ref: 47c48b42c3463844a3fa0ca0a9d6dbc8a2e8b0f6 dir: /sys/src/9/bcm64/init9.s/
TEXT main(SB), 1, $8 MOV $setSB(SB), R28 /* load the SB */ MOV $boot(SB), R0 B startboot(SB)