Change in coreboot[master]: security/intel/txt: Add weak function to skip TXT lockdown

[Arthur Heymans (Code Review)]

Arthur Heymans has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/50236 )

Change subject: security/intel/txt: Add weak function to skip TXT lockdown
......................................................................

security/intel/txt: Add weak function to skip TXT lockdown

RAS error injection requires TXT and other related lockdown steps to
be skipped.

Change-Id: If9193a03be7e1345740ddc705f20dd4d05f3af26
Signed-off-by: Arthur Heymans 
---
M src/security/intel/txt/ramstage.c
M src/security/intel/txt/txt.h
2 files changed, 10 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/36/50236/1

diff --git a/src/security/intel/txt/ramstage.c b/src/security/intel/txt/ramstage.c
index 3401aef..f83193e 100644
--- a/src/security/intel/txt/ramstage.c
+++ b/src/security/intel/txt/ramstage.c
@@ -298,6 +298,11 @@
    push_sinit_heap(&heap_struct, NULL, 0);
 }

+__weak bool skip_intel_txt(void)
+{
+	return false;
+}
+
 /**
  * Finalize the TXT device.
  *
@@ -309,6 +314,9 @@
  */
 static void lockdown_intel_txt(void *unused)
 {
+	if (skip_intel_txt())
+		return;
+
    const uint64_t status = read64((void *)TXT_SPAD);

uint32_t txt_feature_flags = 0;
diff --git a/src/security/intel/txt/txt.h b/src/security/intel/txt/txt.h
index 976cc74..1b9c751 100644
--- a/src/security/intel/txt/txt.h
+++ b/src/security/intel/txt/txt.h
@@ -26,5 +26,7 @@
 void intel_txt_run_sclean(void);
 int intel_txt_run_bios_acm(const u8 input_params);
 bool intel_txt_prepare_txt_env(void);
+/* Allow platform override to skip TXT init, e.g. required for RAS error injection. */
+bool skip_intel_txt(void);

#endif /* SECURITY_INTEL_TXT_H_ */