ref: 41cbc9758b15a6c6dd2e2cc87f904e4dc9f04110 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)