Kernel: Add ioctls to BochsVGADevice for mode setting and page flipping.

Use these in WindowServer instead of poking at the BochsVGADevice directly.

Kernel/BochsVGADevice.cpp

@@ -3,6 +3,7 @@
 #include <Kernel/PCI.h>
 #include <Kernel/MemoryManager.h>
 #include <Kernel/Process.h>
+#include <LibC/errno_numbers.h>
 
 #define VBE_DISPI_IOPORT_INDEX           0x01CE
 #define VBE_DISPI_IOPORT_DATA            0x01CF
@@ -21,6 +22,13 @@
 #define VBE_DISPI_ENABLED                0x01
 #define VBE_DISPI_LFB_ENABLED            0x40
 
+#define BXVGA_DEV_IOCTL_SET_Y_OFFSET     1982
+#define BXVGA_DEV_IOCTL_SET_RESOLUTION   1985
+struct BXVGAResolution {
+    int width;
+    int height;
+};
+
 static BochsVGADevice* s_the;
 
 BochsVGADevice& BochsVGADevice::the()
@@ -87,6 +95,24 @@ dword BochsVGADevice::find_framebuffer_address()
     return framebuffer_address;
 }
 
+int BochsVGADevice::ioctl(Process& process, unsigned int request, unsigned int arg)
+{
+    switch (request) {
+    case BXVGA_DEV_IOCTL_SET_Y_OFFSET:
+        set_y_offset(arg);
+        return 0;
+    case BXVGA_DEV_IOCTL_SET_RESOLUTION: {
+        auto* resolution = (const BXVGAResolution*)arg;
+        if (!process.validate_read_typed(resolution))
+            return -EFAULT;
+        set_resolution(resolution->width, resolution->height);
+        return 0;
+    }
+    default:
+        return -EINVAL;
+    };
+}
+
 bool BochsVGADevice::can_read(Process&) const
 {
     ASSERT_NOT_REACHED();

Kernel/BochsVGADevice.h

@@ -17,7 +17,7 @@ public:
     void set_resolution(int width, int height);
     void set_y_offset(int);
 
-
+    virtual int ioctl(Process&, unsigned request, unsigned arg) override;
     virtual Region* mmap(Process&, LinearAddress preferred_laddr, size_t offset, size_t) override;
 
     size_t framebuffer_size_in_bytes() const { return m_framebuffer_size.area() * sizeof(dword) * 2; }

Kernel/Process.cpp

@@ -1786,9 +1786,9 @@ int Process::sys$ioctl(int fd, unsigned request, unsigned arg)
         *pid = descriptor->socket()->origin_pid();
         return 0;
     }
-    if (!descriptor->is_character_device())
+    if (!descriptor->is_device())
         return -ENOTTY;
-    return descriptor->character_device()->ioctl(*this, request, arg);
+    return descriptor->device()->ioctl(*this, request, arg);
 }
 
 int Process::sys$getdtablesize()

WindowServer/WSWindowManager.cpp

@@ -9,7 +9,6 @@
 #include <SharedGraphics/Painter.h>
 #include <SharedGraphics/CharacterBitmap.h>
 #include <AK/StdLibExtras.h>
-#include <Kernel/BochsVGADevice.h>
 #include <LibC/errno_numbers.h>
 #include "WSMenu.h"
 #include "WSMenuBar.h"
@@ -126,10 +125,11 @@ void WSWindowManager::flip_buffers()
 {
     swap(m_front_bitmap, m_back_bitmap);
     swap(m_front_painter, m_back_painter);
-    if (m_buffers_are_flipped)
-        BochsVGADevice::the().set_y_offset(0);
-    else
-        BochsVGADevice::the().set_y_offset(m_screen_rect.height());
+    if (m_framebuffer_fd != -1) {
+        int new_y_offset = m_buffers_are_flipped ? 0 : m_screen_rect.height();
+        int rc = current->sys$ioctl(m_framebuffer_fd, 1982, new_y_offset);
+        ASSERT(rc == 0);
+    }
     m_buffers_are_flipped = !m_buffers_are_flipped;
 }
 

WindowServer/WSWindowManager.h

@@ -63,8 +63,8 @@ public:
     Color menu_selection_color() const { return m_menu_selection_color; }
     int menubar_menu_margin() const;
 
-    int api$menu_add_separator(int menu_id);
-    int api$menu_add_item(int menu_id, unsigned identifier, String&& text);
+    int framebuffer_fd() const { return m_framebuffer_fd; }
+    void set_framebuffer_fd(int fd) { m_framebuffer_fd = fd; }
 
 private:
     WSWindowManager();
@@ -151,4 +151,6 @@ private:
     Color m_menu_selection_color;
     WeakPtr<WSMenuBar> m_current_menubar;
     WeakPtr<WSMenu> m_current_menu;
+
+    int m_framebuffer_fd { -1 };
 };

WindowServer/main.cpp

@@ -12,27 +12,33 @@ void WindowServer_main()
 {
     WSMessageLoop::the().set_server_process(*current);
     current->set_priority(Process::HighPriority);
-    auto info = current->set_video_resolution(1024, 768);
-
-    dbgprintf("Screen is %ux%ux%ubpp\n", info.width, info.height, info.bpp);
 
     int bxvga_fd = current->sys$open("/dev/bxvga", O_RDWR);
     ASSERT(bxvga_fd >= 0);
 
+    struct BXVGAResolution {
+        int width;
+        int height;
+    };
+    BXVGAResolution resolution { 1024, 768 };
+
+    int rc = current->sys$ioctl(bxvga_fd, 1985, (int)&resolution);
+    ASSERT(rc == 0);
+
     Syscall::SC_mmap_params params;
     memset(&params, 0, sizeof(params));
     params.fd = bxvga_fd;
     params.prot = PROT_READ | PROT_WRITE;
     params.flags = MAP_SHARED;
-    params.size = info.width * info.height * sizeof(RGBA32) * 2;
+    params.size = resolution.width * resolution.height * sizeof(RGBA32) * 2;
     params.offset = 0;
     kprintf("Calling sys$mmap in WS\n");
     void* framebuffer = current->sys$mmap(&params);
     ASSERT(framebuffer && framebuffer != (void*)-1);
 
-    WSScreen screen((dword*)framebuffer, info.width, info.height);
+    WSScreen screen((dword*)framebuffer, resolution.width, resolution.height);
 
-    WSWindowManager::the();
+    WSWindowManager::the().set_framebuffer_fd(bxvga_fd);
 
     dbgprintf("Entering WindowServer main loop.\n");
     WSMessageLoop::the().exec();