/* 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); } /** * 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 || 32 > disk_info[i].lba_count || get_info_flags != disk_info[i].flags) { 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->ending_lba = disk_info[i].lba_count - 1; 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 (VbExIsShutdownRequested()) 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 (VbExIsShutdownRequested()) { 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 (VbExIsShutdownRequested()) 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 (VbExIsShutdownRequested()) 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) { /* * 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")); /* * FIXME(crosbug.com/p/12257): Ensure the VGA Option * ROM is loaded! */ 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; } 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; 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)) { retval = VbEcSoftwareSync(0, cparams); if (retval != VBERROR_SUCCESS) goto VbSelectAndLoadKernel_exit; #ifdef PD_SYNC retval = VbEcSoftwareSync(1, cparams); if (retval != VBERROR_SUCCESS) goto VbSelectAndLoadKernel_exit; #endif } /* 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); 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(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; }