The current code results in
`error: invalid reassignment of non-absolute variable 'isr_stub_start'`.
Use a numbered label instead (as that can be reassigned) and reference
the last occurrence using the b suffix.
We should build with -ffreestanding since we are building an OS kernel and
cannot rely on all hosted environment functionality being present.
Specifically this fixes a compilation error with clang caused by the
the #include_next <limits.h>:
```
In file included from target/pc-x86/config.c:9:
In file included from dev/include/dev/driver.h:10:
In file included from lib/libc/include/sys/types.h:10:
In file included from lib/libc/include/limits.h:5:
In file included from /usr/lib/llvm-15/lib/clang/15.0.7/include/limits.h:21:
/usr/include/limits.h:26:10: fatal error: 'bits/libc-header-start.h' file not found
#include <bits/libc-header-start.h>
```
The flag fixes this issue by ensuring that __STDC_HOSTED__ is no longer set
to 1, so Clang's limits.h will not try to include the host system one.
This only builds a subset of all targets for now since the remaining
ones (32-bit targets) would require libgcc/compiler-rt for the 64-bit
integer and/or double-precision float helper functions.
Currently, only aarch64 targets build with clang, but with follow-up
this can be extended to include x86_64 and RISCV64.
CC, LD, etc was already settable by the environment, but not by
local.mk, since they were assigned in engine.mk as :=. Change the set to
be conditional to fix this.
Clang incorrectly diagnoses msr operations as need a 64-bit operand even
if the underlying register is actually 32 bits. Silence this warning.
There are quite a few occurrences of this warning so I opted to add the
-Wno-flag instead of wrapping all callsites in
`#pragma clang diagnostic ignored -Wasm-operand-widths`.
Currently, clang does not support the -Wno-nonnull-compare and
-Wmaybe-uninitialized warning flags so this adds lots of unknown warning
flag output for each compile job when not using GCC.
This commit adds a makefile macro to check for supported warning flags
and only adds them if the compiler actually supports them.
Clang does not accept this .if condition since phys_offset is a register
alias and not an absolute expression. We can keep these two instructions
here if the argument is zero since the result will be the same.
Additionally, this macro is only called once and always passes a non-zero
argument. If more calls are added in the future and avoiding these two
instructions just before a loop is really important, we could use
`.ifnc \phys_offset,0` instead, but that looks rather obscure to me.
Update arm-m systick current_time() and current_time_hires() to advance
monotonically even when interrupts are disabled.
Previous implementation relied on the systick exception triggering
immediately when the counter wrapped and incrementing the current_ticks
count. But if called when interrutps are disabled, then the systick has
not had a chance to trigger and increment the count, but the counter has
already wrapped around. This would result in the current_time() value
moving backwards.
The implementation in this commit is as follows:
- Access to the systick val csr is always done in conjunction with a
check of the COUNTFLAG bit, which indicates counter reaching zero.
- The global current_ticks count is incremented immediately when
wrap around is detected via COUNTFLAG, rather than waiting for the
systick exception to run.
- The check of the counter value, COUNTFLAG bit, and current_ticks
global count are always done in a critical section to avoid race
conditions between current_time and the systick handler.
- The critical section and workarounds are consolidated into a helper
function shared by current_time() and current_time_hires() to
atomically get the tick count and the cycles since the last tick.
The effect should be that current_time() always returns an accurate
monotonically increasing value, regardless of interrupt enablement
or not.
In the non-QUIET case, the log function pipes output to the tee command.
Without the pipefail option, if a make command fails, but the tee exits
succesfully, the overall status is 0 and the failed project doesn't get
added to the FAILED list and reported. Adding the pipefail option
propagates the make failure appropriately and adds the target to the
FAILED list.
Even though we only need 32 bits here, clang warns that we should be
using a "w" register in the inline assembly (which is not legal with
mrs/msr). Silence the warning by declaring the value as unsigned long.
(cherry picked from commit a0de5d88dfc67b3ba34c0455b1619e12e6cfccae)
In addition to fixing -Wdouble-promition issues in bench_sincos, this also
ensures that the compiler can't replace the calls to sin/cos/sqrt with a
compile-time constant.
Arithmetic on a NULL pointer is undefined behaviour and could be used by
the compiler to optimize out the arithmetic. Use the integer expansion of
chunk2mem(0) instead to silence this warning:
`arithmetic on a null pointer treated as a cast from integer to pointer is a GNU extension [-Wnull-pointer-arithmetic]`
Two handlers accidentally had the wrong prototype, called the wrong
thing and/or had the wrong name.
Should only affect divrem_overflow_abort, negate_overflow_abort.
Add an UBSAN implementation and a new UBSAN switch to the make build.
The implementation is taken from Onyx and handles most of the cases
that should be needed for a kernel build. Floating point and fancy
C++ CFI features are not supported yet.
To build with UBSAN, pass UBSAN=1 to make such as:
PROJECT=pc-x86-64-test make -jN UBSAN=1
Add a few more #defines for the status register
Tweak the FPU context switch to not rewrite the entire status register,
which may not be a generally safe thing to do.
Updated comment regarding clobbers on the SBI call.
Tweak a boot time print of SBI version.
Add a commented out line to the do-qemuriscv to assist in dumping future
device trees.
Update libfdt from https://github.com/dgibson/dtc at revision
73590342fc85ca207ca1e6cbc110179873a96962
Source is verbatim except moving headers into an include directory added
to the path.
Using 2-clause BSD option.
Disable IO and mem decoding around BAR enumation as described in the PCI
Local Bus specification. This behavior should be safer when messing
around BARs for BAR lengths.
Looks like this is described in /reserved_memory/mmode_resv@<address> as
patched by opensbi on top of the existing qemu provided dtb.
Future patch should parse this instead of hard coding it.
Accessing un-mapped address/address-range results in data abort. Ensure
the address and all the pages in the requested range are mapped. Mapping
is checked at page size, also adjusts the stop address to the nearest valid
address mapped.
