Hello,
On i945 northbridge:
ASSERTION ERROR: file 'src/cpu/x86/smm/tseg_region.c', line 31
can be triggered by some configurations. The assert
ASSERT(IS_ALIGNED(sub_base, sub_size));
tests alignment of SMM base with SMM size. The problem is that IGD stolen memory can offset the SMM base by a smaller size than the SMM size. This causes SMM base to be unaligned. For example:
80000000: 2 GiB Top of RAM, stored in TOLUD 7ff00000: 1 MiB Stolen IGD RAM base, address in BSM 7fd00000: 2 MiB SMM base, defined as SMM size in ESMRAMC
-> 0x7fd00000 is not aligned to SMM size. Probably works for different settings too.
RFC: should the assert from
https://elixir.bootlin.com/coreboot/4.16/source/src/cpu/x86/smm/tseg_region....
be removed, changed or ignored on i945? The correct test should be probably for 1 MiB alignement as the base of stolen IGD memory have [31:20] bits. But I understand the smm_subregion() test is a generic one.
regards, Petr