/* * This file is part of the coreboot project. * * Copyright (C) 2011 The ChromiumOS Authors. All rights reserved. * * 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. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #include #include #include #include #include "chromeos.h" //#define EXTRA_LOGGING #define TPM_LARGE_ENOUGH_COMMAND_SIZE 256 /* saves space in the firmware */ #define TPM_SUCCESS ((u32)0x00000000) #define TPM_E_IOERROR ((u32)0x0000001f) #define TPM_E_COMMUNICATION_ERROR ((u32)0x00005004) #define TPM_E_NON_FATAL ((u32)0x00000800) #define TPM_E_INVALID_POSTINIT ((u32)0x00000026) #define TPM_E_NEEDS_SELFTEST ((u32)(TPM_E_NON_FATAL + 1)) #define TPM_E_DOING_SELFTEST ((u32)(TPM_E_NON_FATAL + 2)) static const struct { u8 buffer[12]; } tpm_resume_cmd = { { 0x0, 0xc1, 0x0, 0x0, 0x0, 0xc, 0x0, 0x0, 0x0, 0x99, 0x0, 0x2 } }; static const struct { u8 buffer[10]; } tpm_continueselftest_cmd = { { 0x0, 0xc1, 0x0, 0x0, 0x0, 0xa, 0x0, 0x0, 0x0, 0x53 } }; static inline void FromTpmUint32(const u8 * buffer, u32 * x) { *x = ((buffer[0] << 24) | (buffer[1] << 16) | (buffer[2] << 8) | buffer[3]); } static inline int TpmCommandSize(const u8 * buffer) { u32 size; FromTpmUint32(buffer + sizeof(u16), &size); return (int)size; } /* Gets the code field of a TPM command. */ static inline int TpmCommandCode(const u8 * buffer) { u32 code; FromTpmUint32(buffer + sizeof(u16) + sizeof(u32), &code); return code; } /* Gets the return code field of a TPM result. */ static inline int TpmReturnCode(const u8 * buffer) { return TpmCommandCode(buffer); } /* Like TlclSendReceive below, but do not retry if NEEDS_SELFTEST or * DOING_SELFTEST errors are returned. */ static u32 TlclSendReceiveNoRetry(const u8 * request, u8 * response, int max_length) { size_t response_length = max_length; u32 result; #ifdef EXTRA_LOGGING printk(BIOS_DEBUG, "TPM: command: %x%x %x%x%x%x %x%x%x%x\n", request[0], request[1], request[2], request[3], request[4], request[5], request[6], request[7], request[8], request[9]); #endif result = TPM_SUCCESS; if (tis_sendrecv (request, TpmCommandSize(request), response, &response_length)) result = TPM_E_IOERROR; if (0 != result) { /* Communication with TPM failed, so response is garbage */ printk(BIOS_DEBUG, "TPM: command 0x%x send/receive failed: 0x%x\n", TpmCommandCode(request), result); return TPM_E_COMMUNICATION_ERROR; } /* Otherwise, use the result code from the response */ result = TpmReturnCode(response); /* TODO: add paranoia about returned response_length vs. max_length * (and possibly expected length from the response header). See * crosbug.com/17017 */ #ifdef EXTRA_LOGGING printk(BIOS_DEBUG, "TPM: response: %x%x %x%x%x%x %x%x%x%x\n", response[0], response[1], response[2], response[3], response[4], response[5], response[6], response[7], response[8], response[9]); #endif printk(BIOS_DEBUG, "TPM: command 0x%x returned 0x%x\n", TpmCommandCode(request), result); return result; } static inline u32 TlclContinueSelfTest(void) { u8 response[TPM_LARGE_ENOUGH_COMMAND_SIZE]; printk(BIOS_DEBUG, "TPM: Continue self test\n"); /* Call the No Retry version of SendReceive to avoid recursion. */ return TlclSendReceiveNoRetry(tpm_continueselftest_cmd.buffer, response, sizeof(response)); } /* Sends a TPM command and gets a response. Returns 0 if success or the TPM * error code if error. In the firmware, waits for the self test to complete * if needed. In the host, reports the first error without retries. */ static u32 TlclSendReceive(const u8 * request, u8 * response, int max_length) { u32 result = TlclSendReceiveNoRetry(request, response, max_length); /* When compiling for the firmware, hide command failures due to the self * test not having run or completed. */ /* If the command fails because the self test has not completed, try it * again after attempting to ensure that the self test has completed. */ if (result == TPM_E_NEEDS_SELFTEST || result == TPM_E_DOING_SELFTEST) { result = TlclContinueSelfTest(); if (result != TPM_SUCCESS) { return result; } #if defined(TPM_BLOCKING_CONTINUESELFTEST) || defined(VB_RECOVERY_MODE) /* Retry only once */ result = TlclSendReceiveNoRetry(request, response, max_length); #else /* This needs serious testing. The TPM specification says: * "iii. The caller MUST wait for the actions of * TPM_ContinueSelfTest to complete before reissuing the * command C1." But, if ContinueSelfTest is non-blocking, how * do we know that the actions have completed other than trying * again? */ do { result = TlclSendReceiveNoRetry(request, response, max_length); } while (result == TPM_E_DOING_SELFTEST); #endif } return result; } void init_vboot(void) { u32 result; u8 response[TPM_LARGE_ENOUGH_COMMAND_SIZE]; printk(BIOS_DEBUG, "TPM: Init\n"); if (tis_init()) return; printk(BIOS_DEBUG, "TPM: Open\n"); if (tis_open()) return; printk(BIOS_DEBUG, "TPM: Resume\n"); result = TlclSendReceive(tpm_resume_cmd.buffer, response, sizeof(response)); if (result == TPM_E_INVALID_POSTINIT) { /* We're on a platform where the TPM maintains power in S3, so * it's already initialized. */ printk(BIOS_DEBUG, "TPM: Already initialized.\n"); return; } if (result == TPM_SUCCESS) { printk(BIOS_DEBUG, "TPM: OK.\n"); return; } // TODO(reinauer) hard reboot? }