microblaze: pull in gcc/bintuils/gdb patches from meta-xilinx

[alpsayin]

This commit pulls in the fix for the Microblaze gcc atomic compare-and-swap issue where atomic cas returns the inverse Boolean value of what it should. zephyrproject-rtos/gcc#21

These patchsets fixes many known issues on gnu-toolchain for microblaze.
But mainly the atomic-cas and binutils incorrect relocation issues.
Patches obtained from https://github.com/xilinx/meta-xilinx/ repository,

Fixes

1. microblaze: atomic compare-and-swap returns incorrect value #646
2. microblaze: CAS operation in raise is overwriting the signal handler with SIGDFL picolibc/picolibc#460
3. microblaze: Fix -Os right shift optimization is allowed into delay slot gcc#37
4. and other yet-to-be-seen issues.

I've given up and disabled microblaze64 toolchain build. meta-xilinx patches somehow manage to break the same toolchain that they introduced. I have no intention to support microblaze64 yet and this saves a few CI cycles.

Finally; if/when AMD/Xilinx software group manages to upstream these to gnu-gcc, the squashed commits in individual repositories should provide an easy transition (revert and rebase) when it's time to upgrade zephyr-gcc.

CC @keith-packard

[keith-packard]

I think the whole series of pending microblaze fixes should be added here, not just one of them.

[alpsayin]

I think the whole series of pending microblaze fixes should be added here, not just one of them.

Sorry, I've been busy with work. I'll make use of the holidays now and start applying. I have some catching up to do...

[alpsayin]

Tried to apply all patches I could find in binutils as the 1st step. Came across various conflicts. Tried to solve them naively but it seems I failed.
Will have to approach this a bit more clever.

[alpsayin]

I'll be damned. Binutils patches applied cleanly with 464c189
With the toolchain built in https://github.com/zephyrproject-rtos/sdk-ng/actions/runs/5068098583 , all Zephyr tests passing except builds for picolibc. Using this sdk-ng I also face the same issues as reported before in picolibc/picolibc#460 . I'm now trying to build only with the GCC fix in zephyrproject-rtos/gcc@b4654fb so that I can have a trusted base from which I can continue to apply binutils and gcc patches.

[alpsayin]

GCC and binutils patches applied successfully but GDB patches are problematic. I'm working on it.

[alpsayin]

Started

• microblaze: apply gcc patches from meta-xilinx repository gcc#24
• microblaze: apply binutils patches from meta-xilinx repository binutils-gdb#10
• microblaze: apply gdb patches from meta-xilinx repository binutils-gdb#11

Closed in favour of above.

• microblaze: Fix atomic boolean return value. gcc#21

[alpsayin]

CI building for the last time. I will confirm microblaze toolchain still passes all tests (Zephyr & picolibc) and mark this as "Ready for review". I expect no issues.

[stephanosio]

• microblaze: apply gcc patches from meta-xilinx repository gcc#24
• microblaze: apply binutils patches from meta-xilinx repository binutils-gdb#10
• microblaze: apply gdb patches from meta-xilinx repository binutils-gdb#11

@alpsayin Hi. I have merged the GCC patch and left some reviews on the rest of the PRs.

[stephanosio]

Leaving a -1 until all the relevant toolchain patches are merged and this PR is updated to reference the merged commits.

[alpsayin]

Seen it, on it. Thank you!

[alpsayin]

Note to self: microblaze-qemu might be out of date, I'll need to figure out what's going on with that.
Context:
xlnx,ill-opcode-exception = < 0x01 >; option for Microblaze CPU emulation didn't bite even though it's clearly upstreamed:
qemu/qemu@5143fdf
Example usage:
https://github.com/qemu/qemu/blob/master/pc-bios/petalogix-ml605.dts#L95

[alpsayin]

New issue found, potential fix under test zephyrproject-rtos/gcc#37