Furquan Shaikh has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/41155 )
Change subject: soc/intel/common/block/systemagent: Use TOUUD as base for MMIO above 4G ......................................................................
Patch Set 3:
(1 comment)
https://review.coreboot.org/c/coreboot/+/41155/3/src/soc/intel/tigerlake/inc... File src/soc/intel/tigerlake/include/soc/iomap.h:
https://review.coreboot.org/c/coreboot/+/41155/3/src/soc/intel/tigerlake/inc... PS3, Line 79: #define ABOVE_4GB_MEM_BASE_SIZE (256ULL * GiB)
TGL supports 512GiB of address space (39 bits). So size should really be 512GiB - TOUUD.
I was actually wondering about the same thing. How are all these sizes calculated and why are they static? Currently, these are used to set the total size of high MMIO: gnvs->a4gs = ABOVE_4GB_MEM_BASE_SIZE;
which seems wrong.. Shouldn't this be: gnvs->a4gs = cpu_phys_address_size() - gnvs->a4gb;?