diff options
Diffstat (limited to 'cmd/tpm.c')
-rw-r--r-- | cmd/tpm.c | 802 |
1 files changed, 802 insertions, 0 deletions
diff --git a/cmd/tpm.c b/cmd/tpm.c new file mode 100644 index 0000000..add6bfb --- /dev/null +++ b/cmd/tpm.c @@ -0,0 +1,802 @@ +/* + * Copyright (c) 2013 The Chromium OS Authors. + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <command.h> +#include <dm.h> +#include <malloc.h> +#include <tpm.h> +#include <asm/unaligned.h> +#include <linux/string.h> + +/* Useful constants */ +enum { + DIGEST_LENGTH = 20, + /* max lengths, valid for RSA keys <= 2048 bits */ + TPM_PUBKEY_MAX_LENGTH = 288, +}; + +/** + * 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; + + 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. + * + * @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 void *parse_byte_string(char *bytes, uint8_t *data, size_t *count_ptr) +{ + char byte[3]; + size_t count, length; + int i; + + if (!bytes) + return NULL; + 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); + } + + if (count_ptr) + *count_ptr = count; + + return data; +} + +/** + * report_return_code() - Report any error and return failure or success + * + * @param return_code TPM command return code + * @return value of enum command_ret_t + */ +static int report_return_code(int return_code) +{ + if (return_code) { + printf("Error: %d\n", 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 size; +} + +/** + * 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; + + 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) +{ + 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; + } + } + + 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 0; +} + +static int do_tpm_startup(cmd_tbl_t *cmdtp, int flag, + int argc, char * const argv[]) +{ + enum tpm_startup_type mode; + + 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 report_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 report_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[]) +{ + 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); + + rc = tpm_nv_read_value(index, data, count); + if (!rc) { + puts("area content:\n"); + print_byte_string(data, count); + } + + return report_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; + } + + rc = tpm_nv_write_value(index, data, count); + free(data); + + return report_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; + } + + 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)); + } + + return report_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); + + rc = tpm_pcr_read(index, data, count); + if (!rc) { + puts("Named PCR content:\n"); + print_byte_string(data, count); + } + + return report_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); + + return report_return_code(tpm_tsc_physical_presence(presence)); +} + +static int do_tpm_read_pubek(cmd_tbl_t *cmdtp, int flag, + int argc, char * const argv[]) +{ + 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 report_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); + + return report_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 report_return_code(rc); +} + +#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 report_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 get_tpm(struct udevice **devp) +{ + int rc; + + rc = uclass_first_device(UCLASS_TPM, devp); + if (rc) { + printf("Could not find TPM (ret=%d)\n", rc); + return CMD_RET_FAILURE; + } + + return 0; +} + +static int do_tpm_info(cmd_tbl_t *cmdtp, int flag, int argc, + char *const argv[]) +{ + struct udevice *dev; + char buf[80]; + int rc; + + rc = get_tpm(&dev); + if (rc) + return rc; + rc = tpm_get_desc(dev, buf, sizeof(buf)); + if (rc < 0) { + printf("Couldn't get TPM info (%d)\n", rc); + return CMD_RET_FAILURE; + } + printf("%s\n", buf); + + return 0; +} + +static int do_tpm_raw_transfer(cmd_tbl_t *cmdtp, int flag, + int argc, char * const argv[]) +{ + struct udevice *dev; + 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 = get_tpm(&dev); + if (rc) + return rc; + + rc = tpm_xfer(dev, command, count, response, &response_length); + free(command); + if (!rc) { + puts("tpm response:\n"); + print_byte_string(response, response_length); + } + + return report_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 report_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[]) +{ + 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; + } + + 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 report_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 report_return_code(err); +} + +#ifdef CONFIG_TPM_AUTH_SESSIONS + +static int do_tpm_oiap(cmd_tbl_t *cmdtp, int flag, + int argc, char * const argv[]) +{ + uint32_t auth_handle, err; + + err = tpm_oiap(&auth_handle); + + return report_return_code(err); +} + +static int do_tpm_load_key2_oiap(cmd_tbl_t *cmdtp, int flag, + int argc, char * const argv[]) +{ + uint32_t parent_handle, key_len, key_handle, err; + uint8_t usage_auth[DIGEST_LENGTH]; + void *key; + + if (argc < 5) + return CMD_RET_USAGE; + + parent_handle = simple_strtoul(argv[1], NULL, 0); + key = (void *)simple_strtoul(argv[2], NULL, 0); + key_len = simple_strtoul(argv[3], NULL, 0); + if (strlen(argv[4]) != 2 * DIGEST_LENGTH) + return CMD_RET_FAILURE; + parse_byte_string(argv[4], usage_auth, NULL); + + err = tpm_load_key2_oiap(parent_handle, key, key_len, usage_auth, + &key_handle); + if (!err) + printf("Key handle is 0x%x\n", key_handle); + + return report_return_code(err); +} + +static int do_tpm_get_pub_key_oiap(cmd_tbl_t *cmdtp, int flag, + int argc, char * const argv[]) +{ + uint32_t key_handle, err; + uint8_t usage_auth[DIGEST_LENGTH]; + uint8_t pub_key_buffer[TPM_PUBKEY_MAX_LENGTH]; + size_t pub_key_len = sizeof(pub_key_buffer); + + if (argc < 3) + return CMD_RET_USAGE; + + key_handle = simple_strtoul(argv[1], NULL, 0); + if (strlen(argv[2]) != 2 * DIGEST_LENGTH) + return CMD_RET_FAILURE; + parse_byte_string(argv[2], usage_auth, NULL); + + err = tpm_get_pub_key_oiap(key_handle, usage_auth, + pub_key_buffer, &pub_key_len); + if (!err) { + printf("dump of received pub key structure:\n"); + print_byte_string(pub_key_buffer, pub_key_len); + } + return report_return_code(err); +} + +TPM_COMMAND_NO_ARG(tpm_end_oiap) + +#endif /* CONFIG_TPM_AUTH_SESSIONS */ + +#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(info, 0, 1, do_tpm_info, "", ""), + 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, "", ""), +#ifdef CONFIG_TPM_AUTH_SESSIONS + U_BOOT_CMD_MKENT(oiap, 0, 1, + do_tpm_oiap, "", ""), + U_BOOT_CMD_MKENT(end_oiap, 0, 1, + do_tpm_end_oiap, "", ""), + U_BOOT_CMD_MKENT(load_key2_oiap, 0, 1, + do_tpm_load_key2_oiap, "", ""), + U_BOOT_CMD_MKENT(get_pub_key_oiap, 0, 1, + do_tpm_get_pub_key_oiap, "", ""), +#endif /* CONFIG_TPM_AUTH_SESSIONS */ +}; + +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 tpm_cmd->cmd(cmdtp, flag, argc - 1, argv + 1); +} + +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" +" info - Show information about the TPM\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" +#ifdef CONFIG_TPM_AUTH_SESSIONS +"Storage functions\n" +" loadkey2_oiap parent_handle key_addr key_len usage_auth\n" +" - loads a key data from memory address <key_addr>, <key_len> bytes\n" +" into TPM using the parent key <parent_handle> with authorization\n" +" <usage_auth> (20 bytes hex string).\n" +" get_pub_key_oiap key_handle usage_auth\n" +" - get the public key portion of a loaded key <key_handle> using\n" +" authorization <usage auth> (20 bytes hex string)\n" +#endif /* CONFIG_TPM_AUTH_SESSIONS */ +"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" +#ifdef CONFIG_TPM_AUTH_SESSIONS +"Authorization Sessions\n" +" oiap\n" +" - setup an OIAP session\n" +" end_oiap\n" +" - terminates an active OIAP session\n" +#endif /* CONFIG_TPM_AUTH_SESSIONS */ +"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" +); |