ref: 2dc68de34207d4b1fdf069193c8d8a9b907d834d dir: /sys/src/libc/power64/main9.s/
TEXT _main(SB), 1, $-8 ADD $-16, R1 MOVD $0, R0 MOVD $setSB(SB), R2 MOVD RARG, _tos(SB) MOVD $main(SB), RARG MOVD R0, LR MOVD $_callmain(SB), R4 MOVD R4, CTR BR (CTR)