Julius Werner has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/45418 )
Change subject: sc7180: Add Modem region in memlayout to avoid modem cleanup in Secboot reboot. ......................................................................
Patch Set 2:
(1 comment)
https://review.coreboot.org/c/coreboot/+/45418/1/src/soc/qualcomm/sc7180/mem... File src/soc/qualcomm/sc7180/memlayout.ld:
https://review.coreboot.org/c/coreboot/+/45418/1/src/soc/qualcomm/sc7180/mem... PS1, Line 55: REGION(dram_modem, 0x86000000, 0x8C00000, 0x1000) If this memory is really hard-reserved by the XPUs and any access to it risks hanging the system, we need to also carve it out from the MMU mapping. Otherwise, any random speculative access could hit this and cause an abort.
You need to change src/soc/qualcomm/common/mmu.c to make two mappings for before and behind this range (again, if possible only on SKUs that actually have a modem).