cpu compiles, bootcode loops waiting for rkread to be done
Not bad, nearly making it to the boot prompt

setting up...

setup done.

Initializing SD card...initialization done.

rkstep: RKBA: 0 RKWC: 65024 cylinder: 0 sector: 0
rkstep: RKBA: 512 RKWC: 65280 cylinder: 0 sector: 1
HALT
R0 1020 R1 140000 R2 0 R3 0 R4 2020 R5 0 R6 137000 R7 137002
 [kK Z  ]  instr 137000: 114631
panic