This isn't particularly useful because by the time we've entered
init() the CPU had better support x86_64 anyway. However this shows the
CPU flag in System Monitor - even in 32-bit mode.
This adds just enough stubs to make the kernel compile on x86_64. Obviously
it won't do anything useful - in fact it won't even attempt to boot because
Multiboot doesn't support ELF64 binaries - but it gets those compiler errors
out of the way so more progress can be made getting all the missing
functionality in place.
This doesn't really matter in terms of writability for the kernel text
because we set up proper page mappings anyway which prohibit writing
to the text segment. However, this makes the profiler happy which
previously died when validating the kernel's ELF program headers.
If FXSR is not present, fall back to fnsave and frstor instructions.
These instructions aren't available on the canonical i686 CPU which is
the Pentium Pro processor.
Currently in SMP mode we hard code support for up to only 8 processors.
There is no reason for this to be a dynamic allocation that needs to be
guarded by a spinlock. Instead use a Array<T* with inline storage of 8,
allowing each processor to initialize it self in place, avoiding all
the need for locks.
Hook the kernel page fault handler and capture page fault events when
the fault has a current thread attached in TLS. We capture the eip and
ebp so we can unwind the stack and locate which pieces of code are
generating the most page faults.
Co-authored-by: Gunnar Beutner <gbeutner@serenityos.org>
As we removed the support of VBE modesetting that was done by GRUB early
on boot, we need to determine if we can modeset the resolution with our
drivers, and if not, we should enable text mode and ensure that
SystemServer knows about it too.
Also, SystemServer should first check if there's a framebuffer device
node, which is an indication that text mode was not even if it was
requested. Then, if it doesn't find it, it should check what boot_mode
argument the user specified (in case it's self-test). This way if we
try to use bochs-display device (which is not VGA compatible) and
request a text mode, it will not honor the request and will continue
with graphical mode.
Also try to print critical messages with mininum memory allocations
possible.
In LibVT, We make the implementation flexible for kernel-specific
methods that are implemented in ConsoleImpl class.
We used GRUB to modeset the resolution for a long time, but for good
reasons I see no point with keeping it supported in our kernel. We
support bochs-display device on QEMU (both the VGA compatible and
non-VGA compatible variants), so for QEMU we can still boot the system
in graphical mode even without GRUB help.
Also, we now have a native driver for Intel graphics and although it
doesn't support most Intel graphics cards out there yet, it's a good
starting point to support more cards. If a user wants to boot on
bare-metal in graphical mode, all he needs to do is to add the removed
flag back again, as the kernel still supports pre-set framebuffers.
By constraining two implementations, the compiler will select the best
fitting one. All this will require is duplicating the implementation and
simplifying for the `void` case.
This constraining also informs both the caller and compiler by passing
the callback parameter types as part of the constraint
(e.g.: `IterationFunction<int>`).
Some `for_each` functions in LibELF only take functions which return
`void`. This is a minimal correctness check, as it removes one way for a
function to incompletely do something.
There seems to be a possible idiom where inside a lambda, a `return;` is
the same as `continue;` in a for-loop.
If we are attempting to emit debugging information about an unhandleable
page fault, don't crash trying to kill threads or dump processes if the
current_thread isn't set in TLS. Attempt to keep proceeding in order to
dump as much useful information as possible.
Related: #6948
The variety of checks for Processor::id() == 0 could use some assistance
in the readability department. This change adds a new function to
represent this check, and replaces the comparison everywhere it's used.
This solves a problem where checking whether a thread is an idle
thread may require iterating all processors if it is not the idle
thread of the current processor.
GCC with -flto is more aggressive when it comes to inlining and
discarding functions which is why we must mark some of the functions
as NEVER_INLINE (because they contain asm labels which would be
duplicated in the object files if the compiler decides to inline
the function elsewhere) and __attribute__((used)) for others so
that GCC doesn't discard them.
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 adds PT_PEEKDEBUG and PT_POKEDEBUG to allow for reading/writing
the debug registers, and updates the Kernel's debug handler to read the
new information from the debug status register.
