riscv64imac-unknown-none-elf cross compiler got "error: instruction requires the following: 'M' (Integer Multiplication and Division)"

[elliott10]

When I cross-compile RISCV assembly instructions in file.asm with "rustc 1.60.0-nightly (5e57faa78 2022-01-19) riscv64imac-unknown-none-elf" toolchain.
I got the following error:

error: instruction requires the following: 'M' (Integer Multiplication and Division)
        mul t0, t0, a0
        ^

Please help， How should I avoid this error ?

[sslime336]

Try adding this to your asm file(hope this would work):

.attribute arch, "rv64gc"