ref: a70a544b800281a1e82c4e4e5f6983171718f046
dir: /sys/src/boot/honeycomb/boot.txt/
mw.b 0x80010000 0x0 0x10000
load ${devtype} ${devnum}:${bootpart} 0x80010000 ${prefix}plan9.ini
load ${devtype} ${devnum}:${bootpart} 0x80100000 ${prefix}9honeycomb.u && bootm 0x80100000