1 // SPDX-License-Identifier: GPL-2.0+
19  * Mapping between EFI variables and u-boot variables:
25  *   efi_8be4df61-93ca-11d2-aa0d-00e098032b8c_OsIndicationsSupported=
27  *   efi_8be4df61-93ca-11d2-aa0d-00e098032b8c_BootOrder=
33  *   + ro   - read-only
34  *   + boot - boot-services access
35  *   + run  - runtime access
44  *   + utf8 - raw utf8 string
45  *   + blob - arbitrary length hex string
51 #define PREFIX_LEN (strlen("efi_xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx_"))
54  * efi_to_native() - convert the UEFI variable name and vendor GUID to U-Boot
55  *		     variable name
57  * The U-Boot variable name is a concatenation of prefix 'efi', the hexstring
58  * encoded vendor GUID, and the UTF-8 encoded UEFI variable name separated by
59  * underscores, e.g. 'efi_8be4df61-93ca-11d2-aa0d-00e098032b8c_BootOrder'.
61  * @native:		pointer to pointer to U-Boot variable name
62  * @variable_name:	UEFI variable name
85  * prefix() - skip over prefix
87  * Skip over a prefix string.
89  * @str:	string with prefix
90  * @prefix:	prefix string
91  * Return:	string without prefix, or NULL if prefix not found
93 static const char *prefix(const char *str, const char *prefix)  in prefix()  argument
95 	size_t n = strlen(prefix);  in prefix()
96 	if (!strncmp(prefix, str, n))  in prefix()
102  * parse_attr() - decode attributes part of variable value
107  * @str:	value of U-Boot variable
109  * Return:	pointer to remainder of U-Boot variable value
126 		if ((s = prefix(str, "ro"))) {  in parse_attr()
128 		} else if ((s = prefix(str, "boot"))) {  in parse_attr()
130 		} else if ((s = prefix(str, "run"))) {  in parse_attr()
149  * efi_efi_get_variable() - retrieve value of a UEFI variable
156  * @variable_name:	name of the variable
194 	if ((s = prefix(val, "(blob)"))) {  in efi_get_variable()
215 	} else if ((s = prefix(val, "(utf8)"))) {  in efi_get_variable()
245  * parse_uboot_variable() - parse a u-boot variable and get uefi-related
247  * @variable:		whole data of u-boot variable (ie. name=value)
249  * @variable_name:	name of uefi variable in u16, null-terminated
253  * A uefi variable is encoded into a u-boot variable as described above.
254  * This function parses such a u-boot variable and retrieve uefi-related
256  * is the size of variable name including NULL.
260 			otherwise non-zero status code
268 	char *guid, *name, *end, c;  in parse_uboot_variable()  local
276 	name = strchr(guid, '_');  in parse_uboot_variable()
277 	if (!name)  in parse_uboot_variable()
279 	name++;  in parse_uboot_variable()
280 	end = strchr(name, '=');  in parse_uboot_variable()
284 	name_len = end - name;  in parse_uboot_variable()
291 	/* variable name */  in parse_uboot_variable()
293 	utf8_utf16_strncpy(&p, name, name_len);  in parse_uboot_variable()
298 	c = *(name - 1);  in parse_uboot_variable()
299 	*(name - 1) = '\0'; /* guid need be null-terminated here */  in parse_uboot_variable()
301 	*(name - 1) = c;  in parse_uboot_variable()
310  * efi_get_next_variable_name() - enumerate the current variable names
312  * @variable_name:	name of uefi variable's name in u16
341 		/* check null-terminated string */  in efi_get_next_variable_name()
348 		/* search for the last-returned variable */  in efi_get_next_variable_name()
382 		snprintf(regex, 256, "efi_.*-.*-.*-.*-.*_.*");  in efi_get_next_variable_name()
400  * efi_efi_set_variable() - set value of a UEFI variable
407  * @variable_name:	name of the variable
470 		u32 attr = 1 << (ffs(attributes) - 1);  in efi_set_variable()