AFAIK you can't usually replace CPU microcode, as it is signed. Seizing it here, in RW memory, really begs to toy with it: add instructions, edit them. Could you teach your CPU to understand RISC-V?
This is just one random idea. But altering PSP code is also interesting, to use it for your own purposes, or extract encryption keys / make it lie to clients (breaking DRM, for instance).
This is just one random idea. But altering PSP code is also interesting, to use it for your own purposes, or extract encryption keys / make it lie to clients (breaking DRM, for instance).