intel/fsp2_0: Move temporary RAM to .bss with FSP_USES_CB_STACK
The documentation for StackBase and StackSize in FSPM_ARCH_UPD is
confusing. Previously the region was shared for heap and stack,
starting with FSP2.1 only for heap (or 'temporary RAM') for HOBs.
Moving the allocation outside DCACHE_BSP_STACK_SIZE allows use of
stack guards and reduces amount of reserved CAR for bootblock and
verstage, as the new allocation in .bss is only taken in romstage.
BUG=b:140268415
Change-Id: I4cffcc73a89cb97ab7759dd373196ce9753a6307
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/35233
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
diff --git a/src/drivers/intel/fsp2_0/memory_init.c b/src/drivers/intel/fsp2_0/memory_init.c
index 0797c2e..9789c96 100644
--- a/src/drivers/intel/fsp2_0/memory_init.c
+++ b/src/drivers/intel/fsp2_0/memory_init.c
@@ -34,6 +34,8 @@
#include <fsp/memory_init.h>
#include <types.h>
+static uint8_t temp_ram[CONFIG_FSP_TEMP_RAM_SIZE] __aligned(sizeof(uint64_t));
+
/* TPM MRC hash functionality depends on vboot starting before memory init. */
_Static_assert(!CONFIG(FSP2_0_USES_TPM_MRC_HASH) ||
CONFIG(VBOOT_STARTS_IN_BOOTBLOCK),
@@ -161,6 +163,7 @@
return CB_SUCCESS;
}
+
static enum cb_err setup_fsp_stack_frame(FSPM_ARCH_UPD *arch_upd,
const struct memranges *memmap)
{
@@ -168,17 +171,6 @@
uintptr_t stack_end;
/*
- * FSP 2.1 version would use same stack as coreboot instead of
- * setting up seprate stack frame. FSP 2.1 would not relocate stack
- * top and does not reinitialize stack pointer.
- */
- if (CONFIG(FSP_USES_CB_STACK)) {
- arch_upd->StackBase = (void *)_car_stack_start;
- arch_upd->StackSize = CONFIG_DCACHE_BSP_STACK_SIZE;
- return CB_SUCCESS;
- }
-
- /*
* FSPM_UPD passed here is populated with default values
* provided by the blob itself. We let FSPM use top of CAR
* region of the size it requests.
@@ -197,8 +189,19 @@
bool s3wake, uint32_t fsp_version,
const struct memranges *memmap)
{
- if (setup_fsp_stack_frame(arch_upd, memmap))
+ /*
+ * FSP 2.1 version would use same stack as coreboot instead of
+ * setting up separate stack frame. FSP 2.1 would not relocate stack
+ * top and does not reinitialize stack pointer. The parameters passed
+ * as StackBase and StackSize are actually for temporary RAM and HOBs
+ * and are not related to FSP stack at all.
+ */
+ if (CONFIG(FSP_USES_CB_STACK)) {
+ arch_upd->StackBase = temp_ram;
+ arch_upd->StackSize = sizeof(temp_ram);
+ } else if (setup_fsp_stack_frame(arch_upd, memmap)) {
return CB_ERR;
+ }
fsp_fill_mrc_cache(arch_upd, fsp_version);