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/*
* 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
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