1 // SPDX-License-Identifier: GPL-2.0+
3 * Integrate UEFI variables to u-boot env interface
5 * Copyright (c) 2018 AKASHI Takahiro, Linaro Limited
11 #include <efi_loader.h>
15 #include <linux/kernel.h>
18 * From efi_variable.c,
20 * Mapping between UEFI variables and u-boot variables:
22 * efi_$guid_$varname = {attributes}(type)value
29 {EFI_VARIABLE_NON_VOLATILE, "NV"},
30 {EFI_VARIABLE_BOOTSERVICE_ACCESS, "BS"},
31 {EFI_VARIABLE_RUNTIME_ACCESS, "RT"},
32 {EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS, "AW"},
33 {EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS, "AT"},
37 * efi_dump_single_var() - show information about a UEFI variable
39 * @name: Name of the variable
42 * Show information encoded in one UEFI variable
44 static void efi_dump_single_var(u16 *name, efi_guid_t *guid)
54 ret = EFI_CALL(efi_get_variable(name, guid, &attributes, &size, data));
55 if (ret == EFI_BUFFER_TOO_SMALL) {
60 ret = EFI_CALL(efi_get_variable(name, guid, &attributes, &size,
63 if (ret == EFI_NOT_FOUND) {
64 printf("Error: \"%ls\" not defined\n", name);
67 if (ret != EFI_SUCCESS)
71 for (count = 0, i = 0; i < ARRAY_SIZE(efi_var_attrs); i++)
72 if (attributes & efi_var_attrs[i].mask) {
78 puts(efi_var_attrs[i].text);
80 printf(", DataSize = 0x%zx\n", size);
81 print_hex_dump(" ", DUMP_PREFIX_OFFSET, 16, 1, data, size, true);
88 * efi_dump_vars() - show information about named UEFI variables
90 * @argc: Number of arguments (variables)
91 * @argv: Argument (variable name) array
92 * Return: CMD_RET_SUCCESS on success, or CMD_RET_RET_FAILURE
94 * Show information encoded in named UEFI variables
96 static int efi_dump_vars(int argc, char * const argv[])
99 efi_uintn_t buf_size, size;
102 var_name16 = malloc(buf_size);
104 return CMD_RET_FAILURE;
106 for (; argc > 0; argc--, argv++) {
107 size = (utf8_utf16_strlen(argv[0]) + 1) * sizeof(u16);
108 if (buf_size < size) {
110 p = realloc(var_name16, buf_size);
113 return CMD_RET_FAILURE;
119 utf8_utf16_strcpy(&p, argv[0]);
121 efi_dump_single_var(var_name16,
122 (efi_guid_t *)&efi_global_variable_guid);
127 return CMD_RET_SUCCESS;
131 * efi_dump_vars() - show information about all the UEFI variables
133 * Return: CMD_RET_SUCCESS on success, or CMD_RET_RET_FAILURE
135 * Show information encoded in all the UEFI variables
137 static int efi_dump_var_all(void)
140 efi_uintn_t buf_size, size;
145 var_name16 = malloc(buf_size);
147 return CMD_RET_FAILURE;
152 ret = EFI_CALL(efi_get_next_variable_name(&size, var_name16,
154 if (ret == EFI_NOT_FOUND)
156 if (ret == EFI_BUFFER_TOO_SMALL) {
158 p = realloc(var_name16, buf_size);
161 return CMD_RET_FAILURE;
164 ret = EFI_CALL(efi_get_next_variable_name(&size,
168 if (ret != EFI_SUCCESS) {
170 return CMD_RET_FAILURE;
173 efi_dump_single_var(var_name16, &guid);
178 return CMD_RET_SUCCESS;
182 * do_env_print_efi() - show information about UEFI variables
184 * @cmdtp: Command table
185 * @flag: Command flag
186 * @argc: Number of arguments
187 * @argv: Argument array
188 * Return: CMD_RET_SUCCESS on success, or CMD_RET_RET_FAILURE
190 * This function is for "env print -e" or "printenv -e" command:
191 * => env print -e [var [...]]
192 * If one or more variable names are specified, show information
193 * named UEFI variables, otherwise show all the UEFI variables.
195 int do_env_print_efi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
199 /* Initialize EFI drivers */
200 ret = efi_init_obj_list();
201 if (ret != EFI_SUCCESS) {
202 printf("Error: Cannot initialize UEFI sub-system, r = %lu\n",
203 ret & ~EFI_ERROR_MASK);
204 return CMD_RET_FAILURE;
208 /* show specified UEFI variables */
209 return efi_dump_vars(--argc, ++argv);
211 /* enumerate and show all UEFI variables */
212 return efi_dump_var_all();
216 * append_value() - encode UEFI variable's value
217 * @bufp: Buffer of encoded UEFI variable's value
218 * @sizep: Size of buffer
219 * @data: data to be encoded into the value
220 * Return: 0 on success, -1 otherwise
222 * Interpret a given data string and append it to buffer.
223 * Buffer will be realloc'ed if necessary.
225 * Currently supported formats are:
226 * =0x0123...: Hexadecimal number
227 * =H0123...: Hexadecimal-byte array
228 * ="...", =S"..." or <string>:
231 static int append_value(char **bufp, size_t *sizep, char *data)
233 char *tmp_buf = NULL, *new_buf = NULL, *value;
234 unsigned long len = 0;
236 if (!strncmp(data, "=0x", 2)) { /* hexadecimal number */
243 unsigned long hex_value;
248 if ((len & 0x1)) /* not multiple of two */
259 /* convert hex hexadecimal number */
260 if (strict_strtoul(data, 16, &hex_value) < 0)
263 tmp_buf = malloc(len);
268 tmp_data.u8 = hex_value;
269 hex_ptr = &tmp_data.u8;
270 } else if (len == 2) {
271 tmp_data.u16 = hex_value;
272 hex_ptr = &tmp_data.u16;
273 } else if (len == 4) {
274 tmp_data.u32 = hex_value;
275 hex_ptr = &tmp_data.u32;
277 tmp_data.u64 = hex_value;
278 hex_ptr = &tmp_data.u64;
280 memcpy(tmp_buf, hex_ptr, len);
283 } else if (!strncmp(data, "=H", 2)) { /* hexadecimal-byte array */
286 if (len & 0x1) /* not multiple of two */
290 tmp_buf = malloc(len);
294 if (hex2bin((u8 *)tmp_buf, data, len) < 0) {
295 printf("Error: illegal hexadecimal string\n");
301 } else { /* string */
302 if (!strncmp(data, "=\"", 2) || !strncmp(data, "=S\"", 3)) {
308 len = strlen(data) - 1;
309 if (data[len] != '"')
317 new_buf = realloc(*bufp, *sizep + len);
321 memcpy(new_buf + *sizep, value, len);
332 * do_env_print_efi() - set UEFI variable
334 * @cmdtp: Command table
335 * @flag: Command flag
336 * @argc: Number of arguments
337 * @argv: Argument array
338 * Return: CMD_RET_SUCCESS on success, or CMD_RET_RET_FAILURE
340 * This function is for "env set -e" or "setenv -e" command:
341 * => env set -e var [value ...]]
342 * Encode values specified and set given UEFI variable.
343 * If no value is specified, delete the variable.
345 int do_env_set_efi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
347 char *var_name, *value = NULL;
348 efi_uintn_t size = 0;
349 u16 *var_name16 = NULL, *p;
356 return CMD_RET_USAGE;
358 /* Initialize EFI drivers */
359 ret = efi_init_obj_list();
360 if (ret != EFI_SUCCESS) {
361 printf("Error: Cannot initialize UEFI sub-system, r = %lu\n",
362 ret & ~EFI_ERROR_MASK);
363 return CMD_RET_FAILURE;
366 attributes = EFI_VARIABLE_BOOTSERVICE_ACCESS |
367 EFI_VARIABLE_RUNTIME_ACCESS;
368 if (!strcmp(argv[1], "-nv")) {
369 attributes |= EFI_VARIABLE_NON_VOLATILE;
373 return CMD_RET_SUCCESS;
385 for ( ; argc > 0; argc--, argv++)
386 if (append_value(&value, &size, argv[0]) < 0) {
387 printf("## Failed to process an argument, %s\n",
389 ret = CMD_RET_FAILURE;
394 len = utf8_utf16_strnlen(var_name, strlen(var_name));
395 var_name16 = malloc((len + 1) * 2);
397 printf("## Out of memory\n");
398 ret = CMD_RET_FAILURE;
402 utf8_utf16_strncpy(&p, var_name, len + 1);
404 guid = efi_global_variable_guid;
405 ret = EFI_CALL(efi_set_variable(var_name16, &guid, attributes,
407 if (ret == EFI_SUCCESS) {
408 ret = CMD_RET_SUCCESS;
410 printf("## Failed to set EFI variable\n");
411 ret = CMD_RET_FAILURE;