Make TPM datagrams const, since they cannot be modified in the RO firmware.

firmware/lib/tpm_lite/tlcl.c

 /* Copyright (c) 2010 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.
  */
 
 /* A lightweight TPM command library.
  *
  * The general idea is that TPM commands are array of bytes whose
  * fields are mostly compile-time constant.  The goal is to build much
  * of the commands at compile time (or build time) and change some of
@@ skipping 29 matching lines @@
   return code;
 }
 
 /* Gets the return code field of a TPM result. */
 static INLINE int TpmReturnCode(const uint8_t* buffer) {
   return TpmCommandCode(buffer);
 }
 
 /* Sends a TPM command and gets a response.  Returns 0 if success or the TPM
  * error code if error. */
-static uint32_t TlclSendReceive(uint8_t* request, uint8_t* response,
+static uint32_t TlclSendReceive(const uint8_t* request, uint8_t* response,
                                 int max_length) {
 
   uint32_t result;
 
 #ifdef EXTRA_LOGGING
   VBDEBUG(("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
@@ skipping 17 matching lines @@
 #endif
 
   VBDEBUG(("TPM: command 0x%x returned 0x%x\n",
            TpmCommandCode(request), result));
 
   return result;
 }
 
 
 /* Sends a command and returns the error code. */
-static uint32_t Send(uint8_t* command) {
+static uint32_t Send(const uint8_t* command) {
   uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE];
   return TlclSendReceive(command, response, sizeof(response));
 }
 
 /* Exported functions. */
 
 void TlclLibInit(void) {
   TlclStubInit();
 }
 
@@ skipping 220 matching lines @@
   Memcpy(&cmd, &tpm_getpermissions_cmd, sizeof(cmd));
   ToTpmUint32(cmd.buffer + tpm_getpermissions_cmd.index, index);
   result = TlclSendReceive(cmd.buffer, response, sizeof(response));
   if (result != TPM_SUCCESS)
     return result;
 
   nvdata = response + kTpmResponseHeaderLength + sizeof(size);
   FromTpmUint32(nvdata + kNvDataPublicPermissionsOffset, permissions);
   return result;
 }