ref: 8655ee874cb8fa81e620bab3c80b84b5a39b671d dir: /sys/src/9/bitsy/init9.s/
TEXT _main(SB),$8 MOVW $setR12(SB), R12 /* load the SB */ MOVW $boot(SB), R0 ADD $12, R13, R1 /* get a pointer to 0(FP) */ MOVW R0, 4(R13) MOVW R1, 8(R13) BL startboot(SB)