![]() / / $Id: Kconfig,v 1.11 2005/11/07 11:14:19 gleixner Exp $ Memory Technology Devices (MTD) • Option: MTD • Kernel Versions: 2.6.15.6. • (on/off/module) Memory Technology Device (MTD) support Memory Technology Devices are flash, RAM and similar chips, often used for solid state file systems on embedded devices. This option will provide the generic support for MTD drivers to register themselves with the kernel and for potential users of MTD devices to enumerate the devices which are present and obtain a handle on them. It will also allow you to select individual drivers for particular hardware and users of MTD devices. If unsure, say N. The only two things this module does is load and unload itself. To load a Linux driver, we call the my_init function, and to unload it, we call the my_exit function. The module_init and module_exit macros notify the kernel about driver loading and unloading. • Option: MTD_DEBUG • Kernel Versions: 2.6.15.6. • (on/off) Debugging • depends on MTD This turns on low-level debugging for the entire MTD sub-system. Normally, you should say 'N'. • Option: MTD_DEBUG_VERBOSE • Kernel Versions: 2.6.15.6. 'Debugging verbosity (0 = quiet, 3 = noisy)' • • depends on MTD_DEBUG • default '0' Determines the verbosity level of the MTD debugging messages. • Option: MTD_CONCAT • Kernel Versions: 2.6.15.6. • (on/off/module) MTD concatenating support • depends on MTD Support for concatenating several MTD devices into a single (virtual) one. This allows you to have -for example- a JFFS(2) file system spanning multiple physical flash chips. If unsure, say 'Y'. • Option: MTD_PARTITIONS • Kernel Versions: 2.6.15.6. • (on/off) MTD partitioning support • depends on MTD If you have a device which needs to divide its flash chip(s) up into multiple 'partitions', each of which appears to the user as a separate MTD device, you require this option to be enabled. If unsure, say 'Y'. Note, however, that you don't need this option for the DiskOnChip devices. Partitioning on NFTL 'devices' is a different - that's the 'normal' form of partitioning used on a block device. • Option: MTD_REDBOOT_PARTS • Kernel Versions: 2.6.15.6. • (on/off/module) RedBoot partition table parsing • depends on MTD_PARTITIONS RedBoot is a ROM monitor and bootloader which deals with multiple 'images' in flash devices by putting a table one of the erase blocks on the device, similar to a partition table, which gives the offsets, lengths and names of all the images stored in the flash. If you need code which can detect and parse this table, and register MTD 'partitions' corresponding to each image in the table, enable this option. You will still need the parsing functions to be called by the driver for your particular device. It won't happen automatically. The SA1100 map driver (CONFIG_MTD_SA1100) has an option for this, for example. • Option: MTD_REDBOOT_DIRECTORY_BLOCK • Kernel Versions: 2.6.15.6. 'Location of RedBoot partition table' • • depends on MTD_REDBOOT_PARTS • default '-1' This option is the Linux counterpart to the CYGNUM_REDBOOT_FIS_DIRECTORY_BLOCK RedBoot compile time option. The option specifies which Flash sectors holds the RedBoot partition table. A zero or positive value gives an absolete erase block number. A negative value specifies a number of sectors before the end of the device. For example '2' means block number 2, '-1' means the last block and '-2' means the penultimate block. • Option: MTD_REDBOOT_PARTS_UNALLOCATED • Kernel Versions: 2.6.15.6. • (on/off) Include unallocated flash regions • depends on MTD_REDBOOT_PARTS If you need to register each unallocated flash region as a MTD 'partition', enable this option. • Option: MTD_REDBOOT_PARTS_READONLY • Kernel Versions: 2.6.15.6. • (on/off) Force read-only for RedBoot system images • depends on MTD_REDBOOT_PARTS If you need to force read-only for 'RedBoot', 'RedBoot Config' and 'FIS directory' images, enable this option. • Option: MTD_CMDLINE_PARTS • Kernel Versions: 2.6.15.6. • (on/off) Command line partition table parsing • depends on MTD_PARTITIONS = 'y' Allow generic configuration of the MTD paritition tables via the kernel command line. Multiple flash resources are supported for hardware where different kinds of flash memory are available. You will still need the parsing functions to be called by the driver for your particular device. It won't happen automatically. The SA1100 map driver (CONFIG_MTD_SA1100) has an option for this, for example. The format for the command line is as follows: mtdparts=[;:=:[,]:= [@offset][][ro]:= unique id used in mapping driver/device:= standard linux memsize OR '-' to denote all remaining space:= (NAME) Due to the way Linux handles the command line, no spaces are allowed in the partition definition, including mtd id's and partition names. Examples: 1 flash resource (mtd-id 'sa1100'), with 1 single writable partition: mtdparts=sa1100:- Same flash, but 2 named partitions, the first one being read-only: mtdparts=sa1100:256k(ARMboot)ro,-(root) If unsure, say 'N'. • Option: MTD_AFS_PARTS • Kernel Versions: 2.6.15.6.
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