Kyösti Mälkki has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/34976 )
Change subject: cpu/intel/car: Make stack guards more useful on C_ENV_BOOTBLOCK ......................................................................
Patch Set 5:
(1 comment)
https://review.coreboot.org/c/coreboot/+/34976/5/src/cpu/intel/car/romstage.... File src/cpu/intel/car/romstage.c:
https://review.coreboot.org/c/coreboot/+/34976/5/src/cpu/intel/car/romstage.... PS5, Line 43: _car_stack_end
If we can rely on _car_stack_end why wouldn't we utilize _car_stack_start ?
For !C_ENV_BOOTBLOCK case, _car_stack_start is at _car_relocatable_data_end. We want that case to have guard at _car_stack_end - 0x2000 + 256. This file is not used with CAR_GLOBAL_MIGRATION=n, so lzma scratchpad will not be on the stack.