Vboot wrapper API - crossystem and header files

Header file changes for wrapper API implementation

Crossystem support for reading recovery reason from VbSharedData, and
explicit support for version 1 VbSharedData structs.

BUG=chromium-os:16970
TEST=make && make runtests; run crossystem on Alex and make sure it still reports recovery_reason in recovery mode.

Change-Id: I15195b899583e425d3c9e8df09842d764528e2cb
Reviewed-on: http://gerrit.chromium.org/gerrit/3203
Reviewed-by: Tom Wai-Hong Tam <waihong@chromium.org>
Reviewed-by: Che-Liang Chiou <clchiou@chromium.org>
Tested-by: Randall Spangler <rspangler@chromium.org>

1 files changed, 25 insertions, 5 deletions

diff --git a/host/arch/x86/lib/crossystem_arch.c b/host/arch/x86/lib/crossystem_arch.c
index 8b320e4b..25867e12 100644
--- a/host/arch/x86/lib/crossystem_arch.c
+++ b/host/arch/x86/lib/crossystem_arch.c
@@ -156,8 +156,7 @@ int VbWriteNvStorage(VbNvContext* vnc) {
  *         deallocating the pointer, this will take care of both the structure
  *         and the buffer. Null in case of error.
  */
-static uint8_t* VbGetBuffer(const char* filename, int* buffer_size)
-{
+static uint8_t* VbGetBuffer(const char* filename, int* buffer_size) {
   FILE* f = NULL;
   char* file_buffer = NULL;
   uint8_t* output_buffer = NULL;
@@ -240,14 +239,24 @@ static uint8_t* VbGetBuffer(const char* filename, int* buffer_size)
 
 
 VbSharedDataHeader* VbSharedDataRead(void) {
-
   VbSharedDataHeader* sh;
   int got_size = 0;
+  int expect_size;
 
   sh = (VbSharedDataHeader*)VbGetBuffer(ACPI_VDAT_PATH, &got_size);
   if (!sh)
     return NULL;
-  if (got_size < sizeof(VbSharedDataHeader)) {
+
+  /* Make sure the size is sufficient for the struct version we got.
+   * Check supported old versions first. */
+  if (1 == sh->struct_version)
+    expect_size = VB_SHARED_DATA_HEADER_SIZE_V1;
+  else {
+    /* There'd better be enough data for the current header size. */
+    expect_size = sizeof(VbSharedDataHeader);
+  }
+
+  if (got_size < expect_size) {
     Free(sh);
     return NULL;
   }
@@ -371,7 +380,18 @@ static const char* VbReadMainFwType(char* dest, int size) {
 
 /* Read the recovery reason.  Returns the reason code or -1 if error. */
 static int VbGetRecoveryReason(void) {
-  int value;
+  VbSharedDataHeader* sh;
+  int value = -1;
+
+  /* Try reading from VbSharedData first */
+  sh = VbSharedDataRead();
+  if (sh) {
+    if (sh->struct_version >= 2)
+      value = sh->recovery_reason;
+    Free(sh);
+    if (-1 != value)
+      return value;
+  }
 
   /* Try reading type from BINF.4 */
   value = ReadFileInt(ACPI_BINF_PATH ".4");