ref: ee2174eb6d33da8eea7d1f68101b70deb12a2a4c dir: /sys/src/libc/amd64/main9.s/
TEXT _main(SB), 1, $0 MOVQ AX, _tos(SB) MOVQ $main(SB), RARG PUSHQ RARG PUSHQ $0 MOVQ $_callmain(SB), AX JMP* AX