We use a ScopeGuard to ensure we always set a console of some sort if we
exit early from the initialization sequence in the GraphicsManagement
code. We do so to ensure we can boot into text mode console in an ISA-PC
machine type, because earlier we failed with an assertion due to not
setting any console for VirtualConsole to use.
ISA IDE controllers don't support Bus-master DMA as this feature is only
available for PCI IDE controllers. Therefore, don't try to use DMA mode
for such hardware.
The code in init.cpp is specific to the x86 initialization sequence, so
move it to the Arch/x86 directory in the same fashion like the aarch64
pattern.
The PIC and APIC code are specific to x86 platforms, so move them out of
the general Interrupts directory to Arch/x86/common/Interrupts directory
instead.
That code heavily relies on x86-specific instructions, and while other
CPU architectures and platforms can have PCI IDE controllers, currently
we don't support those, so this code is a special case which needs to be
in the Arch/x86 directory.
In the future it could be put back to the original place when we make it
more generic and suitable for other platforms.
The i8042 controller with its attached devices, the PS2 keyboard and
mouse, rely on x86-specific IO instructions to work. Therefore, move
them to the Arch/x86 directory to make it easier to omit the handling
code of these devices.
The ISA IDE controller code makes sense to be compiled in a x86 build as
it relies on access to the x86 IO space. For other architectures, we can
just omit the code as there's no way we can use that code again.
To ensure we can omit the code easily, we move it to the Arch/x86
directory.
The AHCI code doesn't rely on x86 IO at all as it only uses memory
mapped IO so we can simply remove the header.
We also simply don't use x86 IO in the Intel graphics driver, so we can
simply remove the include of the x86 IO header there too.
Everything else was a bunch of stale includes to the x86 IO header and
are actually not necessary, so let's remove them to make it easier to
compile non-x86 Kernel builds.
The VMWare backdoor handling code involves many x86-specific
instructions and therefore should be in the Arch/x86 directory. This
ensures we can easily omit the code in compile-time for non-x86 builds.
It seems more correct to let each platform to define its own sequence of
initialization of the PCI bus, so let's remove the #if flags and just
put the entire Initializer.cpp file in the appropriate code directory.
Only use the Bochs debug output if we compile a x86 build since bochs
debug output relies on x86 specific instructions.
We also remove the CONSOLE_OUT_TO_BOCHS_DEBUG_PORT flag as we always
compile bochs debug output for x86 builds and we always want to include
the bochs debug output capability as it is very handy and doesn't hurt
bare metal hardware or do any other problem besides taking a small
amount of CPU cycles.
The simple PCI::HostBridge class implements access to the PCI
configuration space by using x86 IO instructions. Therefore, it should
be put in the Arch/x86/PCI directory so it can be easily omitted for
non-x86 builds.
kprintf should not really care about the hardware-specific details of
each UART or serial port out there, so instead of using x86 specific
instructions, let's ensure that we will compile only the relevant code
for debug output for a targeted-specific platform.
The RTC and CMOS are currently only supported for x86 platforms and use
specific x86 instructions to produce only certain x86 plaform operations
and results, therefore, we move them to the Arch/x86 specific directory.
Many code patterns and hardware procedures rely on reliable delay in the
microseconds granularity, and since they are using such delays which are
valid cases, but should not rely on x86 specific code, we allow to
determine in compile time the proper platform-specific code to use to
invoke such delays.
We only use the RTC code in the Kernel, so it doesn't make sense to make
the RTC namespace outside of it. In addition to that, we will need later
on to use the RTC in an x86 specific manner and this will help us to use
this code in such fashion.
We move QEMU and VirtualBox shutdown sequences to a separate file, as
well as moving the i8042 reboot code sequence too to another file.
This allows us to abstract specific methods from the power state node
code of the SysFS filesystem, to allow other architectures to put their
methods there too in the future.
Using the IO address space is only relevant for x86 machines, so let's
not compile instructions to access the PCI configuration space when we
don't target x86 platforms.
This remained undetected for a long time as HeaderCheck is disabled by
default. This commit makes the following file compile again:
// file: compile_me.cpp
#include <Kernel/API/POSIX/ucontext.h>
// That's it, this was enough to cause a compilation error.
According to Dr. POSIX, we should allow to call mmap on inodes even on
ranges that currently don't map to any actual data. Trying to read or
write to those ranges should result in SIGBUS being sent to the thread
that did violating memory access.
We make these methods non-virtual because we want to ensure we properly
enforce locking of the m_inode_lock mutex. Also, for write operations,
we want to call prepare_to_write_data before the actual write. The
previous design required us to ensure the callers do that at various
places which lead to hard-to-find bugs. By moving everything to a place
where we call prepare_to_write_data only once, we eliminate a possibilty
of forgeting to call it on some code path in the kernel.
The block list required a bit of work, and now the only method being
declared const to bypass its const-iness is the read_bytes method that
calls a new method called compute_block_list_with_exclusive_locking that
takes care of proper locking before trying to update the block list data
of the ext2 inode.
Before of this patch, we supported two methods to address a boot device:
1. Specifying root=/dev/hdXY, where X is a-z letter which corresponds to
a boot device, and Y as number from 1 to 16, to indicate the partition
number, which can be omitted to instruct the kernel to use a raw device
rather than a partition on a raw device.
2. Specifying root=PARTUUID: with a GUID string of a GUID partition. In
case of existing storage device with GPT partitions, this is most likely
the safest option to ensure booting from persistent storage.
While option 2 is more advanced and reliable, the first option has 2
caveats:
1. The string prefix "/dev/hd" doesn't mean anything beside a convention
on Linux installations, that was taken into use in Serenity. In Serenity
we don't mount DevTmpFS before we mount the boot device on /, so the
kernel doesn't really access /dev anyway, so this convention is only a
big misleading relic that can easily make the user to assume we access
/dev early on boot.
2. This convention although resemble the simple linux convention, is
quite limited in specifying a correct boot device across hardware setup
changes, so option 2 was recommended to ensure the system is always
bootable.
With these caveats in mind, this commit tries to fix the problem with
adding more addressing options as well as to remove the first option
being mentioned above of addressing.
To sum it up, there are 4 addressing options:
1. Hardware relative address - Each instance of StorageController is
assigned with a index number relative to the type of hardware it handles
which makes it possible to address storage devices with a prefix of the
commandset ("ata" for ATA, "nvme" for NVMe, "ramdisk" for Plain memory),
and then the number for the parent controller relative hardware index,
another number LUN target_id, and a third number for LUN disk_id.
2. LUN address - Similar to the previous option, but instead we rely on
the parent controller absolute index for the first number.
3. Block device major and minor numbers - by specifying the major and
minor numbers, the kernel can simply try to get the corresponding block
device and use it as the boot device.
4. GUID string, in the same fashion like before, so the user use the
"PARTUUID:" string prefix and add the GUID of the GPT partition.
For the new address modes 1 and 2, the user can choose to also specify a
partition out of the selected boot device. To do that, the user needs to
append the semicolon character and then add the string "partX" where X
is to be changed for the partition number. We start counting from 0, and
therefore the first partition number is 0 and not 1 in the kernel boot
argument.
This reworks the way the UHCI schedule is set up to handle interrupt
transfers, creating 11 queue heads each assigned a different
period/latency, so that interrupt transfers can be linked into the
schedule with their specified period more easily.
Modifies the way the UHCI schedule is set up & modified to allow for
multiple transfers of the same type, from one or more devices, to be
queued up and handled simultaneously.
Otherwise we would be holding the MM global data lock and the Process
address space locks in reversed order to the rest of the system, which
can lead to deadlocks.
This is a left-over from back when we didn't have any locking on the
global Process list, nor did we have SMP support, so this acted as some
kind of locking mechanism. We now have proper locks around the Process
list, so this is no longer relevant.
Change the name of set_serial_debug(bool on_or_off) to
set_serial_debug_enabled(bool desired_state). This is to make the names
more expressive and less unclear as to what the function does, as it
only sets the enabled state.
Likewise, change the name of get_serial_debug() to
is_serial_debug_enabled() in order to make clear from the name that
this is simply the state of s_serial_debug_enabled.
Change the name of serial_debug to s_serial_debug_enabled since this is
a static bool describing this state.
Finally, change the signature of set_serial_debug_enabled to return a
bool, as this is more logical and understandable.