Developer Haxxxen over at PSX-Place has discovered a new symbol in Cobra 4.21, which would allow one to mount usb000 at kernel level in stage1.

PS3 veteran Aldostools has ported the symbol to 4.82-4.89, and sent a Pull Request to Evilnat’s Cobra github. According to him, this could allow multiple things that would help push the PS3 hacking scene further, in particular:

• Load fake original firmware or alternative kernel payloads on demand simply by plugging in a USB device.
• Test Cobra / Mamba payloads without the risk of brick / semi-brick.
• Launch custom VSH plugins from USB on Custom Firmware (as USB would be available at boot).
• Maybe it could allow you to read the entire dev_flash from USB.
• Use the flag files on USB for special kernel mode tasks.

Some people also speculate that this could allow loading PS2 ISOs directly from USB (instead of having to load them from memory or hard drive as is currently the case).

You can read more at the PSX-Place forum where scene members are discussing the findings.

Source: Via aldostools