ref: 0d2a10e4416dc7e9d94c8f37e4b0b27ddf2ccc73 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)