ref: 73862cb9cf6058273c3ce9c025bde55433306265
dir: /sys/src/boot/reform/boot.txt/
mw.b 0x40010000 0x0 0x10000
load ${devtype} ${devnum}:${bootpart} 0x40010000 ${prefix}plan9.ini
load ${devtype} ${devnum}:${bootpart} 0x40100000 ${prefix}9reform.u && bootm 0x40100000