[CI] riscv32-unknown-elf-gcc toolchain with more rv extensions.

[cederom]

Is your feature request related to a problem? Please describe.

When building #16424 on my FreeBSD I noticed that default system compiler does not have required components to build the RaspberryPi-2-RV (RP23XX RV cores inside MCU). This problem also happens for our CI.

Describe the solution you'd like

• We would want to have riscv-gnu-toolchain [1] with all extensions enabled to cover all possible MCU families and cores (this is called multilib [2]?).
• Check if adding compiler options in the PR/code so CI knows what specific compiler to use.

Describe alternatives you've considered

I had to build riscv-collab riscv-gnu-toolchain [1] by hand, add to path before system compiler.

Verification

• I have verified before submitting the report.

[1] https://github.com/riscv-collab/riscv-gnu-toolchain
[2] https://github.com/riscv-collab/riscv-gnu-toolchain?tab=readme-ov-file#installation-newliblinux-multilib

[shtirlic]

FYI toolchain built with multilib https://xpack-dev-tools.github.io/riscv-none-elf-gcc-xpack/blog/2024/12/06/riscv-none-elf-gcc-v14-2-0-3-released/

[cederom]

Very cool, thanks @shtirlic, we should switch to xpack on CI Linux builds :-) What do you think @lupyuen ? :-)

[pkarashchenko]

I think we already are using it

nuttx/tools/ci/docker/linux/Dockerfile

Line 246 in 4e4cd77

curl -s -L "https://github.com/xpack-dev-tools/riscv-none-elf-gcc-xpack/releases/download/v13.2.0-2/xpack-riscv-none-elf-gcc-13.2.0-2-linux-x64.tar.gz" \

[xiaoxiang781216]

I think we already are using it

nuttx/tools/ci/docker/linux/Dockerfile

Line 246 in 4e4cd77
curl -s -L "https://github.com/xpack-dev-tools/riscv-none-elf-gcc-xpack/releases/download/v13.2.0-2/xpack-riscv-none-elf-gcc-13.2.0-2-linux-x64.tar.gz" \

@shtirlic please provide a patch to update the version used by docker to the last one:
https://github.com/riscv-collab/riscv-gnu-toolchain/tags

[shtirlic]

@xiaoxiang781216 #16645