The latest version of the ACPI specification (6.4) now has a web
version, making it possible to link directly to the relevant sections
of the specification.
I added links to the stuff that was easy to find.
The spec can be found here: https://uefi.org/specs/ACPI/6.4/index.html
On some cases, the FADT could be on the end of a page, so if we don't
have two pages being mapped, we could easily read from a non-mapped
virtual address, which will trigger the UB sanitizer.
Also, we need to treat the FADT structure as volatile and const, as it
may change at any time, but we should not touch (write) it anyhow.
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
This flag warns on classes which have `virtual` functions but do not
have a `virtual` destructor.
This patch adds both the flag and missing destructors. The access level
of the destructors was determined by a two rules of thumb:
1. A destructor should have a similar or lower access level to that of a
constructor.
2. Having a `private` destructor implicitly deletes the default
constructor, which is probably undesirable for "interface" types
(classes with only virtual functions and no data).
In short, most of the added destructors are `protected`, unless the
compiler complained about access.
Previously all of the CommandLine parsing was spread out around the
Kernel. Instead move it all into the Kernel CommandLine class, and
expose a strongly typed API for querying the state of options.
(...and ASSERT_NOT_REACHED => VERIFY_NOT_REACHED)
Since all of these checks are done in release builds as well,
let's rename them to VERIFY to prevent confusion, as everyone is
used to assertions being compiled out in release.
We can introduce a new ASSERT macro that is specifically for debug
checks, but I'm doing this wholesale conversion first since we've
accumulated thousands of these already, and it's not immediately
obvious which ones are suitable for ASSERT.
This was done with the help of several scripts, I dump them here to
easily find them later:
awk '/#ifdef/ { print "#cmakedefine01 "$2 }' AK/Debug.h.in
for debug_macro in $(awk '/#ifdef/ { print $2 }' AK/Debug.h.in)
do
find . \( -name '*.cpp' -o -name '*.h' -o -name '*.in' \) -not -path './Toolchain/*' -not -path './Build/*' -exec sed -i -E 's/#ifdef '$debug_macro'/#if '$debug_macro'/' {} \;
done
# Remember to remove WRAPPER_GERNERATOR_DEBUG from the list.
awk '/#cmake/ { print "set("$2" ON)" }' AK/Debug.h.in
Problem:
- Many constructors are defined as `{}` rather than using the ` =
default` compiler-provided constructor.
- Some types provide an implicit conversion operator from `nullptr_t`
instead of requiring the caller to default construct. This violates
the C++ Core Guidelines suggestion to declare single-argument
constructors explicit
(https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#c46-by-default-declare-single-argument-constructors-explicit).
Solution:
- Change default constructors to use the compiler-provided default
constructor.
- Remove implicit conversion operators from `nullptr_t` and change
usage to enforce type consistency without conversion.
These changes are arbitrarily divided into multiple commits to make it
easier to find potentially introduced bugs with git bisect.Everything:
The modifications in this commit were automatically made using the
following command:
find . -name '*.cpp' -exec sed -i -E 's/dbg\(\) << ("[^"{]*");/dbgln\(\1\);/' {} \;
Compared to version 10 this fixes a bunch of formatting issues, mostly
around structs/classes with attributes like [[gnu::packed]], and
incorrect insertion of spaces in parameter types ("T &"/"T &&").
I also removed a bunch of // clang-format off/on and FIXME comments that
are no longer relevant - on the other hand it tried to destroy a couple of
neatly formatted comments, so I had to add some as well.
ACPI 2 declared the third revision of FADT, that should have
IAPC_BOOT_ARCH flags in it, also to indicate if i8042 is present.
Q35 machine reports that it has FADT with revision 3, but the code
in QEMU simply ignores these flags and put zero on them no matter
the revision of FADT.
We can now properly initialize all processors without
crashing by sending SMP IPI messages to synchronize memory
between processors.
We now initialize the APs once we have the scheduler running.
This is so that we can process IPI messages from the other
cores.
Also rework interrupt handling a bit so that it's more of a
1:1 mapping. We need to allocate non-sharable interrupts for
IPIs.
This also fixes the occasional hang/crash because all
CPUs now synchronize memory with each other.
Add a MappedROM::find_chunk_starting_with() helper since that's a very
common usage pattern in clients of this code.
Also convert MultiProcessorParser from a persistent singleton object
to a temporary object constructed via a failable factory function.
This patch adds a MappedROM abstraction to the Kernel VM subsystem.
It's basically the read-only byte buffer equivalent of a TypedMapping.
We use this in the ACPI and MP table parsers to scan for interesting
stuff in low memory instead of doing a bunch of address arithmetic.
This was supposed to be the foundation for some kind of pre-kernel
environment, but nobody is working on it right now, so let's move
everything back into the kernel and remove all the confusion.
There was a frequently occurring pattern of "map this physical address
into kernel VM, then read from it, then unmap it again".
This new typed_map() encapsulates that logic by giving you back a
typed pointer to the kind of structure you're interested in accessing.
It returns a TypedMapping<T> that can be used mostly like a pointer.
When destroyed, the TypedMapping object will unmap the memory. :^)
If we don't support ACPI, just don't instantiate an ACPI parser.
This is way less confusing than having a special parser class whose
only purpose is to do nothing.
We now search for the RSDP in ACPI::initialize() instead of letting
the parser constructor do it. This allows us to defer the decision
to create a parser until we're sure we can make a useful one.
