Add TPM support to coreboot

and initialize the TPM on S3 resume

This patch integrates the TPM driver and runs TPM resume upon an ACPI S3
resume without including any other parts of vboot.

We could link against vboot_fw.a but it is compiled with u-boot's CFLAGS
(that are incompatible with coreboot's) and it does a lot more than we
want it to do.

Change-Id: I000d4322ef313e931e23c56defaa17e3a4d7f8cf
Signed-off-by: Stefan Reinauer <reinauer@google.com>
Reviewed-on: http://review.coreboot.org/731
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

1 files changed, 201 insertions, 0 deletions

diff --git a/src/vendorcode/google/chromeos/vboot.c b/src/vendorcode/google/chromeos/vboot.c
new file mode 100644
index 0000000000..e0a8c9b336
--- /dev/null
+++ b/src/vendorcode/google/chromeos/vboot.c
@@ -0,0 +1,201 @@
+/*
+ * 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?
+}