| /* |
| * This file is part of the coreboot project. |
| * |
| * Copyright 2016 Google Inc. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; version 2 of the License. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| */ |
| |
| #include <assert.h> |
| #include <bootmode.h> |
| #include <bootstate.h> |
| #include <cbmem.h> |
| #include <compiler.h> |
| #include <rules.h> |
| #include <string.h> |
| #include <vb2_api.h> |
| #include <security/vboot/misc.h> |
| #include <security/vboot/vbnv.h> |
| #include <security/vboot/vboot_common.h> |
| |
| static int vb2_get_recovery_reason_shared_data(void) |
| { |
| /* Shared data does not exist for Ramstage and Post-CAR stage. */ |
| if (ENV_RAMSTAGE || ENV_POSTCAR) |
| return 0; |
| |
| struct vb2_shared_data *sd = vb2_get_shared_data(); |
| assert(sd); |
| return sd->recovery_reason; |
| } |
| |
| void vb2_save_recovery_reason_vbnv(void) |
| { |
| if (!IS_ENABLED(CONFIG_VBOOT_SAVE_RECOVERY_REASON_ON_REBOOT)) |
| return; |
| |
| int reason = vb2_get_recovery_reason_shared_data(); |
| if (!reason) |
| return; |
| |
| set_recovery_mode_into_vbnv(reason); |
| } |
| |
| static void vb2_clear_recovery_reason_vbnv(void *unused) |
| { |
| if (!IS_ENABLED(CONFIG_VBOOT_SAVE_RECOVERY_REASON_ON_REBOOT)) |
| return; |
| |
| set_recovery_mode_into_vbnv(0); |
| } |
| |
| /* |
| * Recovery reason stored in VBNV needs to be cleared before the state of VBNV |
| * is backed-up anywhere or jumping to the payload (whichever occurs |
| * first). Currently, vbnv_cmos.c backs up VBNV on POST_DEVICE. Thus, we need to |
| * make sure that the stored recovery reason is cleared off before that |
| * happens. |
| * IMPORTANT: Any reboot occurring after BS_DEV_INIT state will cause loss of |
| * recovery reason on reboot. Until now, we have seen reboots occurring on x86 |
| * only in FSP stages which run before BS_DEV_INIT. |
| */ |
| BOOT_STATE_INIT_ENTRY(BS_DEV_INIT, BS_ON_EXIT, |
| vb2_clear_recovery_reason_vbnv, NULL); |
| |
| /* |
| * Returns 1 if vboot is being used and currently in a stage which might have |
| * already executed vboot verification. |
| */ |
| static int vboot_possibly_executed(void) |
| { |
| if (IS_ENABLED(CONFIG_VBOOT_STARTS_IN_BOOTBLOCK)) { |
| if (ENV_BOOTBLOCK && IS_ENABLED(CONFIG_VBOOT_SEPARATE_VERSTAGE)) |
| return 0; |
| return 1; |
| } |
| |
| if (IS_ENABLED(CONFIG_VBOOT_STARTS_IN_ROMSTAGE)) { |
| if (ENV_BOOTBLOCK) |
| return 0; |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * vb2_check_recovery_request looks up different components to identify if there |
| * is a recovery request and returns appropriate reason code: |
| * 1. Checks if recovery mode is initiated by EC. If yes, returns |
| * VB2_RECOVERY_RO_MANUAL. |
| * 2. Checks if recovery request is present in VBNV and returns the code read |
| * from it. |
| * 3. Checks recovery request in handoff for stages post-cbmem. |
| * 4. For non-CBMEM stages, check if vboot verification is done and look-up |
| * selected region to identify if vboot_reference library has requested recovery |
| * path. If yes, return the reason code from shared data. |
| * 5. If nothing applies, return 0 indicating no recovery request. |
| */ |
| int vboot_check_recovery_request(void) |
| { |
| int reason = 0; |
| |
| /* EC-initiated recovery. */ |
| if (get_recovery_mode_switch()) |
| return VB2_RECOVERY_RO_MANUAL; |
| |
| /* Recovery request in VBNV. */ |
| if ((reason = get_recovery_mode_from_vbnv()) != 0) |
| return reason; |
| |
| /* |
| * Check recovery flag in vboot_handoff for stages post CBMEM coming |
| * online. Since for some stages there is no way to know if cbmem has |
| * already come online, try looking up handoff anyways. If it fails, |
| * flow will fallback to looking up shared data. |
| */ |
| if (cbmem_possibly_online() && |
| ((reason = vboot_handoff_get_recovery_reason()) != 0)) |
| return reason; |
| |
| /* |
| * For stages where CBMEM might not be online, identify if vboot |
| * verification is already complete and no slot was selected |
| * i.e. recovery path was requested. |
| */ |
| if (vboot_possibly_executed() && vb2_logic_executed() && |
| !vb2_is_slot_selected()) |
| return vb2_get_recovery_reason_shared_data(); |
| |
| return 0; |
| } |
| |
| int vboot_recovery_mode_enabled(void) |
| { |
| return !!vboot_check_recovery_request(); |
| } |
| |
| int __weak clear_recovery_mode_switch(void) |
| { |
| // Weak implementation. Nothing to do. |
| return 0; |
| } |
| |
| void __weak log_recovery_mode_switch(void) |
| { |
| // Weak implementation. Nothing to do. |
| } |
| |
| int __weak get_recovery_mode_retrain_switch(void) |
| { |
| return 0; |
| } |
| |
| int vboot_recovery_mode_memory_retrain(void) |
| { |
| return get_recovery_mode_retrain_switch(); |
| } |
| |
| int vboot_developer_mode_enabled(void) |
| { |
| if (cbmem_possibly_online() && vboot_handoff_check_developer_flag()) |
| return 1; |
| |
| return 0; |
| } |
| |
| #if IS_ENABLED(CONFIG_VBOOT_NO_BOARD_SUPPORT) |
| /** |
| * TODO: Create flash protection interface which implements get_write_protect_state. |
| * get_recovery_mode_switch should be implemented as default function. |
| */ |
| int __weak get_write_protect_state(void) |
| { |
| return 0; |
| } |
| |
| int __weak get_recovery_mode_switch(void) |
| { |
| return 0; |
| } |
| |
| #endif |