Yabause-PSP's me.prx ORs 0xA0000000 onto its own addresses to share a
buffer with the ME uncached, which is 0xA8xxxxxx for a module in kernel
RAM. The main CPU's space has no views there, so it crashed.
All of kernel segment 1 (0xA0000000-0xBFFFFFFF) now counts as MMIO, and a
device below the hardware registers maps RAM and VRAM onto their uncached
mirrors at 0x40000000. The main CPU's native kernel loads and stores send
the whole segment to that path; the ME keeps 0xBC000000 as the boundary,
since its space maps the rest.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>