// SPDX-License-Identifier: GPL-2.0+ /* * EFI block driver * * Copyright (c) 2017 Heinrich Schuchardt * * The EFI uclass creates a handle for this driver and installs the * driver binding protocol on it. * * The EFI block driver binds to controllers implementing the block io * protocol. * * When the bind function of the EFI block driver is called it creates a * new U-Boot block device. It installs child handles for all partitions and * installs the simple file protocol on these. * * The read and write functions of the EFI block driver delegate calls to the * controller that it is bound to. * * A usage example is as following: * * U-Boot loads the iPXE snp.efi executable. iPXE connects an iSCSI drive and * exposes a handle with the block IO protocol. It calls ConnectController. * * Now the EFI block driver installs the partitions with the simple file * protocol. * * iPXE uses the simple file protocol to load Grub or the Linux Kernel. */ #include #include #include /* * EFI attributes of the udevice handled by this driver. * * handle handle of the controller on which this driver is installed * io block io protocol proxied by this driver */ struct efi_blk_priv { efi_handle_t handle; struct efi_block_io *io; }; /* * Read from block device * * @dev device * @blknr first block to be read * @blkcnt number of blocks to read * @buffer output buffer * @return number of blocks transferred */ static ulong efi_bl_read(struct udevice *dev, lbaint_t blknr, lbaint_t blkcnt, void *buffer) { struct efi_blk_priv *priv = dev->priv; struct efi_block_io *io = priv->io; efi_status_t ret; EFI_PRINT("%s: read '%s', from block " LBAFU ", " LBAFU " blocks\n", __func__, dev->name, blknr, blkcnt); ret = EFI_CALL(io->read_blocks( io, io->media->media_id, (u64)blknr, (efi_uintn_t)blkcnt * (efi_uintn_t)io->media->block_size, buffer)); EFI_PRINT("%s: r = %u\n", __func__, (unsigned int)(ret & ~EFI_ERROR_MASK)); if (ret != EFI_SUCCESS) return 0; return blkcnt; } /* * Write to block device * * @dev device * @blknr first block to be write * @blkcnt number of blocks to write * @buffer input buffer * @return number of blocks transferred */ static ulong efi_bl_write(struct udevice *dev, lbaint_t blknr, lbaint_t blkcnt, const void *buffer) { struct efi_blk_priv *priv = dev->priv; struct efi_block_io *io = priv->io; efi_status_t ret; EFI_PRINT("%s: write '%s', from block " LBAFU ", " LBAFU " blocks\n", __func__, dev->name, blknr, blkcnt); ret = EFI_CALL(io->write_blocks( io, io->media->media_id, (u64)blknr, (efi_uintn_t)blkcnt * (efi_uintn_t)io->media->block_size, (void *)buffer)); EFI_PRINT("%s: r = %u\n", __func__, (unsigned int)(ret & ~EFI_ERROR_MASK)); if (ret != EFI_SUCCESS) return 0; return blkcnt; } /* * Create partions for the block device. * * @handle EFI handle of the block device * @dev udevice of the block device */ static int efi_bl_bind_partitions(efi_handle_t handle, struct udevice *dev) { struct blk_desc *desc; const char *if_typename; desc = dev_get_uclass_platdata(dev); if_typename = blk_get_if_type_name(desc->if_type); return efi_disk_create_partitions(handle, desc, if_typename, desc->devnum, dev->name); } /* * Create a block device for a handle * * @handle handle * @interface block io protocol * @return 0 = success */ static int efi_bl_bind(efi_handle_t handle, void *interface) { struct udevice *bdev, *parent = dm_root(); int ret, devnum; char *name; struct efi_object *obj = efi_search_obj(handle); struct efi_block_io *io = interface; int disks; struct efi_blk_priv *priv; EFI_PRINT("%s: handle %p, interface %p\n", __func__, handle, io); if (!obj) return -ENOENT; devnum = blk_find_max_devnum(IF_TYPE_EFI); if (devnum == -ENODEV) devnum = 0; else if (devnum < 0) return devnum; name = calloc(1, 18); /* strlen("efiblk#2147483648") + 1 */ if (!name) return -ENOMEM; sprintf(name, "efiblk#%d", devnum); /* Create driver model udevice for the EFI block io device */ ret = blk_create_device(parent, "efi_blk", name, IF_TYPE_EFI, devnum, io->media->block_size, (lbaint_t)io->media->last_block, &bdev); if (ret) return ret; if (!bdev) return -ENOENT; /* Allocate priv */ ret = device_probe(bdev); if (ret) return ret; EFI_PRINT("%s: block device '%s' created\n", __func__, bdev->name); priv = bdev->priv; priv->handle = handle; priv->io = interface; ret = blk_prepare_device(bdev); /* Create handles for the partions of the block device */ disks = efi_bl_bind_partitions(handle, bdev); EFI_PRINT("Found %d partitions\n", disks); return 0; } /* Block device driver operators */ static const struct blk_ops efi_blk_ops = { .read = efi_bl_read, .write = efi_bl_write, }; /* Identify as block device driver */ U_BOOT_DRIVER(efi_blk) = { .name = "efi_blk", .id = UCLASS_BLK, .ops = &efi_blk_ops, .priv_auto_alloc_size = sizeof(struct efi_blk_priv), }; /* EFI driver operators */ static const struct efi_driver_ops driver_ops = { .protocol = &efi_block_io_guid, .child_protocol = &efi_block_io_guid, .bind = efi_bl_bind, }; /* Identify as EFI driver */ U_BOOT_DRIVER(efi_block) = { .name = "EFI block driver", .id = UCLASS_EFI, .ops = &driver_ops, };