ::  copy binary
-  //        [%eval ~]                                     ::  eval hoon
   //        [?(%grab %mass) dir=@t]                       ::  gc
   //        [%info dir=@t]                                ::  print
   //        [%meld dir=@t]                                ::  deduplicate
   //        [?(%next %upgrade) dir=@t]                    ::  upgrade
   //        [%pack dir=@t]                                ::  defragment
-  //        [%play dir=@t]                                ::  recompute
   //        [%prep dir=@t]                                ::  prep upgrade
   //        [%queu dir=@t eve=@ud]                        ::  cue state
   //        [?(%vere %fetch-vere) dir=@t]                 ::  download vere
@@ -2268,7 +2044,6 @@ _cw_utils(c3_i argc, c3_c* argv[])
     case c3__meld: _cw_meld(argc, argv); return 1;
     case c3__next: _cw_next(argc, argv); return 2; // continue on
     case c3__pack: _cw_pack(argc, argv); return 1;
-    case c3__play: _cw_play(argc, argv); return 1;
     case c3__prep: _cw_prep(argc, argv); return 2; // continue on
     case c3__queu: _cw_queu(argc, argv); return 1;
     case c3__vere: _cw_vere(argc, argv); return 1;
@@ -2406,12 +2181,6 @@ main(c3_i   argc,
         u3C.wag_w |= u3o_debug_ram;
       }
 
-      /*  Set no-demand flag.
-      */
-      if ( !_(u3_Host.ops_u.map) ) {
-        u3C.wag_w |= u3o_no_demand;
-      }
-
       /*  Set profile flag.
       */
       if ( _(u3_Host.ops_u.pro) ) {
diff --git a/pkg/urbit/daemon/whereami.c b/pkg/urbit/daemon/whereami.c
index 5e31a2490..290005766 100644
--- a/pkg/urbit/daemon/whereami.c
+++ b/pkg/urbit/daemon/whereami.c
@@ -1,6 +1,4 @@
-// (‑●‑●)> dual licensed under the WTFPL v2 and MIT licenses
-//   without any warranty.
-//   by Gregory Pakosz (@gpakosz)
+// (‑●‑●)> released under the WTFPL v2 license, by Gregory Pakosz (@gpakosz)
 // https://github.com/gpakosz/whereami
 
 // in case you want to #include "whereami.c" in a larger compilation unit
@@ -12,15 +10,6 @@
 extern "C" {
 #endif
 
-#if defined(__linux__) || defined(__CYGWIN__)
-#undef _DEFAULT_SOURCE
-#define _DEFAULT_SOURCE
-#elif defined(__APPLE__)
-#undef _DARWIN_C_SOURCE
-#define _DARWIN_C_SOURCE
-#define _DARWIN_BETTER_REALPATH
-#endif
-
 #if !defined(WAI_MALLOC) || !defined(WAI_FREE) || !defined(WAI_REALLOC)
 #include <stdlib.h>
 #endif
@@ -57,9 +46,7 @@ extern "C" {
 
 #if defined(_WIN32)
 
-#ifndef WIN32_LEAN_AND_MEAN
 #define WIN32_LEAN_AND_MEAN
-#endif
 #if defined(_MSC_VER)
 #pragma warning(push, 3)
 #endif
@@ -68,7 +55,6 @@ extern "C" {
 #if defined(_MSC_VER)
 #pragma warning(pop)
 #endif
-#include <stdbool.h>
 
 static int WAI_PREFIX(getModulePath_)(HMODULE module, char* out, int capacity, int* dirname_length)
 {
@@ -76,9 +62,8 @@ static int WAI_PREFIX(getModulePath_)(HMODULE module, char* out, int capacity, i
   wchar_t buffer2[MAX_PATH];
   wchar_t* path = NULL;
   int length = -1;
-  bool ok;
 
-  for (ok = false; !ok; ok = true)
+  for (;;)
   {
     DWORD size;
     int length_, length__;
@@ -134,12 +119,14 @@ static int WAI_PREFIX(getModulePath_)(HMODULE module, char* out, int capacity, i
     }
 
     length = length__;
+
+    break;
   }
 
   if (path != buffer1)
     WAI_FREE(path);
 
-  return ok ? length : -1;
+  return length;
 }
 
 WAI_NOINLINE WAI_FUNCSPEC
@@ -169,7 +156,7 @@ int WAI_PREFIX(getModulePath)(char* out, int capacity, int* dirname_length)
   return length;
 }
 
-#elif defined(__linux__) || defined(__CYGWIN__) || defined(__sun) || defined(WAI_USE_PROC_SELF_EXE)
+#elif defined(__linux__) || defined(__CYGWIN__) || defined(__sun)
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -183,7 +170,6 @@ int WAI_PREFIX(getModulePath)(char* out, int capacity, int* dirname_length)
 #define __STDC_FORMAT_MACROS
 #endif
 #include <inttypes.h>
-#include <stdbool.h>
 
 #if !defined(WAI_PROC_SELF_EXE)
 #if defined(__sun)
@@ -199,9 +185,8 @@ int WAI_PREFIX(getExecutablePath)(char* out, int capacity, int* dirname_length)
   char buffer[PATH_MAX];
   char* resolved = NULL;
   int length = -1;
-  bool ok;
 
-  for (ok = false; !ok; ok = true)
+  for (;;)
   {
     resolved = realpath(WAI_PROC_SELF_EXE, buffer);
     if (!resolved)
@@ -226,9 +211,11 @@ int WAI_PREFIX(getExecutablePath)(char* out, int capacity, int* dirname_length)
         }
       }
     }
+
+    break;
   }
 
-  return ok ? length : -1;
+  return length;
 }
 
 #if !defined(WAI_PROC_SELF_MAPS_RETRY)
@@ -248,7 +235,6 @@ int WAI_PREFIX(getExecutablePath)(char* out, int capacity, int* dirname_length)
 #include <sys/mman.h>
 #include <unistd.h>
 #endif
-#include <stdbool.h>
 
 WAI_NOINLINE WAI_FUNCSPEC
 int WAI_PREFIX(getModulePath)(char* out, int capacity, int* dirname_length)
@@ -295,24 +281,15 @@ int WAI_PREFIX(getModulePath)(char* out, int capacity, int* dirname_length)
               &&buffer[length - 4] == '.')
           {
             int fd = open(path, O_RDONLY);
-            if (fd == -1)
-            {
-              length = -1; // retry
-              break;
-            }
+            char* begin;
+            char* p;
 
-            char* begin = (char*)mmap(0, offset, PROT_READ, MAP_SHARED, fd, 0);
-            if (begin == MAP_FAILED)
-            {
-              close(fd);
-              length = -1; // retry
-              break;
-            }
+            begin = (char*)mmap(0, offset, PROT_READ, MAP_SHARED, fd, 0);
+            p = begin + offset;
 
-            char* p = begin + offset - 30; // minimum size of local file header
             while (p >= begin) // scan backwards
             {
-              if (*((uint32_t*)p) == 0x04034b50UL) // local file header signature found
+              if (*((uint32_t*)p) == 0x04034b50UL) // local file header found
               {
                 uint16_t length_ = *((uint16_t*)(p + 26));
 
@@ -326,7 +303,7 @@ int WAI_PREFIX(getModulePath)(char* out, int capacity, int* dirname_length)
                 break;
               }
 
-              --p;
+              p -= 4;
             }
 
             munmap(begin, offset);
@@ -364,17 +341,20 @@ int WAI_PREFIX(getModulePath)(char* out, int capacity, int* dirname_length)
       break;
   }
 
+  if (maps)
+    fclose(maps);
+
   return length;
 }
 
 #elif defined(__APPLE__)
 
+#define _DARWIN_BETTER_REALPATH
 #include <mach-o/dyld.h>
 #include <limits.h>
 #include <stdlib.h>
 #include <string.h>
 #include <dlfcn.h>
-#include <stdbool.h>
 
 WAI_FUNCSPEC
 int WAI_PREFIX(getExecutablePath)(char* out, int capacity, int* dirname_length)
@@ -384,9 +364,8 @@ int WAI_PREFIX(getExecutablePath)(char* out, int capacity, int* dirname_length)
   char* path = buffer1;
   char* resolved = NULL;
   int length = -1;
-  bool ok;
 
-  for (ok = false; !ok; ok = true)
+  for (;;)
   {
     uint32_t size = (uint32_t)sizeof(buffer1);
     if (_NSGetExecutablePath(path, &size) == -1)
@@ -419,12 +398,14 @@ int WAI_PREFIX(getExecutablePath)(char* out, int capacity, int* dirname_length)
         }
       }
     }
+
+    break;
   }
 
   if (path != buffer1)
     WAI_FREE(path);
 
-  return ok ? length : -1;
+  return length;
 }
 
 WAI_NOINLINE WAI_FUNCSPEC
@@ -478,7 +459,6 @@ int WAI_PREFIX(getModulePath)(char* out, int capacity, int* dirname_length)
 #include <stdlib.h>
 #include <string.h>
 #include <dlfcn.h>
-#include <stdbool.h>
 
 #if !defined(WAI_PROC_SELF_EXE)
 #define WAI_PROC_SELF_EXE "/proc/self/exefile"
@@ -492,9 +472,8 @@ int WAI_PREFIX(getExecutablePath)(char* out, int capacity, int* dirname_length)
   char* resolved = NULL;
   FILE* self_exe = NULL;
   int length = -1;
-  bool ok;
 
-  for (ok = false; !ok; ok = true)
+  for (;;)
   {
     self_exe = fopen(WAI_PROC_SELF_EXE, "r");
     if (!self_exe)
@@ -526,11 +505,13 @@ int WAI_PREFIX(getExecutablePath)(char* out, int capacity, int* dirname_length)
         }
       }
     }
+
+    break;
   }
 
   fclose(self_exe);
 
-  return ok ? length : -1;
+  return length;
 }
 
 WAI_FUNCSPEC
@@ -578,7 +559,7 @@ int WAI_PREFIX(getModulePath)(char* out, int capacity, int* dirname_length)
 }
 
 #elif defined(__DragonFly__) || defined(__FreeBSD__) || \
-      defined(__FreeBSD_kernel__) || defined(__NetBSD__) || defined(__OpenBSD__)
+      defined(__FreeBSD_kernel__) || defined(__NetBSD__)
 
 #include <limits.h>
 #include <stdlib.h>
@@ -586,116 +567,6 @@ int WAI_PREFIX(getModulePath)(char* out, int capacity, int* dirname_length)
 #include <sys/types.h>
 #include <sys/sysctl.h>
 #include <dlfcn.h>
-#include <stdbool.h>
-
-#if defined(__OpenBSD__)
-
-#include <unistd.h>
-
-WAI_FUNCSPEC
-int WAI_PREFIX(getExecutablePath)(char* out, int capacity, int* dirname_length)
-{
-  char buffer1[4096];
-  char buffer2[PATH_MAX];
-  char buffer3[PATH_MAX];
-  char** argv = (char**)buffer1;
-  char* resolved = NULL;
-  int length = -1;
-  bool ok;
-
-  for (ok = false; !ok; ok = true)
-  {
-    int mib[4] = { CTL_KERN, KERN_PROC_ARGS, getpid(), KERN_PROC_ARGV };
-    size_t size;
-
-    if (sysctl(mib, 4, NULL, &size, NULL, 0) != 0)
-        break;
-
-    if (size > sizeof(buffer1))
-    {
-      argv = (char**)WAI_MALLOC(size);
-      if (!argv)
-        break;
-    }
-
-    if (sysctl(mib, 4, argv, &size, NULL, 0) != 0)
-        break;
-
-    if (strchr(argv[0], '/'))
-    {
-      resolved = realpath(argv[0], buffer2);
-      if (!resolved)
-        break;
-    }
-    else
-    {
-      const char* PATH = getenv("PATH");
-      if (!PATH)
-        break;
-
-      size_t argv0_length = strlen(argv[0]);
-
-      const char* begin = PATH;
-      while (1)
-      {
-        const char* separator = strchr(begin, ':');
-        const char* end = separator ? separator : begin + strlen(begin);
-
-        if (end - begin > 0)
-        {
-          if (*(end -1) == '/')
-            --end;
-
-          if (((end - begin) + 1 + argv0_length + 1) <= sizeof(buffer2))
-          {
-            memcpy(buffer2, begin, end - begin);
-            buffer2[end - begin] = '/';
-            memcpy(buffer2 + (end - begin) + 1, argv[0], argv0_length + 1);
-
-            resolved = realpath(buffer2, buffer3);
-            if (resolved)
-              break;
-          }
-        }
-
-        if (!separator)
-          break;
-
-        begin = ++separator;
-      }
-
-      if (!resolved)
-        break;
-    }
-
-    length = (int)strlen(resolved);
-    if (length <= capacity)
-    {
-      memcpy(out, resolved, length);
-
-      if (dirname_length)
-      {
-        int i;
-
-        for (i = length - 1; i >= 0; --i)
-        {
-          if (out[i] == '/')
-          {
-            *dirname_length = i;
-            break;
-          }
-        }
-      }
-    }
-  }
-
-  if (argv != (char**)buffer1)
-    WAI_FREE(argv);
-
-  return ok ? length : -1;
-}
-
-#else
 
 WAI_FUNCSPEC
 int WAI_PREFIX(getExecutablePath)(char* out, int capacity, int* dirname_length)
@@ -705,18 +576,13 @@ int WAI_PREFIX(getExecutablePath)(char* out, int capacity, int* dirname_length)
   char* path = buffer1;
   char* resolved = NULL;
   int length = -1;
-  bool ok;
 
-  for (ok = false; !ok; ok = true)
+  for (;;)
   {
-#if defined(__NetBSD__)
-    int mib[4] = { CTL_KERN, KERN_PROC_ARGS, -1, KERN_PROC_PATHNAME };
-#else
     int mib[4] = { CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1 };
-#endif
     size_t size = sizeof(buffer1);
 
-    if (sysctl(mib, 4, path, &size, NULL, 0) != 0)
+    if (sysctl(mib, (u_int)(sizeof(mib) / sizeof(mib[0])), path, &size, NULL, 0) != 0)
         break;
 
     resolved = realpath(path, buffer2);
@@ -742,12 +608,15 @@ int WAI_PREFIX(getExecutablePath)(char* out, int capacity, int* dirname_length)
         }
       }
     }
+
+    break;
   }
 
-  return ok ? length : -1;
-}
+  if (path != buffer1)
+    WAI_FREE(path);
 
-#endif
+  return length;
+}
 
 WAI_NOINLINE WAI_FUNCSPEC
 int WAI_PREFIX(getModulePath)(char* out, int capacity, int* dirname_length)
@@ -801,4 +670,4 @@ int WAI_PREFIX(getModulePath)(char* out, int capacity, int* dirname_length)
 
 #ifdef __cplusplus
 }
-#endif
\ No newline at end of file
+#endif
diff --git a/pkg/urbit/daemon/whereami.h b/pkg/urbit/daemon/whereami.h
index d5edffb8c..6c81af818 100644
--- a/pkg/urbit/daemon/whereami.h
+++ b/pkg/urbit/daemon/whereami.h
@@ -1,6 +1,4 @@
-// (‑●‑●)> dual licensed under the WTFPL v2 and MIT licenses
-//   without any warranty.
-//   by Gregory Pakosz (@gpakosz)
+// (‑●‑●)> released under the WTFPL v2 license, by Gregory Pakosz (@gpakosz)
 // https://github.com/gpakosz/whereami
 
 #ifndef WHEREAMI_H
@@ -64,4 +62,4 @@ int WAI_PREFIX(getModulePath)(char* out, int capacity, int* dirname_length);
 }
 #endif
 
-#endif // #ifndef WHEREAMI_H
\ No newline at end of file
+#endif // #ifndef WHEREAMI_H
diff --git a/pkg/urbit/include/all.h b/pkg/urbit/include/all.h
index 402b88583..ae647d865 100644
--- a/pkg/urbit/include/all.h
+++ b/pkg/urbit/include/all.h
@@ -11,6 +11,7 @@
 #   include "noun/aliases.h"   //  general u3
 
 #   include "noun/allocate.h"  //  u3a: allocation
+#   include "noun/events.h"    //  u3e: persistence
 #   include "noun/hashtable.h" //  u3h: hashtables
 #   include "noun/imprison.h"  //  u3i: noun construction
 #   include "noun/jets.h"      //  u3j: jet control
diff --git a/pkg/urbit/include/c/defs.h b/pkg/urbit/include/c/defs.h
index a667b85a2..b649a8866 100644
--- a/pkg/urbit/include/c/defs.h
+++ b/pkg/urbit/include/c/defs.h
@@ -1,11 +1,6 @@
 #ifndef C3_DEFS_H
 #define C3_DEFS_H
 
-#include "c/portable.h"
-#include "c/types.h"
-
-#include <errno.h>
-
   /** Loobeans - inverse booleans to match nock.
   **/
 #     define c3y      0
@@ -162,28 +157,4 @@
 #     define c3_fopen(a, b) ({                                  \
         fopen(a, b);})
 
-  /** i/o wrappers
-  ***
-  ***  these handle partial success and retry ephemeral errors
-  ***  up to hardcoded max try count, either reading/writing fully
-  ***  (up to EOF on read) or returning on error.
-  ***
-  ***  a wrapper for read() is not provided, as file cursor position
-  ***  is undefined on error. use pread() or loop yourself.
-  **/
-    /* c3_pread(): full positioned read(), up to eof, retrying errors.
-    */
-      ssize_t
-      c3_pread(c3_i fid_i, void* buf_v, size_t len_i, off_t off_i);
-
-    /* c3_pwrite(): full positioned write(), retrying errors.
-    */
-      ssize_t
-      c3_pwrite(c3_i fid_i, const void* buf_v, size_t len_i, off_t off_i);
-
-    /* c3_write(): full write(), retrying errors.
-    */
-      ssize_t
-      c3_write(c3_i fid_i, const void* buf_v, size_t len_i);
-
 #endif /* ifndef C3_DEFS_H */
diff --git a/pkg/urbit/include/noun/allocate.h b/pkg/urbit/include/noun/allocate.h
index 03b219c08..964de538b 100644
--- a/pkg/urbit/include/noun/allocate.h
+++ b/pkg/urbit/include/noun/allocate.h
@@ -645,11 +645,6 @@
           void
           u3a_print_memory(FILE* fil_u, c3_c* cap_c, c3_w wor_w);
 
-        /* u3a_prof(): mark/measure/print memory profile. RETAIN.
-        */
-          c3_w
-          u3a_prof(FILE* fil_u, c3_w den_w, u3_noun mas);
-
         /* u3a_maid(): maybe print memory.
         */
           c3_w
diff --git a/pkg/urbit/include/noun/events.h b/pkg/urbit/include/noun/events.h
index a8860f53d..c1b95cde8 100644
--- a/pkg/urbit/include/noun/events.h
+++ b/pkg/urbit/include/noun/events.h
@@ -39,22 +39,13 @@
     /* u3e_pool: entire memory system.
     */
       typedef struct _u3e_pool {
-        c3_c*     dir_c;                     //  checkpoint dir
+        c3_c*     dir_c;                     //  path to
         c3_w      dit_w[u3a_pages >> 5];     //  touched since last save
         c3_w      pag_w;                     //  number of pages (<= u3a_pages)
-        c3_w      gar_w;                     //  guard page
         u3e_image nor_u;                     //  north segment
         u3e_image sou_u;                     //  south segment
       } u3e_pool;
 
-    /* u3e_flaw: loom fault result.
-    */
-      typedef enum {
-        u3e_flaw_sham = 0,                  //  bogus state
-        u3e_flaw_base = 1,                  //  vm fail (mprotect)
-        u3e_flaw_meme = 2,                  //  bail:meme
-        u3e_flaw_good = 3                   //  handled
-      } u3e_flaw;
 
   /** Globals.
   **/
@@ -69,26 +60,31 @@
 
   /** Functions.
   **/
-    /* u3e_fault(): handle a memory fault.
+    /* u3e_fault(): handle a memory event with libsigsegv protocol.
     */
-      u3e_flaw
-      u3e_fault(u3_post low_p, u3_post hig_p, u3_post off_p);
+      c3_i
+      u3e_fault(void* adr_v, c3_i ser_i);
 
-    /* u3e_save(): update the checkpoint.
+    /* u3e_save():
     */
       void
-      u3e_save(u3_post low_p, u3_post hig_p);
+      u3e_save(void);
 
     /* u3e_live(): start the persistence system.  Return c3y if no image.
     */
       c3_o
-      u3e_live(c3_c* dir_c);
+      u3e_live(c3_o nuu_o, c3_c* dir_c);
 
     /* u3e_yolo(): disable dirty page tracking, read/write whole loom.
     */
       c3_o
       u3e_yolo(void);
 
+    /* u3e_foul(): dirty all the pages of the loom.
+    */
+      void
+      u3e_foul(void);
+
     /* u3e_init(): initialize guard page tracking.
     */
       void
diff --git a/pkg/urbit/include/noun/manage.h b/pkg/urbit/include/noun/manage.h
index 0ff5b504f..72e29f533 100644
--- a/pkg/urbit/include/noun/manage.h
+++ b/pkg/urbit/include/noun/manage.h
@@ -8,11 +8,6 @@
         c3_d
         u3m_boot(c3_c* dir_c, size_t len_i);
 
-      /* u3m_pier(): make a pier.
-      */
-        c3_c*
-        u3m_pier(c3_c* dir_c);
-
       /* u3m_boot_lite(): start without checkpointing.
       */
         c3_d
@@ -39,21 +34,6 @@
         c3_i
         u3m_bail(c3_m how_m) __attribute__((noreturn));
 
-      /* u3m_fault(): handle a memory event with libsigsegv protocol.
-      */
-        c3_i
-        u3m_fault(void* adr_v, c3_i ser_i);
-
-      /* u3m_save(): update the checkpoint.
-      */
-        void
-        u3m_save(void);
-
-      /* u3m_ward(): tend the guard page.
-      */
-        void
-        u3m_ward(void);
-
       /* u3m_init(): start the environment.
       */
         void
@@ -137,7 +117,7 @@
       /* u3m_water(): produce high and low watermarks.  Asserts u3R == u3H.
       */
         void
-        u3m_water(u3_post* low_p, u3_post* hig_p);
+        u3m_water(c3_w *low_w, c3_w *hig_w);
 
       /* u3m_pretty(): dumb prettyprint to string.  RETAIN.
       */
diff --git a/pkg/urbit/include/noun/options.h b/pkg/urbit/include/noun/options.h
index 26d081f4e..c1fd58c40 100644
--- a/pkg/urbit/include/noun/options.h
+++ b/pkg/urbit/include/noun/options.h
@@ -22,17 +22,15 @@
     **  _check flags are set inside u3 and heard outside it.
     */
       enum u3o_flag {                         //  execution flags
-        u3o_debug_ram =     1 <<  0,          //  debug: gc
-        u3o_debug_cpu =     1 <<  1,          //  debug: profile
-        u3o_check_corrupt = 1 <<  2,          //  check: gc memory
-        u3o_check_fatal =   1 <<  3,          //  check: unrecoverable
-        u3o_verbose =       1 <<  4,          //  be remarkably wordy
-        u3o_dryrun =        1 <<  5,          //  don't touch checkpoint
-        u3o_quiet =         1 <<  6,          //  disable ~&
-        u3o_hashless =      1 <<  7,          //  disable hashboard
-        u3o_trace =         1 <<  8,          //  enables trace dumping
-        u3o_auto_meld =     1 <<  9,          //  enables meld under pressure
-        u3o_no_demand =     1 << 10           //  disables demand paging
+        u3o_debug_ram =     0x1,              //  debug: gc
+        u3o_debug_cpu =     0x2,              //  debug: profile
+        u3o_check_corrupt = 0x4,              //  check: gc memory
+        u3o_check_fatal =   0x8,              //  check: unrecoverable
+        u3o_verbose =       0x10,             //  be remarkably wordy
+        u3o_dryrun =        0x20,             //  don't touch checkpoint
+        u3o_quiet =         0x40,             //  disable ~&
+        u3o_hashless =      0x80,             //  disable hashboard
+        u3o_trace =         0x100             //  enables trace dumping
       };
 
   /** Globals.
diff --git a/pkg/urbit/include/noun/urth.h b/pkg/urbit/include/noun/urth.h
index 2c6617f4b..3fe29792e 100644
--- a/pkg/urbit/include/noun/urth.h
+++ b/pkg/urbit/include/noun/urth.h
@@ -5,7 +5,7 @@
     **/
       /* u3u_meld(): globally deduplicate memory.
       */
-        c3_w
+        void
         u3u_meld(void);
 
       /* u3u_cram(): globably deduplicate memory, and write a rock to disk.
diff --git a/pkg/urbit/include/noun/vortex.h b/pkg/urbit/include/noun/vortex.h
index ed24e691e..92320620a 100644
--- a/pkg/urbit/include/noun/vortex.h
+++ b/pkg/urbit/include/noun/vortex.h
@@ -87,11 +87,6 @@
       u3_noun
       u3v_poke(u3_noun ovo);
 
-    /* u3v_poke_sure(): inject an event, saving new state if successful.
-    */
-      c3_o
-      u3v_poke_sure(c3_w mil_w, u3_noun eve, u3_noun* pro);
-
     /* u3v_tank(): dump single tank.
     */
       void
diff --git a/pkg/urbit/include/vere/db/lmdb.h b/pkg/urbit/include/vere/db/lmdb.h
index a3ca6a414..573a68fa4 100644
--- a/pkg/urbit/include/vere/db/lmdb.h
+++ b/pkg/urbit/include/vere/db/lmdb.h
@@ -6,17 +6,6 @@
   /* lmdb api wrapper
   */
 
-    /* u3_lmdb_iter: event iterator
-    */
-    typedef struct _u3_lmdb_walk {
-      MDB_txn*    txn_u;  //  transaction handle
-      MDB_dbi     mdb_u;  //  db handle
-      MDB_cursor* cur_u;  //  db cursor
-      c3_o        red_o;  //  have we read from this yet?
-      c3_d        nex_d;  //  next event number
-      c3_d        las_d;  //  final event number, inclusive
-    } u3_lmdb_walk;
-
     /* u3_lmdb_init(): open lmdb at [pax_c], mmap up to [siz_i].
     */
       MDB_env*
@@ -72,22 +61,4 @@
                         size_t      val_i,
                         void*       val_p);
 
-    /* u3_lmdb_walk_init(): initialize db iterator.
-    */
-      c3_o
-      u3_lmdb_walk_init(MDB_env*      env_u,
-                        u3_lmdb_walk* itr_u,
-                        c3_d          nex_d,
-                        c3_d          las_d);
-
-    /* u3_lmdb_walk_next(): synchronously read next event from iterator.
-    */
-      c3_o
-      u3_lmdb_walk_next(u3_lmdb_walk* itr_u, size_t* len_i, void** buf_v);
-
-    /* u3_lmdb_walk_done(): close iterator.
-    */
-      void
-      u3_lmdb_walk_done(u3_lmdb_walk* itr_u);
-
 #endif /* ifndef U3_VERE_DB_LMDB_H */
diff --git a/pkg/urbit/include/vere/mars.h b/pkg/urbit/include/vere/mars.h
deleted file mode 100644
index a445af0ac..000000000
--- a/pkg/urbit/include/vere/mars.h
+++ /dev/null
@@ -1,22 +0,0 @@
-#ifndef U3_VERE_MARS_H
-#define U3_VERE_MARS_H
-
-  /** Data types.
-  **/
-    /* u3_mars: the urbit state machine.
-    */
-      typedef struct _u3_mars {
-        c3_d     key_d[4];                  //  disk key
-        u3_disk* log_u;                     //  event log
-        c3_c*    dir_c;                     //  execution directory (pier)
-        c3_d     sen_d;                     //  last event requested
-        c3_d     dun_d;                     //  last event processed
-        c3_l     mug_l;                     //  hash of state
-      } u3_mars;
-
-    /* u3_mars_play(): replay logged events up to [eve_d].
-    */
-      void
-      u3_mars_play(u3_mars* mar_u, c3_d eve_d);
-
-#endif /* ifndef U3_VERE_MARS_H */
diff --git a/pkg/urbit/include/vere/vere.h b/pkg/urbit/include/vere/vere.h
index ed718fd79..d02771343 100644
--- a/pkg/urbit/include/vere/vere.h
+++ b/pkg/urbit/include/vere/vere.h
@@ -313,7 +313,6 @@
         c3_c*   puf_c;                      //  -Z, scry result format
         c3_o    con;                        //      run conn
         c3_o    doc;                        //      dock binary in pier
-        c3_o    map;                        //  --no-demand (reversed)
       } u3_opts;
 
     /* u3_host: entire host.
@@ -563,10 +562,6 @@
           u3_info          put_u;               //  write queue
         } u3_disk;
 
-      /* u3_disk_walk: opaque event log iterator.
-      */
-        typedef struct _u3_disk_walk u3_disk_walk;
-
       /* u3_psat: pier state.
       */
         typedef enum {
@@ -947,23 +942,6 @@
         u3_disk*
         u3_disk_init(c3_c* pax_c, u3_disk_cb cb_u);
 
-      /* u3_disk_etch(): serialize an event for persistence. RETAIN [eve]
-      */
-        size_t
-        u3_disk_etch(u3_disk* log_u,
-                     u3_noun    eve,
-                     c3_l     mug_l,
-                     c3_y**   out_y);
-
-      /* u3_disk_sift(): parse a persisted event buffer.
-      */
-        c3_o
-        u3_disk_sift(u3_disk* log_u,
-                     size_t   len_i,
-                     c3_y*    dat_y,
-                     c3_l*    mug_l,
-                     u3_noun*   job);
-
       /* u3_disk_info(): status info as $mass.
       */
         u3_noun
@@ -1015,33 +993,6 @@
         void
         u3_disk_plan(u3_disk* log_u, u3_fact* tac_u);
 
-      /* u3_disk_read_list(): synchronously read a cons list of events.
-      */
-        u3_weak
-        u3_disk_read_list(u3_disk* log_u, c3_d eve_d, c3_d len_d, c3_l* mug_l);
-
-      /* u3_disk_walk_init(): init iterator.
-      */
-        u3_disk_walk*
-        u3_disk_walk_init(u3_disk* log_u,
-                          c3_d     eve_d,
-                          c3_d     len_d);
-
-      /* u3_disk_walk_live(): check if live.
-      */
-        c3_o
-        u3_disk_walk_live(u3_disk_walk* wok_u);
-
-      /* u3_disk_walk_live(): get next fact.
-      */
-        c3_o
-        u3_disk_walk_step(u3_disk_walk* wok_u, u3_fact* tac_u);
-
-      /* u3_disk_walk_done(): close iterator.
-      */
-        void
-        u3_disk_walk_done(u3_disk_walk* wok_u);
-
       /* u3_lord_init(): start serf.
       */
         u3_lord*
@@ -1510,6 +1461,11 @@
         void
         u3_daemon_init();
 
+      /* u3_write_fd(): retry interrupts, continue partial writes, assert errors.
+      */
+        void
+        u3_write_fd(c3_i fid_i, const void* buf_v, size_t len_i);
+
         c3_w
         u3_readdir_r(DIR *dirp, struct dirent *entry, struct dirent **result);
 
diff --git a/pkg/urbit/noun/allocate.c b/pkg/urbit/noun/allocate.c
index 093c6fefb..f7ce67958 100644
--- a/pkg/urbit/noun/allocate.c
+++ b/pkg/urbit/noun/allocate.c
@@ -425,18 +425,8 @@ _ca_willoc(c3_w len_w, c3_w ald_w, c3_w alp_w)
 
   alp_w = (alp_w + c3_wiseof(u3a_box)) % ald_w;
 
-  /*  XX: this logic is totally bizarre, but preserve it.
-  **
-  **  This means we use the next size bigger instead of the "correct"
-  **  size.  For example, a 20 word allocation will be freed into free
-  **  list 2 but will be allocated from free list 3.
-  **
-  **  This is important to preserve because the sequential search may be
-  **  very slow.  On a real-world task involving many compilations,
-  **  removing this line made this function appear in ~80% of samples.
-  **
-  **  For reference, this was added in cgyarvin/urbit ffed9e748d8f6c.
-  */
+  //  XX: this logic is totally bizarre, but preserve it.
+  //
   if ( (sel_w != 0) && (sel_w != u3a_fbox_no - 1) ) {
     sel_w += 1;
   }
@@ -1627,7 +1617,7 @@ u3a_mark_ptr(void* ptr_v)
     if ( 0 == box_u->eus_w ) {
       siz_w = box_u->siz_w;
     }
-    else if ( 0xffffffff == box_u->eus_w ) {      // see u3a_prof()
+    else if ( 0xffffffff == box_u->eus_w ) {      // see _raft_prof()
       siz_w = 0xffffffff;
       box_u->eus_w = 0;
     }
@@ -1645,7 +1635,7 @@ u3a_mark_ptr(void* ptr_v)
     else {
       c3_assert(use_ws != 0);
 
-      if ( 0x80000000 == (c3_w)use_ws ) {         // see u3a_prof()
+      if ( 0x80000000 == (c3_w)use_ws ) {    // see _raft_prof()
         use_ws = -1;
         siz_w = 0xffffffff;
       }
@@ -1916,7 +1906,7 @@ u3a_print_memory(FILE* fil_u, c3_c* cap_c, c3_w wor_w)
   if ( byt_w ) {
     if ( gib_w ) {
       fprintf(fil_u, "%s: GB/%d.%03d.%03d.%03d\r\n",
-              cap_c, gib_w, mib_w, kib_w, bib_w);
+          cap_c, gib_w, mib_w, kib_w, bib_w);
     }
     else if ( mib_w ) {
       fprintf(fil_u, "%s: MB/%d.%03d.%03d\r\n", cap_c, mib_w, kib_w, bib_w);
@@ -1941,122 +1931,6 @@ u3a_maid(FILE* fil_u, c3_c* cap_c, c3_w wor_w)
   return wor_w;
 }
 
-/* _ca_print_memory(): un-captioned u3a_print_memory().
-*/
-static void
-_ca_print_memory(FILE* fil_u, c3_w wor_w)
-{
-  c3_w byt_w = (wor_w * 4);
-  c3_w gib_w = (byt_w / 1000000000);
-  c3_w mib_w = (byt_w % 1000000000) / 1000000;
-  c3_w kib_w = (byt_w % 1000000) / 1000;
-  c3_w bib_w = (byt_w % 1000);
-
-  if ( gib_w ) {
-    fprintf(fil_u, "GB/%d.%03d.%03d.%03d\r\n",
-            gib_w, mib_w, kib_w, bib_w);
-  }
-  else if ( mib_w ) {
-    fprintf(fil_u, "MB/%d.%03d.%03d\r\n", mib_w, kib_w, bib_w);
-  }
-  else if ( kib_w ) {
-    fprintf(fil_u, "KB/%d.%03d\r\n", kib_w, bib_w);
-  }
-  else {
-    fprintf(fil_u, "B/%d\r\n", bib_w);
-  }
-}
-
-/* u3a_prof(): mark/measure/print memory profile. RETAIN.
-*/
-c3_w
-u3a_prof(FILE* fil_u, c3_w den_w, u3_noun mas)
-{
-  c3_w tot_w = 0;
-  u3_noun h_mas, t_mas;
-
-  if ( c3n == u3r_cell(mas, &h_mas, &t_mas) ) {
-    fprintf(fil_u, "%.*smistyped mass\r\n", den_w, "");
-    return tot_w;
-  }
-  else if ( _(u3du(h_mas)) ) {
-    fprintf(fil_u, "%.*smistyped mass head\r\n", den_w, "");
-    {
-      c3_c* lab_c = u3m_pretty(h_mas);
-      fprintf(fil_u, "h_mas: %s", lab_c);
-      c3_free(lab_c);
-    }
-    return tot_w;
-  }
-  else {
-    {
-      c3_c* lab_c = u3m_pretty(h_mas);
-      fprintf(fil_u, "%*s%s: ", den_w, "", lab_c);
-      c3_free(lab_c);
-    }
-
-    u3_noun it_mas, tt_mas;
-
-    if ( c3n == u3r_cell(t_mas, &it_mas, &tt_mas) ) {
-      fprintf(fil_u, "%*smistyped mass tail\r\n", den_w, "");
-      return tot_w;
-    }
-    else if ( c3y == it_mas ) {
-      tot_w += u3a_mark_noun(tt_mas);
-      _ca_print_memory(fil_u, tot_w);
-
-#if 1
-      /* The basic issue here is that tt_mas is included in .sac
-       * (the whole profile), so they can't both be roots in the
-       * normal sense. When we mark .sac later on, we want tt_mas
-       * to appear unmarked, but its children should be already
-       * marked.
-       *
-       * see u3a_mark_ptr().
-      */
-      if ( _(u3a_is_dog(tt_mas)) ) {
-        u3a_box* box_u = u3a_botox(u3a_to_ptr(tt_mas));
-#ifdef U3_MEMORY_DEBUG
-        if ( 1 == box_u->eus_w ) {
-          box_u->eus_w = 0xffffffff;
-        }
-        else {
-          box_u->eus_w -= 1;
-        }
-#else
-        if ( -1 == (c3_w)box_u->use_w ) {
-          box_u->use_w = 0x80000000;
-        }
-        else {
-          box_u->use_w += 1;
-        }
-#endif
-      }
-#endif
-
-      return tot_w;
-    }
-    else if ( c3n == it_mas ) {
-      fprintf(fil_u, "\r\n");
-
-      while ( _(u3du(tt_mas)) ) {
-        tot_w += u3a_prof(fil_u, den_w+2, u3h(tt_mas));
-        tt_mas = u3t(tt_mas);
-      }
-
-      fprintf(fil_u, "%*s--", den_w, "");
-      _ca_print_memory(fil_u, tot_w);
-
-      return tot_w;
-
-    }
-    else {
-      fprintf(fil_u, "%*smistyped (strange) mass tail\r\n", den_w, "");
-      return tot_w;
-    }
-  }
-}
-
 /* u3a_mark_road(): mark ad-hoc persistent road structures.
 */
 c3_w
diff --git a/pkg/urbit/noun/events.c b/pkg/urbit/noun/events.c
index 7b1f78b21..ceec1bd41 100644
--- a/pkg/urbit/noun/events.c
+++ b/pkg/urbit/noun/events.c
@@ -7,7 +7,7 @@
 //!   - page: 16KB chunk of the loom.
 //!   - north segment (u3e_image, north.bin): low contiguous loom pages,
 //!     (in practice, the home road heap). indexed from low to high:
-//!     in-order on disk. in a file-backed mapping by default.
+//!     in-order on disk.
 //!   - south segment (u3e_image, south.bin): high contiguous loom pages,
 //!     (in practice, the home road stack). indexed from high to low:
 //!     reversed on disk.
@@ -20,8 +20,8 @@
 //!   - with the loom already mapped, all pages are marked dirty in a bitmap.
 //!   - if snapshot is missing or partial, empty segments are created.
 //!   - if a patch is present, it's applied (crash recovery).
-//!   - snapshot segments are mapped or copied onto the loom;
-//!     all included pages are marked clean and protected (read-only).
+//!   - snapshot segments are copied onto the loom; all included pages
+//!     are marked clean and protected (read-only).
 //!
 //! #### page faults (u3e_fault())
 //!
@@ -47,60 +47,43 @@
 //!       contiguous free space).
 //!   - patch pages are written to memory.bin, metadata to control.bin.
 //!   - the patch is applied to the snapshot segments, in-place.
-//!   - memory protections (and file-backed mappings) are re-established.
 //!   - patch files are deleted.
 //!
-//! ### invariants
-//!
-//!  definitions:
-//!    - a clean page is PROT_READ and 0 in the bitmap
-//!    - a dirty page is (PROT_READ|PROT_WRITE) and 1 in the bitmap
-//!    - the guard page is PROT_NONE and 1 in the bitmap
-//!
-//!  assumptions:
-//!    - all memory access patterns are outside-in, a page at a time
-//!      - ad-hoc exceptions are supported by calling u3e_ward()
-//!
-//!  - there is a single guard page, between the segments
-//!  - dirty pages only become clean by being:
-//!    - loaded from a snapshot during initialization
-//!    - present in a snapshot after save
-//!  - clean pages only become dirty by being:
-//!    - modified (and caught by the fault handler)
-//!    - orphaned due to segment truncation (explicitly dirtied)
-//!  - at points of quiescence (initialization, after save)
-//!    - all pages of the north and south segments are clean
-//!    - all other pages are dirty
-//!
 //! ### limitations
 //!
 //!   - loom page size is fixed (16 KB), and must be a multiple of the
-//!     system page size.
-//!   - update atomicity is crucial:
-//!     - patch application must either completely succeed or
-//!       leave on-disk segments (memory image) intact.
-//!     - unapplied patches can be discarded (triggering event replay),
-//!       but once patch application begins it must succeed.
-//!     - may require integration into the overall signal-handling regime.
-//!   - many errors are handled with assertions.
+//!     system page size. (can the size vary at runtime give south.bin's
+//!     reversed order? alternately, if system page size > ours, the fault
+//!     handler could dirty N pages at a time.)
+//!   - update atomicity is suspect: patch application must either
+//!     completely succeed or leave on-disk segments intact. unapplied
+//!     patches can be discarded (triggering event replay), but once
+//!     patch application begins it must succeed (can fail if disk is full).
+//!     may require integration into the overall signal-handling regime.
+//!   - any errors are handled with assertions; failed/partial writes are not
+//!     retried.
 //!
 //! ### enhancements
 //!
 //!   - use platform specific page fault mechanism (mach rpc, userfaultfd, &c).
-//!   - parallelism (conflicts with demand paging)
+//!   - implement demand paging / heuristic page-out.
+//!   - add a guard page in the middle of the loom to reactively handle stack overflow.
+//!   - parallelism
 //!
 
 #include "all.h"
-#include "noun/events.h"
 #include <errno.h>
 #include <fcntl.h>
 #include <sys/stat.h>
 
+// Base loom offset of the guard page.
+static u3p(c3_w) gar_pag_p;
+
 //! Urbit page size in 4-byte words.
-#define pag_wiz_i  ((size_t)1 << u3a_page)
+static const size_t pag_wiz_i = 1 << u3a_page;
 
 //! Urbit page size in bytes.
-#define pag_siz_i  ((size_t)1 << (u3a_page + 2))
+static const size_t pag_siz_i = sizeof(c3_w) * pag_wiz_i;
 
 #ifdef U3_SNAPSHOT_VALIDATION
 /* Image check.
@@ -117,7 +100,7 @@ static c3_w
 _ce_check_page(c3_w pag_w)
 {
   c3_w* mem_w = u3_Loom + (pag_w << u3a_page);
-  c3_w  mug_w = u3r_mug_words(mem_w, pag_wiz_i);
+  c3_w  mug_w = u3r_mug_words(mem_w, (1 << u3a_page));
 
   return mug_w;
 }
@@ -135,8 +118,8 @@ u3e_check(c3_c* cap_c)
 
     u3m_water(&nwr_w, &swu_w);
 
-    nor_w = (nwr_w + (pag_wiz_i - 1)) >> u3a_page;
-    sou_w = (swu_w + (pag_wiz_i - 1)) >> u3a_page;
+    nor_w = (nwr_w + ((1 << u3a_page) - 1)) >> u3a_page;
+    sou_w = (swu_w + ((1 << u3a_page) - 1)) >> u3a_page;
   }
 
   /* Count dirty pages.
@@ -162,115 +145,156 @@ u3e_check(c3_c* cap_c)
     u3l_log("%s: sum %x (%x, %x)\r\n", cap_c, sum_w, nor_w, sou_w);
   }
 }
+
+/* _ce_maplloc(): crude off-loom allocator.
+*/
+static void*
+_ce_maplloc(c3_w len_w)
+{
+  void* map_v;
+
+  map_v = mmap(0,
+               len_w,
+               (PROT_READ | PROT_WRITE),
+               (MAP_ANON | MAP_PRIVATE),
+               -1, 0);
+
+  if ( -1 == (c3_ps)map_v ) {
+    c3_assert(0);
+  }
+  else {
+    c3_w* map_w = map_v;
+
+    map_w[0] = len_w;
+
+    return map_w + 1;
+  }
+}
+
+/* _ce_mapfree(): crude off-loom allocator.
+*/
+static void
+_ce_mapfree(void* map_v)
+{
+  c3_w* map_w = map_v;
+  c3_i res_i;
+
+  map_w -= 1;
+  res_i = munmap(map_w, map_w[0]);
+
+  c3_assert(0 == res_i);
+}
 #endif
 
-/* _ce_flaw_protect(): protect page after fault.
-*/
-static inline c3_i
-_ce_flaw_protect(c3_w pag_w)
-{
-  if ( 0 != mprotect((void *)(u3_Loom + (pag_w << u3a_page)),
-                     pag_siz_i,
-                     (PROT_READ | PROT_WRITE)) )
-  {
-    fprintf(stderr, "loom: fault mprotect (%u): %s\r\n",
-                     pag_w, strerror(errno));
-    return 1;
-  }
-
-  return 0;
-}
-
 #ifdef U3_GUARD_PAGE
-/* _ce_ward_protect(): protect the guard page.
-*/
-static inline c3_i
-_ce_ward_protect(void)
+//! Place a guard page at the (approximate) middle of the free space between
+//! the heap and stack of the current road, bailing if memory has been
+//! exhausted.
+static c3_i
+_ce_center_guard_page(void)
 {
-  if ( 0 != mprotect((void *)(u3_Loom + (u3P.gar_w << u3a_page)),
-                      pag_siz_i,
-                      PROT_NONE) )
-  {
-    fprintf(stderr, "loom: failed to protect guard page (%u): %s\r\n",
-                    u3P.gar_w, strerror(errno));
-    return 1;
+  u3p(c3_w) bot_p, top_p;
+  if ( !u3R ) {
+    top_p = u3a_outa(u3_Loom + u3C.wor_i);
+    bot_p = u3a_outa(u3_Loom);
+  }
+  else if ( c3y == u3a_is_north(u3R) ) {
+    top_p = c3_rod(u3R->cap_p, pag_wiz_i);
+    bot_p = c3_rop(u3R->hat_p, pag_wiz_i);
+  }
+  else {
+    top_p = c3_rod(u3R->hat_p, pag_wiz_i);
+    bot_p = c3_rop(u3R->cap_p, pag_wiz_i);
   }
 
+  if ( top_p < bot_p + pag_wiz_i ) {
+    fprintf(stderr,
+            "loom: not enough memory to recenter the guard page\r\n");
+    goto bail;
+  }
+  const u3p(c3_w) old_gar_p = gar_pag_p;
+  const c3_w      mid_p     = (top_p - bot_p) / 2;
+  gar_pag_p                 = bot_p + c3_rod(mid_p, pag_wiz_i);
+  if ( old_gar_p == gar_pag_p ) {
+    fprintf(stderr,
+            "loom: can't move the guard page to the same location"
+            " (base address %p)\r\n",
+            u3a_into(gar_pag_p));
+    goto bail;
+  }
+
+  if ( -1 == mprotect(u3a_into(gar_pag_p), pag_siz_i, PROT_NONE) ) {
+    fprintf(stderr,
+            "loom: failed to protect the guard page "
+            "(base address %p): %s\r\n",
+            u3a_into(gar_pag_p),
+            strerror(errno));
+    goto fail;
+  }
+
+  return 1;
+
+bail:
+  u3m_signal(c3__meme);
+fail:
   return 0;
 }
-
-/* _ce_ward_post(): set the guard page.
-*/
-static inline c3_i
-_ce_ward_post(c3_w nop_w, c3_w sop_w)
-{
-  u3P.gar_w = nop_w + ((sop_w - nop_w) / 2);
-  return _ce_ward_protect();
-}
-
-/* _ce_ward_clip(): hit the guard page.
-*/
-static inline u3e_flaw
-_ce_ward_clip(c3_w nop_w, c3_w sop_w)
-{
-  c3_w old_w = u3P.gar_w;
-
-  if ( !u3P.gar_w || ((nop_w < u3P.gar_w) && (sop_w > u3P.gar_w)) ) {
-    fprintf(stderr, "loom: ward bogus (>%u %u %u<)\r\n",
-                    nop_w, u3P.gar_w, sop_w);
-    return u3e_flaw_sham;
-  }
-
-  if ( sop_w <= (nop_w + 1) ) {
-    return u3e_flaw_meme;
-  }
-
-  if ( _ce_ward_post(nop_w, sop_w) ) {
-    return u3e_flaw_base;
-  }
-
-  c3_assert( old_w != u3P.gar_w );
-
-  return u3e_flaw_good;
-}
 #endif /* ifdef U3_GUARD_PAGE */
 
-/* u3e_fault(): handle a memory fault.
+/* u3e_fault(): handle a memory event with libsigsegv protocol.
 */
-u3e_flaw
-u3e_fault(u3_post low_p, u3_post hig_p, u3_post off_p)
+c3_i
+u3e_fault(void* adr_v, c3_i ser_i)
 {
-  c3_w pag_w = off_p >> u3a_page;
-  c3_w blk_w = pag_w >> 5;
-  c3_w bit_w = pag_w & 31;
+  //  Let the stack overflow handler run.
+  if ( 0 == ser_i ) {
+    return 0;
+  }
+
+  //  XX u3l_log avoid here, as it can
+  //  cause problems when handling errors
+
+  c3_w* adr_w = (c3_w*) adr_v;
+
+  if ( (adr_w < u3_Loom) || (adr_w >= (u3_Loom + u3C.wor_i)) ) {
+    fprintf(stderr, "address %p out of loom!\r\n", adr_w);
+    fprintf(stderr, "loom: [%p : %p)\r\n", u3_Loom, u3_Loom + u3C.wor_i);
+    c3_assert(0);
+    return 0;
+  }
+
+  u3p(c3_w) adr_p  = u3a_outa(adr_w);
+  c3_w      pag_w  = adr_p >> u3a_page;
+  c3_w      blk_w  = (pag_w >> 5);
+  c3_w      bit_w  = (pag_w & 31);
 
 #ifdef U3_GUARD_PAGE
-  if ( pag_w == u3P.gar_w ) {
-    u3e_flaw fal_e = _ce_ward_clip(low_p >> u3a_page, hig_p >> u3a_page);
-
-    if ( u3e_flaw_good != fal_e ) {
-      return fal_e;
-    }
-
-    if ( !(u3P.dit_w[blk_w] & (1 << bit_w)) ) {
-      fprintf(stderr, "loom: strange guard (%d)\r\n", pag_w);
-      return u3e_flaw_sham;
+  // The fault happened in the guard page.
+  if ( gar_pag_p <= adr_p && adr_p < gar_pag_p + pag_wiz_i ) {
+    if ( 0 == _ce_center_guard_page() ) {
+      return 0;
     }
   }
   else
-#endif
-  if ( u3P.dit_w[blk_w] & (1 << bit_w) ) {
-    fprintf(stderr, "loom: strange page (%d): %x\r\n", pag_w, off_p);
-    return u3e_flaw_sham;
+#endif /* ifdef U3_GUARD_PAGE */
+  if ( 0 != (u3P.dit_w[blk_w] & (1 << bit_w)) ) {
+    fprintf(stderr, "strange page: %d, at %p, off %x\r\n", pag_w, adr_w, adr_p);
+    c3_assert(0);
+    return 0;
   }
 
   u3P.dit_w[blk_w] |= (1 << bit_w);
 
-  if ( _ce_flaw_protect(pag_w) ) {
-    return u3e_flaw_base;
+  if ( -1 == mprotect((void *)(u3_Loom + (pag_w << u3a_page)),
+                      pag_siz_i,
+                      (PROT_READ | PROT_WRITE)) )
+  {
+    fprintf(stderr, "loom: fault mprotect: %s\r\n", strerror(errno));
+    c3_assert(0);
+    return 0;
   }
 
-  return u3e_flaw_good;
+  return 1;
 }
 
 /* _ce_image_open(): open or create image.
@@ -281,7 +305,16 @@ _ce_image_open(u3e_image* img_u)
   c3_i mod_i = O_RDWR | O_CREAT;
   c3_c ful_c[8193];
 
-  snprintf(ful_c, 8192, "%s/%s.bin", u3P.dir_c, img_u->nam_c);
+  snprintf(ful_c, 8192, "%s", u3P.dir_c);
+  c3_mkdir(ful_c, 0700);
+
+  snprintf(ful_c, 8192, "%s/.urb", u3P.dir_c);
+  c3_mkdir(ful_c, 0700);
+
+  snprintf(ful_c, 8192, "%s/.urb/chk", u3P.dir_c);
+  c3_mkdir(ful_c, 0700);
+
+  snprintf(ful_c, 8192, "%s/.urb/chk/%s.bin", u3P.dir_c, img_u->nam_c);
   if ( -1 == (img_u->fid_i = c3_open(ful_c, mod_i, 0666)) ) {
     fprintf(stderr, "loom: c3_open %s: %s\r\n", ful_c, strerror(errno));
     return c3n;
@@ -321,11 +354,17 @@ _ce_image_open(u3e_image* img_u)
 static void
 _ce_patch_write_control(u3_ce_patch* pat_u)
 {
-  c3_w len_w = sizeof(u3e_control) +
-               (pat_u->con_u->pgs_w * sizeof(u3e_line));
+  ssize_t ret_i;
+  c3_w    len_w = sizeof(u3e_control) +
+                  (pat_u->con_u->pgs_w * sizeof(u3e_line));
 
-  if ( 0 > c3_pwrite(pat_u->ctl_i, pat_u->con_u, len_w, 0) ) {
-    fprintf(stderr, "loom: patch write: %s\r\n", strerror(errno));
+  if ( len_w != (ret_i = write(pat_u->ctl_i, pat_u->con_u, len_w)) ) {
+    if ( 0 < ret_i ) {
+      fprintf(stderr, "loom: patch ctl partial write: %zu\r\n", (size_t)ret_i);
+    }
+    else {
+      fprintf(stderr, "loom: patch ctl write: %s\r\n", strerror(errno));
+    }
     c3_assert(0);
   }
 }
@@ -349,9 +388,8 @@ _ce_patch_read_control(u3_ce_patch* pat_u)
   }
 
   pat_u->con_u = c3_malloc(len_w);
-
-  if (  (len_w != c3_pread(pat_u->ctl_i, pat_u->con_u, len_w, 0))
-     || (len_w != sizeof(u3e_control) +
+  if ( (len_w != read(pat_u->ctl_i, pat_u->con_u, len_w)) ||
+        (len_w != sizeof(u3e_control) +
                   (pat_u->con_u->pgs_w * sizeof(u3e_line))) )
   {
     c3_free(pat_u->con_u);
@@ -368,13 +406,19 @@ _ce_patch_create(u3_ce_patch* pat_u)
 {
   c3_c ful_c[8193];
 
-  snprintf(ful_c, 8192, "%s/control.bin", u3P.dir_c);
+  snprintf(ful_c, 8192, "%s", u3P.dir_c);
+  c3_mkdir(ful_c, 0700);
+
+  snprintf(ful_c, 8192, "%s/.urb", u3P.dir_c);
+  c3_mkdir(ful_c, 0700);
+
+  snprintf(ful_c, 8192, "%s/.urb/chk/control.bin", u3P.dir_c);
   if ( -1 == (pat_u->ctl_i = c3_open(ful_c, O_RDWR | O_CREAT | O_EXCL, 0600)) ) {
     fprintf(stderr, "loom: patch c3_open control.bin: %s\r\n", strerror(errno));
     c3_assert(0);
   }
 
-  snprintf(ful_c, 8192, "%s/memory.bin", u3P.dir_c);
+  snprintf(ful_c, 8192, "%s/.urb/chk/memory.bin", u3P.dir_c);
   if ( -1 == (pat_u->mem_i = c3_open(ful_c, O_RDWR | O_CREAT | O_EXCL, 0600)) ) {
     fprintf(stderr, "loom: patch c3_open memory.bin: %s\r\n", strerror(errno));
     c3_assert(0);
@@ -388,13 +432,13 @@ _ce_patch_delete(void)
 {
   c3_c ful_c[8193];
 
-  snprintf(ful_c, 8192, "%s/control.bin", u3P.dir_c);
+   snprintf(ful_c, 8192, "%s/.urb/chk/control.bin", u3P.dir_c);
   if ( unlink(ful_c) ) {
     fprintf(stderr, "loom: failed to delete control.bin: %s\r\n",
                     strerror(errno));
   }
 
-  snprintf(ful_c, 8192, "%s/memory.bin", u3P.dir_c);
+  snprintf(ful_c, 8192, "%s/.urb/chk/memory.bin", u3P.dir_c);
   if ( unlink(ful_c) ) {
     fprintf(stderr, "loom: failed to remove memory.bin: %s\r\n",
                     strerror(errno));
@@ -406,10 +450,8 @@ _ce_patch_delete(void)
 static c3_o
 _ce_patch_verify(u3_ce_patch* pat_u)
 {
-  c3_w i_w, pag_w, mug_w;
-  c3_w      mem_w[pag_wiz_i];
-  size_t    off_i, siz_i = pag_siz_i;
-  ssize_t   ret_i;
+  ssize_t ret_i;
+  c3_w      i_w;
 
   if ( u3e_version != pat_u->con_u->ver_y ) {
     fprintf(stderr, "loom: patch version mismatch: have %u, need %u\r\n",
@@ -419,11 +461,15 @@ _ce_patch_verify(u3_ce_patch* pat_u)
   }
 
   for ( i_w = 0; i_w < pat_u->con_u->pgs_w; i_w++ ) {
-    pag_w = pat_u->con_u->mem_u[i_w].pag_w;
-    mug_w = pat_u->con_u->mem_u[i_w].mug_w;
-    off_i = (size_t)i_w << (u3a_page + 2);
+    c3_w pag_w = pat_u->con_u->mem_u[i_w].pag_w;
+    c3_w mug_w = pat_u->con_u->mem_u[i_w].mug_w;
+    c3_w mem_w[1 << u3a_page];
 
-    if ( siz_i != (ret_i = c3_pread(pat_u->mem_i, mem_w, siz_i, off_i)) ) {
+    if ( -1 == lseek(pat_u->mem_i, (i_w << (u3a_page + 2)), SEEK_SET) ) {
+      fprintf(stderr, "loom: patch seek: %s\r\n", strerror(errno));
+      return c3n;
+    }
+    if ( pag_siz_i != (ret_i = read(pat_u->mem_i, mem_w, pag_siz_i)) ) {
       if ( 0 < ret_i ) {
         fprintf(stderr, "loom: patch partial read: %zu\r\n", (size_t)ret_i);
       }
@@ -432,7 +478,6 @@ _ce_patch_verify(u3_ce_patch* pat_u)
       }
       return c3n;
     }
-
     {
       c3_w nug_w = u3r_mug_words(mem_w, pag_wiz_i);
 
@@ -471,12 +516,18 @@ _ce_patch_open(void)
   c3_c ful_c[8193];
   c3_i ctl_i, mem_i;
 
-  snprintf(ful_c, 8192, "%s/control.bin", u3P.dir_c);
+  snprintf(ful_c, 8192, "%s", u3P.dir_c);
+  c3_mkdir(ful_c, 0700);
+
+  snprintf(ful_c, 8192, "%s/.urb", u3P.dir_c);
+  c3_mkdir(ful_c, 0700);
+
+  snprintf(ful_c, 8192, "%s/.urb/chk/control.bin", u3P.dir_c);
   if ( -1 == (ctl_i = c3_open(ful_c, O_RDWR)) ) {
     return 0;
   }
 
-  snprintf(ful_c, 8192, "%s/memory.bin", u3P.dir_c);
+  snprintf(ful_c, 8192, "%s/.urb/chk/memory.bin", u3P.dir_c);
   if ( -1 == (mem_i = c3_open(ful_c, O_RDWR)) ) {
     close(ctl_i);
 
@@ -504,6 +555,32 @@ _ce_patch_open(void)
   return pat_u;
 }
 
+/* _ce_patch_write_page(): write a page of patch memory.
+*/
+static void
+_ce_patch_write_page(u3_ce_patch* pat_u,
+                     c3_w         pgc_w,
+                     c3_w*        mem_w)
+{
+  ssize_t ret_i;
+
+  if ( -1 == lseek(pat_u->mem_i, pgc_w * pag_siz_i, SEEK_SET) ) {
+    fprintf(stderr, "loom: patch page seek: %s\r\n", strerror(errno));
+    c3_assert(0);
+  }
+
+  if ( pag_siz_i != (ret_i = write(pat_u->mem_i, mem_w, pag_siz_i)) ) {
+    if ( 0 < ret_i ) {
+      fprintf(stderr, "loom: patch page partial write: %zu\r\n",
+                      (size_t)ret_i);
+    }
+    else {
+      fprintf(stderr, "loom: patch page write: %s\r\n", strerror(errno));
+    }
+    c3_assert(0);
+  }
+}
+
 /* _ce_patch_count_page(): count a page, producing new counter.
 */
 static c3_w
@@ -530,17 +607,25 @@ _ce_patch_save_page(u3_ce_patch* pat_u,
   c3_w bit_w = (pag_w & 31);
 
   if ( u3P.dit_w[blk_w] & (1 << bit_w) ) {
-    c3_w*  mem_w = u3_Loom + (pag_w << u3a_page);
-    size_t off_i = (size_t)pgc_w << (u3a_page + 2);
+    c3_w* mem_w = u3_Loom + (pag_w << u3a_page);
 
     pat_u->con_u->mem_u[pgc_w].pag_w = pag_w;
     pat_u->con_u->mem_u[pgc_w].mug_w = u3r_mug_words(mem_w, pag_wiz_i);
 
-    if ( 0 > c3_pwrite(pat_u->mem_i, mem_w, pag_siz_i, off_i) ) {
-      fprintf(stderr, "loom: patch save: %s\r\n", strerror(errno));
+#if 0
+    u3l_log("protect a: page %d\r\n", pag_w);
+#endif
+    _ce_patch_write_page(pat_u, pgc_w, mem_w);
+
+    if ( -1 == mprotect(u3_Loom + (pag_w << u3a_page),
+                        pag_siz_i,
+                        PROT_READ) )
+    {
+      fprintf(stderr, "loom: patch mprotect: %s\r\n", strerror(errno));
       c3_assert(0);
     }
 
+    u3P.dit_w[blk_w] &= ~(1 << bit_w);
     pgc_w += 1;
   }
   return pgc_w;
@@ -549,9 +634,25 @@ _ce_patch_save_page(u3_ce_patch* pat_u,
 /* _ce_patch_compose(): make and write current patch.
 */
 static u3_ce_patch*
-_ce_patch_compose(c3_w nor_w, c3_w sou_w)
+_ce_patch_compose(void)
 {
   c3_w pgs_w = 0;
+  c3_w nor_w = 0;
+  c3_w sou_w = 0;
+
+  /* Calculate number of saved pages, north and south.
+  */
+  {
+    c3_w nwr_w, swu_w;
+
+    u3m_water(&nwr_w, &swu_w);
+
+    nor_w = (nwr_w + (pag_wiz_i - 1)) >> u3a_page;
+    sou_w = (swu_w + (pag_wiz_i - 1)) >> u3a_page;
+
+    c3_assert(  ((gar_pag_p >> u3a_page) >= nor_w)
+             && ((gar_pag_p >> u3a_page) <= (u3a_pages - (sou_w + 1))) );
+  }
 
 #ifdef U3_SNAPSHOT_VALIDATION
   u3K.nor_w = nor_w;
@@ -624,7 +725,8 @@ _ce_image_sync(u3e_image* img_u)
 {
   if ( -1 == c3_sync(img_u->fid_i) ) {
     fprintf(stderr, "loom: image (%s) sync failed: %s\r\n",
-                    img_u->nam_c, strerror(errno));
+                    img_u->nam_c,
+                    strerror(errno));
     c3_assert(!"loom: image sync");
   }
 }
@@ -634,19 +736,11 @@ _ce_image_sync(u3e_image* img_u)
 static void
 _ce_image_resize(u3e_image* img_u, c3_w pgs_w)
 {
-  off_t off_i = (off_t)pgs_w << (u3a_page + 2);
-
   if ( img_u->pgs_w > pgs_w ) {
-    if ( (off_i >> (u3a_page + 2)) != pgs_w ) {
-      fprintf(stderr, "loom: image (%s) truncate: "
-                      "offset overflow (%" PRId64 ") for page %u\r\n",
-                      img_u->nam_c, (c3_ds)off_i, pgs_w);
-      c3_assert(0);
-    }
-
-    if ( ftruncate(img_u->fid_i, off_i) ) {
+    if ( ftruncate(img_u->fid_i, pgs_w << (u3a_page + 2)) ) {
       fprintf(stderr, "loom: image (%s) truncate: %s\r\n",
-                      img_u->nam_c, strerror(errno));
+                      img_u->nam_c,
+                      strerror(errno));
       c3_assert(0);
     }
   }
@@ -659,20 +753,31 @@ _ce_image_resize(u3e_image* img_u, c3_w pgs_w)
 static void
 _ce_patch_apply(u3_ce_patch* pat_u)
 {
-  c3_w i_w, pag_w, off_w, mem_w[pag_wiz_i];
-  c3_i      fid_i;
-  size_t    rof_i, wof_i, siz_i = pag_siz_i;
-  ssize_t   ret_i;
+  ssize_t ret_i;
+  c3_w      i_w;
 
   //  resize images
   //
   _ce_image_resize(&u3P.nor_u, pat_u->con_u->nor_w);
   _ce_image_resize(&u3P.sou_u, pat_u->con_u->sou_w);
 
+  //  seek to begining of patch and images
+  //
+  if (  (-1 == lseek(pat_u->mem_i, 0, SEEK_SET))
+     || (-1 == lseek(u3P.nor_u.fid_i, 0, SEEK_SET))
+     || (-1 == lseek(u3P.sou_u.fid_i, 0, SEEK_SET)) )
+  {
+    fprintf(stderr, "loom: patch apply seek 0: %s\r\n", strerror(errno));
+    c3_assert(0);
+  }
+
   //  write patch pages into the appropriate image
   //
   for ( i_w = 0; i_w < pat_u->con_u->pgs_w; i_w++ ) {
-    pag_w = pat_u->con_u->mem_u[i_w].pag_w;
+    c3_w pag_w = pat_u->con_u->mem_u[i_w].pag_w;
+    c3_w mem_w[pag_wiz_i];
+    c3_i fid_i;
+    c3_w off_w;
 
     if ( pag_w < pat_u->con_u->nor_w ) {
       fid_i = u3P.nor_u.fid_i;
@@ -683,10 +788,7 @@ _ce_patch_apply(u3_ce_patch* pat_u)
       off_w = (u3P.pag_w - (pag_w + 1));
     }
 
-    rof_i = (size_t)i_w   << (u3a_page + 2);
-    wof_i = (size_t)off_w << (u3a_page + 2);
-
-    if ( siz_i != (ret_i = c3_pread(pat_u->mem_i, mem_w, siz_i, rof_i))) {
+    if ( pag_siz_i != (ret_i = read(pat_u->mem_i, mem_w, pag_siz_i)) ) {
       if ( 0 < ret_i ) {
         fprintf(stderr, "loom: patch apply partial read: %zu\r\n",
                         (size_t)ret_i);
@@ -696,10 +798,21 @@ _ce_patch_apply(u3_ce_patch* pat_u)
       }
       c3_assert(0);
     }
-
-    if ( 0 > c3_pwrite(fid_i, mem_w, siz_i, wof_i) ) {
-      fprintf(stderr, "loom: patch apply write: %s\r\n", strerror(errno));
-      c3_assert(0);
+    else {
+      if ( -1 == lseek(fid_i, (off_w << (u3a_page + 2)), SEEK_SET) ) {
+        fprintf(stderr, "loom: patch apply seek: %s\r\n", strerror(errno));
+        c3_assert(0);
+      }
+      if ( pag_siz_i != (ret_i = write(fid_i, mem_w, pag_siz_i)) ) {
+        if ( 0 < ret_i ) {
+          fprintf(stderr, "loom: patch apply partial write: %zu\r\n",
+                          (size_t)ret_i);
+        }
+        else {
+          fprintf(stderr, "loom: patch apply write: %s\r\n", strerror(errno));
+        }
+        c3_assert(0);
+      }
     }
 #if 0
     u3l_log("apply: %d, %x\n", pag_w, u3r_mug_words(mem_w, pag_wiz_i));
@@ -707,294 +820,52 @@ _ce_patch_apply(u3_ce_patch* pat_u)
   }
 }
 
-/* _ce_loom_track_north(): [pgs_w] clean, followed by [dif_w] dirty.
-*/
-void
-_ce_loom_track_north(c3_w pgs_w, c3_w dif_w)
-{
-  c3_w blk_w = pgs_w >> 5;
-  c3_w bit_w = pgs_w & 31;
-  c3_w off_w;
-
-  memset((void*)u3P.dit_w, 0, blk_w << 2);
-
-  if ( bit_w ) {
-    c3_w tib_w = 32 - bit_w;
-    c3_w dat_w = u3P.dit_w[blk_w];
-
-    dat_w   &= 0xffffffff << bit_w;
-
-    if ( dif_w <= tib_w ) {
-      dat_w |= ((1 << dif_w) - 1) << bit_w;
-      dif_w  = 0;
-    }
-    else {
-      dat_w |= 0xffffffff << bit_w;
-      dif_w -= tib_w;
-    }
-
-    u3P.dit_w[blk_w] = dat_w;
-    blk_w += 1;
-  }
-
-  off_w = blk_w;
-  blk_w = dif_w >> 5;
-  bit_w = dif_w & 31;
-
-  memset((void*)(u3P.dit_w + off_w), 0xff, blk_w << 2);
-
-  if ( bit_w ) {
-    u3P.dit_w[off_w + blk_w] |= (1 << bit_w) - 1;
-  }
-}
-
-/* _ce_loom_track_south(): [pgs_w] clean, preceded by [dif_w] dirty.
-*/
-void
-_ce_loom_track_south(c3_w pgs_w, c3_w dif_w)
-{
-  c3_w blk_w = pgs_w >> 5;
-  c3_w bit_w = pgs_w & 31;
-  c3_w bas_w = ((u3P.pag_w - pgs_w) + 31) >> 5;
-  c3_w off_w;
-
-  memset((void*)(u3P.dit_w + bas_w), 0, blk_w << 2);
-
-  //  the following index subtractions (bas_w, off) are safe,
-  //  so long as the south segment never includes all pages
-  //
-  if ( bit_w ) {
-    c3_w tib_w = 32 - bit_w;
-    c3_w dat_w = u3P.dit_w[--bas_w];
-
-    dat_w   &= 0xffffffff >> bit_w;
-
-    if ( dif_w <= tib_w ) {
-      dat_w |= ((1 << dif_w) - 1) << (tib_w - dif_w);
-      dif_w  = 0;
-    }
-    else {
-      dat_w |= 0xffffffff >> bit_w;
-      dif_w -= tib_w;
-    }
-
-    u3P.dit_w[bas_w] = dat_w;
-  }
-
-  blk_w = dif_w >> 5;
-  bit_w = dif_w & 31;
-  off_w = bas_w - blk_w;
-
-  memset((void*)(u3P.dit_w + off_w), 0xff, blk_w << 2);
-
-  if ( bit_w ) {
-    u3P.dit_w[off_w - 1] |= ((1 << bit_w) - 1) << (32 - bit_w);
-  }
-}
-
-/* _ce_loom_protect_north(): protect/track pages from the bottom of memory.
+/* _ce_image_blit(): apply image to memory.
 */
 static void
-_ce_loom_protect_north(c3_w pgs_w, c3_w old_w)
+_ce_image_blit(u3e_image* img_u,
+               c3_w*        ptr_w,
+               c3_ws        stp_ws)
 {
-  if ( pgs_w ) {
-    if ( 0 != mprotect((void*)u3_Loom,
-                       (size_t)pgs_w << (u3a_page + 2),
-                       PROT_READ) )
-    {
-      fprintf(stderr, "loom: pure north (%u pages): %s\r\n",
-                      pgs_w, strerror(errno));
-      c3_assert(0);
-    }
+  if ( 0 == img_u->pgs_w ) {
+    return;
   }
 
-  if ( old_w > pgs_w ) {
-    c3_w dif_w = old_w - pgs_w;
-
-    if ( 0 != mprotect((void*)(u3_Loom + (pgs_w << u3a_page)),
-                       (size_t)dif_w << (u3a_page + 2),
-                       (PROT_READ | PROT_WRITE)) )
-    {
-      fprintf(stderr, "loom: foul north (%u pages, %u old): %s\r\n",
-                      pgs_w, old_w, strerror(errno));
-      c3_assert(0);
-    }
-
-#ifdef U3_GUARD_PAGE
-    //  protect guard page if clobbered
-    //
-    //    NB: < pgs_w is precluded by assertion in u3e_save()
-    //
-    if ( u3P.gar_w < old_w ) {
-      fprintf(stderr, "loom: guard on reprotect\r\n");
-      c3_assert( !_ce_ward_protect() );
-    }
-#endif
-
-    _ce_loom_track_north(pgs_w, dif_w);
-  }
-  else {
-    _ce_loom_track_north(pgs_w, 0);
-  }
-}
-
-/* _ce_loom_protect_south(): protect/track pages from the top of memory.
-*/
-static void
-_ce_loom_protect_south(c3_w pgs_w, c3_w old_w)
-{
-  if ( pgs_w ) {
-    if ( 0 != mprotect((void*)(u3_Loom + ((u3P.pag_w - pgs_w) << u3a_page)),
-                       (size_t)pgs_w << (u3a_page + 2),
-                       PROT_READ) )
-    {
-      fprintf(stderr, "loom: pure south (%u pages): %s\r\n",
-                      pgs_w, strerror(errno));
-      c3_assert(0);
-    }
-  }
-
-  if ( old_w > pgs_w ) {
-    c3_w dif_w = old_w - pgs_w;
-    c3_w off_w = u3P.pag_w - old_w;
-
-    if ( 0 != mprotect((void*)(u3_Loom + (off_w << u3a_page)),
-                       (size_t)dif_w << (u3a_page + 2),
-                       (PROT_READ | PROT_WRITE)) )
-    {
-      fprintf(stderr, "loom: foul south (%u pages, %u old): %s\r\n",
-                      pgs_w, old_w, strerror(errno));
-      c3_assert(0);
-    }
-
-#ifdef U3_GUARD_PAGE
-    //  protect guard page if clobbered
-    //
-    //    NB: >= pgs_w is precluded by assertion in u3e_save()
-    //
-    if ( u3P.gar_w >= off_w ) {
-      fprintf(stderr, "loom: guard on reprotect\r\n");
-      c3_assert( !_ce_ward_protect() );
-    }
-#endif
-
-    _ce_loom_track_south(pgs_w, dif_w);
-  }
-  else {
-    _ce_loom_track_south(pgs_w, 0);
-  }
-}
-
-/* _ce_loom_mapf_north(): map [pgs_w] of [fid_i] into the bottom of memory
-**                        (and anonymize [old_w - pgs_w] after if needed).
-**
-**   NB: _ce_loom_mapf_south() is possible, but it would make separate mappings
-**       for each page since the south segment is reversed on disk.
-**       in practice, the south segment is a single page (and always dirty);
-**       a file-backed mapping for it is just not worthwhile.
-*/
-static void
-_ce_loom_mapf_north(c3_i fid_i, c3_w pgs_w, c3_w old_w)
-{
-  //  XX mingw doesn't support MAP_FIXED clobbering;
-  //  will require explicit unmapping and related bookkeeping.
-  //
-  if ( pgs_w ) {
-    if ( MAP_FAILED == mmap((void*)u3_Loom,
-                            (size_t)pgs_w << (u3a_page + 2),
-                            PROT_READ,
-                            (MAP_FIXED | MAP_PRIVATE),
-                            fid_i, 0) )
-    {
-      fprintf(stderr, "loom: file-backed mmap failed (%u pages): %s\r\n",
-                      pgs_w, strerror(errno));
-      c3_assert(0);
-    }
-  }
-
-  if ( old_w > pgs_w ) {
-    c3_w dif_w = old_w - pgs_w;
-
-    if ( MAP_FAILED == mmap((void*)(u3_Loom + (pgs_w << u3a_page)),
-                            (size_t)dif_w << (u3a_page + 2),
-                            (PROT_READ | PROT_WRITE),
-                            (MAP_ANON | MAP_FIXED | MAP_PRIVATE),
-                            -1, 0) )
-    {
-      fprintf(stderr, "loom: anonymous mmap failed (%u pages, %u old): %s\r\n",
-                      pgs_w, old_w, strerror(errno));
-      c3_assert(0);
-    }
-
-#ifdef U3_GUARD_PAGE
-    //  protect guard page if clobbered
-    //
-    //    NB: < pgs_w is precluded by assertion in u3e_save()
-    //
-    if ( u3P.gar_w < old_w ) {
-      fprintf(stderr, "loom: guard on remap\r\n");
-      c3_assert( !_ce_ward_protect() );
-    }
-#endif
-
-    _ce_loom_track_north(pgs_w, dif_w);
-  }
-  else {
-    _ce_loom_track_north(pgs_w, 0);
-  }
-}
-
-/* _ce_loom_blit_north(): apply pages, in order, from the bottom of memory.
-*/
-static void
-_ce_loom_blit_north(c3_i fid_i, c3_w pgs_w)
-{
-  size_t  len_i = (size_t)pgs_w << (u3a_page + 2);
   ssize_t ret_i;
-
-  if ( pgs_w ) {
-    if ( len_i != (ret_i = c3_pread(fid_i, u3_Loom, len_i, 0)) ) {
-      if ( 0 < ret_i ) {
-        fprintf(stderr, "loom: blit north partial read: %zu\r\n",
-                        (size_t)ret_i);
-      }
-      else {
-        fprintf(stderr, "loom: blit north read: %s\r\n", strerror(errno));
-      }
-      c3_assert(0);
-    }
-  }
-
-  _ce_loom_protect_north(pgs_w, 0);
-}
-
-/* _ce_loom_blit_south(): apply pages, reversed, from the top of memory.
-*/
-static void
-_ce_loom_blit_south(c3_i fid_i, c3_w pgs_w)
-{
   c3_w      i_w;
-  c3_w*   ptr_w;
-  size_t  off_i;
-  ssize_t ret_i;
+  c3_w    siz_w = pag_siz_i;
 
-  for ( i_w = 0; i_w < pgs_w; i_w++ ) {
-    off_i = (size_t)i_w << (u3a_page + 2);
-    ptr_w = u3_Loom + ((u3P.pag_w - (i_w + 1)) << u3a_page);
+  if ( -1 == lseek(img_u->fid_i, 0, SEEK_SET) ) {
+    fprintf(stderr, "loom: image (%s) blit seek 0: %s\r\n",
+                    img_u->nam_c, strerror(errno));
+    c3_assert(0);
+  }
 
-    if ( pag_siz_i != (ret_i = c3_pread(fid_i, ptr_w, pag_siz_i, off_i)) ) {
+  for ( i_w = 0; i_w < img_u->pgs_w; i_w++ ) {
+    if ( siz_w != (ret_i = read(img_u->fid_i, ptr_w, siz_w)) ) {
       if ( 0 < ret_i ) {
-        fprintf(stderr, "loom: blit south partial read: %zu\r\n",
-                        (size_t)ret_i);
+        fprintf(stderr, "loom: image (%s) blit partial read: %zu\r\n",
+                        img_u->nam_c, (size_t)ret_i);
       }
       else {
-        fprintf(stderr, "loom: blit south read: %s\r\n", strerror(errno));
+        fprintf(stderr, "loom: image (%s) blit read: %s\r\n",
+                        img_u->nam_c, strerror(errno));
       }
       c3_assert(0);
     }
-  }
 
-  _ce_loom_protect_south(pgs_w, 0);
+    if ( 0 != mprotect(ptr_w, siz_w, PROT_READ) ) {
+      fprintf(stderr, "loom: live mprotect: %s\r\n", strerror(errno));
+      c3_assert(0);
+    }
+
+    c3_w pag_w = u3a_outa(ptr_w) >> u3a_page;
+    c3_w blk_w = pag_w >> 5;
+    c3_w bit_w = pag_w & 31;
+    u3P.dit_w[blk_w] &= ~(1 << bit_w);
+
+    ptr_w += stp_ws;
+  }
 }
 
 #ifdef U3_SNAPSHOT_VALIDATION
@@ -1002,18 +873,22 @@ _ce_loom_blit_south(c3_i fid_i, c3_w pgs_w)
 */
 static void
 _ce_image_fine(u3e_image* img_u,
-               c3_w*      ptr_w,
-               c3_ws     stp_ws)
+               c3_w*        ptr_w,
+               c3_ws        stp_ws)
 {
-  c3_w i_w, mem_w, fil_w;
-  c3_w      buf_w[pag_wiz_i];
-  size_t    off_i, siz_i = pag_siz_i;
-  ssize_t   ret_i;
+  ssize_t ret_i;
+  c3_w      i_w;
+  c3_w    buf_w[pag_wiz_i];
+
+  if ( -1 == lseek(img_u->fid_i, 0, SEEK_SET) ) {
+    fprintf(stderr, "loom: image fine seek 0: %s\r\n", strerror(errno));
+    c3_assert(0);
+  }
 
   for ( i_w=0; i_w < img_u->pgs_w; i_w++ ) {
-    off_i = (size_t)i_w << (u3a_page + 2);
+    c3_w mem_w, fil_w;
 
-    if ( siz_i != (ret_i = c3_pread(img_u->fid_i, buf_w, siz_i, off_i)) ) {
+    if ( pag_siz_i != (ret_i = read(img_u->fid_i, buf_w, pag_siz_i)) ) {
       if ( 0 < ret_i ) {
         fprintf(stderr, "loom: image (%s) fine partial read: %zu\r\n",
                         img_u->nam_c, (size_t)ret_i);
@@ -1024,7 +899,6 @@ _ce_image_fine(u3e_image* img_u,
       }
       c3_assert(0);
     }
-
     mem_w = u3r_mug_words(ptr_w, pag_wiz_i);
     fil_w = u3r_mug_words(buf_w, pag_wiz_i);
 
@@ -1045,28 +919,36 @@ _ce_image_fine(u3e_image* img_u,
 }
 #endif
 
-/* _ce_image_copy(): copy all of [fom_u] to [tou_u]
-**
-**   XX use reflinks a la _king_copy_file()?
+/* _ce_image_copy():
 */
 static c3_o
 _ce_image_copy(u3e_image* fom_u, u3e_image* tou_u)
 {
-  c3_w    i_w;
-  c3_w    mem_w[pag_wiz_i];
-  size_t  off_i, siz_i = pag_siz_i;
   ssize_t ret_i;
+  c3_w      i_w;
 
   //  resize images
   //
   _ce_image_resize(tou_u, fom_u->pgs_w);
 
+  //  seek to begining of patch and images
+  //
+  if (  (-1 == lseek(fom_u->fid_i, 0, SEEK_SET))
+     || (-1 == lseek(tou_u->fid_i, 0, SEEK_SET)) )
+  {
+    fprintf(stderr, "loom: image (%s) copy seek: %s\r\n",
+                    fom_u->nam_c,
+                    strerror(errno));
+    return c3n;
+  }
+
   //  copy pages into destination image
   //
   for ( i_w = 0; i_w < fom_u->pgs_w; i_w++ ) {
-    off_i = (size_t)i_w << (u3a_page + 2);
+    c3_w mem_w[pag_wiz_i];
+    c3_w off_w = i_w;
 
-    if ( siz_i != (ret_i = c3_pread(fom_u->fid_i, mem_w, siz_i, off_i)) ) {
+    if ( pag_siz_i != (ret_i = read(fom_u->fid_i, mem_w, pag_siz_i)) ) {
       if ( 0 < ret_i ) {
         fprintf(stderr, "loom: image (%s) copy partial read: %zu\r\n",
                         fom_u->nam_c, (size_t)ret_i);
@@ -1077,30 +959,40 @@ _ce_image_copy(u3e_image* fom_u, u3e_image* tou_u)
       }
       return c3n;
     }
-
-    if ( 0 > c3_pwrite(tou_u->fid_i, mem_w, siz_i, off_i) ) {
-      fprintf(stderr, "loom: image (%s) copy write: %s\r\n",
-                      tou_u->nam_c, strerror(errno));
-      return c3n;
+    else {
+      if ( -1 == lseek(tou_u->fid_i, (off_w << (u3a_page + 2)), SEEK_SET) ) {
+        fprintf(stderr, "loom: image (%s) copy seek: %s\r\n",
+                        tou_u->nam_c, strerror(errno));
+        return c3n;
+      }
+      if ( pag_siz_i != (ret_i = write(tou_u->fid_i, mem_w, pag_siz_i)) ) {
+        if ( 0 < ret_i ) {
+          fprintf(stderr, "loom: image (%s) copy partial write: %zu\r\n",
+                          tou_u->nam_c, (size_t)ret_i);
+        }
+        else {
+          fprintf(stderr, "loom: image (%s) copy write: %s\r\n",
+                          tou_u->nam_c, strerror(errno));
+        }
+        return c3n;
+      }
     }
   }
 
   return c3y;
 }
 
-/* _ce_backup(); copy snapshot to .urb/bhk (if it doesn't exist yet).
+/* _ce_backup();
 */
 static void
 _ce_backup(void)
 {
   u3e_image nop_u = { .nam_c = "north", .pgs_w = 0 };
   u3e_image sop_u = { .nam_c = "south", .pgs_w = 0 };
-  c3_i mod_i = O_RDWR | O_CREAT; // XX O_TRUNC ?
+  c3_i mod_i = O_RDWR | O_CREAT;
   c3_c ful_c[8193];
 
-  //  XX move directory creation?
-  //
-  snprintf(ful_c, 8192, "%s/.urb/bhk", u3C.dir_c);
+  snprintf(ful_c, 8192, "%s/.urb/bhk", u3P.dir_c);
 
   if ( c3_mkdir(ful_c, 0700) ) {
     if ( EEXIST != errno ) {
@@ -1109,14 +1001,14 @@ _ce_backup(void)
     return;
   }
 
-  snprintf(ful_c, 8192, "%s/.urb/bhk/%s.bin", u3C.dir_c, nop_u.nam_c);
+  snprintf(ful_c, 8192, "%s/.urb/bhk/%s.bin", u3P.dir_c, nop_u.nam_c);
 
   if ( -1 == (nop_u.fid_i = c3_open(ful_c, mod_i, 0666)) ) {
     fprintf(stderr, "loom: c3_open %s: %s\r\n", ful_c, strerror(errno));
     return;
   }
 
-  snprintf(ful_c, 8192, "%s/.urb/bhk/%s.bin", u3C.dir_c, sop_u.nam_c);
+  snprintf(ful_c, 8192, "%s/.urb/bhk/%s.bin", u3P.dir_c, sop_u.nam_c);
 
   if ( -1 == (sop_u.fid_i = c3_open(ful_c, mod_i, 0666)) ) {
     fprintf(stderr, "loom: c3_open %s: %s\r\n", ful_c, strerror(errno));
@@ -1128,9 +1020,9 @@ _ce_backup(void)
   {
 
     c3_unlink(ful_c);
-    snprintf(ful_c, 8192, "%s/.urb/bhk/%s.bin", u3C.dir_c, nop_u.nam_c);
+    snprintf(ful_c, 8192, "%s/.urb/bhk/%s.bin", u3P.dir_c, nop_u.nam_c);
     c3_unlink(ful_c);
-    snprintf(ful_c, 8192, "%s/.urb/bhk", u3C.dir_c);
+    snprintf(ful_c, 8192, "%s/.urb/bhk", u3P.dir_c);
     c3_rmdir(ful_c);
   }
 
@@ -1159,29 +1051,19 @@ _ce_backup(void)
   before we try to make another snapshot.
 */
 void
-u3e_save(u3_post low_p, u3_post hig_p)
+u3e_save(void)
 {
   u3_ce_patch* pat_u;
-  c3_w  nod_w, sod_w;
 
   if ( u3C.wag_w & u3o_dryrun ) {
     return;
   }
 
-  {
-    c3_w nop_w = (low_p >> u3a_page);
-    c3_w nor_w = (low_p + (pag_wiz_i - 1)) >> u3a_page;
-    c3_w sop_w = hig_p >> u3a_page;
-
-    c3_assert( (u3P.gar_w > nop_w) && (u3P.gar_w < sop_w) );
-
-    if ( !(pat_u = _ce_patch_compose(nor_w, u3P.pag_w - sop_w)) ) {
-      return;
-    }
+  if ( !(pat_u = _ce_patch_compose()) ) {
+    return;
   }
 
-  nod_w = u3P.nor_u.pgs_w;
-  sod_w = u3P.sou_u.pgs_w;
+  // u3a_print_memory(stderr, "sync: save", 4096 * pat_u->con_u->pgs_w);
 
   _ce_patch_sync(pat_u);
 
@@ -1206,15 +1088,6 @@ u3e_save(u3_post low_p, u3_post hig_p)
   }
 #endif
 
-  if ( u3C.wag_w & u3o_no_demand ) {
-    _ce_loom_protect_north(u3P.nor_u.pgs_w, nod_w);
-  }
-  else {
-    _ce_loom_mapf_north(u3P.nor_u.fid_i, u3P.nor_u.pgs_w, nod_w);
-  }
-
-  _ce_loom_protect_south(u3P.sou_u.pgs_w, sod_w);
-
   _ce_image_sync(&u3P.nor_u);
   _ce_image_sync(&u3P.sou_u);
   _ce_patch_free(pat_u);
@@ -1226,16 +1099,8 @@ u3e_save(u3_post low_p, u3_post hig_p)
 /* u3e_live(): start the checkpointing system.
 */
 c3_o
-u3e_live(c3_c* dir_c)
+u3e_live(c3_o nuu_o, c3_c* dir_c)
 {
-  c3_o nuu_o = c3n;
-
-  //  XX demand paging is not supported on windows
-  //
-#ifdef U3_OS_mingw
-  u3C.wag_w |= u3o_no_demand;
-#endif
-
   //  require that our page size is a multiple of the system page size.
   //
   {
@@ -1271,7 +1136,6 @@ u3e_live(c3_c* dir_c)
     }
     else {
       u3_ce_patch* pat_u;
-      c3_w  nor_w, sou_w;
 
       /* Load any patch files; apply them to images.
       */
@@ -1283,52 +1147,41 @@ u3e_live(c3_c* dir_c)
         _ce_patch_delete();
       }
 
-      nor_w = u3P.nor_u.pgs_w;
-      sou_w = u3P.sou_u.pgs_w;
-
       //  detect snapshots from a larger loom
       //
-      if ( (nor_w + sou_w + 1) >= u3P.pag_w ) {
+      if ( (u3P.nor_u.pgs_w + u3P.sou_u.pgs_w + 1) >= u3a_pages ) {
         fprintf(stderr, "boot: snapshot too big for loom\r\n");
         exit(1);
       }
 
       //  mark all pages dirty (pages in the snapshot will be marked clean)
       //
-      _ce_loom_track_north(0, u3P.pag_w);
+      u3e_foul();
 
       /* Write image files to memory; reinstate protection.
       */
       {
-        if ( u3C.wag_w & u3o_no_demand ) {
-          _ce_loom_blit_north(u3P.nor_u.fid_i, nor_w);
-        }
-        else {
-          _ce_loom_mapf_north(u3P.nor_u.fid_i, nor_w, 0);
-        }
+        _ce_image_blit(&u3P.nor_u,
+                       u3_Loom,
+                       pag_wiz_i);
 
-        _ce_loom_blit_south(u3P.sou_u.fid_i, sou_w);
+        _ce_image_blit(&u3P.sou_u,
+                       (u3_Loom + u3C.wor_i) - pag_wiz_i,
+                       -(ssize_t)pag_wiz_i);
 
         u3l_log("boot: protected loom\r\n");
       }
 
       /* If the images were empty, we are logically booting.
       */
-      if ( !nor_w && !sou_w ) {
+      if ( (0 == u3P.nor_u.pgs_w) && (0 == u3P.sou_u.pgs_w) ) {
         u3l_log("live: logical boot\r\n");
         nuu_o = c3y;
       }
-      else  if ( u3C.wag_w & u3o_no_demand ) {
-        u3a_print_memory(stderr, "live: loaded", (nor_w + sou_w) << u3a_page);
-      }
       else {
-        u3a_print_memory(stderr, "live: mapped", nor_w << u3a_page);
-        u3a_print_memory(stderr, "live: loaded", sou_w << u3a_page);
+        u3a_print_memory(stderr, "live: loaded",
+                         (u3P.nor_u.pgs_w + u3P.sou_u.pgs_w) << u3a_page);
       }
-
-#ifdef U3_GUARD_PAGE
-      c3_assert( !_ce_ward_post(nor_w, u3P.pag_w - sou_w) );
-#endif
     }
   }
 
@@ -1352,17 +1205,23 @@ u3e_yolo(void)
     return c3n;
   }
 
-#ifdef U3_GUARD_PAGE
-  c3_assert( !_ce_ward_protect() );
-#endif
-
-  //  mark all pages dirty
-  //
-  _ce_loom_track_north(0, u3P.pag_w);
+  if ( 0 != mprotect(u3a_into(gar_pag_p), pag_siz_i, PROT_NONE) ) {
+    fprintf(stderr, "loom: failed to protect guard page: %s\r\n",
+                    strerror(errno));
+    c3_assert(0);
+  }
 
   return c3y;
 }
 
+/* u3e_foul(): dirty all the pages of the loom.
+*/
+void
+u3e_foul(void)
+{
+  memset((void*)u3P.dit_w, 0xff, sizeof(u3P.dit_w));
+}
+
 /* u3e_init(): initialize guard page tracking.
 */
 void
@@ -1371,10 +1230,8 @@ u3e_init(void)
   u3P.pag_w = u3C.wor_i >> u3a_page;
 
 #ifdef U3_GUARD_PAGE
-  c3_assert( !_ce_ward_post(0, u3P.pag_w) );
+  _ce_center_guard_page();
 #endif
-
-  _ce_loom_track_north(0, u3P.pag_w);
 }
 
 /* u3e_ward(): reposition guard page if needed.
@@ -1383,14 +1240,8 @@ void
 u3e_ward(u3_post low_p, u3_post hig_p)
 {
 #ifdef U3_GUARD_PAGE
-  c3_w nop_w = low_p >> u3a_page;
-  c3_w sop_w = hig_p >> u3a_page;
-  c3_w pag_w = u3P.gar_w;
-
-  if ( !((pag_w > nop_w) && (pag_w < hig_p)) ) {
-    c3_assert( !_ce_ward_post(nop_w, sop_w) );
-    c3_assert( !_ce_flaw_protect(pag_w) );
-    c3_assert( u3P.dit_w[pag_w >> 5] & (1 << (pag_w & 31)) );
+  if ( (low_p > gar_pag_p) || (hig_p < gar_pag_p) ) {
+    _ce_center_guard_page();
   }
 #endif
 }
diff --git a/pkg/urbit/noun/manage.c b/pkg/urbit/noun/manage.c
index bc868309b..33b57a43a 100644
--- a/pkg/urbit/noun/manage.c
+++ b/pkg/urbit/noun/manage.c
@@ -2,7 +2,6 @@
 **
 */
 #include "all.h"
-#include "noun/events.h"
 #include "rsignal.h"
 #include "vere/vere.h"
 #include <errno.h>
@@ -437,7 +436,7 @@ u3m_file(c3_c* pas_c)
   u3l_log("Loading file: %s\r\n", pas_c);
   struct stat buf_b;
   c3_i        fid_i = c3_open(pas_c, O_RDONLY, 0644);
-  c3_w        fln_w;
+  c3_w        fln_w, red_w;
   c3_y*       pad_y;
 
   if ( (fid_i < 0) || (fstat(fid_i, &buf_b) < 0) ) {
@@ -449,10 +448,10 @@ u3m_file(c3_c* pas_c)
   
   pad_y = c3_malloc(buf_b.st_size);
 
-  ssize_t red_i = c3_pread(fid_i, pad_y, fln_w, 0);
+  red_w = read(fid_i, pad_y, fln_w);
   close(fid_i);
 
-  if ( red_i != fln_w ) {
+  if ( fln_w != red_w ) {
     c3_free(pad_y);
     return u3m_bail(c3__fail);
   }
@@ -528,8 +527,6 @@ _pave_north(c3_w* mem_w, c3_w siz_w, c3_w len_w)
   //    the stack starts at the end of the memory segment,
   //    minus space for the road structure [siz_w]
   //
-  //    NB: the returned road is "above" the stack
-  //
   c3_w* rut_w = mem_w;
   c3_w* mat_w = ((mem_w + len_w) - siz_w);
   c3_w* cap_w = mat_w;
@@ -548,8 +545,6 @@ _pave_south(c3_w* mem_w, c3_w siz_w, c3_w len_w)
   //    the stack starts at the base memory pointer [mem_w],
   //    and ends after the space for the road structure [siz_w]
   //
-  //    NB: the returned road is *on* the stack
-  //
   c3_w* rut_w = (mem_w + len_w);
   c3_w* mat_w = mem_w;
   c3_w* cap_w = mat_w + siz_w;
@@ -605,7 +600,7 @@ _find_home(void)
   //  this looks risky, but there are no legitimate scenarios
   //  where it's wrong
   //
-  u3R->cap_p = u3R->mat_p = u3a_outa(u3H);
+  u3R->cap_p = u3R->mat_p = u3C.wor_i - c3_wiseof(*u3H);
 }
 
 /* u3m_pave(): instantiate or activate image.
@@ -824,6 +819,7 @@ u3m_leap(c3_w pad_w)
       u3R->cap_p -= len_w;
 
       rod_u = _pave_south(u3a_into(bot_p), c3_wiseof(u3a_road), len_w);
+      u3e_ward(rod_u->cap_p, rod_u->hat_p);
 #if 0
       fprintf(stderr, "leap: from north %p (cap 0x%x), to south %p\r\n",
               u3R,
@@ -836,6 +832,7 @@ u3m_leap(c3_w pad_w)
       u3R->cap_p += len_w;
 
       rod_u = _pave_north(u3a_into(bot_p), c3_wiseof(u3a_road), len_w);
+      u3e_ward(rod_u->hat_p, rod_u->cap_p);
 #if 0
       fprintf(stderr, "leap: from south %p (cap 0x%x), to north %p\r\n",
               u3R,
@@ -857,7 +854,6 @@ u3m_leap(c3_w pad_w)
   */
   {
     u3R = rod_u;
-    u3m_ward();
     _pave_parts();
   }
 #ifdef U3_MEMORY_DEBUG
@@ -1007,31 +1003,12 @@ u3m_flog(c3_w gof_w)
 /* u3m_water(): produce watermarks.
 */
 void
-u3m_water(u3_post* low_p, u3_post* hig_p)
+u3m_water(c3_w* low_w, c3_w* hig_w)
 {
-  //  allow the segfault handler to fire before the road is set
-  //
-  //    while not explicitly possible in the codebase,
-  //    compiler optimizations can reorder stores
-  //
-  if ( !u3R ) {
-    *low_p = 0;
-    *hig_p = u3C.wor_i - 1;
-  }
-  //  in a north road, hat points to the end of the heap + 1 word,
-  //  while cap points to the top of the stack
-  //
-  else if ( c3y == u3a_is_north(u3R) ) {
-    *low_p = u3R->hat_p - 1;
-    *hig_p = u3R->cap_p;
-  }
-  //  in a south road, hat points to the end of the heap,
-  //  while cap points to the top of the stack + 1 word
-  //
-  else {
-    *low_p = u3R->cap_p - 1;
-    *hig_p = u3R->hat_p;
-  }
+  c3_assert(u3R == &u3H->rod_u);
+
+  *low_w = u3a_heap(u3R);
+  *hig_w = u3a_temp(u3R) + c3_wiseof(u3v_home);
 }
 
 /* u3m_soft_top(): top-level safety wrapper.
@@ -1715,80 +1692,6 @@ _cm_limits(void)
 # endif
 }
 
-/* u3m_fault(): handle a memory event with libsigsegv protocol.
-*/
-c3_i
-u3m_fault(void* adr_v, c3_i ser_i)
-{
-  //  let the stack overflow handler run.
-  //
-  if ( 0 == ser_i ) {
-    return 0;
-  }
-
-  c3_w*   adr_w = (c3_w*)adr_v;
-  u3_post low_p, hig_p;
-
-  if ( (adr_w < u3_Loom) || (adr_w >= (u3_Loom + u3C.wor_i)) ) {
-    fprintf(stderr, "loom: external fault: %p (%p : %p)\r\n\r\n",
-                    adr_w, u3_Loom, u3_Loom + u3C.wor_i);
-    c3_assert(0);
-    return 0;
-  }
-
-  u3m_water(&low_p, &hig_p);
-
-  switch ( u3e_fault(low_p, hig_p, u3a_outa(adr_w)) ) {
-    //  page tracking invariants violated, fatal
-    //
-    case u3e_flaw_sham: {
-      c3_assert(0);
-      return 0;
-    }
-
-    //  virtual memory failure (protections), possibly recoverable XX
-    //
-    case u3e_flaw_base: {
-      c3_assert(0);
-      return 0;
-    }
-
-    //  loom limits exceeded, recoverable
-    //
-    case u3e_flaw_meme: {
-      u3m_signal(c3__meme); // doesn't return
-      return 1;
-    }
-
-    case u3e_flaw_good: return 1;
-  }
-
-  c3_assert(!"unpossible");
-}
-
-/* u3m_save(): update the checkpoint.
-*/
-void
-u3m_save(void)
-{
-  u3_post low_p, hig_p;
-  u3m_water(&low_p, &hig_p);
-
-  c3_assert(u3R == &u3H->rod_u);
-
-  return u3e_save(low_p, hig_p);
-}
-
-/* u3m_ward(): tend the guard page.
-*/
-void
-u3m_ward(void)
-{
-  u3_post low_p, hig_p;
-  u3m_water(&low_p, &hig_p);
-  return u3e_ward(low_p, hig_p);
-}
-
 /* _cm_signals(): set up interrupts, etc.
 */
 static void
@@ -1804,7 +1707,7 @@ _cm_signals(void)
   //  filter (see compat/mingw/seh_handler.c) that handles both memory
   //  access and stack overflow exceptions. It calls u3e_fault directly.
 # else
-  if ( 0 != sigsegv_install_handler(u3m_fault) ) {
+  if ( 0 != sigsegv_install_handler(u3e_fault) ) {
     u3l_log("boot: sigsegv install failed\n");
     exit(1);
   }
@@ -1961,46 +1864,6 @@ void
 u3m_stop()
 {
   u3je_secp_stop();
-
-  //  XX move to jets.c
-  //
-  c3_free(u3D.ray_u);
-}
-
-/* u3m_pier(): make a pier.
-*/
-c3_c*
-u3m_pier(c3_c* dir_c)
-{
-  c3_c ful_c[8193];
-
-  u3C.dir_c = dir_c;
-
-  snprintf(ful_c, 8192, "%s", dir_c);
-  if ( c3_mkdir(ful_c, 0700) ) {
-    if ( EEXIST != errno ) {
-      fprintf(stderr, "loom: pier create: %s\r\n", strerror(errno));
-      c3_assert(0);
-    }
-  }
-
-  snprintf(ful_c, 8192, "%s/.urb", dir_c);
-  if ( c3_mkdir(ful_c, 0700) ) {
-    if ( EEXIST != errno ) {
-      fprintf(stderr, "loom: .urb create: %s\r\n", strerror(errno));
-      c3_assert(0);
-    }
-  }
-
-  snprintf(ful_c, 8192, "%s/.urb/chk", dir_c);
-  if ( c3_mkdir(ful_c, 0700) ) {
-    if ( EEXIST != errno ) {
-      fprintf(stderr, "loom: .urb/chk create: %s\r\n", strerror(errno));
-      c3_assert(0);
-    }
-  }
-
-  return strdup(ful_c);
 }
 
 /* u3m_boot(): start the u3 system. return next event, starting from 1.
@@ -2016,7 +1879,7 @@ u3m_boot(c3_c* dir_c, size_t len_i)
 
   /* Activate the storage system.
   */
-  nuu_o = u3e_live(u3m_pier(dir_c));
+  nuu_o = u3e_live(c3n, dir_c);
 
   /* Activate tracing.
   */
@@ -2029,6 +1892,10 @@ u3m_boot(c3_c* dir_c, size_t len_i)
   */
   u3m_pave(nuu_o);
 
+  /* Place the guard page.
+  */
+  u3e_init();
+
   /* Initialize the jet system.
   */
   {
diff --git a/pkg/urbit/noun/trace.c b/pkg/urbit/noun/trace.c
index 85afcfd46..79d290930 100644
--- a/pkg/urbit/noun/trace.c
+++ b/pkg/urbit/noun/trace.c
@@ -278,19 +278,11 @@ void
 u3t_trace_open(c3_c* dir_c)
 {
   c3_c fil_c[2048];
-
-  if ( !dir_c ) {
-    return;
-  }
-
   snprintf(fil_c, 2048, "%s/.urb/put/trace", dir_c);
 
   struct stat st;
-  if (  (-1 == stat(fil_c, &st))
-     && (-1 == c3_mkdir(fil_c, 0700)) )
-  {
-    fprintf(stderr, "mkdir: %s failed: %s\r\n", fil_c, strerror(errno));
-    return;
+  if ( -1 == stat(fil_c, &st) ) {
+    c3_mkdir(fil_c, 0700);
   }
 
   c3_c lif_c[2056];
@@ -299,11 +291,6 @@ u3t_trace_open(c3_c* dir_c)
   u3_Host.tra_u.fil_u = c3_fopen(lif_c, "w");
   u3_Host.tra_u.nid_w = (int)getpid();
 
-  if ( !u3_Host.tra_u.fil_u) {
-    fprintf(stderr, "trace open: %s\r\n", strerror(errno));
-    return;
-  }
-
   fprintf(u3_Host.tra_u.fil_u, "[ ");
 
   // We have two "threads", the event processing and the nock stuff.
diff --git a/pkg/urbit/noun/urth.c b/pkg/urbit/noun/urth.c
index de4e2d560..30ab44817 100644
--- a/pkg/urbit/noun/urth.c
+++ b/pkg/urbit/noun/urth.c
@@ -2,7 +2,6 @@
 **
 */
 #include "all.h"
-#include "noun/events.h"
 #include "ur/ur.h"
 #include <errno.h>
 #include <fcntl.h>
@@ -417,6 +416,10 @@ _cu_realloc(FILE* fil_u, ur_root_t** tor_u, ur_nvec_t* doc_u)
   //
   u3A->eve_d = eve_d;
 
+  //  mark all pages dirty
+  //
+  u3e_foul();
+
   *tor_u = rot_u;
   *doc_u = cod_u;
 
@@ -426,17 +429,15 @@ _cu_realloc(FILE* fil_u, ur_root_t** tor_u, ur_nvec_t* doc_u)
 /* u3u_meld(): globally deduplicate memory.
 */
 #ifdef U3_MEMORY_DEBUG
-c3_w
+void
 u3u_meld(void)
 {
   fprintf(stderr, "u3: unable to meld under U3_MEMORY_DEBUG\r\n");
-  return 0;
 }
 #else
-c3_w
+void
 u3u_meld(void)
 {
-  c3_w       pre_w = u3a_open(u3R);
   ur_root_t* rot_u;
   ur_nvec_t  cod_u;
 
@@ -448,8 +449,6 @@ u3u_meld(void)
   //
   ur_nvec_free(&cod_u);
   ur_root_free(rot_u);
-
-  return (u3a_open(u3R) - pre_w);
 }
 #endif
 
@@ -565,14 +564,56 @@ _cu_rock_save(c3_c* dir_c, c3_d eve_d, c3_d len_d, c3_y* byt_y)
 
   //  write jam-buffer into [fid_i]
   //
-  ssize_t rit_i = c3_pwrite(fid_i, byt_y, len_d, 0);
-  if ( rit_i < 0 ) {
-    fprintf(stderr, "rock: write failed: %s\r\n", strerror(errno));
+  //    XX deduplicate with _write() wrapper in term.c
+  //
+  {
+    ssize_t ret_i;
+
+    while ( len_d > 0 ) {
+      c3_w lop_w = 0;
+      //  retry interrupt/async errors
+      //
+      do {
+        //  abort pathological retry loop
+        //
+        if ( 100 == ++lop_w ) {
+          fprintf(stderr, "rock: write loop: %s\r\n", strerror(errno));
+          close(fid_i);
+          //  XX unlink file?
+          //
+          return c3n;
+        }
+
+        ret_i = write(fid_i, byt_y, len_d);
+      }
+      while (  (ret_i < 0)
+            && (  (errno == EINTR)
+               || (errno == EAGAIN)
+               || (errno == EWOULDBLOCK) ));
+
+      //  assert on true errors
+      //
+      //    NB: can't call u3l_log here or we would re-enter _write()
+      //
+      if ( ret_i < 0 ) {
+        fprintf(stderr, "rock: write failed %s\r\n", strerror(errno));
+        close(fid_i);
+        //  XX unlink file?
+        //
+        return c3n;
+      }
+      //  continue partial writes
+      //
+      else {
+        len_d -= ret_i;
+        byt_y += ret_i;
+      }
+    }
   }
 
   close(fid_i);
 
-  return rit_i < 0 ? c3n : c3y;
+  return c3y;
 }
 
 /* u3u_cram(): globably deduplicate memory, and write a rock to disk.
@@ -848,6 +889,10 @@ u3u_uncram(c3_c* dir_c, c3_d eve_d)
   //
   u3A->eve_d = eve_d;
 
+  //  mark all pages dirty
+  //
+  u3e_foul();
+
   //  leave rocks on disk
   //
   // if ( 0 != c3_unlink(nam_c) ) {
diff --git a/pkg/urbit/noun/vortex.c b/pkg/urbit/noun/vortex.c
index a37b76888..016588ea8 100644
--- a/pkg/urbit/noun/vortex.c
+++ b/pkg/urbit/noun/vortex.c
@@ -27,18 +27,9 @@ u3v_life(u3_noun eve)
 c3_o
 u3v_boot(u3_noun eve)
 {
-  c3_d len_d;
-
-  {
-    u3_noun len = u3qb_lent(eve);
-    c3_assert( c3y == u3r_safe_chub(len, &len_d) );
-    u3z(len);
-  }
-
   //  ensure zero-initialized kernel
   //
-  u3A->roc   = 0;
-  u3A->eve_d = 0;
+  u3A->roc = 0;
 
   {
     u3_noun pro = u3m_soft(0, u3v_life, eve);
@@ -48,8 +39,7 @@ u3v_boot(u3_noun eve)
       return c3n;
     }
 
-    u3A->roc   = u3k(u3t(pro));
-    u3A->eve_d = len_d;
+    u3A->roc = u3k(u3t(pro));
     u3z(pro);
   }
 
@@ -270,61 +260,6 @@ u3v_poke(u3_noun ovo)
   return pro;
 }
 
-/* _cv_poke_eve(): u3v_poke w/out u3A->now XX replace
-*/
-static u3_noun
-_cv_poke_eve(u3_noun sam)
-{
-  u3_noun fun = u3n_nock_on(u3k(u3A->roc), u3k(u3x_at(_CVX_POKE, u3A->roc)));
-  u3_noun pro;
-
-  {
-# ifdef  U3_MEMORY_DEBUG
-    c3_w cod_w = u3a_lush(u3h(u3t(u3t(sam))));
-# endif
-
-    pro = u3n_slam_on(fun, sam);
-
-# ifdef  U3_MEMORY_DEBUG
-    u3a_lop(cod_w);
-# endif
-  }
-
-  return pro;
-}
-
-/* u3v_poke_sure(): inject an event, saving new state if successful.
-*/
-c3_o
-u3v_poke_sure(c3_w mil_w, u3_noun eve, u3_noun* pro)
-{
-  u3_noun gon = u3m_soft(mil_w, _cv_poke_eve, eve);
-  u3_noun tag, dat;
-  u3x_cell(gon, &tag, &dat);
-
-  //  event failed, produce trace
-  //
-  if ( u3_blip != tag ) {
-    *pro = gon;
-    return c3n;
-  }
-
-  //  event succeeded, persist state and produce effects
-  //
-  {
-    u3_noun vir, cor;
-    u3x_cell(dat, &vir, &cor);
-
-    u3z(u3A->roc);
-    u3A->roc = u3k(cor);
-    u3A->eve_d++;
-
-    *pro = u3k(vir);
-    u3z(gon);
-    return c3y;
-  }
-}
-
 /* u3v_tank(): dump single tank.
 */
 void
diff --git a/pkg/urbit/tests/ames_tests.c b/pkg/urbit/tests/ames_tests.c
index 38581d8ca..0907898d4 100644
--- a/pkg/urbit/tests/ames_tests.c
+++ b/pkg/urbit/tests/ames_tests.c
@@ -6,7 +6,8 @@
 static void
 _setup(void)
 {
-  u3m_boot_lite(1 << 22);
+  u3m_init(1 << 22);
+  u3m_pave(c3y);
 }
 
 /* _test_ames(): spot check ames helpers
diff --git a/pkg/urbit/tests/events_tests.c b/pkg/urbit/tests/events_tests.c
deleted file mode 100644
index 92f1bd2fe..000000000
--- a/pkg/urbit/tests/events_tests.c
+++ /dev/null
@@ -1,251 +0,0 @@
-#include "all.h"
-#include "noun/events.h"
-
-/* _setup(): prepare for tests.
-*/
-static void
-_setup(void)
-{
-  //  NB: no loom
-  //
-  u3P.pag_w = u3a_pages;
-}
-
-static c3_w
-_check_north_clean(void)
-{
-  c3_w i_w, pag_w, blk_w, bit_w;
-
-  for ( i_w = 0; i_w < u3P.pag_w; i_w++ ) {
-    pag_w = i_w;
-    blk_w = pag_w >> 5;
-    bit_w = pag_w & 31;
-
-    if ( u3P.dit_w[blk_w] & (1 << bit_w) ) {
-      break;
-    }
-  }
-
-  return i_w;
-}
-
-static c3_w
-_check_north_dirty(c3_w pgs_w, c3_w max_w)
-{
-  c3_w i_w, pag_w, blk_w, bit_w;
-
-  for ( i_w = 0; i_w < max_w; i_w++ ) {
-    pag_w = i_w + pgs_w;
-    blk_w = pag_w >> 5;
-    bit_w = pag_w & 31;
-
-    if ( !(u3P.dit_w[blk_w] & (1 << bit_w)) ) {
-      break;
-    }
-  }
-
-  return i_w;
-}
-
-static c3_w
-_check_south_clean(void)
-{
-  c3_w i_w, pag_w, blk_w, bit_w;
-
-  for ( i_w = 0; i_w < u3P.pag_w; i_w++ ) {
-    pag_w = u3P.pag_w - (i_w + 1);
-    blk_w = pag_w >> 5;
-    bit_w = pag_w & 31;
-
-    if ( u3P.dit_w[blk_w] & (1 << bit_w) ) {
-      break;
-    }
-  }
-
-  return i_w;
-}
-
-static c3_w
-_check_south_dirty(c3_w pgs_w, c3_w max_w)
-{
-  c3_w i_w, pag_w, blk_w, bit_w;
-
-  for ( i_w = 0; i_w < max_w; i_w++ ) {
-    pag_w = u3P.pag_w - (i_w + pgs_w + 1);
-    blk_w = pag_w >> 5;
-    bit_w = pag_w & 31;
-
-    if ( !(u3P.dit_w[blk_w] & (1 << bit_w)) ) {
-      break;
-    }
-  }
-
-  return i_w;
-}
-
-void
-_ce_loom_track_north(c3_w pgs_w, c3_w dif_w);
-void
-_ce_loom_track_south(c3_w pgs_w, c3_w dif_w);
-
-static c3_i
-_test_tracking(void)
-{
-  c3_w ret_w;
-
-  _ce_loom_track_north(0, u3P.pag_w);
-
-  if ( u3P.pag_w != (ret_w = _check_north_dirty(0, u3P.pag_w)) ) {
-    fprintf(stderr, "test events track north dirty all %u\r\n", ret_w);
-    return 0;
-  }
-
-  if ( 0 != (ret_w = _check_north_clean()) ) {
-    fprintf(stderr, "test events track north init %u\r\n", ret_w);
-    return 0;
-  }
-
-  if ( 0 != (ret_w = _check_south_clean()) ) {
-    fprintf(stderr, "test events track south init %u\r\n", ret_w);
-    return 0;
-  }
-
-  _ce_loom_track_north(100, 0);
-  _ce_loom_track_south(1, 0);
-
-  if ( 100 != (ret_w = _check_north_clean()) ) {
-    fprintf(stderr, "test events track north clean a %u\r\n", ret_w);
-    return 0;
-  }
-
-  if ( 1 != (ret_w = _check_south_clean()) ) {
-    fprintf(stderr, "test events track south clean a %u\r\n", ret_w);
-    return 0;
-  }
-
-  _ce_loom_track_north(75, 25);
-  _ce_loom_track_south(2, 0);
-
-  if ( 75 != (ret_w = _check_north_clean()) ) {
-    fprintf(stderr, "test events track north clean b %u\r\n", ret_w);
-    return 0;
-  }
-
-  if ( 25 != (ret_w = _check_north_dirty(75, 25)) ) {
-    fprintf(stderr, "test events track north dirty b %u\r\n", ret_w);
-    return 0;
-  }
-
-  if ( 2 != (ret_w = _check_south_clean()) ) {
-    fprintf(stderr, "test events track south clean b %u\r\n", ret_w);
-    return 0;
-  }
-
-  _ce_loom_track_north(55, 20);
-  _ce_loom_track_south(1, 1);
-
-  if ( 55 != (ret_w = _check_north_clean()) ) {
-    fprintf(stderr, "test events track north clean c %u\r\n", ret_w);
-    return 0;
-  }
-
-  if ( 20 != (ret_w = _check_north_dirty(55, 20)) ) {
-    fprintf(stderr, "test events track north dirty c %u\r\n", ret_w);
-    return 0;
-  }
-
-  if ( 1 != (ret_w = _check_south_clean()) ) {
-    fprintf(stderr, "test events track south clean c %u\r\n", ret_w);
-    return 0;
-  }
-
-  if ( 1 != (ret_w = _check_south_dirty(1, 1)) ) {
-    fprintf(stderr, "test events track north dirty c %u\r\n", ret_w);
-    return 0;
-  }
-
-  _ce_loom_track_north(255, 0);
-  _ce_loom_track_south(48, 0);
-
-  if ( 255 != (ret_w = _check_north_clean()) ) {
-    fprintf(stderr, "test events track north clean d %u\r\n", ret_w);
-    return 0;
-  }
-
-  if ( 48 != (ret_w = _check_south_clean()) ) {
-    fprintf(stderr, "test events track south clean d %u\r\n", ret_w);
-    return 0;
-  }
-
-  _ce_loom_track_north(213, 42);
-  _ce_loom_track_south(15, 33);
-
-  if ( 213 != (ret_w = _check_north_clean()) ) {
-    fprintf(stderr, "test events track north clean e %u\r\n", ret_w);
-    return 0;
-  }
-
-  if ( 42 != (ret_w = _check_north_dirty(213, 42)) ) {
-    fprintf(stderr, "test events track north dirty e %u\r\n", ret_w);
-    return 0;
-  }
-
-  if ( 15 != (ret_w = _check_south_clean()) ) {
-    fprintf(stderr, "test events track south clean e %u\r\n", ret_w);
-    return 0;
-  }
-
-  if ( 33 != (ret_w = _check_south_dirty(15, 33)) ) {
-    fprintf(stderr, "test events track north dirty e %u\r\n", ret_w);
-    return 0;
-  }
-
-  _ce_loom_track_north(200, 13);
-  _ce_loom_track_south(10, 5);
-
-  if ( 200 != (ret_w = _check_north_clean()) ) {
-    fprintf(stderr, "test events track north clean f %u\r\n", ret_w);
-    return 0;
-  }
-
-  if ( 13 != (ret_w = _check_north_dirty(200, 13)) ) {
-    fprintf(stderr, "test events track north dirty f %u\r\n", ret_w);
-    return 0;
-  }
-
-  if ( 10 != (ret_w = _check_south_clean()) ) {
-    fprintf(stderr, "test events track south clean f %u\r\n", ret_w);
-    return 0;
-  }
-
-  if ( 5 != (ret_w = _check_south_dirty(10, 5)) ) {
-    fprintf(stderr, "test events track north dirty f %u\r\n", ret_w);
-    return 0;
-  }
-
-  _ce_loom_track_north(0, u3P.pag_w);
-
-  if ( u3P.pag_w != (ret_w = _check_north_dirty(0, u3P.pag_w)) ) {
-    fprintf(stderr, "test events track north dirty all %u\r\n", ret_w);
-    return 0;
-  }
-
-  return 1;
-}
-
-/* main(): run all test cases.
-*/
-int
-main(int argc, char* argv[])
-{
-   _setup();
-
-  if ( !_test_tracking() ) {
-    fprintf(stderr, "test_events: tracking: failed\r\n");
-    exit(1);
-  }
-
-  fprintf(stderr, "test_events: ok\n");
-
-  return 0;
-}
diff --git a/pkg/urbit/tests/hashtable_tests.c b/pkg/urbit/tests/hashtable_tests.c
index 051ec709e..3b36dc887 100644
--- a/pkg/urbit/tests/hashtable_tests.c
+++ b/pkg/urbit/tests/hashtable_tests.c
@@ -9,7 +9,8 @@ c3_w _ch_skip_slot(c3_w mug_w, c3_w lef_w);
 static void
 _setup(void)
 {
-  u3m_boot_lite(1 << 26);
+  u3m_init(1 << 26);
+  u3m_pave(c3y);
 }
 
 /* _test_bit_manipulation():
diff --git a/pkg/urbit/tests/jam_tests.c b/pkg/urbit/tests/jam_tests.c
index d32796855..fd416945d 100644
--- a/pkg/urbit/tests/jam_tests.c
+++ b/pkg/urbit/tests/jam_tests.c
@@ -6,7 +6,9 @@
 static void
 _setup(void)
 {
-  u3m_boot_lite(1 << 24);
+  u3m_init(1 << 24);
+  u3m_pave(c3y);
+  u3e_init();
 }
 
 static void
diff --git a/pkg/urbit/tests/jet_tests.c b/pkg/urbit/tests/jet_tests.c
index d88d55e93..4904a959d 100644
--- a/pkg/urbit/tests/jet_tests.c
+++ b/pkg/urbit/tests/jet_tests.c
@@ -5,7 +5,8 @@
 static void
 _setup(void)
 {
-  u3m_boot_lite(1 << 20);
+  u3m_init(1 << 20);
+  u3m_pave(c3y);
 }
 
 static inline c3_i
diff --git a/pkg/urbit/tests/mug_tests.c b/pkg/urbit/tests/mug_tests.c
index 1c9dcddbc..ffd051674 100644
--- a/pkg/urbit/tests/mug_tests.c
+++ b/pkg/urbit/tests/mug_tests.c
@@ -5,7 +5,8 @@
 static void
 _setup(void)
 {
-  u3m_boot_lite(1 << 20);
+  u3m_init(1 << 20);
+  u3m_pave(c3y);
 }
 
 /* _test_mug(): spot check u3r_mug hashes.
diff --git a/pkg/urbit/tests/newt_tests.c b/pkg/urbit/tests/newt_tests.c
index 75c0a07b1..6fdbdb759 100644
--- a/pkg/urbit/tests/newt_tests.c
+++ b/pkg/urbit/tests/newt_tests.c
@@ -6,7 +6,8 @@
 static void
 _setup(void)
 {
-  u3m_boot_lite(1 << 20);
+  u3m_init(1 << 20);
+  u3m_pave(c3y);
 }
 
 /* _newt_encode(): synchronous serialization into a single buffer, for test purposes
diff --git a/pkg/urbit/tests/meme_tests.c b/pkg/urbit/tests/nock_tests.c
similarity index 80%
rename from pkg/urbit/tests/meme_tests.c
rename to pkg/urbit/tests/nock_tests.c
index 751abb985..a96ed09bd 100644
--- a/pkg/urbit/tests/meme_tests.c
+++ b/pkg/urbit/tests/nock_tests.c
@@ -5,7 +5,12 @@
 static void
 _setup(void)
 {
-  u3m_boot_lite(1 << 24);
+  //  XX at 1<<24, this succeeds on mac, but bail:exit's on linux.
+  //  investigate possible u3n_prog corruption
+  //
+  u3m_init(1 << 25);
+  u3m_pave(c3y);
+  u3e_init();
 }
 
 static u3_noun
@@ -48,7 +53,7 @@ _test_nock_meme(void)
 }
 
 static c3_i
-_test_meme(void)
+_test_nock(void)
 {
   c3_i ret_i = 1;
 
@@ -67,8 +72,8 @@ main(int argc, char* argv[])
 {
   _setup();
 
-  if ( !_test_meme() ) {
-    fprintf(stderr, "test meme: failed\r\n");
+  if ( !_test_nock() ) {
+    fprintf(stderr, "test nock: failed\r\n");
     exit(1);
   }
 
@@ -76,6 +81,6 @@ main(int argc, char* argv[])
   //
   u3m_grab(u3_none);
 
-  fprintf(stderr, "test meme: ok\r\n");
+  fprintf(stderr, "test nock: ok\r\n");
   return 0;
 }
diff --git a/pkg/urbit/tests/noun_tests.c b/pkg/urbit/tests/noun_tests.c
index 1f0527bd5..af54cd289 100644
--- a/pkg/urbit/tests/noun_tests.c
+++ b/pkg/urbit/tests/noun_tests.c
@@ -8,7 +8,8 @@
 static void
 _setup(void)
 {
-  u3m_boot_lite(1 << 20);
+  u3m_init(1 << 20);
+  u3m_pave(c3y);
 }
 
 /* _test_u3r_chop: "extract bit slices from atom"
diff --git a/pkg/urbit/vere/db/lmdb.c b/pkg/urbit/vere/db/lmdb.c
index c95cf38c1..443f11525 100644
--- a/pkg/urbit/vere/db/lmdb.c
+++ b/pkg/urbit/vere/db/lmdb.c
@@ -225,112 +225,6 @@ u3_lmdb_gulf(MDB_env* env_u, c3_d* low_d, c3_d* hig_d)
   }
 }
 
-/* u3_lmdb_walk_init(): initialize db iterator.
-*/
-c3_o
-u3_lmdb_walk_init(MDB_env*      env_u,
-                  u3_lmdb_walk* itr_u,
-                  c3_d          nex_d,
-                  c3_d          las_d)
-{
-  //  XX assumes little-endian
-  //
-  MDB_val key_u = { .mv_size = sizeof(c3_d), .mv_data = &nex_d };
-  MDB_val val_u;
-  c3_w    ops_w, ret_w;
-
-  itr_u->red_o = c3n;
-  itr_u->nex_d = nex_d;
-  itr_u->las_d = las_d;
-
-  //  create a read-only transaction.
-  //
-  ops_w = MDB_RDONLY;
-  if ( (ret_w = mdb_txn_begin(env_u, 0, ops_w, &itr_u->txn_u)) ) {
-    mdb_logerror(stderr, ret_w, "lmdb: read txn_begin fail");
-    return c3n;
-  }
-  //  open the database in the transaction
-  //
-  ops_w = MDB_CREATE | MDB_INTEGERKEY;
-  if ( (ret_w = mdb_dbi_open(itr_u->txn_u, "EVENTS", ops_w, &itr_u->mdb_u)) ) {
-    mdb_logerror(stderr, ret_w, "lmdb: read: dbi_open fail");
-    //  XX confirm
-    //
-    mdb_txn_abort(itr_u->txn_u);
-    return c3n;
-  }
-
-  //  creates a cursor to iterate over keys starting at [eve_d]
-  //
-  if ( (ret_w = mdb_cursor_open(itr_u->txn_u, itr_u->mdb_u, &itr_u->cur_u)) ) {
-    mdb_logerror(stderr, ret_w, "lmdb: read: cursor_open fail");
-    //  XX confirm
-    //
-    mdb_txn_abort(itr_u->txn_u);
-    return c3n;
-  }
-
-  //  set the cursor to the position of [eve_d]
-  //
-  ops_w = MDB_SET_KEY;
-  if ( (ret_w = mdb_cursor_get(itr_u->cur_u, &key_u, &val_u, ops_w)) ) {
-    mdb_logerror(stderr, ret_w, "lmdb: read: initial cursor_get failed");
-    fprintf(stderr, "    at %" PRIu64 "\r\n", nex_d);
-    mdb_cursor_close(itr_u->cur_u);
-    //  XX confirm
-    //
-    mdb_txn_abort(itr_u->txn_u);
-    return c3n;
-  }
-
-  return c3y;
-}
-
-/* u3_lmdb_walk_next(): synchronously read next event from iterator.
-*/
-c3_o
-u3_lmdb_walk_next(u3_lmdb_walk* itr_u, size_t* len_i, void** buf_v)
-{
-  MDB_val key_u, val_u;
-  c3_w    ret_w, ops_w;
-
-  c3_assert( itr_u->nex_d <= itr_u->las_d );
-
-  ops_w = ( c3y == itr_u->red_o ) ? MDB_NEXT : MDB_GET_CURRENT;
-  if ( (ret_w = mdb_cursor_get(itr_u->cur_u, &key_u, &val_u, ops_w)) ) {
-    mdb_logerror(stderr, ret_w, "lmdb: walk error");
-    return c3n;
-  }
-
-  //  sanity check: ensure contiguous event numbers
-  //
-  if ( *(c3_d*)key_u.mv_data != itr_u->nex_d ) {
-    fprintf(stderr, "lmdb: read gap: expected %" PRIu64
-                    ", received %" PRIu64 "\r\n",
-                    itr_u->nex_d,
-                    *(c3_d*)key_u.mv_data);
-    return c3n;
-  }
-
-  *len_i = val_u.mv_size;
-  *buf_v = val_u.mv_data;
-
-  itr_u->nex_d++;
-  itr_u->red_o = c3y;
-
-  return c3y;
-}
-
-/* u3_lmdb_walk_done(): close iterator.
-*/
-void
-u3_lmdb_walk_done(u3_lmdb_walk* itr_u)
-{
-  mdb_cursor_close(itr_u->cur_u);
-  mdb_txn_abort(itr_u->txn_u);
-}
-
 /* u3_lmdb_read(): read [len_d] events starting at [eve_d].
 */
 c3_o
diff --git a/pkg/urbit/vere/disk.c b/pkg/urbit/vere/disk.c
index 61fe9f754..eb4a27533 100644
--- a/pkg/urbit/vere/disk.c
+++ b/pkg/urbit/vere/disk.c
@@ -22,12 +22,6 @@ struct _cd_save {
   struct _u3_disk* log_u;
 };
 
-struct _u3_disk_walk {
-  u3_lmdb_walk  itr_u;
-  u3_disk*      log_u;
-  c3_o          liv_o;
-};
-
 #undef VERBOSE_DISK
 #undef DISK_TRACE_JAM
 #undef DISK_TRACE_CUE
@@ -155,47 +149,34 @@ _disk_commit_start(struct _cd_save* req_u)
                                     _disk_commit_after_cb);
 }
 
-
-/* u3_disk_etch(): serialize an event for persistence. RETAIN [eve]
+/* _disk_serialize_v1(): serialize events in format v1.
 */
-size_t
-u3_disk_etch(u3_disk* log_u,
-             u3_noun    eve,
-             c3_l     mug_l,
-             c3_y**   out_y)
+static c3_w
+_disk_serialize_v1(u3_fact* tac_u, c3_y** out_y)
 {
-  size_t len_i;
-  c3_y*  dat_y;
-
 #ifdef DISK_TRACE_JAM
-  u3t_event_trace("disk etch", 'B');
+  u3t_event_trace("king disk jam", 'B');
 #endif
 
-  //  XX check version number in log_u
-  //  XX needs api redesign to limit allocations
-  //
   {
-    u3_atom mat = u3qe_jam(eve);
+    u3_atom mat = u3qe_jam(tac_u->job);
     c3_w  len_w = u3r_met(3, mat);
-
-    len_i = 4 + len_w;
-    dat_y = c3_malloc(len_i);
-
-    dat_y[0] = mug_l & 0xff;
-    dat_y[1] = (mug_l >> 8) & 0xff;
-    dat_y[2] = (mug_l >> 16) & 0xff;
-    dat_y[3] = (mug_l >> 24) & 0xff;
+    c3_y* dat_y = c3_malloc(4 + len_w);
+    dat_y[0] = tac_u->mug_l & 0xff;
+    dat_y[1] = (tac_u->mug_l >> 8) & 0xff;
+    dat_y[2] = (tac_u->mug_l >> 16) & 0xff;
+    dat_y[3] = (tac_u->mug_l >> 24) & 0xff;
     u3r_bytes(0, len_w, dat_y + 4, mat);
 
-    u3z(mat);
-  }
-
 #ifdef DISK_TRACE_JAM
-  u3t_event_trace("disk etch", 'E');
+    u3t_event_trace("king disk jam", 'E');
 #endif
 
-  *out_y = dat_y;
-  return len_i;
+    u3z(mat);
+
+    *out_y = dat_y;
+    return len_w + 4;
+  }
 }
 
 /* _disk_batch(): create a write batch
@@ -219,8 +200,7 @@ _disk_batch(u3_disk* log_u, c3_d len_d)
   for ( c3_d i_d = 0ULL; i_d < len_d; ++i_d) {
     c3_assert( (req_u->eve_d + i_d) == tac_u->eve_d );
 
-    req_u->siz_i[i_d] = u3_disk_etch(log_u, tac_u->job,
-                                     tac_u->mug_l, &req_u->byt_y[i_d]);
+    req_u->siz_i[i_d] = _disk_serialize_v1(tac_u, &req_u->byt_y[i_d]);
 
     tac_u = tac_u->nex_u;
   }
@@ -378,41 +358,6 @@ _disk_read_done_cb(uv_timer_t* tim_u)
   _disk_read_close(red_u);
 }
 
-/* u3_disk_sift(): parse a persisted event buffer.
-*/
-c3_o
-u3_disk_sift(u3_disk* log_u,
-             size_t   len_i,
-             c3_y*    dat_y,
-             c3_l*    mug_l,
-             u3_noun*   job)
-{
-  if ( 4 >= len_i ) {
-    return c3n;
-  }
-
-#ifdef DISK_TRACE_CUE
-  u3t_event_trace("disk sift", 'B');
-#endif
-
-  //  XX check version in log_u
-  //
-  *mug_l = dat_y[0]
-         ^ (dat_y[1] <<  8)
-         ^ (dat_y[2] << 16)
-         ^ (dat_y[3] << 24);
-
-  //  XX u3m_soft?
-  //
-  *job = u3ke_cue(u3i_bytes(len_i - 4, dat_y + 4));
-
-#ifdef DISK_TRACE_CUE
-  u3t_event_trace("disk sift", 'E');
-#endif
-
-  return c3y;
-}
-
 /* _disk_read_one_cb(): lmdb read callback, invoked for each event in order
 */
 static c3_o
@@ -422,13 +367,29 @@ _disk_read_one_cb(void* ptr_v, c3_d eve_d, size_t val_i, void* val_p)
   u3_disk* log_u = red_u->log_u;
   u3_fact* tac_u;
 
+  if ( 4 >= val_i ) {
+    return c3n;
+  }
+
   {
     u3_noun job;
-    c3_l  mug_l;
+    c3_y* dat_y = val_p;
+    c3_l  mug_l = dat_y[0]
+                ^ (dat_y[1] <<  8)
+                ^ (dat_y[2] << 16)
+                ^ (dat_y[3] << 24);
 
-    if ( c3n == u3_disk_sift(log_u, val_i, (c3_y*)val_p, &mug_l, &job) ) {
-      return c3n;
-    }
+#ifdef DISK_TRACE_CUE
+    u3t_event_trace("king disk cue", 'B');
+#endif
+
+    //  XX u3m_soft?
+    //
+    job = u3ke_cue(u3i_bytes(val_i - 4, dat_y + 4));
+
+#ifdef DISK_TRACE_CUE
+    u3t_event_trace("king disk cue", 'E');
+#endif
 
     tac_u = u3_fact_init(eve_d, mug_l, job);
   }
@@ -500,120 +461,6 @@ u3_disk_read(u3_disk* log_u, c3_d eve_d, c3_d len_d)
   uv_timer_start(&red_u->tim_u, _disk_read_start_cb, 0, 0);
 }
 
-struct _cd_list {
-  u3_disk* log_u;
-  u3_noun    eve;
-  c3_l     mug_l;
-};
-
-/* _disk_read_list_cb(): lmdb read callback, invoked for each event in order
-*/
-static c3_o
-_disk_read_list_cb(void* ptr_v, c3_d eve_d, size_t val_i, void* val_p)
-{
-  struct _cd_list* ven_u = ptr_v;
-  u3_disk* log_u = ven_u->log_u;
-
-  {
-    u3_noun job;
-    c3_l  mug_l;
-
-    if ( c3n == u3_disk_sift(log_u, val_i, (c3_y*)val_p, &mug_l, &job) ) {
-      return c3n;
-    }
-
-    ven_u->mug_l = mug_l;
-    ven_u->eve   = u3nc(job, ven_u->eve);
-  }
-
-  return c3y;
-}
-
-/* u3_disk_read_list(): synchronously read a cons list of events.
-*/
-u3_weak
-u3_disk_read_list(u3_disk* log_u, c3_d eve_d, c3_d len_d, c3_l* mug_l)
-{
-  struct _cd_list ven_u = { log_u, u3_nul, 0 };
-
-  if ( c3n == u3_lmdb_read(log_u->mdb_u, &ven_u,
-                           eve_d, len_d, _disk_read_list_cb) )
-  {
-    return u3_none;
-  }
-
-  *mug_l = ven_u.mug_l;
-  return u3kb_flop(ven_u.eve);
-}
-
-/* u3_disk_walk_init(): init iterator.
-*/
-u3_disk_walk*
-u3_disk_walk_init(u3_disk* log_u,
-                  c3_d     eve_d,
-                  c3_d     len_d)
-{
-  u3_disk_walk* wok_u = c3_malloc(sizeof(*wok_u));
-  c3_d          max_d = eve_d + len_d - 1;
-
-  wok_u->log_u = log_u;
-  wok_u->liv_o = u3_lmdb_walk_init(log_u->mdb_u,
-                                  &wok_u->itr_u,
-                                   eve_d,
-                                   c3_min(max_d, log_u->dun_d));
-
-  return wok_u;
-}
-
-/* u3_disk_walk_live(): check if live.
-*/
-c3_o
-u3_disk_walk_live(u3_disk_walk* wok_u)
-{
-  if ( wok_u->itr_u.nex_d > wok_u->itr_u.las_d ) {
-    wok_u->liv_o = c3n;
-  }
-
-  return wok_u->liv_o;
-}
-
-/* u3_disk_walk_step(): get next fact.
-*/
-c3_o
-u3_disk_walk_step(u3_disk_walk* wok_u, u3_fact* tac_u)
-{
-  u3_disk* log_u = wok_u->log_u;
-  size_t   len_i;
-  void*    buf_v;
-
-  tac_u->eve_d = wok_u->itr_u.nex_d;
-
-  if ( c3n == u3_lmdb_walk_next(&wok_u->itr_u, &len_i, &buf_v) ) {
-    fprintf(stderr, "disk: (%" PRIu64 "): read fail\r\n", tac_u->eve_d);
-    return wok_u->liv_o = c3n;
-  }
-
-  if ( c3n == u3_disk_sift(log_u, len_i,
-                           (c3_y*)buf_v,
-                           &tac_u->mug_l,
-                           &tac_u->job) )
-  {
-    fprintf(stderr, "disk: (%" PRIu64 "): sift fail\r\n", tac_u->eve_d);
-    return wok_u->liv_o = c3n;
-  }
-
-  return c3y;
-}
-
-/* u3_disk_walk_done(): close iterator.
-*/
-void
-u3_disk_walk_done(u3_disk_walk* wok_u)
-{
-  u3_lmdb_walk_done(&wok_u->itr_u);
-  c3_free(wok_u);
-}
-
 /* _disk_save_meta(): serialize atom, save as metadata at [key_c].
 */
 static c3_o
diff --git a/pkg/urbit/vere/io/http.c b/pkg/urbit/vere/io/http.c
index 0336cdca2..fa7d778f2 100644
--- a/pkg/urbit/vere/io/http.c
+++ b/pkg/urbit/vere/io/http.c
@@ -1504,61 +1504,6 @@ _http_serv_init_h2o(SSL_CTX* tls_u, c3_o log, c3_o red)
   return h2o_u;
 }
 
-/* _http_serv_start_err(): handle errors in starting http server.
-*/
-static c3_i
-_http_serv_start_err(const c3_c* cap_c, u3_http* htp_u, c3_i sas_i)
-{
-  u3_pier* pir_u = htp_u->htd_u->car_u.pir_u;
-
-  if ( UV_EADDRNOTAVAIL == sas_i ) {
-    u3l_log("http: unavailable ip address %s\r\n", u3_Host.ops_u.bin_c);
-    u3_king_bail();
-    return 0;
-  }
-
-  //  ports specified, no incrementing/retry
-  //
-  if ( c3y == htp_u->dis ) {
-    u3l_log("http: %s (%" PRIu16 "): %s\n",
-            cap_c, htp_u->por_s, uv_strerror(sas_i));
-    u3_king_bail();
-    return 0;
-  }
-
-  //  increment and retry
-  //
-  if ( (UV_EADDRINUSE == sas_i) || (UV_EACCES == sas_i) ) {
-    if ( (c3y == htp_u->sec) && (443 == htp_u->por_s) ) {
-      htp_u->por_s = 8443;
-    }
-    else if ( (c3n == htp_u->sec) && (80 == htp_u->por_s) ) {
-      htp_u->por_s = 8080;
-    }
-    else {
-      htp_u->por_s++;
-      //  XX
-      //
-      if ( c3n == htp_u->lop ) {
-        if ( c3y == htp_u->sec ) {
-          pir_u->pes_s = htp_u->por_s;
-        }
-        else {
-          pir_u->per_s = htp_u->por_s;
-        }
-      }
-    }
-
-    return 1;
-  }
-
-  //  total failure XX bail?
-  //
-  u3l_log("http: %s: %s\n", cap_c, uv_strerror(sas_i));
-  _http_serv_free(htp_u);
-  return 0;
-}
-
 /* _http_serv_start(): start http server.
 */
 static void
@@ -1574,12 +1519,10 @@ _http_serv_start(u3_http* htp_u)
                           INADDR_ANY;
 
   if ( 0 != u3_Host.ops_u.bin_c && c3n == htp_u->lop ) {
-    //  already validated in arguments parser
-    //
     inet_pton(AF_INET, u3_Host.ops_u.bin_c, &adr_u.sin_addr);
   }
 
-  c3_assert( !uv_tcp_init(u3L, &htp_u->wax_u) );
+  uv_tcp_init(u3L, &htp_u->wax_u);
 
   /*  Try ascending ports.
   */
@@ -1589,25 +1532,46 @@ _http_serv_start(u3_http* htp_u)
     adr_u.sin_port = htons(htp_u->por_s);
 
     if ( 0 != (sas_i = uv_tcp_bind(&htp_u->wax_u,
-                                   (const struct sockaddr*)&adr_u, 0)) )
-    {
-      if ( _http_serv_start_err("bind", htp_u, sas_i) ) {
-        continue;
+                                   (const struct sockaddr*)&adr_u, 0)) ||
+         0 != (sas_i = uv_listen((uv_stream_t*)&htp_u->wax_u,
+                                 TCP_BACKLOG, _http_serv_listen_cb)) ) {
+      if ( UV_EADDRNOTAVAIL == sas_i ) {
+        u3l_log("http: ip address not available\n");
+        u3_king_bail();
       }
-      else {
-        return;
+      if ( c3y == htp_u->dis ) {
+        u3l_log("http: listen (%" PRIu16 "): %s\n", htp_u->por_s,
+                uv_strerror(sas_i));
+        u3_king_bail();
       }
-    }
+      if ( (UV_EADDRINUSE == sas_i) || (UV_EACCES == sas_i) ) {
+        if ( (c3y == htp_u->sec) && (443 == htp_u->por_s) ) {
+          htp_u->por_s = 8443;
+        }
+        else if ( (c3n == htp_u->sec) && (80 == htp_u->por_s) ) {
+          htp_u->por_s = 8080;
+        }
+        else {
+          htp_u->por_s++;
+          //  XX
+          //
+          if ( c3n == htp_u->lop ) {
+            if ( c3y == htp_u->sec ) {
+              pir_u->pes_s = htp_u->por_s;
+            }
+            else {
+              pir_u->per_s = htp_u->por_s;
+            }
+          }
+        }
 
-    if ( 0 != (sas_i = uv_listen((uv_stream_t*)&htp_u->wax_u,
-                                 TCP_BACKLOG, _http_serv_listen_cb)) )
-    {
-      if ( _http_serv_start_err("listen", htp_u, sas_i) ) {
         continue;
       }
-      else {
-        return;
-      }
+
+      u3l_log("http: listen: %s\n", uv_strerror(sas_i));
+
+      _http_serv_free(htp_u);
+      return;
     }
 
     u3l_log("http: %s live on %s://localhost:%d\n",
@@ -1713,30 +1677,24 @@ _http_init_tls(uv_buf_t key_u, uv_buf_t cer_u)
 static void
 _http_write_ports_file(u3_httd* htd_u, c3_c *pax_c)
 {
+  c3_c* nam_c = ".http.ports";
+  c3_w len_w = 1 + strlen(pax_c) + 1 + strlen(nam_c);
+
+  c3_c* paf_c = c3_malloc(len_w);
+  snprintf(paf_c, len_w, "%s/%s", pax_c, nam_c);
+
+  c3_i por_i = c3_open(paf_c, O_WRONLY | O_CREAT | O_TRUNC, 0666);
+  c3_free(paf_c);
+
   u3_http* htp_u = htd_u->htp_u;
   u3_pier* pir_u = htd_u->car_u.pir_u;
-  size_t   off_i = 0;
-  c3_i     por_i;
-
-  {
-    c3_c* nam_c = ".http.ports";
-    c3_w  len_w = 1 + strlen(pax_c) + 1 + strlen(nam_c);
-    c3_c* paf_c = c3_malloc(len_w);
-    snprintf(paf_c, len_w, "%s/%s", pax_c, nam_c);
-    por_i = c3_open(paf_c, O_WRONLY | O_CREAT | O_TRUNC, 0666);
-    c3_free(paf_c);
-  }
 
+  c3_c temp[32];
   while ( 0 != htp_u ) {
     if ( 0 < htp_u->por_s ) {
-      c3_c tmp_c[32];
-      c3_i len_i = snprintf(tmp_c, 32, "%u %s %s\n",
-                            htp_u->por_s,
-                            (c3y == htp_u->sec) ? "secure" : "insecure",
-                            (c3y == htp_u->lop) ? "loopback" : "public");
-      c3_assert( 0 < len_i);
-      c3_assert( c3_pwrite(por_i, tmp_c, len_i, off_i) == len_i );
-      off_i += len_i;
+      u3_write_fd(por_i, temp, snprintf(temp, 32, "%u %s %s\n", htp_u->por_s,
+                     (c3y == htp_u->sec) ? "secure" : "insecure",
+                     (c3y == htp_u->lop) ? "loopback" : "public"));
     }
 
     htp_u = htp_u->nex_u;
@@ -1752,12 +1710,13 @@ static void
 _http_release_ports_file(c3_c *pax_c)
 {
   c3_c* nam_c = ".http.ports";
-  c3_w  len_w = 1 + strlen(pax_c) + 1 + strlen(nam_c);
+  c3_w len_w = 1 + strlen(pax_c) + 1 + strlen(nam_c);
   c3_c* paf_c = c3_malloc(len_w);
   c3_i  wit_i;
 
   wit_i = snprintf(paf_c, len_w, "%s/%s", pax_c, nam_c);
-  c3_assert( len_w == (c3_w)wit_i + 1 );
+  c3_assert(wit_i > 0);
+  c3_assert(len_w == (c3_w)wit_i + 1);
 
   c3_unlink(paf_c);
   c3_free(paf_c);
diff --git a/pkg/urbit/vere/io/term.c b/pkg/urbit/vere/io/term.c
index 22b4cce1e..9994fcfcb 100644
--- a/pkg/urbit/vere/io/term.c
+++ b/pkg/urbit/vere/io/term.c
@@ -17,6 +17,48 @@ static void     _term_read_cb(uv_stream_t*    tcp_u,
                               ssize_t         siz_i,
                               const uv_buf_t* buf_u);
 
+/* u3_write_fd(): retry interrupts, continue partial writes, assert errors.
+*/
+void
+u3_write_fd(c3_i fid_i, const void* buf_v, size_t len_i)
+{
+  ssize_t ret_i;
+
+  while ( len_i > 0 ) {
+    c3_w lop_w = 0;
+    //  retry interrupt/async errors
+    //
+    do {
+      //  abort pathological retry loop
+    //
+    if ( 100 == ++lop_w ) {
+      fprintf(stderr, "term: write loop: %s\r\n", strerror(errno));
+      return;
+    }
+      ret_i = write(fid_i, buf_v, len_i);
+    }
+    while (  (ret_i < 0)
+          && (  (errno == EINTR)
+             || (errno == EAGAIN)
+             || (errno == EWOULDBLOCK) ));
+
+    //  assert on true errors
+    //
+    //    NB: can't call u3l_log here or we would re-enter u3_write_fd()
+    //
+    if ( ret_i < 0 ) {
+      fprintf(stderr, "term: write failed %s\r\n", strerror(errno));
+      c3_assert(0);
+    }
+    //  continue partial writes
+    //
+    else {
+      len_i -= ret_i;
+      buf_v += ret_i;
+    }
+  }
+}
+
 /* _term_msc_out_host(): unix microseconds from current host time.
 */
 static c3_d
@@ -213,7 +255,7 @@ u3_term_log_exit(void)
       if ( c3n == uty_u->sto_f(uty_u) ) {
         c3_assert(!"exit-tcsetattr");
       }
-      c3_assert(c3_write(uty_u->fid_i, "\r\n", 2) == 2);
+      u3_write_fd(uty_u->fid_i, "\r\n", 2);
     }
   }
 
@@ -822,7 +864,7 @@ _term_spin_step(u3_utty* uty_u)
       c3_w i_w;
 
       for ( i_w = bac_w; i_w < sol_w; i_w++ ) {
-        if ( c3_write(fid_i, lef_u.base, lef_u.len) < 0 ) {
+        if ( lef_u.len != write(fid_i, lef_u.base, lef_u.len) ) {
           return;
         }
       }
@@ -832,7 +874,7 @@ _term_spin_step(u3_utty* uty_u)
 
     {
       c3_w len_w = cur_c - buf_c;
-      if ( c3_write(fid_i, buf_c, len_w) < 0 ) {
+      if ( len_w != write(fid_i, buf_c, len_w) ) {
         return;
       }
     }
@@ -840,7 +882,7 @@ _term_spin_step(u3_utty* uty_u)
     //  Cursor stays on spinner.
     //
     while ( sol_w-- ) {
-      if ( c3_write(fid_i, lef_u.base, lef_u.len) < 0 ) {
+      if ( lef_u.len != write(fid_i, lef_u.base, lef_u.len) ) {
         return;
       }
     }
@@ -1002,9 +1044,7 @@ u3_term_ef_ctlc(void)
     _term_ovum_plan(uty_u->car_u, wir, cad);
   }
 
-  if ( c3n == u3_Host.ops_u.tem ) {
-    _term_it_refresh_line(uty_u);
-  }
+  _term_it_refresh_line(uty_u);
 }
 
 /*  _term_it_put_value(): put numeric color value on lin_w.
@@ -1342,10 +1382,10 @@ u3_term_io_hija(void)
         if ( c3y != uty_u->hij_f(uty_u) ) {
           c3_assert(!"hija-tcsetattr");
         }
-        c3_assert(c3_write(uty_u->fid_i, "\r", 1) == 1);
+        u3_write_fd(uty_u->fid_i, "\r", 1);
         {
           uv_buf_t* buf_u = &uty_u->ufo_u.out.el_u;
-          c3_assert(c3_write(uty_u->fid_i, buf_u->base, buf_u->len) == buf_u->len);
+          u3_write_fd(uty_u->fid_i, buf_u->base, buf_u->len);
         }
       }
     }
diff --git a/pkg/urbit/vere/io/unix.c b/pkg/urbit/vere/io/unix.c
index ba0145d71..f9e175b5d 100644
--- a/pkg/urbit/vere/io/unix.c
+++ b/pkg/urbit/vere/io/unix.c
@@ -342,11 +342,11 @@ u3_unix_save(c3_c* pax_c, u3_atom pad)
   pad_y = c3_malloc(fln_w);
   u3r_bytes(0, fln_w, pad_y, pad);
   u3z(pad);
-  ssize_t rit_i = c3_pwrite(fid_i, pad_y, fln_w, 0);
+  rit_w = write(fid_i, pad_y, fln_w);
   close(fid_i);
   c3_free(pad_y);
 
-  if ( rit_i < 0 ) {
+  if ( rit_w != fln_w ) {
     u3l_log("%s: %s\n", ful_c, strerror(errno));
     c3_free(ful_c);
     u3m_bail(c3__fail);
@@ -427,7 +427,7 @@ static c3_w
 _unix_write_file_hard(c3_c* pax_c, u3_noun mim)
 {
   c3_i  fid_i = c3_open(pax_c, O_WRONLY | O_CREAT | O_TRUNC, 0666);
-  c3_w  len_w, siz_w, mug_w = 0;
+  c3_w  len_w, rit_w, siz_w, mug_w = 0;
   c3_y* dat_y;
 
   u3_noun dat = u3t(u3t(mim));
@@ -446,10 +446,11 @@ _unix_write_file_hard(c3_c* pax_c, u3_noun mim)
   u3r_bytes(0, len_w, dat_y, dat);
   u3z(mim);
 
-  ssize_t rit_i = c3_pwrite(fid_i, dat_y, siz_w, 0);
+  rit_w = write(fid_i, dat_y, siz_w);
 
-  if ( rit_i < 0 ) {
-    u3l_log("error writing %s: %s\r\n", pax_c, strerror(errno));
+  if ( rit_w != siz_w ) {
+    u3l_log("error writing %s: %s\r\n",
+            pax_c, strerror(errno));
     mug_w = 0;
   }
   else {
@@ -469,7 +470,7 @@ _unix_write_file_soft(u3_ufil* fil_u, u3_noun mim)
 {
   struct stat buf_u;
   c3_i  fid_i = c3_open(fil_u->pax_c, O_RDONLY, 0644);
-  c3_ws len_ws;
+  c3_ws len_ws, red_ws;
   c3_w  old_w;
   c3_y* old_y;
 
@@ -488,21 +489,21 @@ _unix_write_file_soft(u3_ufil* fil_u, u3_noun mim)
   len_ws = buf_u.st_size;
   old_y = c3_malloc(len_ws);
 
-  ssize_t red_i = c3_pread(fid_i, old_y, len_ws, 0);
+  red_ws = read(fid_i, old_y, len_ws);
 
   if ( close(fid_i) < 0 ) {
     u3l_log("error closing file (soft) %s: %s\r\n",
             fil_u->pax_c, strerror(errno));
   }
 
-  if ( red_i != len_ws ) {
-    if ( red_i < 0 ) {
+  if ( len_ws != red_ws ) {
+    if ( red_ws < 0 ) {
       u3l_log("error reading file (soft) %s: %s\r\n",
-              fil_u->pax_c, strerror(-red_i));
+              fil_u->pax_c, strerror(errno));
     }
     else {
-      u3l_log("wrong # of bytes read in file %s: %u %zu\r\n",
-              fil_u->pax_c, len_ws, red_i);
+      u3l_log("wrong # of bytes read in file %s: %d %d\r\n",
+              fil_u->pax_c, len_ws, red_ws);
     }
     c3_free(old_y);
     u3z(mim);
@@ -892,7 +893,7 @@ _unix_update_file(u3_unix* unx_u, u3_ufil* fil_u)
 
   struct stat buf_u;
   c3_i  fid_i = c3_open(fil_u->pax_c, O_RDONLY, 0644);
-  c3_ws len_ws;
+  c3_ws len_ws, red_ws;
   c3_y* dat_y;
 
   if ( fid_i < 0 || fstat(fid_i, &buf_u) < 0 ) {
@@ -909,21 +910,21 @@ _unix_update_file(u3_unix* unx_u, u3_ufil* fil_u)
   len_ws = buf_u.st_size;
   dat_y = c3_malloc(len_ws);
 
-  ssize_t red_i = c3_pread(fid_i, dat_y, len_ws, 0);
+  red_ws = read(fid_i, dat_y, len_ws);
 
   if ( close(fid_i) < 0 ) {
     u3l_log("error closing file %s: %s\r\n",
             fil_u->pax_c, strerror(errno));
   }
 
-  if ( red_i != len_ws ) {
-    if ( red_i < 0 ) {
+  if ( len_ws != red_ws ) {
+    if ( red_ws < 0 ) {
       u3l_log("error reading file %s: %s\r\n",
-              fil_u->pax_c, strerror(-red_i));
+              fil_u->pax_c, strerror(errno));
     }
     else {
-      u3l_log("wrong # of bytes read in file %s: %u %zu\r\n",
-              fil_u->pax_c, len_ws, red_i);
+      u3l_log("wrong # of bytes read in file %s: %d %d\r\n",
+              fil_u->pax_c, len_ws, red_ws);
     }
     c3_free(dat_y);
     return u3_nul;
@@ -1158,7 +1159,7 @@ _unix_initial_update_file(c3_c* pax_c, c3_c* bas_c)
 {
   struct stat buf_u;
   c3_i  fid_i = c3_open(pax_c, O_RDONLY, 0644);
-  c3_ws len_ws;
+  c3_ws len_ws, red_ws;
   c3_y* dat_y;
 
   if ( fid_i < 0 || fstat(fid_i, &buf_u) < 0 ) {
@@ -1175,21 +1176,21 @@ _unix_initial_update_file(c3_c* pax_c, c3_c* bas_c)
   len_ws = buf_u.st_size;
   dat_y = c3_malloc(len_ws);
 
-  ssize_t red_i = c3_pread(fid_i, dat_y, len_ws, 0);
+  red_ws = read(fid_i, dat_y, len_ws);
 
   if ( close(fid_i) < 0 ) {
     u3l_log("error closing initial file %s: %s\r\n",
             pax_c, strerror(errno));
   }
 
-  if ( red_i != len_ws ) {
-    if ( red_i < 0 ) {
+  if ( len_ws != red_ws ) {
+    if ( red_ws < 0 ) {
       u3l_log("error reading initial file %s: %s\r\n",
-              pax_c, strerror(-red_i));
+              pax_c, strerror(errno));
     }
     else {
-      u3l_log("wrong # of bytes read in initial file %s: %u %zu\r\n",
-              pax_c, len_ws, red_i);
+      u3l_log("wrong # of bytes read in initial file %s: %d %d\r\n",
+              pax_c, len_ws, red_ws);
     }
     c3_free(dat_y);
     return u3_nul;
diff --git a/pkg/urbit/vere/king.c b/pkg/urbit/vere/king.c
index b18d7b441..44a8cd502 100644
--- a/pkg/urbit/vere/king.c
+++ b/pkg/urbit/vere/king.c
@@ -307,7 +307,7 @@ _king_get_pace(void)
 {
   struct stat buf_u;
   c3_c*       pat_c;
-  c3_w len_w;
+  c3_w red_w, len_w;
   c3_i ret_i, fid_i;
 
   ret_i = asprintf(&pat_c, "%s/.bin/pace", u3_Host.dir_c);
@@ -324,10 +324,10 @@ _king_get_pace(void)
 
   len_w = buf_u.st_size;
   pat_c = c3_malloc(len_w + 1);
-  ssize_t red_i = c3_pread(fid_i, pat_c, len_w, 0);
+  red_w = read(fid_i, pat_c, len_w);
   close(fid_i);
 
-  if ( red_i != len_w ) {
+  if ( len_w != red_w ) {
     c3_free(pat_c);
     u3l_log("unable to read pace file, "
             "falling back to default (\"live\")\n");
@@ -1038,6 +1038,9 @@ _king_make_pace(c3_c* pac_c)
   return 0;
 }
 
+static c3_i
+_king_write_raw(c3_i fid_i, c3_y* buf_y, size_t len_i);
+
 /* _king_init_pace(): save pace file if not present
 */
 static c3_i
@@ -1061,11 +1064,8 @@ _king_init_pace(c3_c* pac_c)
     }
   }
 
-  size_t  len_i = strlen(pac_c);
-  ssize_t wit_i = c3_pwrite(fid_i, pac_c, len_i, 0);
-  if ( wit_i != len_i ) {
-    u3l_log("dock: init pace (%s) write failed: %s\n",
-            pac_c, strerror(errno));
+  if ( _king_write_raw(fid_i, (c3_y*)pac_c, strlen(pac_c)) ) {
+    u3l_log("dock: init pace (%s): write %s\n", pac_c, strerror(errno));
     close(fid_i);
     c3_free(bin_c);
     return -1;
@@ -1239,24 +1239,62 @@ _king_do_upgrade(c3_c* pac_c, c3_c* ver_c)
   //  XX print restart instructions
 }
 
-static c3_i
-_king_copy_raw(c3_i src_i, c3_i dst_i, c3_y* buf_y, size_t pag_i)
+/* _king_read_raw: read (up to) [len_i] from [fid_i] to [buf_y]
+*/
+static ssize_t
+_king_read_raw(c3_i fid_i, c3_y* buf_y, size_t len_i)
 {
-  size_t  off_i = 0;
   ssize_t ret_i;
 
   do {
-    if ( 0 > (ret_i = c3_pread(src_i, buf_y, pag_i, off_i)) ) {
-      return ret_i;
-    }
-
-    if ( 0 > (ret_i = c3_pwrite(dst_i, buf_y, (size_t)ret_i, off_i)) ) {
-      return ret_i;
-    }
-
-    off_i += (size_t)ret_i;
+    ret_i = read(fid_i, buf_y, len_i);
   }
-  while ( ret_i );
+  while ( (ret_i < 0) && (errno == EINTR) );
+
+  return ret_i;
+}
+
+/* _king_read_raw: write [len_i] from [buf_y] to [fid_i].
+*/
+static c3_i
+_king_write_raw(c3_i fid_i, c3_y* buf_y, size_t len_i)
+{
+  ssize_t ret_i;
+
+  while ( len_i ) {
+
+    do {
+      ret_i = write(fid_i, buf_y, len_i);
+    }
+    while ( (ret_i < 0) && (errno == EINTR) );
+
+    if ( ret_i < 0 ) {
+      return -1;
+    }
+    else {
+      len_i -= ret_i;
+      buf_y += ret_i;
+    }
+  }
+
+  return 0;
+}
+
+static c3_i
+_king_copy_raw(c3_i src_i, c3_i dst_i, c3_y* buf_y, size_t pag_i)
+{
+  ssize_t red_i;
+
+  do {
+    if ( 0 > (red_i = _king_read_raw(src_i, buf_y, pag_i)) ) {
+      return -1;
+    }
+
+    if ( _king_write_raw(dst_i, buf_y, (size_t)red_i) ) {
+      return -1;
+    }
+  }
+  while ( red_i );
 
   return 0;
 }
@@ -1299,8 +1337,6 @@ _king_copy_file(c3_c* src_c, c3_c* dst_c)
       goto done1;
     }
 
-    //  XX O_TRUNC?
-    //
     if ( -1 == (dst_i = open(dst_c, O_RDWR | O_CREAT, 0755)) ) {
       err_i = errno;
       ret_i = -1;
@@ -1367,12 +1403,8 @@ _king_copy_file(c3_c* src_c, c3_c* dst_c)
     {
       size_t pag_i = 1 << 14;;
       c3_y*  buf_y = c3_malloc(pag_i);
-
-      if ( 0 > (ret_i = _king_copy_raw(src_i, dst_i, buf_y, pag_i)) ) {
-        err_i = errno;
-        ret_i = -1;
-      }
-
+      ret_i = _king_copy_raw(src_i, dst_i, buf_y, pag_i);
+      err_i = errno;
       c3_free(buf_y);
     }
 
diff --git a/pkg/urbit/vere/lord.c b/pkg/urbit/vere/lord.c
index d51945530..205190848 100644
--- a/pkg/urbit/vere/lord.c
+++ b/pkg/urbit/vere/lord.c
@@ -1051,7 +1051,7 @@ _lord_on_serf_err_cb(uv_stream_t* pyp_u,
     //  serf used to write to 2 directly
     //  this can't be any worse than that
     //
-    c3_assert(c3_write(STDERR_FILENO, buf_u->base, siz_i) == siz_i);
+    u3_write_fd(2, buf_u->base, siz_i);
   } else {
     uv_read_stop(pyp_u);
 
diff --git a/pkg/urbit/version b/pkg/urbit/version
index 64349e8f7..9f76d37b7 100644
--- a/pkg/urbit/version
+++ b/pkg/urbit/version
@@ -1 +1 @@
-1.14-rc3
\ No newline at end of file
+1.13
\ No newline at end of file
diff --git a/pkg/urbit/worker/mars.c b/pkg/urbit/worker/mars.c
deleted file mode 100644
index 9e38844cc..000000000
--- a/pkg/urbit/worker/mars.c
+++ /dev/null
@@ -1,267 +0,0 @@
-/* worker/mars.c
-**
-**  the main loop of a mars process.
-*/
-#include "all.h"
-#include <vere/vere.h>
-#include <vere/mars.h>
-
-/* _mars_step_trace(): initialize or rotate trace file.
-*/
-static void
-_mars_step_trace(const c3_c* dir_c)
-{
-  if ( u3C.wag_w & u3o_trace ) {
-    if ( u3_Host.tra_u.con_w == 0  && u3_Host.tra_u.fun_w == 0 ) {
-      u3t_trace_open(dir_c);
-    }
-    else if ( u3_Host.tra_u.con_w >= 100000 ) {
-      u3t_trace_close();
-      u3t_trace_open(dir_c);
-    }
-  }
-}
-
-/* _mars_poke_play(): replay an event.
-*/
-static u3_weak
-_mars_poke_play(u3_mars* mar_u, c3_d eve_d, u3_noun job)
-{
-  u3_noun vir;
-
-  if ( c3n == u3v_poke_sure(0, job, &vir) ) {
-    return vir;
-  }
-
-  u3z(vir);
-  return u3_none;
-}
-
-typedef enum {
-  _play_yes_e,  //  success
-  _play_mem_e,  //  %meme
-  _play_int_e,  //  %intr
-  _play_log_e,  //  event log fail
-  _play_mug_e,  //  mug mismatch
-  _play_bad_e   //  total failure
-} _mars_play_e;
-
-/* _mars_play_batch(): replay a batch of events.
-*/
-static _mars_play_e
-_mars_play_batch(u3_mars* mar_u, c3_o mug_o, c3_w bat_w)
-{
-  u3_disk*      log_u = mar_u->log_u;
-  u3_disk_walk* wok_u = u3_disk_walk_init(log_u, mar_u->dun_d + 1, bat_w);
-  u3_fact       tac_u;
-  u3_noun         dud;
-
-  while ( c3y == u3_disk_walk_live(wok_u) ) {
-    if ( c3n == u3_disk_walk_step(wok_u, &tac_u) ) {
-      u3_disk_walk_done(wok_u);
-      return _play_log_e;
-    }
-
-    c3_assert( ++mar_u->sen_d == tac_u.eve_d );
-
-    if ( u3_none != (dud = _mars_poke_play(mar_u, tac_u.eve_d, tac_u.job)) ) {
-      c3_m mot_m;
-
-      mar_u->sen_d = mar_u->dun_d;
-      u3_disk_walk_done(wok_u);
-
-      c3_assert( c3y == u3r_safe_word(u3h(dud), &mot_m) );
-
-      switch ( mot_m ) {
-        case c3__meme: {
-          fprintf(stderr, "play (%" PRIu64 "): %%meme\r\n", tac_u.eve_d);
-          u3z(dud);
-          return _play_mem_e;
-        }
-
-        case c3__intr: {
-          fprintf(stderr, "play (%" PRIu64 "): %%intr\r\n", tac_u.eve_d);
-          u3z(dud);
-          return _play_int_e;
-        }
-
-        default: {
-          fprintf(stderr, "play (%" PRIu64 "): failed\r\n", tac_u.eve_d);
-          u3_pier_punt_goof("play", dud);
-          //  XX say something uplifting
-          //
-          return _play_bad_e;
-        }
-      }
-    }
-
-    mar_u->mug_l = u3r_mug(u3A->roc);
-
-    if ( tac_u.mug_l && (mar_u->mug_l != tac_u.mug_l) ) {
-      fprintf(stderr, "play (%" PRIu64 "): mug mismatch "
-                      "expected %08x, actual %08x\r\n",
-                      tac_u.eve_d, tac_u.mug_l, mar_u->mug_l);
-
-      if ( c3y == mug_o ) {
-        mar_u->sen_d = mar_u->dun_d;
-        u3_disk_walk_done(wok_u);
-        return _play_mug_e;
-      }
-    }
-
-    mar_u->dun_d = mar_u->sen_d;
-  }
-
-  u3_disk_walk_done(wok_u);
-
-  return _play_yes_e;
-}
-
-static c3_o
-_mars_do_boot(u3_disk* log_u, c3_d eve_d)
-{
-  u3_weak eve;
-  c3_l  mug_l;
-
-  if ( u3_none == (eve = u3_disk_read_list(log_u, 1, eve_d, &mug_l)) ) {
-    fprintf(stderr, "boot: read failed\r\n");
-    return c3n;
-  }
-
-  u3l_log("--------------- bootstrap starting ----------------\r\n");
-
-  u3l_log("boot: 1-%u\r\n", u3qb_lent(eve));
-
-  if ( c3n == u3v_boot(eve) ) {
-    return c3n;
-  }
-
-  u3l_log("--------------- bootstrap complete ----------------\r\n");
-  return c3y;
-}
-
-/* u3_mars_play(): replay logged events up to [eve_d].
-*/
-void
-u3_mars_play(u3_mars* mar_u, c3_d eve_d)
-{
-  u3_disk* log_u = mar_u->log_u;
-
-  if ( !eve_d ) {
-    eve_d = log_u->dun_d;
-  }
-  else if ( eve_d <= mar_u->dun_d ) {
-    u3l_log("mars: already computed %" PRIu64 "\r\n", eve_d);
-    u3l_log("      state=%" PRIu64 ", log=%" PRIu64 "\r\n",
-            mar_u->dun_d, log_u->dun_d);
-    return;
-  }
-  else {
-    eve_d = c3_min(eve_d, log_u->dun_d);
-  }
-
-  if ( !mar_u->dun_d ) {
-    c3_w lif_w;
-
-    if ( c3n == u3_disk_read_meta(log_u, 0, 0, &lif_w) ) {
-      fprintf(stderr, "mars: disk read meta fail\r\n");
-      //  XX exit code, cb
-      //
-      exit(1);
-    }
-
-    if ( c3n == _mars_do_boot(mar_u->log_u, lif_w) ) {
-      fprintf(stderr, "mars: boot fail\r\n");
-      //  XX exit code, cb
-      //
-      exit(1);
-    }
-
-    mar_u->sen_d = mar_u->dun_d = lif_w;
-  }
-
-  if ( mar_u->dun_d == log_u->dun_d ) {
-    u3l_log("mars: nothing to do!\r\n");
-    return;
-  }
-
-  u3l_log("---------------- playback starting ----------------\r\n");
-
-  if ( (1ULL + eve_d) == log_u->dun_d ) {
-    u3l_log("play: event %" PRIu64 "\r\n", log_u->dun_d);
-  }
-  else if ( eve_d != log_u->dun_d ) {
-    u3l_log("play: events %" PRIu64 "-%" PRIu64 " of %" PRIu64 "\r\n",
-            (c3_d)(1ULL + mar_u->dun_d),
-            eve_d,
-            log_u->dun_d);
-  }
-  else {
-    u3l_log("play: events %" PRIu64 "-%" PRIu64 "\r\n",
-            (c3_d)(1ULL + mar_u->dun_d),
-            eve_d);
-  }
-
-  {
-    c3_d mem_d = 0;             // last event to meme
-    c3_w try_w = 0;             // [mem_d] retry count
-
-    while ( mar_u->dun_d < eve_d ) {
-      _mars_step_trace(mar_u->dir_c);
-
-      //  XX get batch from args
-      //
-      switch ( _mars_play_batch(mar_u, c3y, 1024) ) {
-        case _play_yes_e: {
-          u3l_log("play (%" PRIu64 "): done\r\n", mar_u->dun_d);
-          u3m_reclaim();
-
-          //  XX save a snapshot every N events?
-          //
-        } break;
-
-        case _play_mem_e: {
-          if ( mem_d != mar_u->dun_d ) {
-            mem_d = mar_u->dun_d;
-            try_w = 0;
-          }
-          else if ( 3 == ++try_w ) {
-            fprintf(stderr, "play (%" PRIu64 "): failed\r\n", mar_u->dun_d + 1);
-            u3m_save();
-            //  XX check loom size, suggest --loom X
-            //  XX exit code, cb
-            //
-            u3_disk_exit(log_u);
-            exit(1);
-          }
-
-          //  XX pack before meld?
-          //
-          if ( u3C.wag_w & u3o_auto_meld ) {
-            u3a_print_memory(stderr, "mars: meld: gained", u3u_meld());
-          }
-          else {
-            u3a_print_memory(stderr, "mars: pack: gained", u3m_pack());
-          }
-        } break;
-
-        //  XX handle any specifically?
-        //
-        case _play_int_e:
-        case _play_log_e:
-        case _play_mug_e:
-        case _play_bad_e: {
-          fprintf(stderr, "play (%" PRIu64 "): failed\r\n", mar_u->dun_d + 1);
-          u3m_save();
-          //  XX exit code, cb
-          //
-          u3_disk_exit(log_u);
-          exit(1);
-        }
-      }
-    }
-  }
-
-  u3l_log("---------------- playback complete ----------------\r\n");
-  u3m_save();
-}
diff --git a/pkg/urbit/worker/serf.c b/pkg/urbit/worker/serf.c
index 377d26fc0..85420a122 100644
--- a/pkg/urbit/worker/serf.c
+++ b/pkg/urbit/worker/serf.c
@@ -49,6 +49,137 @@
 --
 */
 
+/* _serf_space(): print n spaces.
+*/
+static void
+_serf_space(FILE* fil_u,  c3_w n)
+{
+  for (; n > 0; n--)
+    (fprintf(fil_u," "));
+}
+
+/* _serf_print_memory(): print memory amount.
+**
+**  Helper for _serf_prof(), just an un-captioned u3a_print_memory().
+*/
+static void
+_serf_print_memory(FILE* fil_u, c3_w wor_w)
+{
+  c3_w byt_w = (wor_w * 4);
+  c3_w gib_w = (byt_w / 1000000000);
+  c3_w mib_w = (byt_w % 1000000000) / 1000000;
+  c3_w kib_w = (byt_w % 1000000) / 1000;
+  c3_w bib_w = (byt_w % 1000);
+
+  if ( gib_w ) {
+    (fprintf(fil_u, "GB/%d.%03d.%03d.%03d\r\n",
+        gib_w, mib_w, kib_w, bib_w));
+  }
+  else if ( mib_w ) {
+    (fprintf(fil_u, "MB/%d.%03d.%03d\r\n", mib_w, kib_w, bib_w));
+  }
+  else if ( kib_w ) {
+    (fprintf(fil_u, "KB/%d.%03d\r\n", kib_w, bib_w));
+  }
+  else {
+    (fprintf(fil_u, "B/%d\r\n", bib_w));
+  }
+}
+
+/* _serf_prof(): print memory profile. RETAIN.
+*/
+c3_w
+_serf_prof(FILE* fil_u, c3_w den, u3_noun mas)
+{
+  c3_w tot_w = 0;
+  u3_noun h_mas, t_mas;
+
+  if ( c3n == u3r_cell(mas, &h_mas, &t_mas) ) {
+    _serf_space(fil_u, den);
+    fprintf(fil_u, "mistyped mass\r\n");
+    return tot_w;
+  }
+  else if ( _(u3du(h_mas)) ) {
+    _serf_space(fil_u, den);
+    fprintf(fil_u, "mistyped mass head\r\n");
+    {
+      c3_c* lab_c = u3m_pretty(h_mas);
+      fprintf(fil_u, "h_mas: %s", lab_c);
+      c3_free(lab_c);
+    }
+    return tot_w;
+  }
+  else {
+    _serf_space(fil_u, den);
+
+    {
+      c3_c* lab_c = u3m_pretty(h_mas);
+      fprintf(fil_u, "%s: ", lab_c);
+      c3_free(lab_c);
+    }
+
+    u3_noun it_mas, tt_mas;
+
+    if ( c3n == u3r_cell(t_mas, &it_mas, &tt_mas) ) {
+      fprintf(fil_u, "mistyped mass tail\r\n");
+      return tot_w;
+    }
+    else if ( c3y == it_mas ) {
+      tot_w += u3a_mark_noun(tt_mas);
+      _serf_print_memory(fil_u, tot_w);
+
+#if 1
+      /* The basic issue here is that tt_mas is included in .sac
+       * (the whole profile), so they can't both be roots in the
+       * normal sense. When we mark .sac later on, we want tt_mas
+       * to appear unmarked, but its children should be already
+       * marked.
+      */
+      if ( _(u3a_is_dog(tt_mas)) ) {
+        u3a_box* box_u = u3a_botox(u3a_to_ptr(tt_mas));
+#ifdef U3_MEMORY_DEBUG
+        if ( 1 == box_u->eus_w ) {
+          box_u->eus_w = 0xffffffff;
+        }
+        else {
+          box_u->eus_w -= 1;
+        }
+#else
+        if ( -1 == (c3_w)box_u->use_w ) {
+          box_u->use_w = 0x80000000;
+        }
+        else {
+          box_u->use_w += 1;
+        }
+#endif
+      }
+#endif
+
+      return tot_w;
+    }
+    else if ( c3n == it_mas ) {
+      fprintf(fil_u, "\r\n");
+
+      while ( _(u3du(tt_mas)) ) {
+        tot_w += _serf_prof(fil_u, den+2, u3h(tt_mas));
+        tt_mas = u3t(tt_mas);
+      }
+
+      _serf_space(fil_u, den);
+      fprintf(fil_u, "--");
+      _serf_print_memory(fil_u, tot_w);
+
+      return tot_w;
+
+    }
+    else {
+      _serf_space(fil_u, den);
+      fprintf(fil_u, "mistyped (strange) mass tail\r\n");
+      return tot_w;
+    }
+  }
+}
+
 /* _serf_grab(): garbage collect, checking for profiling. RETAIN.
 */
 static void
@@ -69,7 +200,7 @@ _serf_grab(u3_noun sac)
       c3_c* wen_c = u3r_string(wen);
 
       c3_c nam_c[2048];
-      snprintf(nam_c, 2048, "%s/.urb/put/mass", u3C.dir_c);
+      snprintf(nam_c, 2048, "%s/.urb/put/mass", u3P.dir_c);
 
       struct stat st;
       if ( -1 == stat(nam_c, &st) ) {
@@ -94,7 +225,7 @@ _serf_grab(u3_noun sac)
     c3_assert( u3R == &(u3H->rod_u) );
     fprintf(fil_u, "\r\n");
 
-    tot_w += u3a_maid(fil_u, "total userspace", u3a_prof(fil_u, 0, sac));
+    tot_w += u3a_maid(fil_u, "total userspace", _serf_prof(fil_u, 0, sac));
     tot_w += u3m_mark(fil_u);
     tot_w += u3a_maid(fil_u, "space profile", u3a_mark_noun(sac));
 
@@ -708,7 +839,7 @@ _serf_writ_live_exit(u3_serf* sef_u, c3_w cod_w)
       c3_c* wen_c = u3r_string(wen);
 
       c3_c nam_c[2048];
-      snprintf(nam_c, 2048, "%s/.urb/put/profile", u3C.dir_c);
+      snprintf(nam_c, 2048, "%s/.urb/put/profile", u3P.dir_c);
 
       struct stat st;
       if ( -1 == stat(nam_c, &st) ) {
@@ -752,7 +883,7 @@ _serf_writ_live_save(u3_serf* sef_u, c3_d eve_d)
     exit(1);
   }
 
-  u3m_save();
+  u3e_save();
 }
 
 /* u3_serf_live(): apply %live command [com], producing *ret on c3y.
@@ -823,7 +954,7 @@ u3_serf_live(u3_serf* sef_u, u3_noun com, u3_noun* ret)
         return c3n;
       }
 
-      u3m_save();
+      u3e_save();
       u3_serf_grab();
 
       *ret = u3nc(c3__live, u3_nul);
@@ -850,7 +981,7 @@ u3_serf_live(u3_serf* sef_u, u3_noun com, u3_noun* ret)
       }
       else {
         u3z(com);
-        u3a_print_memory(stderr, "serf: meld: gained", u3u_meld());
+        u3u_meld();
         *ret = u3nc(c3__live, u3_nul);
         return c3y;
       }