| /* 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. |
| * |
| * Functions for querying, manipulating and locking rollback indices |
| * stored in the TPM NVRAM. |
| */ |
| |
| #ifndef VBOOT_REFERENCE_ROLLBACK_INDEX_H_ |
| #define VBOOT_REFERENCE_ROLLBACK_INDEX_H_ |
| |
| #include "sysincludes.h" |
| #include "tss_constants.h" |
| |
| /* TPM NVRAM location indices. */ |
| #define FIRMWARE_NV_INDEX 0x1007 |
| #define KERNEL_NV_INDEX 0x1008 |
| |
| /* Structure definitions for TPM spaces */ |
| |
| /* Kernel space - KERNEL_NV_INDEX, locked with physical presence. */ |
| #define ROLLBACK_SPACE_KERNEL_VERSION 2 |
| #define ROLLBACK_SPACE_KERNEL_UID 0x4752574C /* 'GRWL' */ |
| |
| typedef struct RollbackSpaceKernel { |
| /* Struct version, for backwards compatibility */ |
| uint8_t struct_version; |
| /* Unique ID to detect space redefinition */ |
| uint32_t uid; |
| /* Kernel versions */ |
| uint32_t kernel_versions; |
| /* Reserved for future expansion */ |
| uint8_t reserved[3]; |
| /* Checksum (v2 and later only) */ |
| uint8_t crc8; |
| } __attribute__((packed)) RollbackSpaceKernel; |
| |
| /* Flags for firmware space */ |
| /* |
| * Last boot was developer mode. TPM ownership is cleared when transitioning |
| * to/from developer mode. |
| */ |
| #define FLAG_LAST_BOOT_DEVELOPER 0x01 |
| /* |
| * Some systems may not have a dedicated dev-mode switch, but enter and leave |
| * dev-mode through some recovery-mode magic keypresses. For those systems, the |
| * dev-mode "switch" state is in this bit (0=normal, 1=dev). To make it work, a |
| * new flag is passed to VbInit(), indicating that the system lacks a physical |
| * dev-mode switch. If a physical switch is present, this bit is ignored. |
| */ |
| #define FLAG_VIRTUAL_DEV_MODE_ON 0x02 |
| |
| /* Firmware space - FIRMWARE_NV_INDEX, locked with global lock. */ |
| #define ROLLBACK_SPACE_FIRMWARE_VERSION 2 |
| |
| typedef struct RollbackSpaceFirmware { |
| /* Struct version, for backwards compatibility */ |
| uint8_t struct_version; |
| /* Flags (see FLAG_* above) */ |
| uint8_t flags; |
| /* Firmware versions */ |
| uint32_t fw_versions; |
| /* Reserved for future expansion */ |
| uint8_t reserved[3]; |
| /* Checksum (v2 and later only) */ |
| uint8_t crc8; |
| } __attribute__((packed)) RollbackSpaceFirmware; |
| |
| /* All functions return TPM_SUCCESS (zero) if successful, non-zero if error */ |
| |
| /* |
| * These functions are called from VbInit(). They cannot use global |
| * variables. |
| */ |
| |
| uint32_t RollbackS3Resume(void); |
| |
| /* |
| * These functions are callable from VbSelectFirmware(). They cannot use |
| * global variables. |
| */ |
| |
| /** |
| * This must be called. |
| */ |
| uint32_t RollbackFirmwareSetup(int recovery_mode, int is_hw_dev, |
| int disable_dev_request, |
| int clear_tpm_owner_request, |
| /* two outputs on success */ |
| int *is_virt_dev, uint32_t *tpm_version); |
| |
| /** |
| * Write may be called if the versions change. |
| */ |
| uint32_t RollbackFirmwareWrite(uint32_t version); |
| |
| /** |
| * Lock must be called. |
| */ |
| uint32_t RollbackFirmwareLock(void); |
| |
| /* |
| * These functions are callable from VbSelectAndLoadKernel(). They may use |
| * global variables. |
| */ |
| |
| /** |
| * Read stored kernel version. |
| */ |
| uint32_t RollbackKernelRead(uint32_t *version); |
| |
| /** |
| * Write stored kernel version. |
| */ |
| uint32_t RollbackKernelWrite(uint32_t version); |
| |
| /** |
| * Lock must be called. Internally, it's ignored in recovery mode. |
| */ |
| uint32_t RollbackKernelLock(int recovery_mode); |
| |
| /****************************************************************************/ |
| |
| /* |
| * The following functions are internal apis, listed here for use by unit tests |
| * only. |
| */ |
| |
| /** |
| * Issue a TPM_Clear and reenable/reactivate the TPM. |
| */ |
| uint32_t TPMClearAndReenable(void); |
| |
| /** |
| * Like TlclWrite(), but checks for write errors due to hitting the 64-write |
| * limit and clears the TPM when that happens. This can only happen when the |
| * TPM is unowned, so it is OK to clear it (and we really have no choice). |
| * This is not expected to happen frequently, but it could happen. |
| */ |
| uint32_t SafeWrite(uint32_t index, const void *data, uint32_t length); |
| |
| /** |
| * Similarly to SafeWrite(), this ensures we don't fail a DefineSpace because |
| * we hit the TPM write limit. This is even less likely to happen than with |
| * writes because we only define spaces once at initialization, but we'd rather |
| * be paranoid about this. |
| */ |
| uint32_t SafeDefineSpace(uint32_t index, uint32_t perm, uint32_t size); |
| |
| /** |
| * Perform one-time initializations. |
| * |
| * Create the NVRAM spaces, and set their initial values as needed. Sets the |
| * nvLocked bit and ensures the physical presence command is enabled and |
| * locked. |
| */ |
| uint32_t OneTimeInitializeTPM(RollbackSpaceFirmware *rsf, |
| RollbackSpaceKernel *rsk); |
| |
| /** |
| * Start the TPM and establish the root of trust for the anti-rollback |
| * mechanism. |
| */ |
| uint32_t SetupTPM(int recovery_mode, int developer_mode, |
| int disable_dev_request, int clear_tpm_owner_request, |
| RollbackSpaceFirmware *rsf); |
| |
| /** |
| * Utility function to turn the virtual dev-mode flag on or off. 0=off, 1=on. |
| */ |
| uint32_t SetVirtualDevMode(int val); |
| |
| #endif /* VBOOT_REFERENCE_ROLLBACK_INDEX_H_ */ |