1config BLK 2 bool "Support block devices" 3 depends on DM 4 default y if DM_MMC 5 help 6 Enable support for block devices, such as SCSI, MMC and USB 7 flash sticks. These provide a block-level interface which permits 8 reading, writing and (in some cases) erasing blocks. Block 9 devices often have a partition table which allows the device to 10 be partitioned into several areas, called 'partitions' in U-Boot. 11 A filesystem can be placed in each partition. 12 13config SPL_BLK 14 bool "Support block devices in SPL" 15 depends on SPL_DM && BLK 16 default y 17 help 18 Enable support for block devices, such as SCSI, MMC and USB 19 flash sticks. These provide a block-level interface which permits 20 reading, writing and (in some cases) erasing blocks. Block 21 devices often have a partition table which allows the device to 22 be partitioned into several areas, called 'partitions' in U-Boot. 23 A filesystem can be placed in each partition. 24 25config SPL_BLK_READ_PREPARE 26 bool "Support block devices prepare to read data in SPL" 27 depends on SPL_BLK 28 help 29 Enable support for block devices to prefetch data. MMC and mtd_blk 30 devices can be attached to block devices. It is applied to prefetch 31 data in the background and the device run some other process in the 32 same time. 33 34config BLOCK_CACHE 35 bool "Use block device cache" 36 default n 37 help 38 This option enables a disk-block cache for all block devices. 39 This is most useful when accessing filesystems under U-Boot since 40 it will prevent repeated reads from directory structures and other 41 filesystem data structures. 42 43config IDE 44 bool "Support IDE controllers" 45 help 46 Enables support for IDE (Integrated Drive Electronics) hard drives. 47 This allows access to raw blocks and filesystems on an IDE drive 48 from U-Boot. See also CMD_IDE which provides an 'ide' command for 49 performing various IDE operations. 50