Error: unrecognized opcode on riscv64

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