| /* 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. |
| * |
| * EC software sync routines for vboot |
| */ |
| |
| #include "2sysincludes.h" |
| #include "2common.h" |
| #include "2misc.h" |
| #include "2nvstorage.h" |
| |
| #include "sysincludes.h" |
| #include "ec_sync.h" |
| #include "gbb_header.h" |
| #include "vboot_api.h" |
| #include "vboot_common.h" |
| #include "vboot_kernel.h" |
| |
| #define VB2_SD_FLAG_ECSYNC_RW \ |
| (VB2_SD_FLAG_ECSYNC_EC_RW | VB2_SD_FLAG_ECSYNC_PD_RW) |
| #define VB2_SD_FLAG_ECSYNC_ANY \ |
| (VB2_SD_FLAG_ECSYNC_EC_RO | VB2_SD_FLAG_ECSYNC_RW) |
| #define VB2_SD_FLAG_ECSYNC_IN_RW \ |
| (VB2_SD_FLAG_ECSYNC_EC_IN_RW | VB2_SD_FLAG_ECSYNC_PD_IN_RW) |
| |
| #define IN_RW(devidx) \ |
| ((devidx) ? VB2_SD_FLAG_ECSYNC_PD_IN_RW : VB2_SD_FLAG_ECSYNC_EC_IN_RW) |
| |
| #define WHICH_EC(devidx, select) \ |
| ((select) == VB_SELECT_FIRMWARE_READONLY ? VB2_SD_FLAG_ECSYNC_EC_RO : \ |
| ((devidx) ? VB2_SD_FLAG_ECSYNC_PD_RW : VB2_SD_FLAG_ECSYNC_EC_RW)) |
| |
| /* PD doesn't support RW A/B */ |
| #define RW_AB(devidx) ((devidx) ? 0 : VBSD_EC_EFS) |
| |
| static void request_recovery(struct vb2_context *ctx, uint32_t recovery_request) |
| { |
| VB2_DEBUG("request_recovery(%u)\n", recovery_request); |
| |
| vb2_nv_set(ctx, VB2_NV_RECOVERY_REQUEST, recovery_request); |
| } |
| |
| /** |
| * Wrapper around VbExEcProtect() which sets recovery reason on error. |
| */ |
| static VbError_t protect_ec(struct vb2_context *ctx, int devidx, |
| enum VbSelectFirmware_t select) |
| { |
| int rv = VbExEcProtect(devidx, select); |
| |
| if (rv == VBERROR_EC_REBOOT_TO_RO_REQUIRED) { |
| VB2_DEBUG("VbExEcProtect() needs reboot\n"); |
| } else if (rv != VBERROR_SUCCESS) { |
| VB2_DEBUG("VbExEcProtect() returned %d\n", rv); |
| request_recovery(ctx, VB2_RECOVERY_EC_PROTECT); |
| } |
| return rv; |
| } |
| |
| /** |
| * Print a hash to debug output |
| * |
| * @param hash Pointer to the hash |
| * @param hash_size Size of the hash in bytes |
| * @param desc Description of what's being hashed |
| */ |
| static void print_hash(const uint8_t *hash, uint32_t hash_size, |
| const char *desc) |
| { |
| int i; |
| |
| VB2_DEBUG("%s hash: ", desc); |
| for (i = 0; i < hash_size; i++) |
| VB2_DEBUG_RAW("%02x", hash[i]); |
| VB2_DEBUG_RAW("\n"); |
| } |
| |
| static const char *image_name_to_string(enum VbSelectFirmware_t select) |
| { |
| switch (select) { |
| case VB_SELECT_FIRMWARE_READONLY: |
| return "RO"; |
| case VB_SELECT_FIRMWARE_EC_ACTIVE: |
| return "RW(active)"; |
| case VB_SELECT_FIRMWARE_EC_UPDATE: |
| return "RW(update)"; |
| default: |
| return "UNKNOWN"; |
| } |
| } |
| |
| /** |
| * Check if the hash of the EC code matches the expected hash. |
| * |
| * @param ctx Vboot2 context |
| * @param devidx Index of EC device to check |
| * @param select Which firmware image to check |
| * @return VB2_SUCCESS, or non-zero error code. |
| */ |
| static int check_ec_hash(struct vb2_context *ctx, int devidx, |
| enum VbSelectFirmware_t select) |
| { |
| struct vb2_shared_data *sd = vb2_get_sd(ctx); |
| |
| /* Get current EC hash. */ |
| const uint8_t *ec_hash = NULL; |
| int ec_hash_size; |
| int rv = VbExEcHashImage(devidx, select, &ec_hash, &ec_hash_size); |
| if (rv) { |
| VB2_DEBUG("VbExEcHashImage() returned %d\n", rv); |
| request_recovery(ctx, VB2_RECOVERY_EC_HASH_FAILED); |
| return VB2_ERROR_EC_HASH_IMAGE; |
| } |
| print_hash(ec_hash, ec_hash_size, image_name_to_string(select)); |
| |
| /* Get expected EC hash. */ |
| const uint8_t *hash = NULL; |
| int hash_size; |
| rv = VbExEcGetExpectedImageHash(devidx, select, &hash, &hash_size); |
| if (rv) { |
| VB2_DEBUG("VbExEcGetExpectedImageHash() returned %d\n", rv); |
| request_recovery(ctx, VB2_RECOVERY_EC_EXPECTED_HASH); |
| return VB2_ERROR_EC_HASH_EXPECTED; |
| } |
| if (ec_hash_size != hash_size) { |
| VB2_DEBUG("EC uses %d-byte hash, but AP-RW contains %d bytes\n", |
| ec_hash_size, hash_size); |
| request_recovery(ctx, VB2_RECOVERY_EC_HASH_SIZE); |
| return VB2_ERROR_EC_HASH_SIZE; |
| } |
| |
| if (vb2_safe_memcmp(ec_hash, hash, hash_size)) { |
| print_hash(hash, hash_size, "Expected"); |
| sd->flags |= WHICH_EC(devidx, select); |
| } |
| |
| return VB2_SUCCESS; |
| } |
| |
| /** |
| * Update the specified EC and verify the update succeeded |
| * |
| * @param ctx Vboot2 context |
| * @param devidx Index of EC device to check |
| * @param select Which firmware image to check |
| * @return VBERROR_SUCCESS, or non-zero error code. |
| */ |
| static VbError_t update_ec(struct vb2_context *ctx, int devidx, |
| enum VbSelectFirmware_t select) |
| { |
| struct vb2_shared_data *sd = vb2_get_sd(ctx); |
| |
| VB2_DEBUG("Updating %s...\n", image_name_to_string(select)); |
| |
| /* Get expected EC image */ |
| const uint8_t *want = NULL; |
| int want_size; |
| int rv = VbExEcGetExpectedImage(devidx, select, &want, &want_size); |
| if (rv) { |
| VB2_DEBUG("VbExEcGetExpectedImage() returned %d\n", rv); |
| request_recovery(ctx, VB2_RECOVERY_EC_EXPECTED_IMAGE); |
| return rv; |
| } |
| VB2_DEBUG("image len = %d\n", want_size); |
| |
| rv = VbExEcUpdateImage(devidx, select, want, want_size); |
| if (rv != VBERROR_SUCCESS) { |
| VB2_DEBUG("VbExEcUpdateImage() returned %d\n", rv); |
| |
| /* |
| * The EC may know it needs a reboot. It may need to |
| * unprotect the region before updating, or may need to |
| * reboot after updating. 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) |
| request_recovery(ctx, VB2_RECOVERY_EC_UPDATE); |
| |
| return rv; |
| } |
| |
| /* Verify the EC was updated properly */ |
| sd->flags &= ~WHICH_EC(devidx, select); |
| if (check_ec_hash(ctx, devidx, select) != VB2_SUCCESS) |
| return VBERROR_EC_REBOOT_TO_RO_REQUIRED; |
| if (sd->flags & WHICH_EC(devidx, select)) { |
| VB2_DEBUG("Failed to update\n"); |
| request_recovery(ctx, VB2_RECOVERY_EC_UPDATE); |
| return VBERROR_EC_REBOOT_TO_RO_REQUIRED; |
| } |
| |
| return VBERROR_SUCCESS; |
| } |
| |
| /** |
| * Set IN_RW flag for a EC |
| * |
| * @param ctx Vboot2 context |
| * @param devidx Which device (EC=0, PD=1) |
| */ |
| static VbError_t check_ec_active(struct vb2_context *ctx, int devidx) |
| { |
| struct vb2_shared_data *sd = vb2_get_sd(ctx); |
| int in_rw = 0; |
| /* |
| * We don't use VbExTrustEC, which checks EC_IN_RW. It is controlled by |
| * cr50 but on some platforms, cr50 can't know when a EC resets. So, we |
| * trust what EC-RW says. If it lies it's in RO, we'll flash RW while |
| * it's in RW. |
| */ |
| int rv = VbExEcRunningRW(devidx, &in_rw); |
| |
| /* If we couldn't determine where the EC was, reboot to recovery. */ |
| if (rv != VBERROR_SUCCESS) { |
| VB2_DEBUG("VbExEcRunningRW() returned %d\n", rv); |
| request_recovery(ctx, VB2_RECOVERY_EC_UNKNOWN_IMAGE); |
| return VBERROR_EC_REBOOT_TO_RO_REQUIRED; |
| } |
| |
| if (in_rw) |
| sd->flags |= IN_RW(devidx); |
| |
| return VBERROR_SUCCESS; |
| } |
| |
| #define RO_RETRIES 2 /* Maximum times to retry flashing RO */ |
| |
| /** |
| * Sync, jump, and protect one EC device |
| * |
| * @param ctx Vboot2 context |
| * @param devidx Which device (EC=0, PD=1) |
| * @return VBERROR_SUCCESS, or non-zero if error. |
| */ |
| static VbError_t sync_one_ec(struct vb2_context *ctx, int devidx, |
| VbCommonParams *cparams) |
| { |
| VbSharedDataHeader *shared = |
| (VbSharedDataHeader *)cparams->shared_data_blob; |
| struct vb2_shared_data *sd = vb2_get_sd(ctx); |
| int is_rw_ab = shared->flags & RW_AB(devidx); |
| int rv; |
| |
| const enum VbSelectFirmware_t select_rw = is_rw_ab ? |
| VB_SELECT_FIRMWARE_EC_UPDATE : |
| VB_SELECT_FIRMWARE_EC_ACTIVE; |
| VB2_DEBUG("devidx=%d select_rw=%d\n", devidx, select_rw); |
| |
| /* Update the RW Image */ |
| if (sd->flags & WHICH_EC(devidx, select_rw)) { |
| if (VB2_SUCCESS != update_ec(ctx, devidx, select_rw)) |
| return VBERROR_EC_REBOOT_TO_RO_REQUIRED; |
| /* Updated successfully. Cold reboot to switch to the new RW. |
| * TODO: Switch slot and proceed if EC is still in RO. */ |
| if (is_rw_ab) { |
| VB2_DEBUG("Rebooting to jump to new EC-RW\n"); |
| return VBERROR_EC_REBOOT_TO_SWITCH_RW; |
| } |
| } |
| |
| /* Tell EC to jump to its RW image */ |
| if (!(sd->flags & IN_RW(devidx))) { |
| VB2_DEBUG("jumping to EC-RW\n"); |
| rv = VbExEcJumpToRW(devidx); |
| if (rv != VBERROR_SUCCESS) { |
| VB2_DEBUG("VbExEcJumpToRW() returned %x\n", rv); |
| |
| /* |
| * If 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) |
| request_recovery(ctx, VB2_RECOVERY_EC_JUMP_RW); |
| |
| return VBERROR_EC_REBOOT_TO_RO_REQUIRED; |
| } |
| } |
| |
| /* Might need to update EC-RO (but not PD-RO) */ |
| if (sd->flags & VB2_SD_FLAG_ECSYNC_EC_RO) { |
| VB2_DEBUG("RO Software Sync\n"); |
| |
| /* Reset RO Software Sync NV flag */ |
| vb2_nv_set(ctx, VB2_NV_TRY_RO_SYNC, 0); |
| |
| /* |
| * Get the current recovery request (if any). This gets |
| * overwritten by a failed try. If a later try succeeds, we'll |
| * need to restore this request (or the lack of a request), or |
| * else we'll end up in recovery mode even though RO software |
| * sync did eventually succeed. |
| */ |
| uint32_t recovery_request = |
| vb2_nv_get(ctx, VB2_NV_RECOVERY_REQUEST); |
| |
| /* Update the RO Image. */ |
| int num_tries; |
| for (num_tries = 0; num_tries < RO_RETRIES; num_tries++) { |
| if (VB2_SUCCESS == |
| update_ec(ctx, devidx, VB_SELECT_FIRMWARE_READONLY)) |
| break; |
| } |
| if (num_tries == RO_RETRIES) { |
| /* Ran out of tries */ |
| return VBERROR_EC_REBOOT_TO_RO_REQUIRED; |
| } else if (num_tries) { |
| /* |
| * Update succeeded after a failure, so we've polluted |
| * the recovery request. Restore it. |
| */ |
| request_recovery(ctx, recovery_request); |
| } |
| } |
| |
| /* Protect RO flash */ |
| rv = protect_ec(ctx, devidx, VB_SELECT_FIRMWARE_READONLY); |
| if (rv != VBERROR_SUCCESS) |
| return rv; |
| |
| /* Protect RW flash */ |
| rv = protect_ec(ctx, devidx, select_rw); |
| if (rv != VBERROR_SUCCESS) |
| return rv; |
| |
| rv = VbExEcDisableJump(devidx); |
| if (rv != VBERROR_SUCCESS) { |
| VB2_DEBUG("VbExEcDisableJump() returned %d\n", rv); |
| request_recovery(ctx, VB2_RECOVERY_EC_SOFTWARE_SYNC); |
| return VBERROR_EC_REBOOT_TO_RO_REQUIRED; |
| } |
| |
| return rv; |
| } |
| |
| VbError_t ec_sync_phase1(struct vb2_context *ctx, VbCommonParams *cparams) |
| { |
| VbSharedDataHeader *shared = |
| (VbSharedDataHeader *)cparams->shared_data_blob; |
| struct vb2_shared_data *sd = vb2_get_sd(ctx); |
| |
| /* Reasons not to do sync at all */ |
| if (!(shared->flags & VBSD_EC_SOFTWARE_SYNC)) |
| return VBERROR_SUCCESS; |
| if (cparams->gbb->flags & GBB_FLAG_DISABLE_EC_SOFTWARE_SYNC) |
| return VBERROR_SUCCESS; |
| |
| #ifdef PD_SYNC |
| const int do_pd_sync = !(cparams->gbb->flags & |
| GBB_FLAG_DISABLE_PD_SOFTWARE_SYNC); |
| #else |
| const int do_pd_sync = 0; |
| #endif |
| |
| /* Set IN_RW flags */ |
| if (check_ec_active(ctx, 0)) |
| return VBERROR_EC_REBOOT_TO_RO_REQUIRED; |
| if (do_pd_sync && check_ec_active(ctx, 1)) |
| return VBERROR_EC_REBOOT_TO_RO_REQUIRED; |
| |
| /* Check if we need to update RW. Failures trigger recovery mode. */ |
| if (check_ec_hash(ctx, 0, VB_SELECT_FIRMWARE_EC_ACTIVE)) |
| return VBERROR_EC_REBOOT_TO_RO_REQUIRED; |
| if (do_pd_sync && check_ec_hash(ctx, 1, VB_SELECT_FIRMWARE_EC_ACTIVE)) |
| return VBERROR_EC_REBOOT_TO_RO_REQUIRED; |
| /* |
| * See if we need to update EC-RO (devidx=0). |
| * |
| * If we want to extend this in the future to update PD-RO, we'll use a |
| * different NV flag so we can track EC-RO and PD-RO updates |
| * separately. |
| */ |
| if (vb2_nv_get(ctx, VB2_NV_TRY_RO_SYNC) && |
| !(shared->flags & VBSD_BOOT_FIRMWARE_WP_ENABLED) && |
| check_ec_hash(ctx, 0, VB_SELECT_FIRMWARE_READONLY)) { |
| return VBERROR_EC_REBOOT_TO_RO_REQUIRED; |
| } |
| |
| /* |
| * If we're in RW, we need to reboot back to RO because RW can't be |
| * updated while we're running it. |
| * |
| * If EC supports RW-A/B slots, we can proceed but we need |
| * to jump to the new RW version later. |
| */ |
| if ((sd->flags & VB2_SD_FLAG_ECSYNC_RW) && |
| (sd->flags & VB2_SD_FLAG_ECSYNC_IN_RW) && |
| !(shared->flags & VBSD_EC_EFS)) { |
| return VBERROR_EC_REBOOT_TO_RO_REQUIRED; |
| } |
| |
| return VBERROR_SUCCESS; |
| } |
| |
| int ec_will_update_slowly(struct vb2_context *ctx, VbCommonParams *cparams) |
| { |
| VbSharedDataHeader *shared = |
| (VbSharedDataHeader *)cparams->shared_data_blob; |
| struct vb2_shared_data *sd = vb2_get_sd(ctx); |
| |
| return ((sd->flags & VB2_SD_FLAG_ECSYNC_ANY) && |
| (shared->flags & VBSD_EC_SLOW_UPDATE)); |
| } |
| |
| /** |
| * determine if we can update the EC |
| * |
| * @param ctx Vboot2 context |
| * @param cparams Vboot common params |
| * @return boolean (true iff we can update the EC) |
| */ |
| |
| static int ec_sync_allowed(struct vb2_context *ctx, VbCommonParams *cparams) |
| { |
| VbSharedDataHeader *shared = |
| (VbSharedDataHeader *)cparams->shared_data_blob; |
| struct vb2_shared_data *sd = vb2_get_sd(ctx); |
| |
| /* Reasons not to do sync at all */ |
| if (!(shared->flags & VBSD_EC_SOFTWARE_SYNC)) |
| return 0; |
| if (cparams->gbb->flags & GBB_FLAG_DISABLE_EC_SOFTWARE_SYNC) |
| return 0; |
| if (sd->recovery_reason) |
| return 0; |
| return 1; |
| } |
| |
| VbError_t ec_sync_check_aux_fw(struct vb2_context *ctx, |
| VbCommonParams *cparams, |
| VbAuxFwUpdateSeverity_t *severity) |
| { |
| /* If we're not updating the EC, skip aux fw syncs as well */ |
| if (!ec_sync_allowed(ctx, cparams) || |
| (cparams->gbb->flags & GBB_FLAG_DISABLE_PD_SOFTWARE_SYNC)) { |
| *severity = VB_AUX_FW_NO_UPDATE; |
| return VBERROR_SUCCESS; |
| } |
| return VbExCheckAuxFw(severity); |
| } |
| |
| VbError_t ec_sync_phase2(struct vb2_context *ctx, VbCommonParams *cparams) |
| { |
| if (!ec_sync_allowed(ctx, cparams)) |
| return VBERROR_SUCCESS; |
| |
| /* Handle updates and jumps for EC */ |
| VbError_t retval = sync_one_ec(ctx, 0, cparams); |
| if (retval != VBERROR_SUCCESS) |
| return retval; |
| |
| #ifdef PD_SYNC |
| /* Handle updates and jumps for PD */ |
| if (!(cparams->gbb->flags & GBB_FLAG_DISABLE_PD_SOFTWARE_SYNC)) { |
| retval = sync_one_ec(ctx, 1, cparams); |
| if (retval != VBERROR_SUCCESS) |
| return retval; |
| } |
| #endif |
| |
| return VBERROR_SUCCESS; |
| } |
| |
| VbError_t ec_sync_phase3(struct vb2_context *ctx, VbCommonParams *cparams) |
| { |
| VbSharedDataHeader *shared = |
| (VbSharedDataHeader *)cparams->shared_data_blob; |
| |
| /* EC verification (and possibly updating / jumping) is done */ |
| VbError_t rv = VbExEcVbootDone(!!shared->recovery_reason); |
| if (rv) |
| return rv; |
| |
| /* Check if we need to cut-off battery. This must be done after EC |
| * firmware updating and before kernel started. */ |
| if (vb2_nv_get(ctx, VB2_NV_BATTERY_CUTOFF_REQUEST)) { |
| VB2_DEBUG("Request to cut-off battery\n"); |
| vb2_nv_set(ctx, VB2_NV_BATTERY_CUTOFF_REQUEST, 0); |
| VbExEcBatteryCutOff(); |
| return VBERROR_SHUTDOWN_REQUESTED; |
| } |
| |
| return VBERROR_SUCCESS; |
| } |