blob: dd111cd092c71205af967a0ed4fcc142d4416169 [file] [log] [blame]
/* Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*
* High-level firmware wrapper API - entry points for kernel selection
*/
#include "gbb_header.h"
#include "load_kernel_fw.h"
#include "rollback_index.h"
#include "utility.h"
#include "vboot_api.h"
#include "vboot_audio.h"
#include "vboot_common.h"
#include "vboot_display.h"
#include "vboot_nvstorage.h"
/* Global variables */
static VbNvContext vnc;
#ifdef CHROMEOS_ENVIRONMENT
/* Global variable accessors for unit tests */
VbNvContext* VbApiKernelGetVnc(void) {
return &vnc;
}
#endif
/* Set recovery request */
static void VbSetRecoveryRequest(uint32_t recovery_request) {
VBDEBUG(("VbSetRecoveryRequest(%d)\n", (int)recovery_request));
VbNvSet(&vnc, VBNV_RECOVERY_REQUEST, recovery_request);
}
/* Attempt loading a kernel from the specified type(s) of disks. If
* successful, sets p->disk_handle to the disk for the kernel and returns
* VBERROR_SUCCESS.
*
* Returns VBERROR_NO_DISK_FOUND if no disks of the specified type were found.
*
* May return other VBERROR_ codes for other failures. */
uint32_t VbTryLoadKernel(VbCommonParams* cparams, LoadKernelParams* p,
uint32_t get_info_flags) {
VbError_t retval = VBERROR_UNKNOWN;
VbDiskInfo* disk_info = NULL;
uint32_t disk_count = 0;
uint32_t i;
VBDEBUG(("VbTryLoadKernel() start, get_info_flags=0x%x\n",
(unsigned)get_info_flags));
p->disk_handle = NULL;
/* Find disks */
if (VBERROR_SUCCESS != VbExDiskGetInfo(&disk_info, &disk_count,
get_info_flags))
disk_count = 0;
VBDEBUG(("VbTryLoadKernel() found %d disks\n", (int)disk_count));
if (0 == disk_count) {
VbSetRecoveryRequest(VBNV_RECOVERY_RW_NO_DISK);
return VBERROR_NO_DISK_FOUND;
}
/* Loop over disks */
for (i = 0; i < disk_count; i++) {
VBDEBUG(("VbTryLoadKernel() trying disk %d\n", (int)i));
/* Sanity-check what we can. FWIW, VbTryLoadKernel() is always called
* with only a single bit set in get_info_flags
*/
if (512 != disk_info[i].bytes_per_lba || /* cgptlib restriction */
32 > disk_info[i].lba_count || /* ditto */
get_info_flags != disk_info[i].flags) { /* got only what we asked for */
VBDEBUG((" skipping: bytes_per_lba=%Ld lba_count=%Ld flags=0x%x\n",
disk_info[i].bytes_per_lba, disk_info[i].lba_count,
disk_info[i].flags));
continue;
}
p->disk_handle = disk_info[i].handle;
p->bytes_per_lba = disk_info[i].bytes_per_lba;
p->ending_lba = disk_info[i].lba_count - 1;
retval = LoadKernel(p);
VBDEBUG(("VbTryLoadKernel() LoadKernel() returned %d\n", retval));
/* Stop now if we found a kernel */
/* TODO: If recovery requested, should track the farthest we get, instead
* of just returning the value from the last disk attempted. */
if (VBERROR_SUCCESS == retval)
break;
}
/* If we didn't find any good kernels, don't return a disk handle. */
if (VBERROR_SUCCESS != retval) {
VbSetRecoveryRequest(VBNV_RECOVERY_RW_NO_KERNEL);
p->disk_handle = NULL;
}
VbExDiskFreeInfo(disk_info, p->disk_handle);
/* Pass through return code. Recovery reason (if any) has already been set
* by LoadKernel(). */
return retval;
}
/* Ask the user to confirm something. We should display whatever the question
* is first, then call this. ESC is always "no", ENTER is always "yes", and
* we'll specify what SPACE means. We don't return until one of those keys is
* pressed, or until asked to shut down.
*
* Returns: 1=yes, 0=no, -1 = shutdown.
*/
static int VbUserConfirms(VbCommonParams* cparams, int space_means_no) {
uint32_t key;
VBDEBUG(("Entering %s(%d)\n", __func__, space_means_no));
/* Await further instructions */
while (1) {
if (VbExIsShutdownRequested())
return -1;
key = VbExKeyboardRead();
switch (key) {
case '\r':
VBDEBUG(("%s() - Yes (1)\n", __func__));
return 1;
break;
case ' ':
VBDEBUG(("%s() - Space (%s)\n", __func__, space_means_no));
if (space_means_no)
return 0;
break;
case 0x1b:
VBDEBUG(("%s() - No (0)\n", __func__));
return 0;
break;
default:
VbCheckDisplayKey(cparams, key, &vnc);
}
VbExSleepMs(1000);
}
/* not reached, but compiler will complain without it */
return -1;
}
/* Handle a normal boot. */
VbError_t VbBootNormal(VbCommonParams* cparams, LoadKernelParams* p) {
/* Boot from fixed disk only */
VBDEBUG(("Entering %s()\n", __func__));
return VbTryLoadKernel(cparams, p, VB_DISK_FLAG_FIXED);
}
/* Handle a developer-mode boot */
VbError_t VbBootDeveloper(VbCommonParams* cparams, LoadKernelParams* p) {
GoogleBinaryBlockHeader* gbb = (GoogleBinaryBlockHeader*)cparams->gbb_data;
VbSharedDataHeader* shared = (VbSharedDataHeader*)cparams->shared_data_blob;
uint32_t allow_usb = 0;
VbAudioContext* audio = 0;
VBDEBUG(("Entering %s()\n", __func__));
/* Check if USB booting is allowed */
VbNvGet(&vnc, VBNV_DEV_BOOT_USB, &allow_usb);
/* Handle GBB flag override */
if (gbb->flags & GBB_FLAG_FORCE_DEV_BOOT_USB)
allow_usb = 1;
/* Show the dev mode warning screen */
VbDisplayScreen(cparams, VB_SCREEN_DEVELOPER_WARNING, 0, &vnc);
/* Get audio/delay context */
audio = VbAudioOpen(cparams);
/* We'll loop until we finish the delay or are interrupted */
do {
uint32_t key;
if (VbExIsShutdownRequested()) {
VBDEBUG(("VbBootDeveloper() - shutdown is requested!\n"));
VbAudioClose(audio);
return VBERROR_SHUTDOWN_REQUESTED;
}
key = VbExKeyboardRead();
switch (key) {
case 0:
/* nothing pressed */
break;
case '\r':
/* Enter only disables the virtual dev switch if allowed by GBB */
if (!(gbb->flags & GBB_FLAG_ENTER_TRIGGERS_TONORM))
break;
case ' ':
/* See if we should disable the virtual dev-mode switch. */
VBDEBUG(("%s shared->flags=0x%x\n", __func__, shared->flags));
if (shared->flags & VBSD_HONOR_VIRT_DEV_SWITCH &&
shared->flags & VBSD_BOOT_DEV_SWITCH_ON) {
VbAudioClose(audio); /* Stop the countdown while we go ask... */
VbDisplayScreen(cparams, VB_SCREEN_DEVELOPER_TO_NORM, 0, &vnc);
switch (VbUserConfirms(cparams, 0)) { /* Ignore space */
case 1:
VBDEBUG(("%s() - leaving dev-mode...\n", __func__));
VbNvSet(&vnc, VBNV_DISABLE_DEV_REQUEST, 1);
VbDisplayScreen(cparams, VB_SCREEN_TO_NORM_CONFIRMED, 0, &vnc);
VbExSleepMs(5000);
return VBERROR_TPM_REBOOT_REQUIRED;
case -1:
VBDEBUG(("%s() - shutdown requested\n", __func__));
return VBERROR_SHUTDOWN_REQUESTED;
default: /* stay in dev-mode */
VBDEBUG(("%s() - stay in dev-mode\n", __func__));
VbDisplayScreen(cparams, VB_SCREEN_DEVELOPER_WARNING, 0, &vnc);
audio = VbAudioOpen(cparams); /* Start new countdown */
}
} else {
/* No virtual dev-mode switch, so go directly to recovery mode */
VBDEBUG(("%s() - going to recovery\n", __func__));
VbSetRecoveryRequest(VBNV_RECOVERY_RW_DEV_SCREEN);
VbAudioClose(audio);
return VBERROR_LOAD_KERNEL_RECOVERY;
}
break;
case 0x04:
/* Ctrl+D = dismiss warning; advance to timeout */
VBDEBUG(("VbBootDeveloper() - user pressed Ctrl+D; skip delay\n"));
goto fallout;
break;
/* The Ctrl-Enter is special for Lumpy test purpose. */
case VB_KEY_CTRL_ENTER:
case 0x15:
/* Ctrl+U = try USB boot, or beep if failure */
VBDEBUG(("VbBootDeveloper() - user pressed Ctrl+U; try USB\n"));
if (!allow_usb) {
VBDEBUG(("VbBootDeveloper() - USB booting is disabled\n"));
VbExBeep(120, 400);
VbExSleepMs(120);
VbExBeep(120, 400);
} else {
/* Clear the screen to show we get the Ctrl+U key press. */
VbDisplayScreen(cparams, VB_SCREEN_BLANK, 0, &vnc);
if (VBERROR_SUCCESS ==
VbTryLoadKernel(cparams, p, VB_DISK_FLAG_REMOVABLE)) {
VBDEBUG(("VbBootDeveloper() - booting USB\n"));
VbAudioClose(audio);
return VBERROR_SUCCESS;
} else {
VBDEBUG(("VbBootDeveloper() - no kernel found on USB\n"));
VbExBeep(250, 200);
VbExSleepMs(120);
/* Clear recovery requests from failed kernel loading, so
* that powering off at this point doesn't put us into
* recovery mode. */
VbSetRecoveryRequest(VBNV_RECOVERY_NOT_REQUESTED);
/* Show the dev mode warning screen again */
VbDisplayScreen(cparams, VB_SCREEN_DEVELOPER_WARNING, 0, &vnc);
}
}
break;
default:
VBDEBUG(("VbBootDeveloper() - pressed key %d\n", key));
VbCheckDisplayKey(cparams, key, &vnc);
break;
}
} while( VbAudioLooping(audio) );
fallout:
/* Timeout or Ctrl+D; attempt loading from fixed disk */
VBDEBUG(("VbBootDeveloper() - trying fixed disk\n"));
VbAudioClose(audio);
return VbTryLoadKernel(cparams, p, VB_DISK_FLAG_FIXED);
}
/* Delay between disk checks in recovery mode */
#define REC_DELAY_INCREMENT 250
/* Handle a recovery-mode boot */
VbError_t VbBootRecovery(VbCommonParams* cparams, LoadKernelParams* p) {
VbSharedDataHeader* shared = (VbSharedDataHeader*)cparams->shared_data_blob;
uint32_t retval;
uint32_t key;
int i;
VBDEBUG(("VbBootRecovery() start\n"));
/* If the dev-mode switch is off and the user didn't press the recovery
* button, require removal of all external media. */
if (!(shared->flags & VBSD_BOOT_DEV_SWITCH_ON) &&
!(shared->flags & VBSD_BOOT_REC_SWITCH_ON)) {
VbDiskInfo* disk_info = NULL;
uint32_t disk_count = 0;
VBDEBUG(("VbBootRecovery() forcing device removal\n"));
while (1) {
if (VBERROR_SUCCESS != VbExDiskGetInfo(&disk_info, &disk_count,
VB_DISK_FLAG_REMOVABLE))
disk_count = 0;
VbExDiskFreeInfo(disk_info, NULL);
if (0 == disk_count) {
VbDisplayScreen(cparams, VB_SCREEN_BLANK, 0, &vnc);
break;
}
VBDEBUG(("VbBootRecovery() waiting for %d disks to be removed\n",
(int)disk_count));
VbDisplayScreen(cparams, VB_SCREEN_RECOVERY_REMOVE, 0, &vnc);
/* Scan keyboard more frequently than media, since x86 platforms
* don't like to scan USB too rapidly. */
for (i = 0; i < 4; i++) {
VbCheckDisplayKey(cparams, VbExKeyboardRead(), &vnc);
if (VbExIsShutdownRequested())
return VBERROR_SHUTDOWN_REQUESTED;
VbExSleepMs(REC_DELAY_INCREMENT);
}
}
}
/* Loop and wait for a recovery image */
while (1) {
VBDEBUG(("VbBootRecovery() attempting to load kernel\n"));
retval = VbTryLoadKernel(cparams, p, VB_DISK_FLAG_REMOVABLE);
/* Clear recovery requests from failed kernel loading, since we're
* already in recovery mode. Do this now, so that powering off after
* inserting an invalid disk doesn't leave us stuck in recovery mode. */
VbSetRecoveryRequest(VBNV_RECOVERY_NOT_REQUESTED);
if (VBERROR_SUCCESS == retval)
break; /* Found a recovery kernel */
VbDisplayScreen(cparams, VBERROR_NO_DISK_FOUND == retval ?
VB_SCREEN_RECOVERY_INSERT : VB_SCREEN_RECOVERY_NO_GOOD,
0, &vnc);
/* Scan keyboard more frequently than media, since x86 platforms don't like
* to scan USB too rapidly. */
for (i = 0; i < 4; i++) {
key = VbExKeyboardRead();
/* We might want to enter dev-mode from the Insert screen if... */
if (key == 0x04 && /* user pressed Ctrl-D */
shared->flags & VBSD_HONOR_VIRT_DEV_SWITCH && /* we can do that */
!(shared->flags & VBSD_BOOT_DEV_SWITCH_ON) && /* not in dev-mode */
(shared->flags & VBSD_BOOT_REC_SWITCH_ON) && /* user forced rec */
VbExTrustEC()) { /* EC isn't pwned */
/* Ask the user to confirm entering dev-mode */
VbDisplayScreen(cparams, VB_SCREEN_RECOVERY_TO_DEV, 0, &vnc);
switch (VbUserConfirms(cparams, 1)) { /* SPACE means no */
case 1:
VBDEBUG(("%s() - Enabling dev-mode...\n", __func__));
if (TPM_SUCCESS != SetVirtualDevMode(1))
return VBERROR_TPM_SET_BOOT_MODE_STATE;
VBDEBUG(("%s() - Reboot so it will take effect\n", __func__));
return VBERROR_TPM_REBOOT_REQUIRED;
case -1:
VBDEBUG(("%s() - Shutdown requested\n", __func__));
return VBERROR_SHUTDOWN_REQUESTED;
default: /* zero, actually */
VBDEBUG(("%s() - Not enabling dev-mode\n", __func__));
/* Jump out of the outer loop to refresh the display quickly. */
i = 4;
break;
}
} else
VbCheckDisplayKey(cparams, key, &vnc);
if (VbExIsShutdownRequested())
return VBERROR_SHUTDOWN_REQUESTED;
VbExSleepMs(REC_DELAY_INCREMENT);
}
}
return VBERROR_SUCCESS;
}
/* Wrapper around VbExEcProtectRW() which sets recovery reason on error */
static VbError_t EcProtectRW(void) {
int rv = VbExEcProtectRW();
if (rv == VBERROR_EC_REBOOT_TO_RO_REQUIRED) {
VBDEBUG(("VbExEcProtectRW() needs reboot\n"));
} else if (rv != VBERROR_SUCCESS) {
VBDEBUG(("VbExEcProtectRW() returned %d\n", rv));
VbSetRecoveryRequest(VBNV_RECOVERY_EC_PROTECT);
}
return rv;
}
VbError_t VbEcSoftwareSync(VbCommonParams* cparams) {
VbSharedDataHeader* shared = (VbSharedDataHeader*)cparams->shared_data_blob;
int in_rw = 0;
int rv;
const uint8_t *ec_hash;
int ec_hash_size;
const uint8_t *expected;
int expected_size;
uint8_t expected_hash[SHA256_DIGEST_SIZE];
int need_update;
int i;
/* Determine whether the EC is in RO or RW */
rv = VbExEcRunningRW(&in_rw);
if (shared->recovery_reason) {
/* Recovery mode; just verify the EC is in RO code */
if (rv == VBERROR_SUCCESS && in_rw == 1) {
/* EC is definitely in RW firmware. We want it in read-only code, so
* preserve the current recovery reason and reboot.
*
* We don't reboot on error or unknown EC code, because we could end
* up in an endless reboot loop. If we had some way to track that we'd
* already rebooted for this reason, we could retry only once. */
VBDEBUG(("VbEcSoftwareSync() - want recovery but got EC-RW\n"));
VbSetRecoveryRequest(shared->recovery_reason);
return VBERROR_EC_REBOOT_TO_RO_REQUIRED;
}
VBDEBUG(("VbEcSoftwareSync() in recovery; EC-RO\n"));
return VBERROR_SUCCESS;
}
/* Not in recovery. If we couldn't determine where the EC was,
* reboot to recovery. */
if (rv != VBERROR_SUCCESS) {
VBDEBUG(("VbEcSoftwareSync() - VbEcSoftwareSync() returned %d\n", rv));
VbSetRecoveryRequest(VBNV_RECOVERY_EC_UNKNOWN_IMAGE);
return VBERROR_EC_REBOOT_TO_RO_REQUIRED;
}
/* If AP is read-only normal, EC should be in its RO code also. */
if (shared->flags & VBSD_LF_USE_RO_NORMAL) {
/* If EC is in RW code, request reboot back to RO */
if (in_rw == 1) {
VBDEBUG(("VbEcSoftwareSync() - want RO-normal but got EC-RW\n"));
return VBERROR_EC_REBOOT_TO_RO_REQUIRED;
}
/* Protect the RW flash and stay in EC-RO */
rv = EcProtectRW();
if (rv != VBERROR_SUCCESS)
return rv;
rv = VbExEcStayInRO();
if (rv != VBERROR_SUCCESS) {
VBDEBUG(("VbEcSoftwareSync() - VbExEcStayInRO() returned %d\n", rv));
VbSetRecoveryRequest(VBNV_RECOVERY_EC_SOFTWARE_SYNC);
return VBERROR_EC_REBOOT_TO_RO_REQUIRED;
}
VBDEBUG(("VbEcSoftwareSync() in RO-Normal; EC-RO\n"));
/* If shutdown is requested, just power the AP back off. This covers the
* case where the lid is closed when then system boots. */
if (VbExIsShutdownRequested()) {
VBDEBUG(("VbEcSoftwareSync() sees shutdown-requested\n"));
return VBERROR_SHUTDOWN_REQUESTED;
}
return VBERROR_SUCCESS;
}
/* Get hash of EC-RW */
rv = VbExEcHashRW(&ec_hash, &ec_hash_size);
if (rv) {
VBDEBUG(("VbEcSoftwareSync() - VbExEcHashRW() returned %d\n", rv));
VbSetRecoveryRequest(VBNV_RECOVERY_EC_HASH_FAILED);
return VBERROR_EC_REBOOT_TO_RO_REQUIRED;
}
if (ec_hash_size != SHA256_DIGEST_SIZE) {
VBDEBUG(("VbEcSoftwareSync() - VbExEcHashRW() says size %d, not %d\n",
ec_hash_size, SHA256_DIGEST_SIZE));
VbSetRecoveryRequest(VBNV_RECOVERY_EC_HASH_SIZE);
return VBERROR_EC_REBOOT_TO_RO_REQUIRED;
}
VBDEBUG(("EC hash:"));
for (i = 0; i < SHA256_DIGEST_SIZE; i++)
VBDEBUG(("%02x", ec_hash[i]));
VBDEBUG(("\n"));
/* Get expected EC-RW code. Note that we've already checked for RO_NORMAL,
* so we know that the BIOS must be RW-A or RW-B, and therefore the EC must
* match. */
rv = VbExEcGetExpectedRW(
shared->firmware_index ? VB_SELECT_FIRMWARE_B : VB_SELECT_FIRMWARE_A,
&expected, &expected_size);
if (rv) {
VBDEBUG(("VbEcSoftwareSync() - VbExEcGetExpectedRW() returned %d\n", rv));
VbSetRecoveryRequest(VBNV_RECOVERY_EC_EXPECTED_IMAGE);
return VBERROR_EC_REBOOT_TO_RO_REQUIRED;
}
VBDEBUG(("VbEcSoftwareSync() - expected len = %d\n", expected_size));
/* Hash expected code */
internal_SHA256(expected, expected_size, expected_hash);
VBDEBUG(("Expected hash:"));
for (i = 0; i < SHA256_DIGEST_SIZE; i++)
VBDEBUG(("%02x", expected_hash[i]));
VBDEBUG(("\n"));
need_update = SafeMemcmp(ec_hash, expected_hash, SHA256_DIGEST_SIZE);
/* TODO: GBB flag to override whether we need update; needed for EC
* development */
if (in_rw) {
if (need_update) {
/* EC is running the wrong RW code. Reboot the EC to RO so we can update
* it on the next boot. */
VBDEBUG(("VbEcSoftwareSync() - in RW, need to update RW, so reboot\n"));
return VBERROR_EC_REBOOT_TO_RO_REQUIRED;
}
VBDEBUG(("VbEcSoftwareSync() in EC-RW and it matches\n"));
return VBERROR_SUCCESS;
}
/* Update EC if necessary */
if (need_update) {
VBDEBUG(("VbEcSoftwareSync() updating EC-RW...\n"));
if (shared->flags & VBSD_EC_SLOW_UPDATE) {
VBDEBUG(("VbEcSoftwareSync() - EC is slow. Show WAIT screen.\n"));
/* FIXME(crosbug.com/p/12257): Ensure the VGA Option ROM is loaded! */
VbDisplayScreen(cparams, VB_SCREEN_WAIT, 0, &vnc);
}
rv = VbExEcUpdateRW(expected, expected_size);
if (rv == VBERROR_EC_REBOOT_TO_RO_REQUIRED) {
/* Reboot required. May need to unprotect RW before updating,
* or may need to reboot after RW updated. Either way, it's not
* an error requiring recovery mode. */
VBDEBUG(("VbEcSoftwareSync() - VbExEcUpdateRW() needs reboot\n"));
return rv;
} else if (rv != VBERROR_SUCCESS) {
VBDEBUG(("VbEcSoftwareSync() - VbExEcUpdateRW() returned %d\n", rv));
VbSetRecoveryRequest(VBNV_RECOVERY_EC_UPDATE);
return VBERROR_EC_REBOOT_TO_RO_REQUIRED;
}
/*
* TODO: should ask EC to recompute its hash to verify it's correct
* before continuing?
*/
}
/* Protect EC-RW flash */
rv = EcProtectRW();
if (rv != VBERROR_SUCCESS)
return rv;
/* Tell EC to jump to its RW code */
VBDEBUG(("VbEcSoftwareSync() jumping to EC-RW\n"));
rv = VbExEcJumpToRW();
if (rv != VBERROR_SUCCESS) {
VBDEBUG(("VbEcSoftwareSync() - VbExEcJumpToRW() returned %d\n", rv));
VbSetRecoveryRequest(VBNV_RECOVERY_EC_JUMP_RW);
return VBERROR_EC_REBOOT_TO_RO_REQUIRED;
}
VBDEBUG(("VbEcSoftwareSync() in RW; done\n"));
/* If shutdown is requested, just power the AP back off. This covers the
* case where the lid is closed when then system boots. */
if (VbExIsShutdownRequested()) {
VBDEBUG(("VbEcSoftwareSync() sees shutdown-requested\n"));
return VBERROR_SHUTDOWN_REQUESTED;
}
return VBERROR_SUCCESS;
}
VbError_t VbSelectAndLoadKernel(VbCommonParams* cparams,
VbSelectAndLoadKernelParams* kparams) {
VbSharedDataHeader* shared = (VbSharedDataHeader*)cparams->shared_data_blob;
VbError_t retval = VBERROR_SUCCESS;
LoadKernelParams p;
uint32_t tpm_status = 0;
/* Start timer */
shared->timer_vb_select_and_load_kernel_enter = VbExGetTimer();
VbExNvStorageRead(vnc.raw);
VbNvSetup(&vnc);
/* Clear output params in case we fail */
kparams->disk_handle = NULL;
kparams->partition_number = 0;
kparams->bootloader_address = 0;
kparams->bootloader_size = 0;
Memset(kparams->partition_guid, 0, sizeof(kparams->partition_guid));
/* Do EC software sync if necessary */
if (shared->flags & VBSD_EC_SOFTWARE_SYNC) {
retval = VbEcSoftwareSync(cparams);
if (retval != VBERROR_SUCCESS)
goto VbSelectAndLoadKernel_exit;
}
/* Read the kernel version from the TPM. Ignore errors in recovery mode. */
tpm_status = RollbackKernelRead(&shared->kernel_version_tpm);
if (0 != tpm_status) {
VBDEBUG(("Unable to get kernel versions from TPM\n"));
if (!shared->recovery_reason) {
VbSetRecoveryRequest(VBNV_RECOVERY_RW_TPM_R_ERROR);
retval = VBERROR_TPM_READ_KERNEL;
goto VbSelectAndLoadKernel_exit;
}
}
shared->kernel_version_tpm_start = shared->kernel_version_tpm;
/* Fill in params for calls to LoadKernel() */
Memset(&p, 0, sizeof(p));
p.shared_data_blob = cparams->shared_data_blob;
p.shared_data_size = cparams->shared_data_size;
p.gbb_data = cparams->gbb_data;
p.gbb_size = cparams->gbb_size;
/*
* this could be set to NULL, in which case the vboot header information
* about the load address and size will be used
*/
p.kernel_buffer = kparams->kernel_buffer;
p.kernel_buffer_size = kparams->kernel_buffer_size;
p.nv_context = &vnc;
p.boot_flags = 0;
if (shared->flags & VBSD_BOOT_DEV_SWITCH_ON)
p.boot_flags |= BOOT_FLAG_DEVELOPER;
/* Handle separate normal and developer firmware builds. */
#if defined(VBOOT_FIRMWARE_TYPE_NORMAL)
/* Normal-type firmware always acts like the dev switch is off. */
p.boot_flags &= ~BOOT_FLAG_DEVELOPER;
#elif defined(VBOOT_FIRMWARE_TYPE_DEVELOPER)
/* Developer-type firmware fails if the dev switch is off. */
if (!(p.boot_flags & BOOT_FLAG_DEVELOPER)) {
/* Dev firmware should be signed with a key that only verifies
* when the dev switch is on, so we should never get here. */
VBDEBUG(("Developer firmware called with dev switch off!\n"));
VbSetRecoveryRequest(VBNV_RECOVERY_RW_DEV_MISMATCH);
retval = VBERROR_DEV_FIRMWARE_SWITCH_MISMATCH;
goto VbSelectAndLoadKernel_exit;
}
#else
/* Recovery firmware, or merged normal+developer firmware. No
* need to override flags. */
#endif
/* Select boot path */
if (shared->recovery_reason) {
/* Recovery boot */
p.boot_flags |= BOOT_FLAG_RECOVERY;
retval = VbBootRecovery(cparams, &p);
VbDisplayScreen(cparams, VB_SCREEN_BLANK, 0, &vnc);
} else if (p.boot_flags & BOOT_FLAG_DEVELOPER) {
/* Developer boot */
retval = VbBootDeveloper(cparams, &p);
VbDisplayScreen(cparams, VB_SCREEN_BLANK, 0, &vnc);
} else {
/* Normal boot */
retval = VbBootNormal(cparams, &p);
if ((1 == shared->firmware_index) && (shared->flags & VBSD_FWB_TRIED)) {
/* Special cases for when we're trying a new firmware B. These are
* needed because firmware updates also usually change the kernel key,
* which means that the B firmware can only boot a new kernel, and the
* old firmware in A can only boot the previous kernel. */
/* Don't advance the TPM if we're trying a new firmware B, because we
* don't yet know if the new kernel will successfully boot. We still
* want to be able to fall back to the previous firmware+kernel if the
* new firmware+kernel fails. */
/* If we found only invalid kernels, reboot and try again. This allows
* us to fall back to the previous firmware+kernel instead of giving up
* and going to recovery mode right away. We'll still go to recovery
* mode if we run out of tries and the old firmware can't find a kernel
* it likes. */
if (VBERROR_INVALID_KERNEL_FOUND == retval) {
VBDEBUG(("Trying firmware B, and only found invalid kernels.\n"));
VbSetRecoveryRequest(VBNV_RECOVERY_NOT_REQUESTED);
goto VbSelectAndLoadKernel_exit;
}
} else {
/* Not trying a new firmware B. */
/* See if we need to update the TPM. */
VBDEBUG(("Checking if TPM kernel version needs advancing\n"));
if (shared->kernel_version_tpm > shared->kernel_version_tpm_start) {
tpm_status = RollbackKernelWrite(shared->kernel_version_tpm);
if (0 != tpm_status) {
VBDEBUG(("Error writing kernel versions to TPM.\n"));
VbSetRecoveryRequest(VBNV_RECOVERY_RW_TPM_W_ERROR);
retval = VBERROR_TPM_WRITE_KERNEL;
goto VbSelectAndLoadKernel_exit;
}
}
}
}
if (VBERROR_SUCCESS != retval)
goto VbSelectAndLoadKernel_exit;
/* Save disk parameters */
kparams->disk_handle = p.disk_handle;
kparams->partition_number = (uint32_t)p.partition_number;
kparams->bootloader_address = p.bootloader_address;
kparams->bootloader_size = (uint32_t)p.bootloader_size;
Memcpy(kparams->partition_guid, p.partition_guid,
sizeof(kparams->partition_guid));
/* Lock the kernel versions. Ignore errors in recovery mode. */
tpm_status = RollbackKernelLock();
if (0 != tpm_status) {
VBDEBUG(("Error locking kernel versions.\n"));
if (!shared->recovery_reason) {
VbSetRecoveryRequest(VBNV_RECOVERY_RW_TPM_L_ERROR);
retval = VBERROR_TPM_LOCK_KERNEL;
goto VbSelectAndLoadKernel_exit;
}
}
VbSelectAndLoadKernel_exit:
VbNvTeardown(&vnc);
if (vnc.raw_changed)
VbExNvStorageWrite(vnc.raw);
/* Stop timer */
shared->timer_vb_select_and_load_kernel_exit = VbExGetTimer();
kparams->kernel_buffer = p.kernel_buffer;
kparams->kernel_buffer_size = p.kernel_buffer_size;
VBDEBUG(("VbSelectAndLoadKernel() returning %d\n", (int)retval));
/* Pass through return value from boot path */
return retval;
}