Error: unrecognized opcode on riscv64

[Alex]

Attempting to compile the latest master code for qemu (virt) and the unmatched 
shows the following error:

  arch/riscv/cpu/cpu.c: Assembler messages:
  arch/riscv/cpu/cpu.c:96: Error: unrecognized opcode `csrs sstatus,a5'
  arch/riscv/cpu/cpu.c:97: Error: unrecognized opcode `csrw 0x003,0'


Any ideas on what's going on?

Toolchain:

  riscv64-linux-gnu-gcc   -  gcc version 12.1.0 (GCC) 
  riscv64-linux-gnu-as     -  GNU assembler (GNU Binutils) 2.36.1

Compiling on ArchLinux


 -- Alex