config BLK bool "Support block devices" depends on DM default y if DM_MMC help Enable support for block devices, such as SCSI, MMC and USB flash sticks. These provide a block-level interface which permits reading, writing and (in some cases) erasing blocks. Block devices often have a partition table which allows the device to be partitioned into several areas, called 'partitions' in U-Boot. A filesystem can be placed in each partition. config HAVE_BLOCK_DEVICE bool "Enable Legacy Block Device" help Some devices require block support whether or not DM is enabled config SPL_BLK bool "Support block devices in SPL" depends on SPL_DM && BLK default y help Enable support for block devices, such as SCSI, MMC and USB flash sticks. These provide a block-level interface which permits reading, writing and (in some cases) erasing blocks. Block devices often have a partition table which allows the device to be partitioned into several areas, called 'partitions' in U-Boot. A filesystem can be placed in each partition. config TPL_BLK bool "Support block devices in TPL" depends on TPL_DM && BLK default y help Enable support for block devices, such as SCSI, MMC and USB flash sticks. These provide a block-level interface which permits reading, writing and (in some cases) erasing blocks. Block devices often have a partition table which allows the device to be partitioned into several areas, called 'partitions' in U-Boot. A filesystem can be placed in each partition. config BLOCK_CACHE bool "Use block device cache" depends on BLK default y help This option enables a disk-block cache for all block devices. This is most useful when accessing filesystems under U-Boot since it will prevent repeated reads from directory structures and other filesystem data structures. config SPL_BLOCK_CACHE bool "Use block device cache in SPL" depends on SPL_BLK default n help This option enables the disk-block cache in SPL config TPL_BLOCK_CACHE bool "Use block device cache in TPL" depends on TPL_BLK default n help This option enables the disk-block cache in TPL config IDE bool "Support IDE controllers" select HAVE_BLOCK_DEVICE help Enables support for IDE (Integrated Drive Electronics) hard drives. This allows access to raw blocks and filesystems on an IDE drive from U-Boot. See also CMD_IDE which provides an 'ide' command for performing various IDE operations.