built my riscv64-unknown-elf-gcc, but now getting

unrecognized opcode

errors:

➜  blink git:(main) ✗ make
generating hex for [blink]
riscv64-unknown-elf-gcc -I../fpga_bitstreams/ -I../common/ -O0 -mabi=ilp32 -march=rv32i -D__vexriscv__ -Wl,-Bstatic,-T,../common/sections.lds,--strip-debug -ffreestanding -nostdlib -o blink.elf ../common/crt0_vex.S ../common/isr.c ../common/gpio_program.c blink.c
../common/crt0_vex.S: Assembler messages:
../common/crt0_vex.S:59: Error: unrecognized opcode `csrw mtvec,a0', extension `zicsr' required
../common/crt0_vex.S:87: Error: unrecognized opcode `csrw mie,a0', extension `zicsr' required
../common/irq_vex.h: Assembler messages:
../common/irq_vex.h:31: Error: unrecognized opcode `csrw 3008,a5', extension `zicsr' required
make: *** [../common/common_makefile.mk:16: blink.elf] Error 1