ref: 1b44caa0c40d7b722a7d9edd0a6eaefe1616c4b0 dir: /sys/src/9/arm64/init9.s/
TEXT main(SB), 1, $8 MOV $setSB(SB), R28 /* load the SB */ MOV $boot(SB), R0 B startboot(SB)