ref: 94d2ee527af44610a498d6f6adbba8f0b6d76f17
dir: /sys/src/libc/amd64/main9p.s/
TEXT _mainp(SB), 1, $0 MOVQ AX, _tos(SB) MOVQ $_profmain(SB), RARG PUSHQ RARG PUSHQ $0 JMPF _callmain(SB) TEXT _savearg(SB), 1, $0 MOVQ RARG, AX RET TEXT _saveret(SB), 1, $0 RET /* we want RARG in RARG */ TEXT _callpc(SB), 1, $0 MOVQ 8(RARG), AX RET