blob: b1739d99201c3788be614bc6c2b07ad08666908a [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0+
/*
* EFI application disk support
*
* Copyright (c) 2016 Alexander Graf
*/
#define LOG_CATEGORY LOGC_EFI
#include <blk.h>
#include <dm.h>
#include <dm/device-internal.h>
#include <dm/tag.h>
#include <event.h>
#include <efi_driver.h>
#include <efi_loader.h>
#include <fs.h>
#include <log.h>
#include <part.h>
#include <malloc.h>
struct efi_system_partition efi_system_partition = {
.uclass_id = UCLASS_INVALID,
};
const efi_guid_t efi_block_io_guid = EFI_BLOCK_IO_PROTOCOL_GUID;
const efi_guid_t efi_system_partition_guid = PARTITION_SYSTEM_GUID;
/**
* struct efi_disk_obj - EFI disk object
*
* @header: EFI object header
* @ops: EFI disk I/O protocol interface
* @media: block I/O media information
* @dp: device path to the block device
* @volume: simple file system protocol of the partition
*/
struct efi_disk_obj {
struct efi_object header;
struct efi_block_io ops;
struct efi_block_io_media media;
struct efi_device_path *dp;
struct efi_simple_file_system_protocol *volume;
};
/**
* efi_disk_reset() - reset block device
*
* This function implements the Reset service of the EFI_BLOCK_IO_PROTOCOL.
*
* As U-Boot's block devices do not have a reset function simply return
* EFI_SUCCESS.
*
* See the Unified Extensible Firmware Interface (UEFI) specification for
* details.
*
* @this: pointer to the BLOCK_IO_PROTOCOL
* @extended_verification: extended verification
* Return: status code
*/
static efi_status_t EFIAPI efi_disk_reset(struct efi_block_io *this,
char extended_verification)
{
EFI_ENTRY("%p, %x", this, extended_verification);
return EFI_EXIT(EFI_SUCCESS);
}
/**
* efi_disk_is_removable() - check if the device is removable media
* @handle: efi object handle;
*
* Examine the device and determine if the device is a local block device
* and removable media.
*
* Return: true if removable, false otherwise
*/
bool efi_disk_is_removable(efi_handle_t handle)
{
struct efi_handler *handler;
struct efi_block_io *io;
efi_status_t ret;
ret = efi_search_protocol(handle, &efi_block_io_guid, &handler);
if (ret != EFI_SUCCESS)
return false;
io = handler->protocol_interface;
if (!io || !io->media)
return false;
return (bool)io->media->removable_media;
}
enum efi_disk_direction {
EFI_DISK_READ,
EFI_DISK_WRITE,
};
static efi_status_t efi_disk_rw_blocks(struct efi_block_io *this,
u32 media_id, u64 lba, unsigned long buffer_size,
void *buffer, enum efi_disk_direction direction)
{
struct efi_disk_obj *diskobj;
int blksz;
int blocks;
unsigned long n;
diskobj = container_of(this, struct efi_disk_obj, ops);
blksz = diskobj->media.block_size;
blocks = buffer_size / blksz;
EFI_PRINT("blocks=%x lba=%llx blksz=%x dir=%d\n",
blocks, lba, blksz, direction);
/* We only support full block access */
if (buffer_size & (blksz - 1))
return EFI_BAD_BUFFER_SIZE;
if (CONFIG_IS_ENABLED(PARTITIONS) &&
device_get_uclass_id(diskobj->header.dev) == UCLASS_PARTITION) {
if (direction == EFI_DISK_READ)
n = disk_blk_read(diskobj->header.dev, lba, blocks,
buffer);
else
n = disk_blk_write(diskobj->header.dev, lba, blocks,
buffer);
} else {
/* dev is a block device (UCLASS_BLK) */
struct blk_desc *desc;
desc = dev_get_uclass_plat(diskobj->header.dev);
if (direction == EFI_DISK_READ)
n = blk_dread(desc, lba, blocks, buffer);
else
n = blk_dwrite(desc, lba, blocks, buffer);
}
/* We don't do interrupts, so check for timers cooperatively */
efi_timer_check();
EFI_PRINT("n=%lx blocks=%x\n", n, blocks);
if (n != blocks)
return EFI_DEVICE_ERROR;
return EFI_SUCCESS;
}
/**
* efi_disk_read_blocks() - reads blocks from device
*
* This function implements the ReadBlocks service of the EFI_BLOCK_IO_PROTOCOL.
*
* See the Unified Extensible Firmware Interface (UEFI) specification for
* details.
*
* @this: pointer to the BLOCK_IO_PROTOCOL
* @media_id: id of the medium to be read from
* @lba: starting logical block for reading
* @buffer_size: size of the read buffer
* @buffer: pointer to the destination buffer
* Return: status code
*/
static efi_status_t EFIAPI efi_disk_read_blocks(struct efi_block_io *this,
u32 media_id, u64 lba, efi_uintn_t buffer_size,
void *buffer)
{
void *real_buffer = buffer;
efi_status_t r;
if (!this)
return EFI_INVALID_PARAMETER;
/* TODO: check for media changes */
if (media_id != this->media->media_id)
return EFI_MEDIA_CHANGED;
if (!this->media->media_present)
return EFI_NO_MEDIA;
/* media->io_align is a power of 2 or 0 */
if (this->media->io_align &&
(uintptr_t)buffer & (this->media->io_align - 1))
return EFI_INVALID_PARAMETER;
if (lba * this->media->block_size + buffer_size >
(this->media->last_block + 1) * this->media->block_size)
return EFI_INVALID_PARAMETER;
#ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
r = efi_disk_read_blocks(this, media_id, lba,
EFI_LOADER_BOUNCE_BUFFER_SIZE, buffer);
if (r != EFI_SUCCESS)
return r;
return efi_disk_read_blocks(this, media_id, lba +
EFI_LOADER_BOUNCE_BUFFER_SIZE / this->media->block_size,
buffer_size - EFI_LOADER_BOUNCE_BUFFER_SIZE,
buffer + EFI_LOADER_BOUNCE_BUFFER_SIZE);
}
real_buffer = efi_bounce_buffer;
#endif
EFI_ENTRY("%p, %x, %llx, %zx, %p", this, media_id, lba,
buffer_size, buffer);
r = efi_disk_rw_blocks(this, media_id, lba, buffer_size, real_buffer,
EFI_DISK_READ);
/* Copy from bounce buffer to real buffer if necessary */
if ((r == EFI_SUCCESS) && (real_buffer != buffer))
memcpy(buffer, real_buffer, buffer_size);
return EFI_EXIT(r);
}
/**
* efi_disk_write_blocks() - writes blocks to device
*
* This function implements the WriteBlocks service of the
* EFI_BLOCK_IO_PROTOCOL.
*
* See the Unified Extensible Firmware Interface (UEFI) specification for
* details.
*
* @this: pointer to the BLOCK_IO_PROTOCOL
* @media_id: id of the medium to be written to
* @lba: starting logical block for writing
* @buffer_size: size of the write buffer
* @buffer: pointer to the source buffer
* Return: status code
*/
static efi_status_t EFIAPI efi_disk_write_blocks(struct efi_block_io *this,
u32 media_id, u64 lba, efi_uintn_t buffer_size,
void *buffer)
{
void *real_buffer = buffer;
efi_status_t r;
if (!this)
return EFI_INVALID_PARAMETER;
if (this->media->read_only)
return EFI_WRITE_PROTECTED;
/* TODO: check for media changes */
if (media_id != this->media->media_id)
return EFI_MEDIA_CHANGED;
if (!this->media->media_present)
return EFI_NO_MEDIA;
/* media->io_align is a power of 2 or 0 */
if (this->media->io_align &&
(uintptr_t)buffer & (this->media->io_align - 1))
return EFI_INVALID_PARAMETER;
if (lba * this->media->block_size + buffer_size >
(this->media->last_block + 1) * this->media->block_size)
return EFI_INVALID_PARAMETER;
#ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
r = efi_disk_write_blocks(this, media_id, lba,
EFI_LOADER_BOUNCE_BUFFER_SIZE, buffer);
if (r != EFI_SUCCESS)
return r;
return efi_disk_write_blocks(this, media_id, lba +
EFI_LOADER_BOUNCE_BUFFER_SIZE / this->media->block_size,
buffer_size - EFI_LOADER_BOUNCE_BUFFER_SIZE,
buffer + EFI_LOADER_BOUNCE_BUFFER_SIZE);
}
real_buffer = efi_bounce_buffer;
#endif
EFI_ENTRY("%p, %x, %llx, %zx, %p", this, media_id, lba,
buffer_size, buffer);
/* Populate bounce buffer if necessary */
if (real_buffer != buffer)
memcpy(real_buffer, buffer, buffer_size);
r = efi_disk_rw_blocks(this, media_id, lba, buffer_size, real_buffer,
EFI_DISK_WRITE);
return EFI_EXIT(r);
}
/**
* efi_disk_flush_blocks() - flushes modified data to the device
*
* This function implements the FlushBlocks service of the
* EFI_BLOCK_IO_PROTOCOL.
*
* As we always write synchronously nothing is done here.
*
* See the Unified Extensible Firmware Interface (UEFI) specification for
* details.
*
* @this: pointer to the BLOCK_IO_PROTOCOL
* Return: status code
*/
static efi_status_t EFIAPI efi_disk_flush_blocks(struct efi_block_io *this)
{
EFI_ENTRY("%p", this);
return EFI_EXIT(EFI_SUCCESS);
}
static const struct efi_block_io block_io_disk_template = {
.reset = &efi_disk_reset,
.read_blocks = &efi_disk_read_blocks,
.write_blocks = &efi_disk_write_blocks,
.flush_blocks = &efi_disk_flush_blocks,
};
/**
* efi_fs_from_path() - retrieve simple file system protocol
*
* Gets the simple file system protocol for a file device path.
*
* The full path provided is split into device part and into a file
* part. The device part is used to find the handle on which the
* simple file system protocol is installed.
*
* @full_path: device path including device and file
* Return: simple file system protocol
*/
struct efi_simple_file_system_protocol *
efi_fs_from_path(struct efi_device_path *full_path)
{
struct efi_object *efiobj;
struct efi_handler *handler;
struct efi_device_path *device_path;
struct efi_device_path *file_path;
efi_status_t ret;
/* Split the path into a device part and a file part */
ret = efi_dp_split_file_path(full_path, &device_path, &file_path);
if (ret != EFI_SUCCESS)
return NULL;
efi_free_pool(file_path);
/* Get the EFI object for the partition */
efiobj = efi_dp_find_obj(device_path, NULL, NULL);
efi_free_pool(device_path);
if (!efiobj)
return NULL;
/* Find the simple file system protocol */
ret = efi_search_protocol(efiobj, &efi_simple_file_system_protocol_guid,
&handler);
if (ret != EFI_SUCCESS)
return NULL;
/* Return the simple file system protocol for the partition */
return handler->protocol_interface;
}
/**
* efi_fs_exists() - check if a partition bears a file system
*
* @desc: block device descriptor
* @part: partition number
* Return: 1 if a file system exists on the partition
* 0 otherwise
*/
static int efi_fs_exists(struct blk_desc *desc, int part)
{
if (fs_set_blk_dev_with_part(desc, part))
return 0;
if (fs_get_type() == FS_TYPE_ANY)
return 0;
fs_close();
return 1;
}
static void efi_disk_free_diskobj(struct efi_disk_obj *diskobj)
{
struct efi_device_path *dp = diskobj->dp;
struct efi_simple_file_system_protocol *volume = diskobj->volume;
/*
* ignore error of efi_delete_handle() since this function
* is expected to be called in error path.
*/
efi_delete_handle(&diskobj->header);
efi_free_pool(dp);
free(volume);
}
/**
* efi_disk_add_dev() - create a handle for a partition or disk
*
* @parent: parent handle
* @dp_parent: parent device path
* @desc: internal block device
* @part_info: partition info
* @part: partition
* @disk: pointer to receive the created handle
* @agent_handle: handle of the EFI block driver
* Return: disk object
*/
static efi_status_t efi_disk_add_dev(
efi_handle_t parent,
struct efi_device_path *dp_parent,
struct blk_desc *desc,
struct disk_partition *part_info,
unsigned int part,
struct efi_disk_obj **disk,
efi_handle_t agent_handle)
{
struct efi_disk_obj *diskobj;
struct efi_object *handle;
const efi_guid_t *esp_guid = NULL;
efi_status_t ret;
/* Don't add empty devices */
if (!desc->lba)
return EFI_NOT_READY;
diskobj = calloc(1, sizeof(*diskobj));
if (!diskobj)
return EFI_OUT_OF_RESOURCES;
/* Hook up to the device list */
efi_add_handle(&diskobj->header);
/* Fill in object data */
if (part_info) {
struct efi_device_path *node = efi_dp_part_node(desc, part);
struct efi_handler *handler;
void *protocol_interface;
if (!node) {
ret = EFI_OUT_OF_RESOURCES;
log_debug("no node\n");
goto error;
}
/* Parent must expose EFI_BLOCK_IO_PROTOCOL */
ret = efi_search_protocol(parent, &efi_block_io_guid, &handler);
if (ret != EFI_SUCCESS) {
log_debug("search failed\n");
goto error;
}
/*
* Link the partition (child controller) to the block device
* (controller).
*/
ret = efi_protocol_open(handler, &protocol_interface, NULL,
&diskobj->header,
EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER);
if (ret != EFI_SUCCESS) {
log_debug("prot open failed\n");
goto error;
}
diskobj->dp = efi_dp_append_node(dp_parent, node);
efi_free_pool(node);
diskobj->media.last_block = part_info->size - 1;
if (part_info->bootable & PART_EFI_SYSTEM_PARTITION)
esp_guid = &efi_system_partition_guid;
} else {
diskobj->dp = efi_dp_from_part(desc, part);
diskobj->media.last_block = desc->lba - 1;
}
/*
* Install the device path and the block IO protocol.
*
* InstallMultipleProtocolInterfaces() checks if the device path is
* already installed on an other handle and returns EFI_ALREADY_STARTED
* in this case.
*/
handle = &diskobj->header;
ret = efi_install_multiple_protocol_interfaces(
&handle,
&efi_guid_device_path, diskobj->dp,
&efi_block_io_guid, &diskobj->ops,
/*
* esp_guid must be last entry as it
* can be NULL. Its interface is NULL.
*/
esp_guid, NULL,
NULL);
if (ret != EFI_SUCCESS) {
log_debug("install failed %lx\n", ret);
goto error;
}
/*
* On partitions or whole disks without partitions install the
* simple file system protocol if a file system is available.
*/
if ((part || desc->part_type == PART_TYPE_UNKNOWN) &&
efi_fs_exists(desc, part)) {
ret = efi_create_simple_file_system(desc, part, diskobj->dp,
&diskobj->volume);
if (ret != EFI_SUCCESS)
goto error;
ret = efi_add_protocol(&diskobj->header,
&efi_simple_file_system_protocol_guid,
diskobj->volume);
if (ret != EFI_SUCCESS)
goto error;
}
diskobj->ops = block_io_disk_template;
/* Fill in EFI IO Media info (for read/write callbacks) */
diskobj->media.removable_media = desc->removable;
diskobj->media.media_present = 1;
/*
* MediaID is just an arbitrary counter.
* We have to change it if the medium is removed or changed.
*/
diskobj->media.media_id = 1;
diskobj->media.block_size = desc->blksz;
diskobj->media.io_align = desc->blksz;
if (part)
diskobj->media.logical_partition = 1;
diskobj->ops.media = &diskobj->media;
if (disk)
*disk = diskobj;
EFI_PRINT("BlockIO: part %u, present %d, logical %d, removable %d"
", last_block %llu\n",
part,
diskobj->media.media_present,
diskobj->media.logical_partition,
diskobj->media.removable_media,
diskobj->media.last_block);
/* Store first EFI system partition */
if (part && efi_system_partition.uclass_id == UCLASS_INVALID) {
if (part_info->bootable & PART_EFI_SYSTEM_PARTITION) {
efi_system_partition.uclass_id = desc->uclass_id;
efi_system_partition.devnum = desc->devnum;
efi_system_partition.part = part;
EFI_PRINT("EFI system partition: %s %x:%x\n",
blk_get_uclass_name(desc->uclass_id),
desc->devnum, part);
}
}
return EFI_SUCCESS;
error:
efi_disk_free_diskobj(diskobj);
return ret;
}
/**
* efi_disk_create_raw() - create a handle for a whole raw disk
*
* @dev: udevice (UCLASS_BLK)
* @agent_handle: handle of the EFI block driver
*
* Create an efi_disk object which is associated with @dev.
* The type of @dev must be UCLASS_BLK.
*
* Return: 0 on success, -1 otherwise
*/
static int efi_disk_create_raw(struct udevice *dev, efi_handle_t agent_handle)
{
struct efi_disk_obj *disk;
struct blk_desc *desc;
int diskid;
efi_status_t ret;
desc = dev_get_uclass_plat(dev);
diskid = desc->devnum;
ret = efi_disk_add_dev(NULL, NULL, desc,
NULL, 0, &disk, agent_handle);
if (ret != EFI_SUCCESS) {
if (ret == EFI_NOT_READY) {
log_notice("Disk %s not ready\n", dev->name);
ret = -EBUSY;
} else {
log_err("Adding disk for %s failed (err=%ld/%#lx)\n", dev->name, ret, ret);
ret = -ENOENT;
}
return ret;
}
if (efi_link_dev(&disk->header, dev)) {
efi_disk_free_diskobj(disk);
return -EINVAL;
}
return 0;
}
/**
* efi_disk_create_part() - create a handle for a disk partition
*
* @dev: udevice (UCLASS_PARTITION)
* @agent_handle: handle of the EFI block driver
*
* Create an efi_disk object which is associated with @dev.
* The type of @dev must be UCLASS_PARTITION.
*
* Return: 0 on success, -1 otherwise
*/
static int efi_disk_create_part(struct udevice *dev, efi_handle_t agent_handle)
{
efi_handle_t parent;
struct blk_desc *desc;
struct disk_part *part_data;
struct disk_partition *info;
unsigned int part;
int diskid;
struct efi_handler *handler;
struct efi_device_path *dp_parent;
struct efi_disk_obj *disk;
efi_status_t ret;
if (dev_tag_get_ptr(dev_get_parent(dev), DM_TAG_EFI, (void **)&parent))
return -1;
desc = dev_get_uclass_plat(dev_get_parent(dev));
diskid = desc->devnum;
part_data = dev_get_uclass_plat(dev);
part = part_data->partnum;
info = &part_data->gpt_part_info;
ret = efi_search_protocol(parent, &efi_guid_device_path, &handler);
if (ret != EFI_SUCCESS)
return -1;
dp_parent = (struct efi_device_path *)handler->protocol_interface;
ret = efi_disk_add_dev(parent, dp_parent, desc,
info, part, &disk, agent_handle);
if (ret != EFI_SUCCESS) {
log_err("Adding partition for %s failed\n", dev->name);
return -1;
}
if (efi_link_dev(&disk->header, dev)) {
efi_disk_free_diskobj(disk);
/* TODO: closing the parent EFI_BLOCK_IO_PROTOCOL is missing. */
return -1;
}
return 0;
}
/**
* efi_disk_probe() - create efi_disk objects for a block device
*
* @ctx: event context - driver binding protocol
* @event: EV_PM_POST_PROBE event
*
* Create efi_disk objects for partitions as well as a raw disk
* which is associated with @dev.
* The type of @dev must be UCLASS_BLK.
* This function is expected to be called at EV_PM_POST_PROBE.
*
* Return: 0 on success, -1 otherwise
*/
int efi_disk_probe(void *ctx, struct event *event)
{
struct udevice *dev;
enum uclass_id id;
struct blk_desc *desc;
struct udevice *child;
struct efi_driver_binding_extended_protocol *db_prot = ctx;
efi_handle_t agent_handle = db_prot->bp.driver_binding_handle;
int ret;
dev = event->data.dm.dev;
id = device_get_uclass_id(dev);
/* We won't support partitions in a partition */
if (id != UCLASS_BLK)
return 0;
/*
* Avoid creating duplicated objects now that efi_driver
* has already created an efi_disk at this moment.
*/
desc = dev_get_uclass_plat(dev);
if (desc->uclass_id != UCLASS_EFI_LOADER) {
ret = efi_disk_create_raw(dev, agent_handle);
if (ret)
return -1;
}
device_foreach_child(child, dev) {
ret = efi_disk_create_part(child, agent_handle);
if (ret)
return -1;
}
/* only do the boot option management when UEFI sub-system is initialized */
if (IS_ENABLED(CONFIG_CMD_BOOTEFI_BOOTMGR) && efi_obj_list_initialized == EFI_SUCCESS) {
ret = efi_bootmgr_update_media_device_boot_option();
if (ret != EFI_SUCCESS)
return -1;
}
return 0;
}
/**
* efi_disk_remove - delete an efi_disk object for a block device or partition
*
* @ctx: event context: driver binding protocol
* @event: EV_PM_PRE_REMOVE event
*
* Delete an efi_disk object which is associated with the UCLASS_BLK or
* UCLASS_PARTITION device for which the EV_PM_PRE_REMOVE event is raised.
*
* Return: 0 on success, -1 otherwise
*/
int efi_disk_remove(void *ctx, struct event *event)
{
enum uclass_id id;
struct udevice *dev = event->data.dm.dev;
efi_handle_t handle;
struct blk_desc *desc;
struct efi_device_path *dp = NULL;
struct efi_disk_obj *diskobj = NULL;
struct efi_simple_file_system_protocol *volume = NULL;
efi_status_t ret;
if (dev_tag_get_ptr(dev, DM_TAG_EFI, (void **)&handle))
return 0;
id = device_get_uclass_id(dev);
switch (id) {
case UCLASS_BLK:
desc = dev_get_uclass_plat(dev);
if (desc && desc->uclass_id == UCLASS_EFI_LOADER)
/*
* EFI application/driver manages the EFI handle,
* no need to delete EFI handle.
*/
return 0;
diskobj = (struct efi_disk_obj *)handle;
break;
case UCLASS_PARTITION:
diskobj = (struct efi_disk_obj *)handle;
/* TODO: closing the parent EFI_BLOCK_IO_PROTOCOL is missing. */
break;
default:
return 0;
}
dp = diskobj->dp;
volume = diskobj->volume;
ret = efi_delete_handle(handle);
/* Do not delete DM device if there are still EFI drivers attached. */
if (ret != EFI_SUCCESS)
return -1;
efi_free_pool(dp);
free(volume);
dev_tag_del(dev, DM_TAG_EFI);
return 0;
/*
* TODO A flag to distinguish below 2 different scenarios of this
* function call is needed:
* a) Unplugging of a removable media under U-Boot
* b) U-Boot exiting and booting an OS
* In case of scenario a), efi_bootmgr_update_media_device_boot_option()
* needs to be invoked here to update the boot options and remove the
* unnecessary ones.
*/
}
/**
* efi_disk_get_device_name() - get U-Boot device name associated with EFI handle
*
* @handle: pointer to the EFI handle
* @buf: pointer to the buffer to store the string
* @size: size of buffer
* Return: status code
*/
efi_status_t efi_disk_get_device_name(const efi_handle_t handle, char *buf, int size)
{
int count;
int diskid;
enum uclass_id id;
unsigned int part;
struct udevice *dev;
struct blk_desc *desc;
const char *if_typename;
bool is_partition = false;
struct disk_part *part_data;
if (!handle || !buf || !size)
return EFI_INVALID_PARAMETER;
dev = handle->dev;
id = device_get_uclass_id(dev);
if (id == UCLASS_BLK) {
desc = dev_get_uclass_plat(dev);
} else if (id == UCLASS_PARTITION) {
desc = dev_get_uclass_plat(dev_get_parent(dev));
is_partition = true;
} else {
return EFI_INVALID_PARAMETER;
}
if_typename = blk_get_uclass_name(desc->uclass_id);
diskid = desc->devnum;
if (is_partition) {
part_data = dev_get_uclass_plat(dev);
part = part_data->partnum;
count = snprintf(buf, size, "%s %d:%u", if_typename, diskid,
part);
} else {
count = snprintf(buf, size, "%s %d", if_typename, diskid);
}
if (count < 0 || (count + 1) > size)
return EFI_INVALID_PARAMETER;
return EFI_SUCCESS;
}
/**
* efi_disks_register() - ensure all block devices are available in UEFI
*
* The function probes all block devices. As we store UEFI variables on the
* EFI system partition this function has to be called before enabling
* variable services.
*/
efi_status_t efi_disks_register(void)
{
struct udevice *dev;
uclass_foreach_dev_probe(UCLASS_BLK, dev) {
}
return EFI_SUCCESS;
}