ref: bd773dee09460f5d77c96f2fe3d34ec5ee0b54ce dir: /sys/src/libc/amd64/main9.s/
TEXT _main(SB), 1, $0 MOVQ AX, _tos(SB) MOVQ $main(SB), RARG PUSHQ RARG PUSHQ $0 JMPF _callmain(SB)