The kernel is crashing just after EARLY_PRINTK is switching into initramfs. Also, the same crash occurs in the pcsx2 in the same place. Don't know if this can be debugged further - seems that there is no way to debug what is happening between the vmode switch. Or maybe we should wait until EE-SIO will be implemented.

Also, some notes. Seems that PS3 supports gcont in both modes nicely. Also, PS3 can handle video modes up to 576i/480p.

wiki:
COK-001 found in CECHA & CECHB models of PS3 includes the combined EE+GS chip and PS2 RAMBUS. COK-002 was included in CECHC & CECHE models. It has a few changes, mainly the EE & RAMBUS removed but the GS remaining, the Samsung NAND chips containing the system firmware have moved, and the southbridge is in a smaller package.

This COK-001 came from a CECHA00 system (00 = Japan), the COK-002 came from a CECHC03 system (03 = UK).