ref: 484d1f2eac4ead9a162d1cd2d57ca99b2edf48d8 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)