tpm2: add nvmem data to the right segment

Modules in board/cr50/tpm2 are part of the TPM task, and their .bss
segment needs to be wiped out along with other TPM modules' when TPM
is reset.

The only module from this directory which has static variables is
NVMem.c. This patch groups the variables into a structure, and makes
sure that the structure is stored in the part of .bss which is zeroed
when TPM is reset.

BRANCH=none
BUG=none
TEST=verified that TPM wipeout happening during RMA reset is
     successful.

Change-Id: I5f80dc5e4f5f7cdce2d1a1ed59e0fbac354c5bf6
Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/733814
Reviewed-by: Randall Spangler <rspangler@chromium.org>
Reviewed-by: Scott Collyer <scollyer@chromium.org>

1 files changed, 23 insertions, 21 deletions

diff --git a/board/cr50/tpm2/NVMem.c b/board/cr50/tpm2/NVMem.c
index 7874a89e86..7921270fb2 100644
--- a/board/cr50/tpm2/NVMem.c
+++ b/board/cr50/tpm2/NVMem.c
@@ -18,21 +18,22 @@
 #include "nvmem.h"
 
 /* Local state */
+static struct {
 #ifndef CONFIG_FLASH_NVMEM
-static unsigned char s_NV[NV_MEMORY_SIZE];
+	uint8_t s_NV[NV_MEMORY_SIZE];
 #endif
-static BOOL s_NvIsAvailable;
-static BOOL s_NV_unrecoverable;
-static BOOL s_NV_recoverable;
-
+	BOOL s_NvIsAvailable;
+	BOOL s_NV_unrecoverable;
+	BOOL s_NV_recoverable;
+} local_state  __attribute__((section("Tpm2_common.bss")));
 /*
  * This function is used by the simulator to set the error flags in the NV
  * subsystem to simulate an error in the NV loading process.
  */
 void _plat__NvErrors(BOOL recoverable, BOOL unrecoverable)
 {
-	s_NV_unrecoverable = unrecoverable;
-	s_NV_recoverable = recoverable;
+	local_state.s_NV_unrecoverable = unrecoverable;
+	local_state.s_NV_recoverable = recoverable;
 }
 
 /*
@@ -52,8 +53,8 @@ void _plat__NvErrors(BOOL recoverable, BOOL unrecoverable)
  */
 int _plat__NVEnable(void *platParameter)
 {
-	s_NV_unrecoverable = FALSE;
-	s_NV_recoverable = FALSE;
+	local_state.s_NV_unrecoverable = FALSE;
+	local_state.s_NV_recoverable = FALSE;
 
 #ifdef CONFIG_FLASH_NVMEM
 	/* TODO: Need to define what is recoverable and unrecoverable
@@ -63,12 +64,12 @@ int _plat__NVEnable(void *platParameter)
 	 * determines that NvMem is fully erased and configures  a valid
 	 * partition. Setting both variables TRUE if NvMem is not available
 	 */
-	s_NV_recoverable = nvmem_get_error_state() != 0;
-	s_NV_unrecoverable = s_NV_recoverable;
+	local_state.s_NV_recoverable = nvmem_get_error_state() != 0;
+	local_state.s_NV_unrecoverable = local_state.s_NV_recoverable;
 #endif
-	if (s_NV_unrecoverable)
+	if (local_state.s_NV_unrecoverable)
 		return -1;
-	return s_NV_recoverable;
+	return local_state.s_NV_recoverable;
 }
 
 void _plat__NVDisable(void)
@@ -96,10 +97,10 @@ int _plat__IsNvAvailable(void)
 	 * the on chip NvMem area must be in the correct state for NvMem
 	 * to be in 'NV is available' state.
 	 */
-	rv = !s_NvIsAvailable || nvmem_get_error_state();
+	rv = !local_state.s_NvIsAvailable || nvmem_get_error_state();
 	return rv;
 #else
-	if (!s_NvIsAvailable)
+	if (!local_state.s_NvIsAvailable)
 		return 1;
 
 	return 0;
@@ -118,7 +119,7 @@ void _plat__NvMemoryRead(unsigned int startOffset,
 #ifdef CONFIG_FLASH_NVMEM
 	nvmem_read(startOffset, size, data, NVMEM_TPM);
 #else
-	memcpy(data, &s_NV[startOffset], size);
+	memcpy(data, &local_state.s_NV[startOffset], size);
 #endif
 	return;
 }
@@ -135,7 +136,7 @@ _plat__NvIsDifferent(unsigned int startOffset,
 #ifdef CONFIG_FLASH_NVMEM
 	return (nvmem_is_different(startOffset, size, data, NVMEM_TPM) != 0);
 #else
-	return !DCRYPTO_equals(&s_NV[startOffset], data, size);
+	return !DCRYPTO_equals(&local_state.s_NV[startOffset], data, size);
 #endif
 }
 
@@ -153,7 +154,7 @@ void _plat__NvMemoryWrite(unsigned int startOffset,
 #ifdef CONFIG_FLASH_NVMEM
 	nvmem_write(startOffset, size, data, NVMEM_TPM);
 #else
-	memcpy(&s_NV[startOffset], data, size);
+	memcpy(&local_state.s_NV[startOffset], data, size);
 #endif
 }
 
@@ -171,7 +172,8 @@ void _plat__NvMemoryMove(unsigned int sourceOffset,
 	nvmem_move(sourceOffset, destOffset, size, NVMEM_TPM);
 #else
 	/* Move data in RAM */
-	memmove(&s_NV[destOffset], &s_NV[sourceOffset], size);
+	memmove(&local_state.s_NV[destOffset],
+		&local_state.s_NV[sourceOffset], size);
 #endif
 	return;
 }
@@ -199,7 +201,7 @@ int _plat__NvCommit(void)
  */
 void _plat__SetNvAvail(void)
 {
-	s_NvIsAvailable = TRUE;
+	local_state.s_NvIsAvailable = TRUE;
 	return;
 }
 
@@ -209,6 +211,6 @@ void _plat__SetNvAvail(void)
  */
 void _plat__ClearNvAvail(void)
 {
-	s_NvIsAvailable = FALSE;
+	local_state.s_NvIsAvailable = FALSE;
 	return;
 }