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- // SPDX-License-Identifier: GPL-2.0+
- /*
- * Copyright (c) 2020, Linaro Limited
- */
- #define LOG_CATEGORY LOGC_EFI
- #include <common.h>
- #include <env.h>
- #include <malloc.h>
- #include <dm.h>
- #include <fs.h>
- #include <efi_load_initrd.h>
- #include <efi_loader.h>
- #include <efi_variable.h>
- /**
- * efi_create_current_boot_var() - Return Boot#### name were #### is replaced by
- * the value of BootCurrent
- *
- * @var_name: variable name
- * @var_name_size: size of var_name
- *
- * Return: Status code
- */
- static efi_status_t efi_create_current_boot_var(u16 var_name[],
- size_t var_name_size)
- {
- efi_uintn_t boot_current_size;
- efi_status_t ret;
- u16 boot_current;
- u16 *pos;
- boot_current_size = sizeof(boot_current);
- ret = efi_get_variable_int(L"BootCurrent",
- &efi_global_variable_guid, NULL,
- &boot_current_size, &boot_current, NULL);
- if (ret != EFI_SUCCESS)
- goto out;
- pos = efi_create_indexed_name(var_name, var_name_size, "Boot",
- boot_current);
- if (!pos) {
- ret = EFI_OUT_OF_RESOURCES;
- goto out;
- }
- out:
- return ret;
- }
- /**
- * efi_get_dp_from_boot() - Retrieve and return a device path from an EFI
- * Boot### variable.
- * A boot option may contain an array of device paths.
- * We use a VenMedia() with a specific GUID to identify
- * the usage of the array members. This function is
- * used to extract a specific device path
- *
- * @guid: vendor GUID of the VenMedia() device path node identifying the
- * device path
- *
- * Return: device path or NULL. Caller must free the returned value
- */
- struct efi_device_path *efi_get_dp_from_boot(const efi_guid_t guid)
- {
- struct efi_device_path *file_path = NULL;
- struct efi_device_path *tmp = NULL;
- struct efi_load_option lo;
- void *var_value = NULL;
- efi_uintn_t size;
- efi_status_t ret;
- u16 var_name[16];
- ret = efi_create_current_boot_var(var_name, sizeof(var_name));
- if (ret != EFI_SUCCESS)
- return NULL;
- var_value = efi_get_var(var_name, &efi_global_variable_guid, &size);
- if (!var_value)
- return NULL;
- ret = efi_deserialize_load_option(&lo, var_value, &size);
- if (ret != EFI_SUCCESS)
- goto out;
- tmp = efi_dp_from_lo(&lo, &size, guid);
- if (!tmp)
- goto out;
- /* efi_dp_dup will just return NULL if efi_dp_next is NULL */
- file_path = efi_dp_dup(efi_dp_next(tmp));
- out:
- efi_free_pool(tmp);
- free(var_value);
- return file_path;
- }
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