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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>
#if defined(CONFIG_CMD_EFIDEBUG) || defined(CONFIG_EFI_LOAD_FILE2_INITRD)
/* GUID used by Linux to identify the LoadFile2 protocol with the initrd */
const efi_guid_t efi_lf2_initrd_guid = EFI_INITRD_MEDIA_GUID;
#endif
/**
* 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(u"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_load_option lo;
void *var_value;
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 err;
return efi_dp_from_lo(&lo, &guid);
err:
free(var_value);
return NULL;
}
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