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https://github.com/Telecominfraproject/OpenCellular.git
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ec8df1628c
BUG=chrome-os-partner:9706
TEST=manual
Currently, Link is the only platform that enables this feature.
To enter dev-mode:
Boot into recovery mode using the magic key chord. At the Insert screen,
press Ctrl-D. You'll be asked if you want to enter developer mode. If you
then press ENTER, it will reboot with dev-mode enabled. If you press SPACE
or ESC, it will return to the Insert screen.
If you enter recovery mode through any other means, or if dev-mode is
already enabled, pressing Ctrl-D at the Insert screen will have no effect.
To return to normal mode:
Reboot. At the Dev screen, press ENTER or SPACE. It will reboot to
recovery mode and ask you if you want to return to normal mode. If you
press ESC or power off, you'll still be in dev-mode. Press ENTER or SPACE,
and it will reboot into normal mode (of course, if you've messed up your
images while in dev-mode, you'll just come right back to recovery mode
again).
You can also request a direct return to normal mode by running
crossystem disable_dev_request=1
and rebooting.
Change-Id: I435905855a6c39932ee466cc046bdc4c4c860f98
Reviewed-on: https://gerrit.chromium.org/gerrit/24160
Tested-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-by: Bill Richardson <wfrichar@chromium.org>
Commit-Ready: Bill Richardson <wfrichar@chromium.org>
127 lines
5.2 KiB
C
127 lines
5.2 KiB
C
/* Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*
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* Functions for querying, manipulating and locking rollback indices
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* stored in the TPM NVRAM.
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*/
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#ifndef VBOOT_REFERENCE_ROLLBACK_INDEX_H_
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#define VBOOT_REFERENCE_ROLLBACK_INDEX_H_
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#include "sysincludes.h"
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#include "tss_constants.h"
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/* TPM NVRAM location indices. */
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#define FIRMWARE_NV_INDEX 0x1007
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#define KERNEL_NV_INDEX 0x1008
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/* Structure definitions for TPM spaces */
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__pragma(pack(push, 1)) /* Support packing for MSVC. */
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/* Kernel space - KERNEL_NV_INDEX, locked with physical presence. */
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#define ROLLBACK_SPACE_KERNEL_VERSION 2
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#define ROLLBACK_SPACE_KERNEL_UID 0x4752574C /* 'GRWL' */
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typedef struct RollbackSpaceKernel {
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uint8_t struct_version; /* Struct version, for backwards
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* compatibility */
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uint32_t uid; /* Unique ID to detect space redefinition */
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uint32_t kernel_versions; /* Kernel versions */
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uint8_t reserved[3]; /* Reserved for future expansion */
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uint8_t crc8; /* Checksum (v2 and later only) */
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} __attribute__((packed)) RollbackSpaceKernel;
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/* Flags for firmware space */
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/* Last boot was developer mode. TPM ownership is cleared when
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* transitioning to/from developer mode. */
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#define FLAG_LAST_BOOT_DEVELOPER 0x01
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/* Some systems may not have a dedicated dev-mode switch, but enter and leave
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* dev-mode through some recovery-mode magic keypresses. For those systems,
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* the dev-mode "switch" state is in this bit (0=normal, 1=dev). To make it
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* work, a new flag is passed to VbInit(), indicating that the system lacks a
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* physical dev-mode switch. If a physical switch is present, this bit is
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* ignored. */
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#define FLAG_VIRTUAL_DEV_MODE_ON 0x02
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#define ROLLBACK_SPACE_FIRMWARE_VERSION 2
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/* Firmware space - FIRMWARE_NV_INDEX, locked with global lock. */
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typedef struct RollbackSpaceFirmware {
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uint8_t struct_version; /* Struct version, for backwards compatibility */
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uint8_t flags; /* Flags (see FLAG_* above) */
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uint32_t fw_versions; /* Firmware versions */
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uint8_t reserved[3]; /* Reserved for future expansion */
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uint8_t crc8; /* Checksum (v2 and later only) */
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} __attribute__((packed)) RollbackSpaceFirmware;
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__pragma(pack(pop)) /* Support packing for MSVC. */
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/* All functions return TPM_SUCCESS (zero) if successful, non-zero if error */
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/* These functions are called from VbInit(). They cannot use global
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* variables. */
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uint32_t RollbackS3Resume(void);
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/* These functions are callable from VbSelectFirmware(). They cannot use
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* global variables. */
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/* This must be called. */
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uint32_t RollbackFirmwareSetup(int recovery_mode, int is_hw_dev,
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int disable_dev_request,
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/* two outputs on success */
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int *is_virt_dev, uint32_t *tpm_version);
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/* Write may be called if the versions change */
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uint32_t RollbackFirmwareWrite(uint32_t version);
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/* Lock must be called */
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uint32_t RollbackFirmwareLock(void);
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/* These functions are callable from VbSelectAndLoadKernel(). They
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* may use global variables. */
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/* Read and write may be called to read and write the kernel version. */
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uint32_t RollbackKernelRead(uint32_t* version);
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uint32_t RollbackKernelWrite(uint32_t version);
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/* Lock must be called. Internally, it's ignored in recovery mode. */
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uint32_t RollbackKernelLock(void);
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/****************************************************************************/
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/* The following functions are internal apis, listed here for use by
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* unit tests only. */
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/* Issue a TPM_Clear and reenable/reactivate the TPM. */
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uint32_t TPMClearAndReenable(void);
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/* Like TlclWrite(), but checks for write errors due to hitting the 64-write
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* limit and clears the TPM when that happens. This can only happen when the
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* TPM is unowned, so it is OK to clear it (and we really have no choice).
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* This is not expected to happen frequently, but it could happen. */
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uint32_t SafeWrite(uint32_t index, const void* data, uint32_t length);
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/* Similarly to SafeWrite(), this ensures we don't fail a DefineSpace because
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* we hit the TPM write limit. This is even less likely to happen than with
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* writes because we only define spaces once at initialization, but we'd rather
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* be paranoid about this. */
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uint32_t SafeDefineSpace(uint32_t index, uint32_t perm, uint32_t size);
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/* Performs one-time initializations. Creates the NVRAM spaces, and sets their
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* initial values as needed. Sets the nvLocked bit and ensures the physical
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* presence command is enabled and locked.
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*/
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uint32_t OneTimeInitializeTPM(RollbackSpaceFirmware* rsf,
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RollbackSpaceKernel* rsk);
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/* SetupTPM starts the TPM and establishes the root of trust for the
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* anti-rollback mechanism. */
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uint32_t SetupTPM(int recovery_mode, int developer_mode,
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int disable_dev_request, RollbackSpaceFirmware* rsf);
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/* Utility function to turn the virtual dev-mode flag on or off. 0=off, 1=on */
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uint32_t SetVirtualDevMode(int val);
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#endif /* VBOOT_REFERENCE_ROLLBACK_INDEX_H_ */
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