Instead, use the FixedCharBuffer class to ensure we always use a static
buffer storage for these names. This ensures that if a Process or a
Thread were created, there's a guarantee that setting a new name will
never fail, as only copying of strings should be done to that static
storage.
The limits which are set are 32 characters for processes' names and 64
characters for thread names - this is because threads' names could be
more verbose than processes' names.
This resolves the various "implicit truncation from int to a one-bit
wide bit-field changes value from 1 to -1" warnings produced by Clang
16+ when assigning to single-bit bitfields.
Instead of using ifdefs to use the correct platform-specific methods, we
can just use the same pattern we use for the microseconds_delay function
which has specific implementations for each Arch CPU subdirectory.
When linking a kernel image, the actual correct and platform-specific
power-state changing methods will be called in Firmware/PowerState.cpp
file.
Once LibC is installed to the sysroot and its conflicts with libc++
are resolved, including LibC headers in such a way will cause errors
with a modern LLVM-based toolchain.
To ensure actual PS2 code is not tied to the i8042 code, we make them
separated in the following ways:
- PS2KeyboardDevice and PS2MouseDevice classes are no longer inheriting
from the IRQHandler class. Instead we have specific IRQHandler derived
class for the i8042 controller implementation, which is used to ensure
that we don't end up mixing PS2 code with low-level interrupt handling
functionality. In the future this means that we could add a driver for
other PS2 controllers that might have only one interrupt handler but
multiple PS2 devices are attached, therefore, making it easier to put
the right propagation flow from the controller driver all the way to
the HID core code.
- A simple abstraction layer is added between the PS2 command set which
devices could use and the actual implementation low-level commands.
This means that the code in PS2MouseDevice and PS2KeyboardDevice
classes is no longer tied to i8042 implementation-specific commands,
so now these objects could send PS2 commands to their PS2 controller
and get a PS2Response which abstracts the given response too.
The HIDController class is removed and instead adding SerialIOController
class. The HIDController class was a mistake - there's no such thing in
real hardware as host controller only for human interface devices
(VirtIO PCI input controller being the exception here, but it could be
technically treated as serial IO controller too).
Instead, we simply add a new abstraction layer - the SerialIO "bus",
which will hold all the code that is related to serial communications
with other devices. A PS2 controller is simply a serial IO controller,
and the Intel 8042 Controller is simply a specific implementation of a
PS2 controller.
All code that is related to PC BIOS should not be in the Kernel/Firmware
directory as this directory is for abstracted and platform-agnostic code
like ACPI (and device tree parsing in the future).
This fixes a problem with the aarch64 architecure, as these machines
don't have any PC-BIOS in them so actually trying to access these memory
locations (EBDA, BIOS ROM) does not make any sense, as they're specific
to x86 machines only.
This code is very x86-specific, because Intel introduced the actual
MultiProcessor specification back in 1993, qouted here as a proof:
"The MP specification covers PC/AT-compatible MP platform designs based
on Intel processor architectures and Advanced Programmable Interrupt
Controller (APIC) architectures"
Most of the ACPI static parsing methods (methods that can be called
without initializing a full AML parser) are not tied to any specific
platform or CPU architecture.
The only method that is platform-specific is the one that finds the RSDP
structure. Thus, each CPU architecture/platform needs to implement it.
This means that now aarch64 can implement its own method to find the
ACPI RSDP structure, which would be hooked into the rest of the ACPI
code elegantly, but for now I just added a FIXME and that method returns
empty value of Optional<PhysicalAddress>.
Instead of having a single available memory range that encompasses the
whole 0x00000000-0x3EFFFFFF range of physical memory, create a separate
reserved entry for the RAM range used by the VideoCore. This fixes a
crash that happens when we try to allocate physical pages in the GPU's
reserved range.
This will eventually be replaced with parsing the data from the device
tree, but for now, this should solve some of the recurring CI failures.
Like the HID, Audio and Storage subsystem, the Graphics subsystem (which
handles GPUs technically) exposes unix device files (typically in /dev).
To ensure consistency across the repository, move all related files to a
new directory under Kernel/Devices called "GPU".
Also remove the redundant "GPU" word from the VirtIO driver directory,
and the word "Graphics" from GraphicsManagement.{h,cpp} filenames.
This has KString, KBuffer, DoubleBuffer, KBufferBuilder, IOWindow,
UserOrKernelBuffer and ScopedCritical classes being moved to the
Kernel/Library subdirectory.
Also, move the panic and assertions handling code to that directory.
The Storage subsystem, like the Audio and HID subsystems, exposes Unix
device files (for example, in the /dev directory). To ensure consistency
across the repository, we should make the Storage subsystem to reside in
the Kernel/Devices directory like the two other mentioned subsystems.
This is enforced by the hardware and an exception is generated when the
stack pointer is not properly aligned. This brings us closer to booting
the aarch64 Kernel on baremetal.
This is the only kernel issue blocking us from running the test suite.
Having userspace backtraces printed to the debug console during crashes
isn't vital to the system's function, so let's just return an empty
trace and print a FIXME instead of crashing.
"Wherever applicable" = most places, actually :^), especially for
networking and filesystem timestamps.
This includes changes to unzip, which uses DOSPackedTime, since that is
changed for the FAT file systems.
That's what this class really is; in fact that's what the first line of
the comment says it is.
This commit does not rename the main files, since those will contain
other time-related classes in a little bit.
This commit lets us differentiate whether access faults are caused by
accessing junk memory addresses given to us by userspace or if we hit a
kernel bug.
The stub implementations of the `safe_*` functions currently don't let
us jump back into them and return a value indicating failure, so we
panic if such a fault happens. Practically, this means that we still
crash, but if the access violation was caused by something else, we take
the usual kernel crash code path and print a register and memory dump,
rather than hitting the `TODO_AARCH64` in `handle_safe_access_fault`.
These are used in futexes, which are needed if we want to get further in
`run-tests`.
For now, we have no way to return a non-fatal error if an access fault
is raised while executing these, so the kernel will panic. Some would
consider this a DoS vulnerability where a malicious userspace app can
crash the kernel by passing bogus pointers to it, but I prefer to call
it progress :^)
Enabling these will fix the Unsupported Exclusive or Atomic access data
fault we get on bare metal Raspberry Pi 3. On A53/A57 chips (and newer),
atomic compare-exchange operations require the data cache to be enabled.
Referencing ARM DDI 0487J.a, update the names of previously reserved
fields, and set the reset_value() of the SCTLR_EL1 struct to reflect
the defaults we want for this register on reboot.
Otherwise, the message's contents might be in the cache only, so
VideoCore will read stale/garbage data from main memory.
This fixes framebuffer setup on bare metal with the data cache enabled.
While the PL011-based UART0 is currently reserved for the kernel
console, UART1 is free to be exposed to the userspace as `/dev/ttyS0`.
This will be used as the stdout of `run-tests-and-shutdown.sh` when
testing the AArch64 kernel.
The Raspberry Pi hardware doesn't support a proper software-initiated
shutdown, so this instead uses the watchdog to reboot to a special
partition which the firmware interprets as an immediate halt on
shutdown. When running under Qemu, this causes the emulator to exit.
We now have everything in the AArch64 kernel to be able to use the full
`__panic` implementation, so we can share the code with x86-64.
I have kept `__assertion_failed` separate for now, as the x86-64 version
directly executes inline assembly, thus `Kernel/Arch/aarch64/Panic.cpp`
could not be removed.
This logo was actually used as a first sign of life in the very early
days of the aarch64 port.
Now that we boot into the graphical mode of the system just fine there's
no need to keep this.
MSIx table entry is used to program interrupt vectors and it is
architecture specific. Add helper functions declaration in
Arch/PCIMSI.h. The definition of the function is placed in the
respective arch specific code.
MSI(x) interrupts need to reserve IRQs so that it can be programmed by
the device. Add an API to reserve contiguous ranges of interrupt
handlers so that it can used by PCI devices that use MSI(x) mechanism.
This API needs to be implemented by aarch64 architecture.
Set pin-based interrupt handler as reserved during PCI bus init.
This is required so that MSI(x) based interrupts can avoid sharing the
IRQ which has been marked as reserved.
Since multiboot_modules_count is set to 0, we can safely set the
multiboot_modules pointer to 0 (null pointer), as we don't use multiboot
on aarch64 anyway.
This reuses the existing `RPi::Mailbox` interface to read the command
line via a VideoCore-specific mailbox message. This will have to be
replaced if that interface starts being smarter, as this is needed very
early, and nothing guarantees that a smarter Mailbox interface wouldn't
need to allocate or log, which is a no-no during early boot.
As the response string can be arbitrarily long, it's the caller's job to
provide a long enough buffer for `Mailbox::query_kernel_command_line`.
This commit chose 512 bytes, as it provides a large enough headroom over
the 150-200 characters implicitly added by the VC firmware.
The portable way would be to parse the `/chosen/bootargs` property of
the device tree, but we currently lack the scaffolding for doing that.
Support for this in QEMU relies on a patch that has not yet been
accepted upstream, but is available via our `Toolchain/BuildQEMU.sh`
script. It should, however, work on bare metal.
Tested-By: Timon Kruiper <timonkruiper@gmail.com>
