coreboot-kgpe-d16/src/security/vboot/gbb.c

78 lines
1.8 KiB
C

/*
* This file is part of the coreboot project.
*
* Copyright 2018 Google LLC
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <commonlib/region.h>
#include <console/console.h>
#include <fmap.h>
#include <gbb_header.h>
#include <security/vboot/gbb.h>
#include <string.h>
#define GBB_FMAP_REGION_NAME "GBB"
/* Copy of GBB header read from boot media. */
static GoogleBinaryBlockHeader gbb_header;
/*
* Read "GBB" region from SPI flash to obtain GBB header and validate
* signature.
*
* Return value:
* Success = 0
* Error = 1
*/
static int gbb_init(void)
{
static bool init_done = false;
struct region_device gbb_rdev;
if (init_done != false)
return 0;
if (fmap_locate_area_as_rdev(GBB_FMAP_REGION_NAME, &gbb_rdev))
return 1;
if (rdev_readat(&gbb_rdev, &gbb_header, 0,
sizeof(GoogleBinaryBlockHeader)) !=
sizeof(GoogleBinaryBlockHeader)) {
printk(BIOS_ERR, "%s: Failure to read GBB header!\n", __func__);
return 1;
}
if (memcmp(gbb_header.signature, GBB_SIGNATURE, GBB_SIGNATURE_SIZE)) {
printk(BIOS_ERR, "%s: Signature check failed!\n", __func__);
return 1;
}
init_done = true;
return 0;
}
uint32_t gbb_get_flags(void)
{
if (gbb_init()) {
printk(BIOS_ERR,
"%s: Failure to initialize GBB. Returning flags as 0!\n",
__func__);
return 0;
}
return gbb_header.flags;
}
bool gbb_is_flag_set(uint32_t flag)
{
return !!(gbb_get_flags() & flag);
}