On Wed, Dec 29, 2021 at 2:21 PM Anders Montonen <Anders.Montonen@...> wrote:

Hi,

On 29 Dec 2021, at 9:53, davis roman <davis.roman84@...> wrote:

I generated an internal mips toolchain built against musl and I tried
to compile u-boot but unfortunately, I'm getting "opcode not
supported" error messages. https://pastebin.com/QdcLxy69
If instead I use the realtek provided prebuilt toolchain then u-boot
compiles successfully. https://pastebin.com/zcQ5kc20

I'm thinking that Realtek's toolchain has patches specific to their
SoC that have not been pushed upstream. Could this be the reason I'm
unable to compile uboot?

I’m guessing that your U-Boot config doesn’t set the correct MIPS architecture revision. The compiler error shows that you’re trying to assemble a MIPS32r1 instruction, but the compiler is targeting the original MIPS1 architecture. The Realtek toolchain may have set the default architecture to match the SoC, but the fix is to update the config to match the hardware.

You're right. I didn't realize the RX5281 core on the RTS3916N only
supports mips1 or mips16 (https://pasteboard.co/IpsqN6GkBYAs.png).

I happened to have a mips sourcery toolchain installed on my machine
(https://sourcery.sw.siemens.com/GNUToolchain/package12797/public/mips-linux-gnu/mips-2014.05-27-mips-linux-gnu-i686-pc-linux-gnu.tar.bz2)
so I pointed that to u-boot without modifying anything else and it was
able to compile u-boot successfully. Woot!
https://pastebin.com/ySPFae5u

I suppose the next step would be to generate a mips1 yocto toolchain
however according to the available tune values it appears only mips32
or mips64 is available

Any suggestions on how to generate a mips1 yocto toolchain or if
that's even supported?

Regards,
Anders Montonen