Instead of using absolute paths which is considered an abstraction layer
violation between the kernel and userspace, let's not hardcode the path
to children PID directories but instead we can use relative path links
to them.
Having this function return `nullptr` explicitly triggers the compiler's
inbuilt checker, as it knows the destination is null. Having this as a
static (scoped) variable for now circumvents this problem.
Decompose the current monolithic USBD Pipe interface into several
subclasses, one for each pair of endpoint type & direction. This is to
make it more clear what data and functionality belongs to which Pipe
type, and prevent nonsensical things like trying to execute a control
transfer on a non-control pipe. This is important, because the Pipe
class is the interface by which USB device drivers will interact with
the HCD, so the clearer and more explicit this interface is the better.
Allocate DMA buffer pages for use within the USBD Pipe class, and allow
for the user to specify the size of this buffer, rounding up to the
next page boundary.
This sets up the RPi::Timer to trigger an interurpt every 4ms using one
of the comparators. The actual time is calculated by looking at the main
counter of the RPi::Timer using the Timer::update_time function.
A stub for Scheduler::timer_tick is also added, since the TimeManagement
code now calls the function.
Instead of just having a giant KBuffer that is not resizeable easily, we
use multiple AnonymousVMObjects in one Vector to store them.
The idea is to not have to do giant memcpy or memset each time we need
to allocate or de-allocate memory for TmpFS inodes, but instead, we can
allocate only the desired block range when trying to write to it.
Therefore, it is also possible to have data holes in the inode content
in case of skipping an entire set of one data block or more when writing
to the inode content, thus, making memory usage much more efficient.
To ensure we don't run out of virtual memory range, don't allocate a
Region in advance to each TmpFSInode, but instead try to allocate a
Region on IO operation, and then use that Region to map the VMObjects
in IO loop.
This makes it easier to differentiate between cases where certain
functionality is not implemented vs. cases where a code location
should really be unreachable.
It costs us nothing, and some utilities (such as the known file utility)
rely on the exposed file size (after doing lstat on it), to show
anything useful besides saying the file is "empty".
In a few places we check `!Processor::in_critical()` to validate
that the current processor doesn't hold any kernel spinlocks.
Instead lets provide it a first class name for readability.
I'll also be adding more of these, so I would rather add more
usages of a nice API instead of this implicit/assumed logic.
This change ensures that the scheduler doesn't depend on a platform
specific or arch-specific code when it initializes itself, but rather we
ensure that in compile-time we will generate the appropriate code to
find the correct arch-specific current time methods.
For some odd reason we used to return PhysicalPtr for a page_table_base
result, but when setting it we accepted only a 32 bit value, so we
truncated valid 64 bit addresses into 32 bit addresses by doing that.
With this commit being applied, now PageDirectories can be located
beyond the 4 GiB barrier.
This was found by sin-ack, therefore he should be credited with this fix
appropriately with Co-authored-by sign.
Co-authored-by: sin-ack <sin-ack@users.noreply.github.com>
There is no particular reason why this section should be marked as
`NOBITS` (as it might very well include initialized values), and it
resolves 90% of the mismatches between the input and output sections,
which LLD now warns about when linking.
Doesn't use them in libc headers so that those don't have to pull in
AK/Platform.h.
AK_COMPILER_GCC is set _only_ for gcc, not for clang too. (__GNUC__ is
defined in clang builds as well.) Using AK_COMPILER_GCC simplifies
things some.
AK_COMPILER_CLANG isn't as much of a win, other than that it's
consistent with AK_COMPILER_GCC.
