From f92c2311ecfc01d70a1bee93adbecd4cf63e165d Mon Sep 17 00:00:00 2001 From: Stefan Reinauer Date: Tue, 15 Mar 2011 16:29:06 -0700 Subject: only update tpm if version if not default value Change-Id: I697de80aa2f0454164cd3651e5a53d06e60a837e BUG=2782 TEST=boot tested Review URL: http://codereview.chromium.org/6677067 (cherry picked from commit 55db6a67176a4933427d2ee556180f6e814f60d9) Review URL: http://codereview.chromium.org/6673067 --- firmware/lib/vboot_kernel.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/firmware/lib/vboot_kernel.c b/firmware/lib/vboot_kernel.c index ee2890cf..3d082679 100644 --- a/firmware/lib/vboot_kernel.c +++ b/firmware/lib/vboot_kernel.c @@ -18,6 +18,7 @@ #include "vboot_common.h" #define KBUF_SIZE 65536 /* Bytes to read at start of kernel partition */ +#define LOWEST_TPM_VERSION 0xffffffff typedef enum BootMode { kBootNormal, /* Normal firmware */ @@ -132,7 +133,7 @@ int LoadKernel(LoadKernelParams* params) { int good_partition = -1; int good_partition_key_block_valid = 0; uint32_t tpm_version = 0; - uint64_t lowest_version = 0xFFFFFFFF; + uint64_t lowest_version = LOWEST_TPM_VERSION; int rec_switch, dev_switch; BootMode boot_mode; uint32_t status; @@ -356,6 +357,10 @@ int LoadKernel(LoadKernelParams* params) { /* Check for lowest version from a valid header. */ if (key_block_valid && lowest_version > combined_version) lowest_version = combined_version; + else { + VBDEBUG(("Key block valid: %d\n", key_block_valid)); + VBDEBUG(("Combined version: %" PRIu64 "\n", combined_version)); + } /* If we already have a good kernel, no need to read another * one; we only needed to look at the versions to check for @@ -482,7 +487,9 @@ int LoadKernel(LoadKernelParams* params) { * mode, the TPM stays PP-unlocked, so anything we write gets blown away * by the firmware when we go back to normal mode. */ VBDEBUG(("Boot_flags = not recovery\n")); - if (lowest_version > tpm_version) { + + if ((lowest_version > tpm_version) && + (lowest_version != LOWEST_TPM_VERSION)) { status = RollbackKernelWrite((uint32_t)lowest_version); if (0 != status) { VBDEBUG(("Error writing kernel versions to TPM.\n")); -- cgit v1.2.1