Change in coreboot[master]: smm: Clear SMRAM when debugging

[Raul Rangel (Code Review)]

Raul Rangel has uploaded this change for review. ( https://review.coreboot.org/27227

Change subject: smm: Clear SMRAM when debugging
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smm: Clear SMRAM when debugging

This makes it easier to spot unused RAM.

BUG=b:80539294
TEST=built and tested on grunt. Verified unused memory was set to 0xcdcdcdcd

Change-Id: I335eaf642bd8526f31819eaac95ce80c2df3c300
Signed-off-by: Raul E Rangel 
---
M src/cpu/x86/smm/smm_module_loader.c
1 file changed, 4 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/27/27227/1

diff --git a/src/cpu/x86/smm/smm_module_loader.c b/src/cpu/x86/smm/smm_module_loader.c
index 3d7952f..e92fa05 100644
--- a/src/cpu/x86/smm/smm_module_loader.c
+++ b/src/cpu/x86/smm/smm_module_loader.c
@@ -346,6 +346,10 @@
    if (rmodule_parse(&_binary_smm_start, &smm_mod))
    	return -1;

+	/* Clear SMM region */
+	if (IS_ENABLED(CONFIG_DEBUG_SMI))
+		memset(smram, 0xcd, size);
+
    total_stack_size = params->per_cpu_stack_size *
    		   params->num_concurrent_stacks;