/* Copyright (c) 2013 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 "sysincludes.h"
#include "gbb_access.h"
#include "gbb_header.h"
#include "load_kernel_fw.h"
#include "region.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_kernel.h"
#include "vboot_nvstorage.h"
/* Global variables */
static VbNvContext vnc;
#ifdef CHROMEOS_ENVIRONMENT
/* Global variable accessor for unit tests */
VbNvContext *VbApiKernelGetVnc(void)
{
return &vnc;
}
#endif
/**
* Set recovery request (called from vboot_api_kernel.c functions only)
*/
static void VbSetRecoveryRequest(uint32_t recovery_request)
{
VBDEBUG(("VbSetRecoveryRequest(%d)\n", (int)recovery_request));
VbNvSet(&vnc, VBNV_RECOVERY_REQUEST, recovery_request);
}
/**
* Checks GBB flags against VbExIsShutdownRequested() shutdown request to
* determine if a shutdown is required.
*
* Returns true if a shutdown is required and false if no shutdown is required.
*/
static int VbWantShutdown(uint32_t gbb_flags)
{
uint32_t shutdown_request = VbExIsShutdownRequested();
/* If desired, ignore shutdown request due to lid closure. */
if (gbb_flags & GBB_FLAG_DISABLE_LID_SHUTDOWN)
shutdown_request &= ~VB_SHUTDOWN_REQUEST_LID_CLOSED;
return !!shutdown_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.
*
* Ensure 512-byte sectors and non-trivially sized disk (for
* cgptlib) and that we got a partition with only the flags we
* asked for.
*/
if (512 != disk_info[i].bytes_per_lba ||
16 > disk_info[i].lba_count ||
get_info_flags != (disk_info[i].flags & ~VB_DISK_FLAG_EXTERNAL_GPT)) {
VBDEBUG((" skipping: bytes_per_lba=%" PRIu64
" lba_count=%" PRIu64 " 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->gpt_lba_count = disk_info[i].lba_count;
p->streaming_lba_count = disk_info[i].streaming_lba_count
?: p->gpt_lba_count;
p->boot_flags |= disk_info[i].flags & VB_DISK_FLAG_EXTERNAL_GPT
? BOOT_FLAG_EXTERNAL_GPT : 0;
retval = LoadKernel(p, cparams);
VBDEBUG(("VbTryLoadKernel() LoadKernel() = %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;
}
#define CONFIRM_KEY_DELAY 20 /* Check confirm screen keys every 20ms */
int VbUserConfirms(VbCommonParams *cparams, uint32_t confirm_flags)
{
VbSharedDataHeader *shared =
(VbSharedDataHeader *)cparams->shared_data_blob;
uint32_t key;
uint32_t key_flags;
uint32_t button;
int rec_button_was_pressed = 0;
VBDEBUG(("Entering %s(0x%x)\n", __func__, confirm_flags));
/* Await further instructions */
while (1) {
if (VbWantShutdown(cparams->gbb->flags))
return -1;
key = VbExKeyboardReadWithFlags(&key_flags);
button = VbExGetSwitches(VB_INIT_FLAG_REC_BUTTON_PRESSED);
switch (key) {
case '\r':
/* If we require a trusted keyboard for confirmation,
* but the keyboard may be faked (for instance, a USB
* device), beep and keep waiting.
*/
if (confirm_flags & VB_CONFIRM_MUST_TRUST_KEYBOARD &&
!(key_flags & VB_KEY_FLAG_TRUSTED_KEYBOARD)) {
VbExBeep(120, 400);
break;
}
VBDEBUG(("%s() - Yes (1)\n", __func__));
return 1;
break;
case ' ':
VBDEBUG(("%s() - Space (%d)\n", __func__,
confirm_flags & VB_CONFIRM_SPACE_MEANS_NO));
if (confirm_flags & VB_CONFIRM_SPACE_MEANS_NO)
return 0;
break;
case 0x1b:
VBDEBUG(("%s() - No (0)\n", __func__));
return 0;
break;
default:
/* If the recovery button is physical, and is pressed,
* this is also a YES, but must wait for release.
*/
if (!(shared->flags & VBSD_BOOT_REC_SWITCH_VIRTUAL)) {
if (button) {
VBDEBUG(("%s() - Rec button pressed\n",
__func__));
rec_button_was_pressed = 1;
} else if (rec_button_was_pressed) {
VBDEBUG(("%s() - Rec button (1)\n",
__func__));
return 1;
}
}
VbCheckDisplayKey(cparams, key, &vnc);
}
VbExSleepMs(CONFIRM_KEY_DELAY);
}
/* Not reached, but compiler will complain without it */
return -1;
}
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);
}
VbError_t VbBootDeveloper(VbCommonParams *cparams, LoadKernelParams *p)
{
GoogleBinaryBlockHeader *gbb = cparams->gbb;
VbSharedDataHeader *shared =
(VbSharedDataHeader *)cparams->shared_data_blob;
uint32_t allow_usb = 0, allow_legacy = 0, ctrl_d_pressed = 0;
VbAudioContext *audio = 0;
VBDEBUG(("Entering %s()\n", __func__));
/* Check if USB booting is allowed */
VbNvGet(&vnc, VBNV_DEV_BOOT_USB, &allow_usb);
VbNvGet(&vnc, VBNV_DEV_BOOT_LEGACY, &allow_legacy);
/* Handle GBB flag override */
if (gbb->flags & GBB_FLAG_FORCE_DEV_BOOT_USB)
allow_usb = 1;
if (gbb->flags & GBB_FLAG_FORCE_DEV_BOOT_LEGACY)
allow_legacy = 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 (VbWantShutdown(gbb->flags)) {
VBDEBUG(("VbBootDeveloper() - shutdown requested!\n"));
VbAudioClose(audio);
return VBERROR_SHUTDOWN_REQUESTED;
}
key = VbExKeyboardRead();
switch (key) {
case 0:
/* nothing pressed */
break;
case '\r':
/* Only disable virtual dev switch if allowed by GBB */
if (!(gbb->flags & GBB_FLAG_ENTER_TRIGGERS_TONORM))
break;
case ' ':
/* See if we should disable 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) {
/* Stop the countdown while we go ask... */
VbAudioClose(audio);
if (gbb->flags & GBB_FLAG_FORCE_DEV_SWITCH_ON) {
/*
* TONORM won't work (only for
* non-shipping devices).
*/
VBDEBUG(("%s() - TONORM rejected by "
"FORCE_DEV_SWITCH_ON\n",
__func__));
VbExDisplayDebugInfo(
"WARNING: TONORM prohibited by "
"GBB FORCE_DEV_SWITCH_ON.\n\n");
VbExBeep(120, 400);
break;
}
VbDisplayScreen(cparams,
VB_SCREEN_DEVELOPER_TO_NORM,
0, &vnc);
/* Ignore space in VbUserConfirms()... */
switch (VbUserConfirms(cparams, 0)) {
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);
/* Start new countdown */
audio = VbAudioOpen(cparams);
}
} 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"));
ctrl_d_pressed = 1;
goto fallout;
break;
case 0x0c:
VBDEBUG(("VbBootDeveloper() - "
"user pressed Ctrl+L; Try legacy boot\n"));
/*
* If VbExLegacy() succeeds, it will never return. If
* it returns, beep.
*/
if (allow_legacy)
VbExLegacy();
else
VBDEBUG(("VbBootDeveloper() - "
"Legacy boot is disabled\n"));
VbExBeep(120, 400);
VbExSleepMs(120);
VbExBeep(120, 400);
break;
case VB_KEY_CTRL_ENTER:
/*
* The Ctrl-Enter is special for Lumpy test purpose;
* fall through to Ctrl+U handler.
*/
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"));
VbExDisplayDebugInfo(
"WARNING: Booting from external media "
"(USB/SD) has not been enabled. Refer "
"to the developer-mode documentation "
"for details.\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 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:
/* If defaulting to legacy boot, try that unless Ctrl+D was pressed */
if ((gbb->flags & GBB_FLAG_DEFAULT_DEV_BOOT_LEGACY) &&
!ctrl_d_pressed) {
VBDEBUG(("VbBootDeveloper() - defaulting to legacy\n"));
VbExLegacy();
/* If that fails, beep and fall through to fixed disk */
VbExBeep(120, 400);
VbExSleepMs(120);
VbExBeep(120, 400);
}
/* 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 in recovery mode */
#define REC_DISK_DELAY 1000 /* Check disks every 1s */
#define REC_KEY_DELAY 20 /* Check keys every 20ms */
#define REC_MEDIA_INIT_DELAY 500 /* Check removable media every 500ms */
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"));
/* If no media is detected initially, delay and make one extra
* attempt, in case devices appear later than expected. */
if (VBERROR_SUCCESS != VbExDiskGetInfo(&disk_info, &disk_count,
VB_DISK_FLAG_REMOVABLE))
disk_count = 0;
VbExDiskFreeInfo(disk_info, NULL);
if (0 == disk_count)
VbExSleepMs(REC_MEDIA_INIT_DELAY);
while (1) {
disk_info = NULL;
disk_count = 0;
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 < REC_DISK_DELAY; i += REC_KEY_DELAY) {
VbCheckDisplayKey(cparams, VbExKeyboardRead(),
&vnc);
if (VbWantShutdown(cparams->gbb->flags))
return VBERROR_SHUTDOWN_REQUESTED;
VbExSleepMs(REC_KEY_DELAY);
}
}
}
/* Loop and wait for a recovery image */
while (1) {
VBDEBUG(("VbBootRecovery() attempting to load kernel2\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 < REC_DISK_DELAY; i += REC_KEY_DELAY) {
key = VbExKeyboardRead();
/*
* We might want to enter dev-mode from the Insert
* screen if all of the following are true:
* - user pressed Ctrl-D
* - we can honor the virtual dev switch
* - not already in dev mode
* - user forced recovery mode
* - EC isn't pwned
*/
if (key == 0x04 &&
shared->flags & VBSD_HONOR_VIRT_DEV_SWITCH &&
!(shared->flags & VBSD_BOOT_DEV_SWITCH_ON) &&
(shared->flags & VBSD_BOOT_REC_SWITCH_ON) &&
VbExTrustEC(0)) {
if (!(shared->flags &
VBSD_BOOT_REC_SWITCH_VIRTUAL) &&
VbExGetSwitches(
VB_INIT_FLAG_REC_BUTTON_PRESSED)) {
/*
* Is the recovery button stuck? In
* any case we don't like this. Beep
* and ignore.
*/
VBDEBUG(("%s() - ^D but rec switch "
"is pressed\n", __func__));
VbExBeep(120, 400);
continue;
}
/* Ask the user to confirm entering dev-mode */
VbDisplayScreen(cparams,
VB_SCREEN_RECOVERY_TO_DEV,
0, &vnc);
/* SPACE means no... */
uint32_t vbc_flags =
VB_CONFIRM_SPACE_MEANS_NO |
VB_CONFIRM_MUST_TRUST_KEYBOARD;
switch (VbUserConfirms(cparams, vbc_flags)) {
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 (VbWantShutdown(cparams->gbb->flags))
return VBERROR_SHUTDOWN_REQUESTED;
VbExSleepMs(REC_KEY_DELAY);
}
}
return VBERROR_SUCCESS;
}
/**
* Wrapper around VbExEcProtectRW() which sets recovery reason on error.
*/
static VbError_t EcProtectRW(int devidx)
{
int rv = VbExEcProtectRW(devidx);
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(int devidx, VbCommonParams *cparams)
{
VbSharedDataHeader *shared =
(VbSharedDataHeader *)cparams->shared_data_blob;
int in_rw = 0;
int rv;
const uint8_t *ec_hash = NULL;
int ec_hash_size;
const uint8_t *rw_hash = NULL;
int rw_hash_size;
const uint8_t *expected = NULL;
int expected_size;
uint8_t expected_hash[SHA256_DIGEST_SIZE];
int need_update = 0;
int i;
VBDEBUG(("VbEcSoftwareSync(devidx=%d)\n", devidx));
/* Determine whether the EC is in RO or RW */
rv = VbExEcRunningRW(devidx, &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() - "
"VbExEcRunningRW() 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(devidx);
if (rv != VBERROR_SUCCESS)
return rv;
rv = VbExEcDisableJump(devidx);
if (rv != VBERROR_SUCCESS) {
VBDEBUG(("VbEcSoftwareSync() - "
"VbExEcDisableJump() 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"));
return VBERROR_SUCCESS;
}
/* Get hash of EC-RW */
rv = VbExEcHashRW(devidx, &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 hash. 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 = VbExEcGetExpectedRWHash(devidx, shared->firmware_index ?
VB_SELECT_FIRMWARE_B : VB_SELECT_FIRMWARE_A,
&rw_hash, &rw_hash_size);
if (rv == VBERROR_EC_GET_EXPECTED_HASH_FROM_IMAGE) {
/*
* BIOS has verified EC image but doesn't have a precomputed
* hash for it, so we must compute the hash ourselves.
*/
rw_hash = NULL;
} else if (rv) {
VBDEBUG(("VbEcSoftwareSync() - "
"VbExEcGetExpectedRWHash() returned %d\n", rv));
VbSetRecoveryRequest(VBNV_RECOVERY_EC_EXPECTED_HASH);
return VBERROR_EC_REBOOT_TO_RO_REQUIRED;
} else if (rw_hash_size != SHA256_DIGEST_SIZE) {
VBDEBUG(("VbEcSoftwareSync() - "
"VbExEcGetExpectedRWHash() says size %d, not %d\n",
rw_hash_size, SHA256_DIGEST_SIZE));
VbSetRecoveryRequest(VBNV_RECOVERY_EC_EXPECTED_HASH);
return VBERROR_EC_REBOOT_TO_RO_REQUIRED;
} else {
VBDEBUG(("Expected hash:"));
for (i = 0; i < SHA256_DIGEST_SIZE; i++)
VBDEBUG(("%02x", rw_hash[i]));
VBDEBUG(("\n"));
need_update = SafeMemcmp(ec_hash, rw_hash, SHA256_DIGEST_SIZE);
}
/*
* Get expected EC-RW image if we're sure we need to update (because the
* expected hash didn't match the EC) or we still don't know (because
* there was no expected hash and we need the image to compute one
* ourselves).
*/
if (need_update || !rw_hash) {
/* Get expected EC-RW image */
rv = VbExEcGetExpectedRW(devidx, 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 image */
internal_SHA256(expected, expected_size, expected_hash);
VBDEBUG(("Computed hash of expected image:"));
for (i = 0; i < SHA256_DIGEST_SIZE; i++)
VBDEBUG(("%02x", expected_hash[i]));
VBDEBUG(("\n"));
}
if (!rw_hash) {
/*
* BIOS didn't have expected EC hash, so check if we need
* update by comparing EC hash to the one we just computed.
*/
need_update = SafeMemcmp(ec_hash, expected_hash,
SHA256_DIGEST_SIZE);
} else if (need_update &&
SafeMemcmp(rw_hash, expected_hash, SHA256_DIGEST_SIZE)) {
/*
* We need to update, but the expected EC image doesn't match
* the expected EC hash we were given.
*/
VBDEBUG(("VbEcSoftwareSync() - "
"VbExEcGetExpectedRW() returned %d\n", rv));
VbSetRecoveryRequest(VBNV_RECOVERY_EC_HASH_MISMATCH);
return VBERROR_EC_REBOOT_TO_RO_REQUIRED;
}
/*
* TODO: GBB flag to override whether we need update; needed for EC
* development.
*/
if (in_rw) {
if (need_update) {
/*
* Check if BIOS should also load VGA Option ROM when
* rebooting to save another reboot if possible.
*/
if ((shared->flags & VBSD_EC_SLOW_UPDATE) &&
(shared->flags & VBSD_OPROM_MATTERS) &&
!(shared->flags & VBSD_OPROM_LOADED)) {
VBDEBUG(("VbEcSoftwareSync() - Reboot to "
"load VGA Option ROM\n"));
VbNvSet(&vnc, VBNV_OPROM_NEEDED, 1);
}
/*
* EC is running the wrong RW image. 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"));
/* Ensure the VGA Option ROM is loaded */
if ((shared->flags & VBSD_OPROM_MATTERS) &&
!(shared->flags & VBSD_OPROM_LOADED)) {
VBDEBUG(("VbEcSoftwareSync() - Reboot to "
"load VGA Option ROM\n"));
VbNvSet(&vnc, VBNV_OPROM_NEEDED, 1);
return VBERROR_VGA_OPROM_MISMATCH;
}
VbDisplayScreen(cparams, VB_SCREEN_WAIT, 0, &vnc);
}
rv = VbExEcUpdateRW(devidx, expected, expected_size);
if (rv != VBERROR_SUCCESS) {
VBDEBUG(("VbEcSoftwareSync() - "
"VbExEcUpdateRW() returned %d\n", rv));
/*
* The EC may know it needs a reboot. It 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.
*
* If we fail for any other reason, trigger recovery
* mode.
*/
if (rv != VBERROR_EC_REBOOT_TO_RO_REQUIRED)
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(devidx);
if (rv != VBERROR_SUCCESS)
return rv;
/* Tell EC to jump to its RW image */
VBDEBUG(("VbEcSoftwareSync() jumping to EC-RW\n"));
rv = VbExEcJumpToRW(devidx);
if (rv != VBERROR_SUCCESS) {
VBDEBUG(("VbEcSoftwareSync() - "
"VbExEcJumpToRW() returned %d\n", rv));
/*
* If the EC booted RO-normal and a previous AP boot has called
* VbExEcStayInRO(), we need to reboot the EC to unlock the
* ability to jump to the RW firmware.
*
* All other errors trigger recovery mode.
*/
if (rv != VBERROR_EC_REBOOT_TO_RO_REQUIRED)
VbSetRecoveryRequest(VBNV_RECOVERY_EC_JUMP_RW);
return VBERROR_EC_REBOOT_TO_RO_REQUIRED;
}
VBDEBUG(("VbEcSoftwareSync() jumped to EC-RW\n"));
rv = VbExEcDisableJump(devidx);
if (rv != VBERROR_SUCCESS) {
VBDEBUG(("VbEcSoftwareSync() - "
"VbExEcDisableJump() returned %d\n", rv));
VbSetRecoveryRequest(VBNV_RECOVERY_EC_SOFTWARE_SYNC);
return VBERROR_EC_REBOOT_TO_RO_REQUIRED;
}
/*
* Reboot to unload VGA Option ROM if:
* - RW update was done
* - the system is NOT in developer mode
* - the system has slow EC update flag set
* - the VGA Option ROM was needed and loaded
*/
if (need_update &&
!(shared->flags & VBSD_BOOT_DEV_SWITCH_ON) &&
(shared->flags & VBSD_EC_SLOW_UPDATE) &&
(shared->flags & VBSD_OPROM_MATTERS) &&
(shared->flags & VBSD_OPROM_LOADED)) {
VBDEBUG(("VbEcSoftwareSync() - Reboot to "
"unload VGA Option ROM\n"));
return VBERROR_VGA_OPROM_MISMATCH;
}
VBDEBUG(("VbEcSoftwareSync() in RW; done\n"));
return VBERROR_SUCCESS;
}
/* This function is also used by tests */
void VbApiKernelFree(VbCommonParams *cparams)
{
/* VbSelectAndLoadKernel() always allocates this, tests don't */
if (cparams->gbb) {
VbExFree(cparams->gbb);
cparams->gbb = NULL;
}
if (cparams->bmp) {
VbExFree(cparams->bmp);
cparams->bmp = NULL;
}
}
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;
kparams->flags = 0;
Memset(kparams->partition_guid, 0, sizeof(kparams->partition_guid));
cparams->bmp = NULL;
cparams->gbb = VbExMalloc(sizeof(*cparams->gbb));
retval = VbGbbReadHeader_static(cparams, cparams->gbb);
if (VBERROR_SUCCESS != retval)
goto VbSelectAndLoadKernel_exit;
/* Do EC software sync if necessary */
if ((shared->flags & VBSD_EC_SOFTWARE_SYNC) &&
!(cparams->gbb->flags & GBB_FLAG_DISABLE_EC_SOFTWARE_SYNC)) {
int oprom_mismatch = 0;
retval = VbEcSoftwareSync(0, cparams);
/* Save reboot requested until after possible PD sync */
if (retval == VBERROR_VGA_OPROM_MISMATCH)
oprom_mismatch = 1;
else if (retval != VBERROR_SUCCESS)
goto VbSelectAndLoadKernel_exit;
#ifdef PD_SYNC
if (!(cparams->gbb->flags &
GBB_FLAG_DISABLE_PD_SOFTWARE_SYNC)) {
retval = VbEcSoftwareSync(1, cparams);
if (retval == VBERROR_VGA_OPROM_MISMATCH)
oprom_mismatch = 1;
else if (retval != VBERROR_SUCCESS)
goto VbSelectAndLoadKernel_exit;
}
#endif
/* Request reboot to unload VGA Option ROM */
if (oprom_mismatch) {
retval = VBERROR_VGA_OPROM_MISMATCH;
goto VbSelectAndLoadKernel_exit;
}
}
/* Read 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);
VbExEcEnteringMode(0, VB_EC_RECOVERY);
VbDisplayScreen(cparams, VB_SCREEN_BLANK, 0, &vnc);
} else if (p.boot_flags & BOOT_FLAG_DEVELOPER) {
/* Developer boot */
retval = VbBootDeveloper(cparams, &p);
VbExEcEnteringMode(0, VB_EC_DEVELOPER);
VbDisplayScreen(cparams, VB_SCREEN_BLANK, 0, &vnc);
} else {
/* Normal boot */
VbExEcEnteringMode(0, VB_EC_NORMAL);
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;
kparams->flags = p.flags;
Memcpy(kparams->partition_guid, p.partition_guid,
sizeof(kparams->partition_guid));
/* Lock the kernel versions. Ignore errors in recovery mode. */
tpm_status = RollbackKernelLock(shared->recovery_reason);
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:
VbApiKernelFree(cparams);
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;
}