/*
- * Copyright (c) 2011 The Chromium OS Authors.
+ * Copyright (c) 2013 The Chromium OS Authors.
  *
  * See file CREDITS for list of people who contributed to this
  * project.
 
 #include <common.h>
 #include <command.h>
+#include <malloc.h>
 #include <tpm.h>
+#include <asm/unaligned.h>
+#include <linux/string.h>
 
-#define MAX_TRANSACTION_SIZE 30
+/**
+ * Print a byte string in hexdecimal format, 16-bytes per line.
+ *
+ * @param data         byte string to be printed
+ * @param count                number of bytes to be printed
+ */
+static void print_byte_string(uint8_t *data, size_t count)
+{
+       int i, print_newline = 0;
 
-/*
- * tpm_write() expects a variable number of parameters: the internal address
- * followed by data to write, byte by byte.
+       for (i = 0; i < count; i++) {
+               printf(" %02x", data[i]);
+               print_newline = (i % 16 == 15);
+               if (print_newline)
+                       putc('\n');
+       }
+       /* Avoid duplicated newline at the end */
+       if (!print_newline)
+               putc('\n');
+}
+
+/**
+ * Convert a text string of hexdecimal values into a byte string.
  *
- * Returns 0 on success or -1 on errors (wrong arguments or TPM failure).
+ * @param bytes                text string of hexdecimal values with no space
+ *                     between them
+ * @param data         output buffer for byte string.  The caller has to make
+ *                     sure it is large enough for storing the output.  If
+ *                     NULL is passed, a large enough buffer will be allocated,
+ *                     and the caller must free it.
+ * @param count_ptr    output variable for the length of byte string
+ * @return pointer to output buffer
  */
-static int tpm_process(int argc, char * const argv[], cmd_tbl_t *cmdtp)
-{
-       u8 tpm_buffer[MAX_TRANSACTION_SIZE];
-       u32 write_size, read_size;
-       char *p;
-       int rv = -1;
-
-       for (write_size = 0; write_size < argc; write_size++) {
-               u32 datum = simple_strtoul(argv[write_size], &p, 0);
-               if (*p || (datum > 0xff)) {
-                       printf("\n%s: bad data value\n\n", argv[write_size]);
-                       cmd_usage(cmdtp);
-                       return rv;
-               }
-               tpm_buffer[write_size] = (u8)datum;
+static void *parse_byte_string(char *bytes, uint8_t *data, size_t *count_ptr)
+{
+       char byte[3];
+       size_t count, length;
+       int i;
+
+       length = strlen(bytes);
+       count = length / 2;
+
+       if (!data)
+               data = malloc(count);
+       if (!data)
+               return NULL;
+
+       byte[2] = '\0';
+       for (i = 0; i < length; i += 2) {
+               byte[0] = bytes[i];
+               byte[1] = bytes[i + 1];
+               data[i / 2] = (uint8_t)simple_strtoul(byte, NULL, 16);
        }
 
-       read_size = sizeof(tpm_buffer);
-       if (!tis_sendrecv(tpm_buffer, write_size, tpm_buffer, &read_size)) {
-               int i;
-               puts("Got TPM response:\n");
-               for (i = 0; i < read_size; i++)
-                       printf(" %2.2x", tpm_buffer[i]);
-               puts("\n");
-               rv = 0;
-       } else {
-               puts("tpm command failed\n");
+       if (count_ptr)
+               *count_ptr = count;
+
+       return data;
+}
+
+/**
+ * Convert TPM command return code to U-Boot command error codes.
+ *
+ * @param return_code  TPM command return code
+ * @return value of enum command_ret_t
+ */
+static int convert_return_code(uint32_t return_code)
+{
+       if (return_code)
+               return CMD_RET_FAILURE;
+       else
+               return CMD_RET_SUCCESS;
+}
+
+/**
+ * Return number of values defined by a type string.
+ *
+ * @param type_str     type string
+ * @return number of values of type string
+ */
+static int type_string_get_num_values(const char *type_str)
+{
+       return strlen(type_str);
+}
+
+/**
+ * Return total size of values defined by a type string.
+ *
+ * @param type_str     type string
+ * @return total size of values of type string, or 0 if type string
+ *  contains illegal type character.
+ */
+static size_t type_string_get_space_size(const char *type_str)
+{
+       size_t size;
+
+       for (size = 0; *type_str; type_str++) {
+               switch (*type_str) {
+               case 'b':
+                       size += 1;
+                       break;
+               case 'w':
+                       size += 2;
+                       break;
+               case 'd':
+                       size += 4;
+                       break;
+               default:
+                       return 0;
+               }
        }
-       return rv;
+
+       return size;
 }
 
-#define CHECK(exp) do {                                                        \
-               int _rv = exp;                                          \
-               if (_rv) {                                              \
-                       printf("CHECK: %s %d %x\n", #exp, __LINE__, _rv);\
-               }                                                       \
-       } while (0)
+/**
+ * Allocate a buffer large enough to hold values defined by a type
+ * string.  The caller has to free the buffer.
+ *
+ * @param type_str     type string
+ * @param count                pointer for storing size of buffer
+ * @return pointer to buffer or NULL on error
+ */
+static void *type_string_alloc(const char *type_str, uint32_t *count)
+{
+       void *data;
+       size_t size;
+
+       size = type_string_get_space_size(type_str);
+       if (!size)
+               return NULL;
+       data = malloc(size);
+       if (data)
+               *count = size;
 
-static int tpm_process_stress(int repeat_count)
+       return data;
+}
+
+/**
+ * Pack values defined by a type string into a buffer.  The buffer must have
+ * large enough space.
+ *
+ * @param type_str     type string
+ * @param values       text strings of values to be packed
+ * @param data         output buffer of values
+ * @return 0 on success, non-0 on error
+ */
+static int type_string_pack(const char *type_str, char * const values[],
+               uint8_t *data)
 {
-       int i;
-       int rv = 0;
-       u8 request[] = {0x0, 0xc1,
-                       0x0, 0x0, 0x0, 0x16,
-                       0x0, 0x0, 0x0, 0x65,
-                       0x0, 0x0, 0x0, 0x4,
-                       0x0, 0x0, 0x0, 0x4,
-                       0x0, 0x0, 0x1, 0x9};
-       u8 response[MAX_TRANSACTION_SIZE];
-       u32 rlength = MAX_TRANSACTION_SIZE;
-
-       CHECK(tis_init());
-
-       for (i = 0; i < repeat_count; i++) {
-               CHECK(tis_open());
-               rv = tis_sendrecv(request, sizeof(request), response, &rlength);
-               if (rv) {
-                       printf("tpm test failed at step %d with 0x%x\n", i, rv);
-                       CHECK(tis_close());
+       size_t offset;
+       uint32_t value;
+
+       for (offset = 0; *type_str; type_str++, values++) {
+               value = simple_strtoul(values[0], NULL, 0);
+               switch (*type_str) {
+               case 'b':
+                       data[offset] = value;
+                       offset += 1;
+                       break;
+               case 'w':
+                       put_unaligned_be16(value, data + offset);
+                       offset += 2;
+                       break;
+               case 'd':
+                       put_unaligned_be32(value, data + offset);
+                       offset += 4;
                        break;
+               default:
+                       return -1;
                }
-               CHECK(tis_close());
-               if ((response[6] || response[7] || response[8] || response[9])
-                   && response[9] != 0x26) {
-                       /* Ignore postinit errors */
-                       printf("tpm command failed at step %d\n"
-                              "tpm error code: %02x%02x%02x%02x\n", i,
-                              response[6], response[7],
-                              response[8], response[9]);
-                       rv = -1;
+       }
+
+       return 0;
+}
+
+/**
+ * Read values defined by a type string from a buffer, and write these values
+ * to environment variables.
+ *
+ * @param type_str     type string
+ * @param data         input buffer of values
+ * @param vars         names of environment variables
+ * @return 0 on success, non-0 on error
+ */
+static int type_string_write_vars(const char *type_str, uint8_t *data,
+               char * const vars[])
+{
+       size_t offset;
+       uint32_t value;
+
+       for (offset = 0; *type_str; type_str++, vars++) {
+               switch (*type_str) {
+               case 'b':
+                       value = data[offset];
+                       offset += 1;
+                       break;
+               case 'w':
+                       value = get_unaligned_be16(data + offset);
+                       offset += 2;
                        break;
+               case 'd':
+                       value = get_unaligned_be32(data + offset);
+                       offset += 4;
+                       break;
+               default:
+                       return -1;
                }
+               if (setenv_ulong(*vars, value))
+                       return -1;
        }
-       return rv;
+
+       return 0;
 }
 
+static int do_tpm_startup(cmd_tbl_t *cmdtp, int flag,
+               int argc, char * const argv[])
+{
+       enum tpm_startup_type mode;
 
-static int do_tpm_many(cmd_tbl_t *cmdtp, int flag,
-                      int argc, char * const argv[], int repeat_count)
+       if (argc != 2)
+               return CMD_RET_USAGE;
+       if (!strcasecmp("TPM_ST_CLEAR", argv[1])) {
+               mode = TPM_ST_CLEAR;
+       } else if (!strcasecmp("TPM_ST_STATE", argv[1])) {
+               mode = TPM_ST_STATE;
+       } else if (!strcasecmp("TPM_ST_DEACTIVATED", argv[1])) {
+               mode = TPM_ST_DEACTIVATED;
+       } else {
+               printf("Couldn't recognize mode string: %s\n", argv[1]);
+               return CMD_RET_FAILURE;
+       }
+
+       return convert_return_code(tpm_startup(mode));
+}
+
+static int do_tpm_nv_define_space(cmd_tbl_t *cmdtp, int flag,
+               int argc, char * const argv[])
+{
+       uint32_t index, perm, size;
+
+       if (argc != 4)
+               return CMD_RET_USAGE;
+       index = simple_strtoul(argv[1], NULL, 0);
+       perm = simple_strtoul(argv[2], NULL, 0);
+       size = simple_strtoul(argv[3], NULL, 0);
+
+       return convert_return_code(tpm_nv_define_space(index, perm, size));
+}
 
+static int do_tpm_nv_read_value(cmd_tbl_t *cmdtp, int flag,
+               int argc, char * const argv[])
 {
-       int rv = 0;
+       uint32_t index, count, rc;
+       void *data;
 
-       if (argc < 7 && repeat_count == 0) {
-               puts("command should be at least six bytes in size\n");
-               return -1;
+       if (argc != 4)
+               return CMD_RET_USAGE;
+       index = simple_strtoul(argv[1], NULL, 0);
+       data = (void *)simple_strtoul(argv[2], NULL, 0);
+       count = simple_strtoul(argv[3], NULL, 0);
+
+       rc = tpm_nv_read_value(index, data, count);
+       if (!rc) {
+               puts("area content:\n");
+               print_byte_string(data, count);
        }
 
-       if (repeat_count > 0) {
-               rv = tpm_process_stress(repeat_count);
-               return rv;
+       return convert_return_code(rc);
+}
+
+static int do_tpm_nv_write_value(cmd_tbl_t *cmdtp, int flag,
+               int argc, char * const argv[])
+{
+       uint32_t index, rc;
+       size_t count;
+       void *data;
+
+       if (argc != 3)
+               return CMD_RET_USAGE;
+       index = simple_strtoul(argv[1], NULL, 0);
+       data = parse_byte_string(argv[2], NULL, &count);
+       if (!data) {
+               printf("Couldn't parse byte string %s\n", argv[2]);
+               return CMD_RET_FAILURE;
        }
 
-       if (tis_init()) {
-               puts("tis_init() failed!\n");
-               return -1;
+       rc = tpm_nv_write_value(index, data, count);
+       free(data);
+
+       return convert_return_code(rc);
+}
+
+static int do_tpm_extend(cmd_tbl_t *cmdtp, int flag,
+               int argc, char * const argv[])
+{
+       uint32_t index, rc;
+       uint8_t in_digest[20], out_digest[20];
+
+       if (argc != 3)
+               return CMD_RET_USAGE;
+       index = simple_strtoul(argv[1], NULL, 0);
+       if (!parse_byte_string(argv[2], in_digest, NULL)) {
+               printf("Couldn't parse byte string %s\n", argv[2]);
+               return CMD_RET_FAILURE;
        }
 
-       if (tis_open()) {
-               puts("tis_open() failed!\n");
-               return -1;
+       rc = tpm_extend(index, in_digest, out_digest);
+       if (!rc) {
+               puts("PCR value after execution of the command:\n");
+               print_byte_string(out_digest, sizeof(out_digest));
        }
 
-       rv = tpm_process(argc - 1, argv + 1, cmdtp);
+       return convert_return_code(rc);
+}
+
+static int do_tpm_pcr_read(cmd_tbl_t *cmdtp, int flag,
+               int argc, char * const argv[])
+{
+       uint32_t index, count, rc;
+       void *data;
+
+       if (argc != 4)
+               return CMD_RET_USAGE;
+       index = simple_strtoul(argv[1], NULL, 0);
+       data = (void *)simple_strtoul(argv[2], NULL, 0);
+       count = simple_strtoul(argv[3], NULL, 0);
 
-       if (tis_close()) {
-               puts("tis_close() failed!\n");
-               rv = -1;
+       rc = tpm_pcr_read(index, data, count);
+       if (!rc) {
+               puts("Named PCR content:\n");
+               print_byte_string(data, count);
        }
 
-       return rv;
+       return convert_return_code(rc);
 }
 
+static int do_tpm_tsc_physical_presence(cmd_tbl_t *cmdtp, int flag,
+               int argc, char * const argv[])
+{
+       uint16_t presence;
+
+       if (argc != 2)
+               return CMD_RET_USAGE;
+       presence = (uint16_t)simple_strtoul(argv[1], NULL, 0);
 
-static int do_tpm(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+       return convert_return_code(tpm_tsc_physical_presence(presence));
+}
+
+static int do_tpm_read_pubek(cmd_tbl_t *cmdtp, int flag,
+               int argc, char * const argv[])
 {
-       return do_tpm_many(cmdtp, flag, argc, argv, 0);
+       uint32_t count, rc;
+       void *data;
+
+       if (argc != 3)
+               return CMD_RET_USAGE;
+       data = (void *)simple_strtoul(argv[1], NULL, 0);
+       count = simple_strtoul(argv[2], NULL, 0);
+
+       rc = tpm_read_pubek(data, count);
+       if (!rc) {
+               puts("pubek value:\n");
+               print_byte_string(data, count);
+       }
+
+       return convert_return_code(rc);
 }
 
+static int do_tpm_physical_set_deactivated(cmd_tbl_t *cmdtp, int flag,
+               int argc, char * const argv[])
+{
+       uint8_t state;
+
+       if (argc != 2)
+               return CMD_RET_USAGE;
+       state = (uint8_t)simple_strtoul(argv[1], NULL, 0);
 
-U_BOOT_CMD(tpm, MAX_TRANSACTION_SIZE, 1, do_tpm,
-          "<byte> [<byte> ...]   - write data and read response",
-          "send arbitrary data (at least 6 bytes) to the TPM "
-          "device and read the response"
-);
+       return convert_return_code(tpm_physical_set_deactivated(state));
+}
+
+static int do_tpm_get_capability(cmd_tbl_t *cmdtp, int flag,
+               int argc, char * const argv[])
+{
+       uint32_t cap_area, sub_cap, rc;
+       void *cap;
+       size_t count;
+
+       if (argc != 5)
+               return CMD_RET_USAGE;
+       cap_area = simple_strtoul(argv[1], NULL, 0);
+       sub_cap = simple_strtoul(argv[2], NULL, 0);
+       cap = (void *)simple_strtoul(argv[3], NULL, 0);
+       count = simple_strtoul(argv[4], NULL, 0);
+
+       rc = tpm_get_capability(cap_area, sub_cap, cap, count);
+       if (!rc) {
+               puts("capability information:\n");
+               print_byte_string(cap, count);
+       }
+
+       return convert_return_code(rc);
+}
 
-static int do_tpm_stress(cmd_tbl_t *cmdtp, int flag,
-                        int argc, char * const argv[])
+#define TPM_COMMAND_NO_ARG(cmd)                                \
+static int do_##cmd(cmd_tbl_t *cmdtp, int flag,                \
+               int argc, char * const argv[])          \
+{                                                      \
+       if (argc != 1)                                  \
+               return CMD_RET_USAGE;                   \
+       return convert_return_code(cmd());              \
+}
+
+TPM_COMMAND_NO_ARG(tpm_init)
+TPM_COMMAND_NO_ARG(tpm_self_test_full)
+TPM_COMMAND_NO_ARG(tpm_continue_self_test)
+TPM_COMMAND_NO_ARG(tpm_force_clear)
+TPM_COMMAND_NO_ARG(tpm_physical_enable)
+TPM_COMMAND_NO_ARG(tpm_physical_disable)
+
+static int do_tpm_raw_transfer(cmd_tbl_t *cmdtp, int flag,
+               int argc, char * const argv[])
+{
+       void *command;
+       uint8_t response[1024];
+       size_t count, response_length = sizeof(response);
+       uint32_t rc;
+
+       command = parse_byte_string(argv[1], NULL, &count);
+       if (!command) {
+               printf("Couldn't parse byte string %s\n", argv[1]);
+               return CMD_RET_FAILURE;
+       }
+
+       rc = tis_sendrecv(command, count, response, &response_length);
+       free(command);
+       if (!rc) {
+               puts("tpm response:\n");
+               print_byte_string(response, response_length);
+       }
+
+       return convert_return_code(rc);
+}
+
+static int do_tpm_nv_define(cmd_tbl_t *cmdtp, int flag,
+               int argc, char * const argv[])
+{
+       uint32_t index, perm, size;
+
+       if (argc != 4)
+               return CMD_RET_USAGE;
+       size = type_string_get_space_size(argv[1]);
+       if (!size) {
+               printf("Couldn't parse arguments\n");
+               return CMD_RET_USAGE;
+       }
+       index = simple_strtoul(argv[2], NULL, 0);
+       perm = simple_strtoul(argv[3], NULL, 0);
+
+       return convert_return_code(tpm_nv_define_space(index, perm, size));
+}
+
+static int do_tpm_nv_read(cmd_tbl_t *cmdtp, int flag,
+               int argc, char * const argv[])
 {
-       long unsigned int n;
-       int rv;
+       uint32_t index, count, err;
+       void *data;
 
-       if (argc != 2) {
-               puts("usage: tpm_stress <count>\n");
-               return -1;
+       if (argc < 3)
+               return CMD_RET_USAGE;
+       if (argc != 3 + type_string_get_num_values(argv[1]))
+               return CMD_RET_USAGE;
+       index = simple_strtoul(argv[2], NULL, 0);
+       data = type_string_alloc(argv[1], &count);
+       if (!data) {
+               printf("Couldn't parse arguments\n");
+               return CMD_RET_USAGE;
        }
 
-       rv = strict_strtoul(argv[1], 10, &n);
-       if (rv) {
-               puts("tpm_stress: bad count");
-               return -1;
+       err = tpm_nv_read_value(index, data, count);
+       if (!err) {
+               if (type_string_write_vars(argv[1], data, argv + 3)) {
+                       printf("Couldn't write to variables\n");
+                       err = ~0;
+               }
        }
+       free(data);
+
+       return convert_return_code(err);
+}
+
+static int do_tpm_nv_write(cmd_tbl_t *cmdtp, int flag,
+               int argc, char * const argv[])
+{
+       uint32_t index, count, err;
+       void *data;
+
+       if (argc < 3)
+               return CMD_RET_USAGE;
+       if (argc != 3 + type_string_get_num_values(argv[1]))
+               return CMD_RET_USAGE;
+       index = simple_strtoul(argv[2], NULL, 0);
+       data = type_string_alloc(argv[1], &count);
+       if (!data) {
+               printf("Couldn't parse arguments\n");
+               return CMD_RET_USAGE;
+       }
+       if (type_string_pack(argv[1], argv + 3, data)) {
+               printf("Couldn't parse arguments\n");
+               free(data);
+               return CMD_RET_USAGE;
+       }
+
+       err = tpm_nv_write_value(index, data, count);
+       free(data);
+
+       return convert_return_code(err);
+}
+
+#define MAKE_TPM_CMD_ENTRY(cmd) \
+       U_BOOT_CMD_MKENT(cmd, 0, 1, do_tpm_ ## cmd, "", "")
+
+static cmd_tbl_t tpm_commands[] = {
+       U_BOOT_CMD_MKENT(init, 0, 1,
+                       do_tpm_init, "", ""),
+       U_BOOT_CMD_MKENT(startup, 0, 1,
+                       do_tpm_startup, "", ""),
+       U_BOOT_CMD_MKENT(self_test_full, 0, 1,
+                       do_tpm_self_test_full, "", ""),
+       U_BOOT_CMD_MKENT(continue_self_test, 0, 1,
+                       do_tpm_continue_self_test, "", ""),
+       U_BOOT_CMD_MKENT(force_clear, 0, 1,
+                       do_tpm_force_clear, "", ""),
+       U_BOOT_CMD_MKENT(physical_enable, 0, 1,
+                       do_tpm_physical_enable, "", ""),
+       U_BOOT_CMD_MKENT(physical_disable, 0, 1,
+                       do_tpm_physical_disable, "", ""),
+       U_BOOT_CMD_MKENT(nv_define_space, 0, 1,
+                       do_tpm_nv_define_space, "", ""),
+       U_BOOT_CMD_MKENT(nv_read_value, 0, 1,
+                       do_tpm_nv_read_value, "", ""),
+       U_BOOT_CMD_MKENT(nv_write_value, 0, 1,
+                       do_tpm_nv_write_value, "", ""),
+       U_BOOT_CMD_MKENT(extend, 0, 1,
+                       do_tpm_extend, "", ""),
+       U_BOOT_CMD_MKENT(pcr_read, 0, 1,
+                       do_tpm_pcr_read, "", ""),
+       U_BOOT_CMD_MKENT(tsc_physical_presence, 0, 1,
+                       do_tpm_tsc_physical_presence, "", ""),
+       U_BOOT_CMD_MKENT(read_pubek, 0, 1,
+                       do_tpm_read_pubek, "", ""),
+       U_BOOT_CMD_MKENT(physical_set_deactivated, 0, 1,
+                       do_tpm_physical_set_deactivated, "", ""),
+       U_BOOT_CMD_MKENT(get_capability, 0, 1,
+                       do_tpm_get_capability, "", ""),
+       U_BOOT_CMD_MKENT(raw_transfer, 0, 1,
+                       do_tpm_raw_transfer, "", ""),
+       U_BOOT_CMD_MKENT(nv_define, 0, 1,
+                       do_tpm_nv_define, "", ""),
+       U_BOOT_CMD_MKENT(nv_read, 0, 1,
+                       do_tpm_nv_read, "", ""),
+       U_BOOT_CMD_MKENT(nv_write, 0, 1,
+                       do_tpm_nv_write, "", ""),
+};
+
+static int do_tpm(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+       cmd_tbl_t *tpm_cmd;
+
+       if (argc < 2)
+               return CMD_RET_USAGE;
+       tpm_cmd = find_cmd_tbl(argv[1], tpm_commands, ARRAY_SIZE(tpm_commands));
+       if (!tpm_cmd)
+               return CMD_RET_USAGE;
 
-       return do_tpm_many(cmdtp, flag, argc, argv, n);
+       return tpm_cmd->cmd(cmdtp, flag, argc - 1, argv + 1);
 }
 
-U_BOOT_CMD(tpm_stress, 2, 1, do_tpm_stress,
-          "<n>   - stress-test communication with TPM",
-          "Repeat a TPM transaction (request-response) N times"
+U_BOOT_CMD(tpm, CONFIG_SYS_MAXARGS, 1, do_tpm,
+"Issue a TPM command",
+"cmd args...\n"
+"    - Issue TPM command <cmd> with arguments <args...>.\n"
+"Admin Startup and State Commands:\n"
+"  init\n"
+"    - Put TPM into a state where it waits for 'startup' command.\n"
+"  startup mode\n"
+"    - Issue TPM_Starup command.  <mode> is one of TPM_ST_CLEAR,\n"
+"      TPM_ST_STATE, and TPM_ST_DEACTIVATED.\n"
+"Admin Testing Commands:\n"
+"  self_test_full\n"
+"    - Test all of the TPM capabilities.\n"
+"  continue_self_test\n"
+"    - Inform TPM that it should complete the self-test.\n"
+"Admin Opt-in Commands:\n"
+"  physical_enable\n"
+"    - Set the PERMANENT disable flag to FALSE using physical presence as\n"
+"      authorization.\n"
+"  physical_disable\n"
+"    - Set the PERMANENT disable flag to TRUE using physical presence as\n"
+"      authorization.\n"
+"  physical_set_deactivated 0|1\n"
+"    - Set deactivated flag.\n"
+"Admin Ownership Commands:\n"
+"  force_clear\n"
+"    - Issue TPM_ForceClear command.\n"
+"  tsc_physical_presence flags\n"
+"    - Set TPM device's Physical Presence flags to <flags>.\n"
+"The Capability Commands:\n"
+"  get_capability cap_area sub_cap addr count\n"
+"    - Read <count> bytes of TPM capability indexed by <cap_area> and\n"
+"      <sub_cap> to memory address <addr>.\n"
+"Endorsement Key Handling Commands:\n"
+"  read_pubek addr count\n"
+"    - Read <count> bytes of the public endorsement key to memory\n"
+"      address <addr>\n"
+"Integrity Collection and Reporting Commands:\n"
+"  extend index digest_hex_string\n"
+"    - Add a new measurement to a PCR.  Update PCR <index> with the 20-bytes\n"
+"      <digest_hex_string>\n"
+"  pcr_read index addr count\n"
+"    - Read <count> bytes from PCR <index> to memory address <addr>.\n"
+"Non-volatile Storage Commands:\n"
+"  nv_define_space index permission size\n"
+"    - Establish a space at index <index> with <permission> of <size> bytes.\n"
+"  nv_read_value index addr count\n"
+"    - Read <count> bytes from space <index> to memory address <addr>.\n"
+"  nv_write_value index addr count\n"
+"    - Write <count> bytes from memory address <addr> to space <index>.\n"
+"Miscellaneous helper functions:\n"
+"  raw_transfer byte_string\n"
+"    - Send a byte string <byte_string> to TPM and print the response.\n"
+" Non-volatile storage helper functions:\n"
+"    These helper functions treat a non-volatile space as a non-padded\n"
+"    sequence of integer values.  These integer values are defined by a type\n"
+"    string, which is a text string of 'bwd' characters: 'b' means a 8-bit\n"
+"    value, 'w' 16-bit value, 'd' 32-bit value.  All helper functions take\n"
+"    a type string as their first argument.\n"
+"  nv_define type_string index perm\n"
+"    - Define a space <index> with permission <perm>.\n"
+"  nv_read types_string index vars...\n"
+"    - Read from space <index> to environment variables <vars...>.\n"
+"  nv_write types_string index values...\n"
+"    - Write to space <index> from values <values...>.\n"
 );
 
--- /dev/null
+/*
+ * Copyright (c) 2011 The Chromium OS Authors.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#ifndef __TIS_H
+#define __TIS_H
+
+#include <common.h>
+
+/* Low-level interface to access TPM */
+
+/*
+ * tis_init()
+ *
+ * Initialize the TPM device. Returns 0 on success or -1 on
+ * failure (in case device probing did not succeed).
+ */
+int tis_init(void);
+
+/*
+ * tis_open()
+ *
+ * Requests access to locality 0 for the caller. After all commands have been
+ * completed the caller is supposed to call tis_close().
+ *
+ * Returns 0 on success, -1 on failure.
+ */
+int tis_open(void);
+
+/*
+ * tis_close()
+ *
+ * terminate the currect session with the TPM by releasing the locked
+ * locality. Returns 0 on success of -1 on failure (in case lock
+ * removal did not succeed).
+ */
+int tis_close(void);
+
+/*
+ * tis_sendrecv()
+ *
+ * Send the requested data to the TPM and then try to get its response
+ *
+ * @sendbuf - buffer of the data to send
+ * @send_size size of the data to send
+ * @recvbuf - memory to save the response to
+ * @recv_len - pointer to the size of the response buffer
+ *
+ * Returns 0 on success (and places the number of response bytes at recv_len)
+ * or -1 on failure.
+ */
+int tis_sendrecv(const uint8_t *sendbuf, size_t send_size, uint8_t *recvbuf,
+                       size_t *recv_len);
+
+#endif /* __TIS_H */
 
 /*
- * Copyright (c) 2011 The Chromium OS Authors.
+ * Copyright (c) 2013 The Chromium OS Authors.
  *
  * See file CREDITS for list of people who contributed to this
  * project.
  * MA 02111-1307 USA
  */
 
-#ifndef _INCLUDE_TPM_H_
-#define _INCLUDE_TPM_H_
+#ifndef __TPM_H
+#define __TPM_H
 
-#include <common.h>
+#include <tis.h>
 
 /*
- * tis_init()
+ * Here is a partial implementation of TPM commands.  Please consult TCG Main
+ * Specification for definitions of TPM commands.
+ */
+
+enum tpm_startup_type {
+       TPM_ST_CLEAR            = 0x0001,
+       TPM_ST_STATE            = 0x0002,
+       TPM_ST_DEACTIVATED      = 0x0003,
+};
+
+enum tpm_physical_presence {
+       TPM_PHYSICAL_PRESENCE_HW_DISABLE        = 0x0200,
+       TPM_PHYSICAL_PRESENCE_CMD_DISABLE       = 0x0100,
+       TPM_PHYSICAL_PRESENCE_LIFETIME_LOCK     = 0x0080,
+       TPM_PHYSICAL_PRESENCE_HW_ENABLE         = 0x0040,
+       TPM_PHYSICAL_PRESENCE_CMD_ENABLE        = 0x0020,
+       TPM_PHYSICAL_PRESENCE_NOTPRESENT        = 0x0010,
+       TPM_PHYSICAL_PRESENCE_PRESENT           = 0x0008,
+       TPM_PHYSICAL_PRESENCE_LOCK              = 0x0004,
+};
+
+enum tpm_nv_index {
+       TPM_NV_INDEX_LOCK       = 0xffffffff,
+       TPM_NV_INDEX_0          = 0x00000000,
+       TPM_NV_INDEX_DIR        = 0x10000001,
+};
+
+/**
+ * Initialize TPM device.  It must be called before any TPM commands.
  *
- * Initialize the TPM device. Returns 0 on success or -1 on
- * failure (in case device probing did not succeed).
+ * @return 0 on success, non-0 on error.
  */
-int tis_init(void);
+uint32_t tpm_init(void);
 
-/*
- * tis_open()
+/**
+ * Issue a TPM_Startup command.
  *
- * Requests access to locality 0 for the caller. After all commands have been
- * completed the caller is supposed to call tis_close().
+ * @param mode         TPM startup mode
+ * @return return code of the operation
+ */
+uint32_t tpm_startup(enum tpm_startup_type mode);
+
+/**
+ * Issue a TPM_SelfTestFull command.
  *
- * Returns 0 on success, -1 on failure.
+ * @return return code of the operation
  */
-int tis_open(void);
+uint32_t tpm_self_test_full(void);
 
-/*
- * tis_close()
+/**
+ * Issue a TPM_ContinueSelfTest command.
  *
- * terminate the currect session with the TPM by releasing the locked
- * locality. Returns 0 on success of -1 on failure (in case lock
- * removal did not succeed).
+ * @return return code of the operation
  */
-int tis_close(void);
+uint32_t tpm_continue_self_test(void);
 
-/*
- * tis_sendrecv()
+/**
+ * Issue a TPM_NV_DefineSpace command.  The implementation is limited
+ * to specify TPM_NV_ATTRIBUTES and size of the area.  The area index
+ * could be one of the special value listed in enum tpm_nv_index.
  *
- * Send the requested data to the TPM and then try to get its response
+ * @param index                index of the area
+ * @param perm         TPM_NV_ATTRIBUTES of the area
+ * @param size         size of the area
+ * @return return code of the operation
+ */
+uint32_t tpm_nv_define_space(uint32_t index, uint32_t perm, uint32_t size);
+
+/**
+ * Issue a TPM_NV_ReadValue command.  This implementation is limited
+ * to read the area from offset 0.  The area index could be one of
+ * the special value listed in enum tpm_nv_index.
+ *
+ * @param index                index of the area
+ * @param data         output buffer of the area contents
+ * @param count                size of output buffer
+ * @return return code of the operation
+ */
+uint32_t tpm_nv_read_value(uint32_t index, void *data, uint32_t count);
+
+/**
+ * Issue a TPM_NV_WriteValue command.  This implementation is limited
+ * to write the area from offset 0.  The area index could be one of
+ * the special value listed in enum tpm_nv_index.
+ *
+ * @param index                index of the area
+ * @param data         input buffer to be wrote to the area
+ * @param length       length of data bytes of input buffer
+ * @return return code of the operation
+ */
+uint32_t tpm_nv_write_value(uint32_t index, const void *data, uint32_t length);
+
+/**
+ * Issue a TPM_Extend command.
+ *
+ * @param index                index of the PCR
+ * @param in_digest    160-bit value representing the event to be
+ *                     recorded
+ * @param out_digest   160-bit PCR value after execution of the
+ *                     command
+ * @return return code of the operation
+ */
+uint32_t tpm_extend(uint32_t index, const void *in_digest, void *out_digest);
+
+/**
+ * Issue a TPM_PCRRead command.
  *
- * @sendbuf - buffer of the data to send
- * @send_size size of the data to send
- * @recvbuf - memory to save the response to
- * @recv_len - pointer to the size of the response buffer
+ * @param index                index of the PCR
+ * @param data         output buffer for contents of the named PCR
+ * @param count                size of output buffer
+ * @return return code of the operation
+ */
+uint32_t tpm_pcr_read(uint32_t index, void *data, size_t count);
+
+/**
+ * Issue a TSC_PhysicalPresence command.  TPM physical presence flag
+ * is bit-wise OR'ed of flags listed in enum tpm_physical_presence.
+ *
+ * @param presence     TPM physical presence flag
+ * @return return code of the operation
+ */
+uint32_t tpm_tsc_physical_presence(uint16_t presence);
+
+/**
+ * Issue a TPM_ReadPubek command.
+ *
+ * @param data         output buffer for the public endorsement key
+ * @param count                size of ouput buffer
+ * @return return code of the operation
+ */
+uint32_t tpm_read_pubek(void *data, size_t count);
+
+/**
+ * Issue a TPM_ForceClear command.
+ *
+ * @return return code of the operation
+ */
+uint32_t tpm_force_clear(void);
+
+/**
+ * Issue a TPM_PhysicalEnable command.
+ *
+ * @return return code of the operation
+ */
+uint32_t tpm_physical_enable(void);
+
+/**
+ * Issue a TPM_PhysicalDisable command.
+ *
+ * @return return code of the operation
+ */
+uint32_t tpm_physical_disable(void);
+
+/**
+ * Issue a TPM_PhysicalSetDeactivated command.
+ *
+ * @param state                boolean state of the deactivated flag
+ * @return return code of the operation
+ */
+uint32_t tpm_physical_set_deactivated(uint8_t state);
+
+/**
+ * Issue a TPM_GetCapability command.  This implementation is limited
+ * to query sub_cap index that is 4-byte wide.
  *
- * Returns 0 on success (and places the number of response bytes at recv_len)
- * or -1 on failure.
+ * @param cap_area     partition of capabilities
+ * @param sub_cap      further definition of capability, which is
+ *                     limited to be 4-byte wide
+ * @param cap          output buffer for capability information
+ * @param count                size of ouput buffer
+ * @return return code of the operation
  */
-int tis_sendrecv(const uint8_t *sendbuf, size_t send_size, uint8_t *recvbuf,
-                       size_t *recv_len);
+uint32_t tpm_get_capability(uint32_t cap_area, uint32_t sub_cap,
+               void *cap, size_t count);
 
-#endif /* _INCLUDE_TPM_H_ */
+#endif /* __TPM_H */
 
 COBJS-$(CONFIG_SHA1) += sha1.o
 COBJS-$(CONFIG_SHA256) += sha256.o
 COBJS-y        += strmhz.o
+COBJS-$(CONFIG_TPM) += tpm.o
 COBJS-$(CONFIG_RBTREE) += rbtree.o
 endif
 
 
--- /dev/null
+/*
+ * Copyright (c) 2013 The Chromium OS Authors.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <stdarg.h>
+#include <tpm.h>
+#include <asm/unaligned.h>
+
+/* Internal error of TPM command library */
+#define TPM_LIB_ERROR  ((uint32_t)~0u)
+
+/* Useful constants */
+enum {
+       COMMAND_BUFFER_SIZE             = 256,
+       TPM_PUBEK_SIZE                  = 256,
+       TPM_REQUEST_HEADER_LENGTH       = 10,
+       TPM_RESPONSE_HEADER_LENGTH      = 10,
+       PCR_DIGEST_LENGTH               = 20,
+};
+
+/**
+ * Pack data into a byte string.  The data types are specified in
+ * the format string: 'b' means unsigned byte, 'w' unsigned word,
+ * 'd' unsigned double word, and 's' byte string.  The data are a
+ * series of offsets and values (for type byte string there are also
+ * lengths).  The data values are packed into the byte string
+ * sequentially, and so a latter value could over-write a former
+ * value.
+ *
+ * @param str          output string
+ * @param size         size of output string
+ * @param format       format string
+ * @param ...          data points
+ * @return 0 on success, non-0 on error
+ */
+int pack_byte_string(uint8_t *str, size_t size, const char *format, ...)
+{
+       va_list args;
+       size_t offset = 0, length = 0;
+       uint8_t *data = NULL;
+       uint32_t value = 0;
+
+       va_start(args, format);
+       for (; *format; format++) {
+               switch (*format) {
+               case 'b':
+                       offset = va_arg(args, size_t);
+                       value = va_arg(args, int);
+                       length = 1;
+                       break;
+               case 'w':
+                       offset = va_arg(args, size_t);
+                       value = va_arg(args, int);
+                       length = 2;
+                       break;
+               case 'd':
+                       offset = va_arg(args, size_t);
+                       value = va_arg(args, uint32_t);
+                       length = 4;
+                       break;
+               case 's':
+                       offset = va_arg(args, size_t);
+                       data = va_arg(args, uint8_t *);
+                       length = va_arg(args, uint32_t);
+                       break;
+               default:
+                       debug("Couldn't recognize format string\n");
+                       return -1;
+               }
+
+               if (offset + length > size)
+                       return -1;
+
+               switch (*format) {
+               case 'b':
+                       str[offset] = value;
+                       break;
+               case 'w':
+                       put_unaligned_be16(value, str + offset);
+                       break;
+               case 'd':
+                       put_unaligned_be32(value, str + offset);
+                       break;
+               case 's':
+                       memcpy(str + offset, data, length);
+                       break;
+               }
+       }
+       va_end(args);
+
+       return 0;
+}
+
+/**
+ * Unpack data from a byte string.  The data types are specified in
+ * the format string: 'b' means unsigned byte, 'w' unsigned word,
+ * 'd' unsigned double word, and 's' byte string.  The data are a
+ * series of offsets and pointers (for type byte string there are also
+ * lengths).
+ *
+ * @param str          output string
+ * @param size         size of output string
+ * @param format       format string
+ * @param ...          data points
+ * @return 0 on success, non-0 on error
+ */
+int unpack_byte_string(const uint8_t *str, size_t size, const char *format, ...)
+{
+       va_list args;
+       size_t offset = 0, length = 0;
+       uint8_t *ptr8 = NULL;
+       uint16_t *ptr16 = NULL;
+       uint32_t *ptr32 = NULL;
+
+       va_start(args, format);
+       for (; *format; format++) {
+               switch (*format) {
+               case 'b':
+                       offset = va_arg(args, size_t);
+                       ptr8 = va_arg(args, uint8_t *);
+                       length = 1;
+                       break;
+               case 'w':
+                       offset = va_arg(args, size_t);
+                       ptr16 = va_arg(args, uint16_t *);
+                       length = 2;
+                       break;
+               case 'd':
+                       offset = va_arg(args, size_t);
+                       ptr32 = va_arg(args, uint32_t *);
+                       length = 4;
+                       break;
+               case 's':
+                       offset = va_arg(args, size_t);
+                       ptr8 = va_arg(args, uint8_t *);
+                       length = va_arg(args, uint32_t);
+                       break;
+               default:
+                       debug("Couldn't recognize format string\n");
+                       return -1;
+               }
+
+               if (offset + length > size)
+                       return -1;
+
+               switch (*format) {
+               case 'b':
+                       *ptr8 = str[offset];
+                       break;
+               case 'w':
+                       *ptr16 = get_unaligned_be16(str + offset);
+                       break;
+               case 'd':
+                       *ptr32 = get_unaligned_be32(str + offset);
+                       break;
+               case 's':
+                       memcpy(ptr8, str + offset, length);
+                       break;
+               }
+       }
+       va_end(args);
+
+       return 0;
+}
+
+/**
+ * Get TPM command size.
+ *
+ * @param command      byte string of TPM command
+ * @return command size of the TPM command
+ */
+static uint32_t tpm_command_size(const void *command)
+{
+       const size_t command_size_offset = 2;
+       return get_unaligned_be32(command + command_size_offset);
+}
+
+/**
+ * Get TPM response return code, which is one of TPM_RESULT values.
+ *
+ * @param response     byte string of TPM response
+ * @return return code of the TPM response
+ */
+static uint32_t tpm_return_code(const void *response)
+{
+       const size_t return_code_offset = 6;
+       return get_unaligned_be32(response + return_code_offset);
+}
+
+/**
+ * Send a TPM command and return response's return code, and optionally
+ * return response to caller.
+ *
+ * @param command      byte string of TPM command
+ * @param response     output buffer for TPM response, or NULL if the
+ *                     caller does not care about it
+ * @param size_ptr     output buffer size (input parameter) and TPM
+ *                     response length (output parameter); this parameter
+ *                     is a bidirectional
+ * @return return code of the TPM response
+ */
+static uint32_t tpm_sendrecv_command(const void *command,
+               void *response, size_t *size_ptr)
+{
+       uint8_t response_buffer[COMMAND_BUFFER_SIZE];
+       size_t response_length;
+       uint32_t err;
+
+       if (response) {
+               response_length = *size_ptr;
+       } else {
+               response = response_buffer;
+               response_length = sizeof(response_buffer);
+       }
+       err = tis_sendrecv(command, tpm_command_size(command),
+                       response, &response_length);
+       if (err)
+               return TPM_LIB_ERROR;
+       if (response)
+               *size_ptr = response_length;
+
+       return tpm_return_code(response);
+}
+
+uint32_t tpm_init(void)
+{
+       uint32_t err;
+
+       err = tis_init();
+       if (err)
+               return err;
+
+       return tis_open();
+}
+
+uint32_t tpm_startup(enum tpm_startup_type mode)
+{
+       const uint8_t command[12] = {
+               0x0, 0xc1, 0x0, 0x0, 0x0, 0xc, 0x0, 0x0, 0x0, 0x99, 0x0, 0x0,
+       };
+       const size_t mode_offset = 10;
+       uint8_t buf[COMMAND_BUFFER_SIZE];
+
+       if (pack_byte_string(buf, sizeof(buf), "sw",
+                               0, command, sizeof(command),
+                               mode_offset, mode))
+               return TPM_LIB_ERROR;
+
+       return tpm_sendrecv_command(buf, NULL, NULL);
+}
+
+uint32_t tpm_self_test_full(void)
+{
+       const uint8_t command[10] = {
+               0x0, 0xc1, 0x0, 0x0, 0x0, 0xa, 0x0, 0x0, 0x0, 0x50,
+       };
+       return tpm_sendrecv_command(command, NULL, NULL);
+}
+
+uint32_t tpm_continue_self_test(void)
+{
+       const uint8_t command[10] = {
+               0x0, 0xc1, 0x0, 0x0, 0x0, 0xa, 0x0, 0x0, 0x0, 0x53,
+       };
+       return tpm_sendrecv_command(command, NULL, NULL);
+}
+
+uint32_t tpm_nv_define_space(uint32_t index, uint32_t perm, uint32_t size)
+{
+       const uint8_t command[101] = {
+               0x0, 0xc1,              /* TPM_TAG */
+               0x0, 0x0, 0x0, 0x65,    /* parameter size */
+               0x0, 0x0, 0x0, 0xcc,    /* TPM_COMMAND_CODE */
+               /* TPM_NV_DATA_PUBLIC->... */
+               0x0, 0x18,              /* ...->TPM_STRUCTURE_TAG */
+               0, 0, 0, 0,             /* ...->TPM_NV_INDEX */
+               /* TPM_NV_DATA_PUBLIC->TPM_PCR_INFO_SHORT */
+               0x0, 0x3,
+               0, 0, 0,
+               0x1f,
+               0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+               /* TPM_NV_DATA_PUBLIC->TPM_PCR_INFO_SHORT */
+               0x0, 0x3,
+               0, 0, 0,
+               0x1f,
+               0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+               /* TPM_NV_ATTRIBUTES->... */
+               0x0, 0x17,              /* ...->TPM_STRUCTURE_TAG */
+               0, 0, 0, 0,             /* ...->attributes */
+               /* End of TPM_NV_ATTRIBUTES */
+               0,                      /* bReadSTClear */
+               0,                      /* bWriteSTClear */
+               0,                      /* bWriteDefine */
+               0, 0, 0, 0,             /* size */
+       };
+       const size_t index_offset = 12;
+       const size_t perm_offset = 70;
+       const size_t size_offset = 77;
+       uint8_t buf[COMMAND_BUFFER_SIZE];
+
+       if (pack_byte_string(buf, sizeof(buf), "sddd",
+                               0, command, sizeof(command),
+                               index_offset, index,
+                               perm_offset, perm,
+                               size_offset, size))
+               return TPM_LIB_ERROR;
+
+       return tpm_sendrecv_command(buf, NULL, NULL);
+}
+
+uint32_t tpm_nv_read_value(uint32_t index, void *data, uint32_t count)
+{
+       const uint8_t command[22] = {
+               0x0, 0xc1, 0x0, 0x0, 0x0, 0x16, 0x0, 0x0, 0x0, 0xcf,
+       };
+       const size_t index_offset = 10;
+       const size_t length_offset = 18;
+       const size_t data_size_offset = 10;
+       const size_t data_offset = 14;
+       uint8_t buf[COMMAND_BUFFER_SIZE], response[COMMAND_BUFFER_SIZE];
+       size_t response_length = sizeof(response);
+       uint32_t data_size;
+       uint32_t err;
+
+       if (pack_byte_string(buf, sizeof(buf), "sdd",
+                               0, command, sizeof(command),
+                               index_offset, index,
+                               length_offset, count))
+               return TPM_LIB_ERROR;
+       err = tpm_sendrecv_command(buf, response, &response_length);
+       if (err)
+               return err;
+       if (unpack_byte_string(response, response_length, "d",
+                               data_size_offset, &data_size))
+               return TPM_LIB_ERROR;
+       if (data_size > count)
+               return TPM_LIB_ERROR;
+       if (unpack_byte_string(response, response_length, "s",
+                               data_offset, data, data_size))
+               return TPM_LIB_ERROR;
+
+       return 0;
+}
+
+uint32_t tpm_nv_write_value(uint32_t index, const void *data, uint32_t length)
+{
+       const uint8_t command[256] = {
+               0x0, 0xc1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xcd,
+       };
+       const size_t command_size_offset = 2;
+       const size_t index_offset = 10;
+       const size_t length_offset = 18;
+       const size_t data_offset = 22;
+       const size_t write_info_size = 12;
+       const uint32_t total_length =
+               TPM_REQUEST_HEADER_LENGTH + write_info_size + length;
+       uint8_t buf[COMMAND_BUFFER_SIZE], response[COMMAND_BUFFER_SIZE];
+       size_t response_length = sizeof(response);
+       uint32_t err;
+
+       if (pack_byte_string(buf, sizeof(buf), "sddds",
+                               0, command, sizeof(command),
+                               command_size_offset, total_length,
+                               index_offset, index,
+                               length_offset, length,
+                               data_offset, data, length))
+               return TPM_LIB_ERROR;
+       err = tpm_sendrecv_command(buf, response, &response_length);
+       if (err)
+               return err;
+
+       return 0;
+}
+
+uint32_t tpm_extend(uint32_t index, const void *in_digest, void *out_digest)
+{
+       const uint8_t command[34] = {
+               0x0, 0xc1, 0x0, 0x0, 0x0, 0x22, 0x0, 0x0, 0x0, 0x14,
+       };
+       const size_t index_offset = 10;
+       const size_t in_digest_offset = 14;
+       const size_t out_digest_offset = 10;
+       uint8_t buf[COMMAND_BUFFER_SIZE];
+       uint8_t response[TPM_RESPONSE_HEADER_LENGTH + PCR_DIGEST_LENGTH];
+       size_t response_length = sizeof(response);
+       uint32_t err;
+
+       if (pack_byte_string(buf, sizeof(buf), "sds",
+                               0, command, sizeof(command),
+                               index_offset, index,
+                               in_digest_offset, in_digest,
+                               PCR_DIGEST_LENGTH))
+               return TPM_LIB_ERROR;
+       err = tpm_sendrecv_command(buf, response, &response_length);
+       if (err)
+               return err;
+
+       if (unpack_byte_string(response, response_length, "s",
+                               out_digest_offset, out_digest,
+                               PCR_DIGEST_LENGTH))
+               return TPM_LIB_ERROR;
+
+       return 0;
+}
+
+uint32_t tpm_pcr_read(uint32_t index, void *data, size_t count)
+{
+       const uint8_t command[14] = {
+               0x0, 0xc1, 0x0, 0x0, 0x0, 0xe, 0x0, 0x0, 0x0, 0x15,
+       };
+       const size_t index_offset = 10;
+       const size_t out_digest_offset = 10;
+       uint8_t buf[COMMAND_BUFFER_SIZE], response[COMMAND_BUFFER_SIZE];
+       size_t response_length = sizeof(response);
+       uint32_t err;
+
+       if (count < PCR_DIGEST_LENGTH)
+               return TPM_LIB_ERROR;
+
+       if (pack_byte_string(buf, sizeof(buf), "sd",
+                               0, command, sizeof(command),
+                               index_offset, index))
+               return TPM_LIB_ERROR;
+       err = tpm_sendrecv_command(buf, response, &response_length);
+       if (err)
+               return err;
+       if (unpack_byte_string(response, response_length, "s",
+                               out_digest_offset, data, PCR_DIGEST_LENGTH))
+               return TPM_LIB_ERROR;
+
+       return 0;
+}
+
+uint32_t tpm_tsc_physical_presence(uint16_t presence)
+{
+       const uint8_t command[12] = {
+               0x0, 0xc1, 0x0, 0x0, 0x0, 0xc, 0x40, 0x0, 0x0, 0xa, 0x0, 0x0,
+       };
+       const size_t presence_offset = 10;
+       uint8_t buf[COMMAND_BUFFER_SIZE];
+
+       if (pack_byte_string(buf, sizeof(buf), "sw",
+                               0, command, sizeof(command),
+                               presence_offset, presence))
+               return TPM_LIB_ERROR;
+
+       return tpm_sendrecv_command(buf, NULL, NULL);
+}
+
+uint32_t tpm_read_pubek(void *data, size_t count)
+{
+       const uint8_t command[30] = {
+               0x0, 0xc1, 0x0, 0x0, 0x0, 0x1e, 0x0, 0x0, 0x0, 0x7c,
+       };
+       const size_t response_size_offset = 2;
+       const size_t data_offset = 10;
+       const size_t header_and_checksum_size = TPM_RESPONSE_HEADER_LENGTH + 20;
+       uint8_t response[COMMAND_BUFFER_SIZE + TPM_PUBEK_SIZE];
+       size_t response_length = sizeof(response);
+       uint32_t data_size;
+       uint32_t err;
+
+       err = tpm_sendrecv_command(command, response, &response_length);
+       if (err)
+               return err;
+       if (unpack_byte_string(response, response_length, "d",
+                               response_size_offset, &data_size))
+               return TPM_LIB_ERROR;
+       if (data_size < header_and_checksum_size)
+               return TPM_LIB_ERROR;
+       data_size -= header_and_checksum_size;
+       if (data_size > count)
+               return TPM_LIB_ERROR;
+       if (unpack_byte_string(response, response_length, "s",
+                               data_offset, data, data_size))
+               return TPM_LIB_ERROR;
+
+       return 0;
+}
+
+uint32_t tpm_force_clear(void)
+{
+       const uint8_t command[10] = {
+               0x0, 0xc1, 0x0, 0x0, 0x0, 0xa, 0x0, 0x0, 0x0, 0x5d,
+       };
+
+       return tpm_sendrecv_command(command, NULL, NULL);
+}
+
+uint32_t tpm_physical_enable(void)
+{
+       const uint8_t command[10] = {
+               0x0, 0xc1, 0x0, 0x0, 0x0, 0xa, 0x0, 0x0, 0x0, 0x6f,
+       };
+
+       return tpm_sendrecv_command(command, NULL, NULL);
+}
+
+uint32_t tpm_physical_disable(void)
+{
+       const uint8_t command[10] = {
+               0x0, 0xc1, 0x0, 0x0, 0x0, 0xa, 0x0, 0x0, 0x0, 0x70,
+       };
+
+       return tpm_sendrecv_command(command, NULL, NULL);
+}
+
+uint32_t tpm_physical_set_deactivated(uint8_t state)
+{
+       const uint8_t command[11] = {
+               0x0, 0xc1, 0x0, 0x0, 0x0, 0xb, 0x0, 0x0, 0x0, 0x72,
+       };
+       const size_t state_offset = 10;
+       uint8_t buf[COMMAND_BUFFER_SIZE];
+
+       if (pack_byte_string(buf, sizeof(buf), "sb",
+                               0, command, sizeof(command),
+                               state_offset, state))
+               return TPM_LIB_ERROR;
+
+       return tpm_sendrecv_command(buf, NULL, NULL);
+}
+
+uint32_t tpm_get_capability(uint32_t cap_area, uint32_t sub_cap,
+               void *cap, size_t count)
+{
+       const uint8_t command[22] = {
+               0x0, 0xc1,              /* TPM_TAG */
+               0x0, 0x0, 0x0, 0x16,    /* parameter size */
+               0x0, 0x0, 0x0, 0x65,    /* TPM_COMMAND_CODE */
+               0x0, 0x0, 0x0, 0x0,     /* TPM_CAPABILITY_AREA */
+               0x0, 0x0, 0x0, 0x4,     /* subcap size */
+               0x0, 0x0, 0x0, 0x0,     /* subcap value */
+       };
+       const size_t cap_area_offset = 10;
+       const size_t sub_cap_offset = 18;
+       const size_t cap_offset = 14;
+       const size_t cap_size_offset = 10;
+       uint8_t buf[COMMAND_BUFFER_SIZE], response[COMMAND_BUFFER_SIZE];
+       size_t response_length = sizeof(response);
+       uint32_t cap_size;
+       uint32_t err;
+
+       if (pack_byte_string(buf, sizeof(buf), "sdd",
+                               0, command, sizeof(command),
+                               cap_area_offset, cap_area,
+                               sub_cap_offset, sub_cap))
+               return TPM_LIB_ERROR;
+       err = tpm_sendrecv_command(buf, response, &response_length);
+       if (err)
+               return err;
+       if (unpack_byte_string(response, response_length, "d",
+                               cap_size_offset, &cap_size))
+               return TPM_LIB_ERROR;
+       if (cap_size > response_length || cap_size > count)
+               return TPM_LIB_ERROR;
+       if (unpack_byte_string(response, response_length, "s",
+                               cap_offset, cap, cap_size))
+               return TPM_LIB_ERROR;
+
+       return 0;
+}