644 lines
16 KiB
C
644 lines
16 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* EFI utils
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*
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* Copyright (c) 2017 Rob Clark
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*/
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#include <common.h>
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#include <efi_loader.h>
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#include <env_internal.h>
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#include <hexdump.h>
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#include <malloc.h>
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#include <search.h>
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#include <u-boot/crc.h>
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#define READ_ONLY BIT(31)
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/*
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* Mapping between EFI variables and u-boot variables:
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*
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* efi_$guid_$varname = {attributes}(type)value
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*
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* For example:
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*
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* efi_8be4df61-93ca-11d2-aa0d-00e098032b8c_OsIndicationsSupported=
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* "{ro,boot,run}(blob)0000000000000000"
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* efi_8be4df61-93ca-11d2-aa0d-00e098032b8c_BootOrder=
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* "(blob)00010000"
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*
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* The attributes are a comma separated list of these possible
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* attributes:
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*
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* + ro - read-only
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* + boot - boot-services access
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* + run - runtime access
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*
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* NOTE: with current implementation, no variables are available after
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* ExitBootServices, and all are persisted (if possible).
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*
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* If not specified, the attributes default to "{boot}".
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*
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* The required type is one of:
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*
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* + utf8 - raw utf8 string
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* + blob - arbitrary length hex string
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*
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* Maybe a utf16 type would be useful to for a string value to be auto
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* converted to utf16?
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*/
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#define PREFIX_LEN (strlen("efi_xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx_"))
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/**
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* efi_to_native() - convert the UEFI variable name and vendor GUID to U-Boot
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* variable name
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*
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* The U-Boot variable name is a concatenation of prefix 'efi', the hexstring
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* encoded vendor GUID, and the UTF-8 encoded UEFI variable name separated by
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* underscores, e.g. 'efi_8be4df61-93ca-11d2-aa0d-00e098032b8c_BootOrder'.
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*
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* @native: pointer to pointer to U-Boot variable name
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* @variable_name: UEFI variable name
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* @vendor: vendor GUID
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* Return: status code
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*/
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static efi_status_t efi_to_native(char **native, const u16 *variable_name,
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const efi_guid_t *vendor)
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{
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size_t len;
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char *pos;
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len = PREFIX_LEN + utf16_utf8_strlen(variable_name) + 1;
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*native = malloc(len);
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if (!*native)
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return EFI_OUT_OF_RESOURCES;
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pos = *native;
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pos += sprintf(pos, "efi_%pUl_", vendor);
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utf16_utf8_strcpy(&pos, variable_name);
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return EFI_SUCCESS;
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}
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/**
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* prefix() - skip over prefix
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*
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* Skip over a prefix string.
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*
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* @str: string with prefix
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* @prefix: prefix string
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* Return: string without prefix, or NULL if prefix not found
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*/
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static const char *prefix(const char *str, const char *prefix)
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{
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size_t n = strlen(prefix);
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if (!strncmp(prefix, str, n))
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return str + n;
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return NULL;
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}
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/**
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* parse_attr() - decode attributes part of variable value
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*
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* Convert the string encoded attributes of a UEFI variable to a bit mask.
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* TODO: Several attributes are not supported.
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*
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* @str: value of U-Boot variable
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* @attrp: pointer to UEFI attributes
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* Return: pointer to remainder of U-Boot variable value
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*/
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static const char *parse_attr(const char *str, u32 *attrp)
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{
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u32 attr = 0;
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char sep = '{';
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if (*str != '{') {
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*attrp = EFI_VARIABLE_BOOTSERVICE_ACCESS;
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return str;
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}
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while (*str == sep) {
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const char *s;
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str++;
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if ((s = prefix(str, "ro"))) {
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attr |= READ_ONLY;
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} else if ((s = prefix(str, "nv"))) {
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attr |= EFI_VARIABLE_NON_VOLATILE;
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} else if ((s = prefix(str, "boot"))) {
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attr |= EFI_VARIABLE_BOOTSERVICE_ACCESS;
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} else if ((s = prefix(str, "run"))) {
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attr |= EFI_VARIABLE_RUNTIME_ACCESS;
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} else {
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printf("invalid attribute: %s\n", str);
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break;
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}
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str = s;
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sep = ',';
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}
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str++;
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*attrp = attr;
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return str;
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}
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/**
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* efi_get_variable() - retrieve value of a UEFI variable
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*
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* This function implements the GetVariable runtime service.
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*
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* See the Unified Extensible Firmware Interface (UEFI) specification for
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* details.
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*
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* @variable_name: name of the variable
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* @vendor: vendor GUID
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* @attributes: attributes of the variable
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* @data_size: size of the buffer to which the variable value is copied
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* @data: buffer to which the variable value is copied
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* Return: status code
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*/
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efi_status_t EFIAPI efi_get_variable(u16 *variable_name,
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const efi_guid_t *vendor, u32 *attributes,
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efi_uintn_t *data_size, void *data)
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{
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char *native_name;
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efi_status_t ret;
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unsigned long in_size;
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const char *val, *s;
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u32 attr;
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EFI_ENTRY("\"%ls\" %pUl %p %p %p", variable_name, vendor, attributes,
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data_size, data);
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if (!variable_name || !vendor || !data_size)
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return EFI_EXIT(EFI_INVALID_PARAMETER);
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ret = efi_to_native(&native_name, variable_name, vendor);
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if (ret)
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return EFI_EXIT(ret);
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EFI_PRINT("get '%s'\n", native_name);
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val = env_get(native_name);
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free(native_name);
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if (!val)
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return EFI_EXIT(EFI_NOT_FOUND);
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val = parse_attr(val, &attr);
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in_size = *data_size;
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if ((s = prefix(val, "(blob)"))) {
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size_t len = strlen(s);
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/* number of hexadecimal digits must be even */
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if (len & 1)
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return EFI_EXIT(EFI_DEVICE_ERROR);
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/* two characters per byte: */
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len /= 2;
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*data_size = len;
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if (in_size < len) {
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ret = EFI_BUFFER_TOO_SMALL;
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goto out;
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}
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if (!data)
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return EFI_EXIT(EFI_INVALID_PARAMETER);
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if (hex2bin(data, s, len))
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return EFI_EXIT(EFI_DEVICE_ERROR);
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EFI_PRINT("got value: \"%s\"\n", s);
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} else if ((s = prefix(val, "(utf8)"))) {
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unsigned len = strlen(s) + 1;
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*data_size = len;
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if (in_size < len) {
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ret = EFI_BUFFER_TOO_SMALL;
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goto out;
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}
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if (!data)
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return EFI_EXIT(EFI_INVALID_PARAMETER);
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memcpy(data, s, len);
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((char *)data)[len] = '\0';
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EFI_PRINT("got value: \"%s\"\n", (char *)data);
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} else {
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EFI_PRINT("invalid value: '%s'\n", val);
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return EFI_EXIT(EFI_DEVICE_ERROR);
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}
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out:
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if (attributes)
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*attributes = attr & EFI_VARIABLE_MASK;
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return EFI_EXIT(ret);
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}
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static char *efi_variables_list;
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static char *efi_cur_variable;
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/**
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* parse_uboot_variable() - parse a u-boot variable and get uefi-related
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* information
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* @variable: whole data of u-boot variable (ie. name=value)
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* @variable_name_size: size of variable_name buffer in byte
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* @variable_name: name of uefi variable in u16, null-terminated
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* @vendor: vendor's guid
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* @attributes: attributes
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*
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* A uefi variable is encoded into a u-boot variable as described above.
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* This function parses such a u-boot variable and retrieve uefi-related
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* information into respective parameters. In return, variable_name_size
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* is the size of variable name including NULL.
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*
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* Return: EFI_SUCCESS if parsing is OK, EFI_NOT_FOUND when
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* the entire variable list has been returned,
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* otherwise non-zero status code
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*/
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static efi_status_t parse_uboot_variable(char *variable,
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efi_uintn_t *variable_name_size,
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u16 *variable_name,
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const efi_guid_t *vendor,
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u32 *attributes)
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{
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char *guid, *name, *end, c;
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unsigned long name_len;
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u16 *p;
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guid = strchr(variable, '_');
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if (!guid)
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return EFI_INVALID_PARAMETER;
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guid++;
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name = strchr(guid, '_');
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if (!name)
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return EFI_INVALID_PARAMETER;
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name++;
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end = strchr(name, '=');
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if (!end)
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return EFI_INVALID_PARAMETER;
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name_len = end - name;
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if (*variable_name_size < (name_len + 1)) {
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*variable_name_size = name_len + 1;
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return EFI_BUFFER_TOO_SMALL;
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}
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end++; /* point to value */
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/* variable name */
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p = variable_name;
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utf8_utf16_strncpy(&p, name, name_len);
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variable_name[name_len] = 0;
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*variable_name_size = name_len + 1;
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/* guid */
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c = *(name - 1);
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*(name - 1) = '\0'; /* guid need be null-terminated here */
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uuid_str_to_bin(guid, (unsigned char *)vendor, UUID_STR_FORMAT_GUID);
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*(name - 1) = c;
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/* attributes */
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parse_attr(end, attributes);
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return EFI_SUCCESS;
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}
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/**
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* efi_get_next_variable_name() - enumerate the current variable names
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*
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* @variable_name_size: size of variable_name buffer in byte
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* @variable_name: name of uefi variable's name in u16
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* @vendor: vendor's guid
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*
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* This function implements the GetNextVariableName service.
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*
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* See the Unified Extensible Firmware Interface (UEFI) specification for
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* details.
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*
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* Return: status code
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*/
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efi_status_t EFIAPI efi_get_next_variable_name(efi_uintn_t *variable_name_size,
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u16 *variable_name,
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const efi_guid_t *vendor)
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{
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char *native_name, *variable;
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ssize_t name_len, list_len;
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char regex[256];
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char * const regexlist[] = {regex};
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u32 attributes;
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int i;
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efi_status_t ret;
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EFI_ENTRY("%p \"%ls\" %pUl", variable_name_size, variable_name, vendor);
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if (!variable_name_size || !variable_name || !vendor)
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return EFI_EXIT(EFI_INVALID_PARAMETER);
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if (variable_name[0]) {
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/* check null-terminated string */
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for (i = 0; i < *variable_name_size; i++)
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if (!variable_name[i])
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break;
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if (i >= *variable_name_size)
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return EFI_EXIT(EFI_INVALID_PARAMETER);
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/* search for the last-returned variable */
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ret = efi_to_native(&native_name, variable_name, vendor);
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if (ret)
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return EFI_EXIT(ret);
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name_len = strlen(native_name);
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for (variable = efi_variables_list; variable && *variable;) {
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if (!strncmp(variable, native_name, name_len) &&
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variable[name_len] == '=')
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break;
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variable = strchr(variable, '\n');
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if (variable)
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variable++;
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}
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free(native_name);
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if (!(variable && *variable))
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return EFI_EXIT(EFI_INVALID_PARAMETER);
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/* next variable */
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variable = strchr(variable, '\n');
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if (variable)
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variable++;
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if (!(variable && *variable))
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return EFI_EXIT(EFI_NOT_FOUND);
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} else {
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/*
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*new search: free a list used in the previous search
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*/
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free(efi_variables_list);
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efi_variables_list = NULL;
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efi_cur_variable = NULL;
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snprintf(regex, 256, "efi_.*-.*-.*-.*-.*_.*");
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list_len = hexport_r(&env_htab, '\n',
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H_MATCH_REGEX | H_MATCH_KEY,
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&efi_variables_list, 0, 1, regexlist);
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/* 1 indicates that no match was found */
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if (list_len <= 1)
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return EFI_EXIT(EFI_NOT_FOUND);
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variable = efi_variables_list;
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}
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ret = parse_uboot_variable(variable, variable_name_size, variable_name,
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vendor, &attributes);
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return EFI_EXIT(ret);
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}
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/**
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* efi_set_variable() - set value of a UEFI variable
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*
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* This function implements the SetVariable runtime service.
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*
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* See the Unified Extensible Firmware Interface (UEFI) specification for
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* details.
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*
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* @variable_name: name of the variable
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* @vendor: vendor GUID
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* @attributes: attributes of the variable
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* @data_size: size of the buffer with the variable value
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* @data: buffer with the variable value
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* Return: status code
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*/
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efi_status_t EFIAPI efi_set_variable(u16 *variable_name,
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const efi_guid_t *vendor, u32 attributes,
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efi_uintn_t data_size, const void *data)
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{
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char *native_name = NULL, *val = NULL, *s;
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const char *old_val;
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size_t old_size;
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efi_status_t ret = EFI_SUCCESS;
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u32 attr;
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EFI_ENTRY("\"%ls\" %pUl %x %zu %p", variable_name, vendor, attributes,
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data_size, data);
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if (!variable_name || !*variable_name || !vendor ||
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((attributes & EFI_VARIABLE_RUNTIME_ACCESS) &&
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!(attributes & EFI_VARIABLE_BOOTSERVICE_ACCESS))) {
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ret = EFI_INVALID_PARAMETER;
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goto out;
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}
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ret = efi_to_native(&native_name, variable_name, vendor);
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if (ret)
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goto out;
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old_val = env_get(native_name);
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if (old_val) {
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old_val = parse_attr(old_val, &attr);
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/* check read-only first */
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if (attr & READ_ONLY) {
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ret = EFI_WRITE_PROTECTED;
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goto out;
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}
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if ((data_size == 0 &&
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!(attributes & EFI_VARIABLE_APPEND_WRITE)) ||
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!attributes) {
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/* delete the variable: */
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env_set(native_name, NULL);
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ret = EFI_SUCCESS;
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goto out;
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}
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/* attributes won't be changed */
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if (attr != (attributes & ~EFI_VARIABLE_APPEND_WRITE)) {
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ret = EFI_INVALID_PARAMETER;
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goto out;
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}
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if (attributes & EFI_VARIABLE_APPEND_WRITE) {
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if (!prefix(old_val, "(blob)")) {
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ret = EFI_DEVICE_ERROR;
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goto out;
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}
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old_size = strlen(old_val);
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} else {
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old_size = 0;
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}
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} else {
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if (data_size == 0 || !attributes ||
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(attributes & EFI_VARIABLE_APPEND_WRITE)) {
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/*
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* Trying to delete or to update a non-existent
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* variable.
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*/
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ret = EFI_NOT_FOUND;
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goto out;
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}
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old_size = 0;
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}
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val = malloc(old_size + 2 * data_size
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+ strlen("{ro,run,boot,nv}(blob)") + 1);
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if (!val) {
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ret = EFI_OUT_OF_RESOURCES;
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goto out;
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}
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s = val;
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/* store attributes */
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attributes &= (EFI_VARIABLE_NON_VOLATILE |
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EFI_VARIABLE_BOOTSERVICE_ACCESS |
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EFI_VARIABLE_RUNTIME_ACCESS);
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s += sprintf(s, "{");
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while (attributes) {
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u32 attr = 1 << (ffs(attributes) - 1);
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if (attr == EFI_VARIABLE_NON_VOLATILE)
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s += sprintf(s, "nv");
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else if (attr == EFI_VARIABLE_BOOTSERVICE_ACCESS)
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s += sprintf(s, "boot");
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else if (attr == EFI_VARIABLE_RUNTIME_ACCESS)
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s += sprintf(s, "run");
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attributes &= ~attr;
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if (attributes)
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s += sprintf(s, ",");
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}
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s += sprintf(s, "}");
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if (old_size)
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/* APPEND_WRITE */
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s += sprintf(s, old_val);
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else
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s += sprintf(s, "(blob)");
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/* store payload: */
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s = bin2hex(s, data, data_size);
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*s = '\0';
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EFI_PRINT("setting: %s=%s\n", native_name, val);
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if (env_set(native_name, val))
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ret = EFI_DEVICE_ERROR;
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out:
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free(native_name);
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free(val);
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return EFI_EXIT(ret);
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}
|
|
|
|
/**
|
|
* efi_query_variable_info() - get information about EFI variables
|
|
*
|
|
* This function implements the QueryVariableInfo() runtime service.
|
|
*
|
|
* See the Unified Extensible Firmware Interface (UEFI) specification for
|
|
* details.
|
|
*
|
|
* @attributes: bitmask to select variables to be
|
|
* queried
|
|
* @maximum_variable_storage_size: maximum size of storage area for the
|
|
* selected variable types
|
|
* @remaining_variable_storage_size: remaining size of storage are for the
|
|
* selected variable types
|
|
* @maximum_variable_size: maximum size of a variable of the
|
|
* selected type
|
|
* Returns: status code
|
|
*/
|
|
efi_status_t __efi_runtime EFIAPI efi_query_variable_info(
|
|
u32 attributes,
|
|
u64 *maximum_variable_storage_size,
|
|
u64 *remaining_variable_storage_size,
|
|
u64 *maximum_variable_size)
|
|
{
|
|
return EFI_UNSUPPORTED;
|
|
}
|
|
|
|
/**
|
|
* efi_get_variable_runtime() - runtime implementation of GetVariable()
|
|
*
|
|
* @variable_name: name of the variable
|
|
* @vendor: vendor GUID
|
|
* @attributes: attributes of the variable
|
|
* @data_size: size of the buffer to which the variable value is copied
|
|
* @data: buffer to which the variable value is copied
|
|
* Return: status code
|
|
*/
|
|
static efi_status_t __efi_runtime EFIAPI
|
|
efi_get_variable_runtime(u16 *variable_name, const efi_guid_t *vendor,
|
|
u32 *attributes, efi_uintn_t *data_size, void *data)
|
|
{
|
|
return EFI_UNSUPPORTED;
|
|
}
|
|
|
|
/**
|
|
* efi_get_next_variable_name_runtime() - runtime implementation of
|
|
* GetNextVariable()
|
|
*
|
|
* @variable_name_size: size of variable_name buffer in byte
|
|
* @variable_name: name of uefi variable's name in u16
|
|
* @vendor: vendor's guid
|
|
* Return: status code
|
|
*/
|
|
static efi_status_t __efi_runtime EFIAPI
|
|
efi_get_next_variable_name_runtime(efi_uintn_t *variable_name_size,
|
|
u16 *variable_name, const efi_guid_t *vendor)
|
|
{
|
|
return EFI_UNSUPPORTED;
|
|
}
|
|
|
|
/**
|
|
* efi_set_variable_runtime() - runtime implementation of SetVariable()
|
|
*
|
|
* @variable_name: name of the variable
|
|
* @vendor: vendor GUID
|
|
* @attributes: attributes of the variable
|
|
* @data_size: size of the buffer with the variable value
|
|
* @data: buffer with the variable value
|
|
* Return: status code
|
|
*/
|
|
static efi_status_t __efi_runtime EFIAPI
|
|
efi_set_variable_runtime(u16 *variable_name, const efi_guid_t *vendor,
|
|
u32 attributes, efi_uintn_t data_size,
|
|
const void *data)
|
|
{
|
|
return EFI_UNSUPPORTED;
|
|
}
|
|
|
|
/**
|
|
* efi_variables_boot_exit_notify() - notify ExitBootServices() is called
|
|
*/
|
|
void efi_variables_boot_exit_notify(void)
|
|
{
|
|
efi_runtime_services.get_variable = efi_get_variable_runtime;
|
|
efi_runtime_services.get_next_variable_name =
|
|
efi_get_next_variable_name_runtime;
|
|
efi_runtime_services.set_variable = efi_set_variable_runtime;
|
|
efi_update_table_header_crc32(&efi_runtime_services.hdr);
|
|
}
|
|
|
|
/**
|
|
* efi_init_variables() - initialize variable services
|
|
*
|
|
* Return: status code
|
|
*/
|
|
efi_status_t efi_init_variables(void)
|
|
{
|
|
return EFI_SUCCESS;
|
|
}
|