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/*
* 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 <types.h>
#include <console/console.h>
#include <arch/acpi.h>
#include <pc80/tpm.h>
#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?
}
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