You can use any riscv64 ELF/GNU/musl toolchain.

1.build mmc
make CROSS_COMPILE=riscv64-linux-musl- p=sun20iw1p1 mmc

2.build nand
make CROSS_COMPILE=riscv64-linux-musl- p=sun20iw1p1 nand

3.build spinor
make CROSS_COMPILE=riscv64-linux-musl- p=sun20iw1p1 spinor

4.build fes
make CROSS_COMPILE=riscv64-linux-musl- p=sun20iw1p1 fes
