ref: eefed496c103543aaf85dbdadb8c8c03ebb87d28 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)