diff options
Diffstat (limited to 'src/vboot/bootmode.c')
-rw-r--r-- | src/vboot/bootmode.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/src/vboot/bootmode.c b/src/vboot/bootmode.c new file mode 100644 index 0000000000..12a4dc0c8d --- /dev/null +++ b/src/vboot/bootmode.c @@ -0,0 +1,177 @@ +/* + * 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 <rules.h> +#include <string.h> +#include <vb2_api.h> +#include <vboot/misc.h> +#include <vboot/vbnv.h> +#include <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 occuring 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 0 for the stages where we know that cbmem does not come online. + * Even if this function returns 1 for romstage, depending upon the point in + * bootup, cbmem might not actually be online. + */ +static int cbmem_possibly_online(void) +{ + if (ENV_BOOTBLOCK) + return 0; + + if (ENV_VERSTAGE && IS_ENABLED(CONFIG_VBOOT_STARTS_IN_BOOTBLOCK)) + return 0; + + return 1; +} + +/* + * 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)) + return 0; + + if (IS_ENABLED(CONFIG_VBOOT_STARTS_IN_BOOTBLOCK)) { + if (ENV_BOOTBLOCK && IS_ENABLED(CONFIG_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_refence 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) +{ + if (!IS_ENABLED(CONFIG_VBOOT)) + return 0; + + return !!vboot_check_recovery_request(); +} + +int vboot_developer_mode_enabled(void) +{ + if (!IS_ENABLED(CONFIG_VBOOT)) + return 0; + + if (get_developer_mode_switch()) + return 1; + + if (cbmem_possibly_online() && vboot_handoff_check_developer_flag()) + return 1; + + return 0; +} |