Boot the kernel directly off a memory card

[frno7]

At the moment, the simplest method to boot the PlayStation 2 Linux kernel is to use uLaunchELF. It would be faster and simpler to boot it directly off a PlayStation 2 memory card (SCPH-10020) accessory.

[sp193]

I am not sure what you were hoping for, but only signed software can be booted from the memory card. And the software will still be booted by the EE kernel, after being located by the browser.

[frno7]

I had the impression that the Free MC Boot was not officially signed, which implied that any kind of software including the Linux kernel could be booted with an appropriate workaround. Are you informed on the details of the Free MC Boot?

[sp193]

It is signed. A really long time ago, it used to be that the FMCB installer would use a vulnerability in MagicGate to embed the FMCB installer within. But the logic remaiks: the software within the boot ROM (the EE and IOP kernels) were designed to only accept signed code from user-writable devices like the memory card. This mechanism that boots FMCB, is the update-booting mechanism.

Even if the Sony MagicGate DRM was not involved, the fact that the EE kernel would still be used to boot the update will still prevent the kernel from being booted directly.

[frno7]

Who signed the Free MC Boot as an update-boot? Is it possible to obtain the capability to sign software? I am rather unfamiliar with the steps and the restrictions of the boot process.

[sp193]

It was an anonymous contribution, from long ago. It is also possible to boot an update from the HDD unit.

Both the EE and IOP share the same boot ROM and reset vector, but the code branches according to the CPUID. Each CPU will boot its own kernel. The EE kernel will boot OSDSYS from ROM, which is the browser. The browser may attempt to locate and boot updates from other devices.

The PPC device that replaced the IOP also seems to share the boot ROM, but it has its own ROM image (DECKARD) at the end of the chip instead.