ref: 0ed8a3bd7b1bbe2a3857f2abcaabdc4edd2d8b05 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)