ref: a74c7ca5ea3290dd55c6f2a03aa7c3bcd22d3f61 dir: /sys/src/ape/lib/ap/arm64/main9.s/
GLOBL _tos(SB), $8 TEXT _main(SB), 1, $0 SUB $16, SP MOV $setSB(SB), R28 MOV R0, _tos(SB) MOV $_apemain(SB), R0 MOV $0, R30 B _callmain(SB)