RISC-V requires "zicsr" ISA extension to build with FSF GNAT 12.1.1 about ada_drivers_library HOT 11 CLOSED

It may also be possible to directly insert an assembler directive in the generated code for the packages that require the CSRR and CSRW instructions. I think you need to add
.option arch,+zicsr

near the top of the generated .s file. Can this be done with package Machine_Code?

Details in the RISC-V specific section of the most recent GNU as manual.

from ada_drivers_library.

For reference, my local changes to SPARKNaCl to get GNAT 12.1.1 working are here:
rod-chapman/SPARKNaCl#28

from ada_drivers_library.

.option arch,+zicsr in inlined machine code would be the best option in my opinion. Did you try it?

from ada_drivers_library.

Yes... but I couldn't work out the exact syntax required...

See https://sourceware.org/binutils/docs/as/RISC_002dV_002dDirectives.html#RISC_002dV_002dDirectives

from ada_drivers_library.

Might be because we don't have the latest binutils: enjoy-digital/litex@91d79ae

I will build a toolchain with the latest and try again.

from ada_drivers_library.

Confirmed, I started build for a new release of the toolchains with binutils 2.38.

from ada_drivers_library.

OK... let me know when it's ready (and how to get it) and I will give it a try...

from ada_drivers_library.

Reading the ISA spec more carefully, I think you actually should generate

.option push
.option arch,+zicsr
# do stuff with CSRs or whatever...
.option pop

so that the existing state of the "arch" setting is saved and restored properly.

from ada_drivers_library.

The SPARKNaCl performance test program now seems to build OK with the new GNAT 12.1.2 with no modification to the assembly language component(s), so looking good.

from ada_drivers_library.

Without the .option arch,+zicsr?

Thanks for the update,

from ada_drivers_library.

Yes... my sources (see SPARKNaCl/perf/csrs.s) are unmodified and it builds OK...

from ada_drivers_library.