ref: 5ea540e75def56d3c2b5ef16f0f4e91d5f5c0ad1 dir: /sys/src/libc/mips/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4