660685d9d1
The MTD subsystem has historically tried to be as configurable as possible. The
side-effect of this is that its configuration menu is rather large, and we are
gradually shrinking it. For example, we recently merged partitions support with
the mtdcore.
This patch does the next step - it merges the mtdchar module to mtdcore. And in
this case this is not only about eliminating too fine-grained separation and
simplifying the configuration menu. This is also about eliminating seemingly
useless kernel module.
Indeed, mtdchar is a module that allows user-space making use of MTD devices
via /dev/mtd* character devices. If users do not enable it, they simply cannot
use MTD devices at all. They cannot read or write the flash contents. Is it a
sane and useful setup? I believe not. And everyone just enables mtdchar.
Having mtdchar separate is also a little bit harmful. People sometimes miss the
fact that they need to enable an additional configuration option to have
user-space MTD interfaces, and then they wonder why on earth the kernel does
not allow using the flash? They spend time asking around.
Thus, let's just get rid of this module and make it part of mtd core.
Note, mtdchar had additional configuration option to enable OTP interfaces,
which are present on some flashes. I removed that option as well - it saves a
really tiny amount space.
[dwmw2: Strictly speaking, you can mount file systems on MTD devices just
fine without the mtdchar (or mtdblock) devices; you just can't do
other manipulations directly on the underlying device. But still I
agree that it makes sense to make this unconditional. And Yay! we
get to kill off an instance of checking CONFIG_foo_MODULE, which is
an abomination that should never happen.]
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
325 lines
11 KiB
Text
325 lines
11 KiB
Text
menuconfig MTD
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tristate "Memory Technology Device (MTD) support"
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depends on GENERIC_IO
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help
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Memory Technology Devices are flash, RAM and similar chips, often
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used for solid state file systems on embedded devices. This option
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will provide the generic support for MTD drivers to register
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themselves with the kernel and for potential users of MTD devices
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to enumerate the devices which are present and obtain a handle on
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them. It will also allow you to select individual drivers for
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particular hardware and users of MTD devices. If unsure, say N.
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if MTD
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config MTD_TESTS
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tristate "MTD tests support (DANGEROUS)"
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depends on m
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help
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This option includes various MTD tests into compilation. The tests
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should normally be compiled as kernel modules. The modules perform
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various checks and verifications when loaded.
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WARNING: some of the tests will ERASE entire MTD device which they
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test. Do not use these tests unless you really know what you do.
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config MTD_REDBOOT_PARTS
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tristate "RedBoot partition table parsing"
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---help---
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RedBoot is a ROM monitor and bootloader which deals with multiple
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'images' in flash devices by putting a table one of the erase
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blocks on the device, similar to a partition table, which gives
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the offsets, lengths and names of all the images stored in the
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flash.
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If you need code which can detect and parse this table, and register
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MTD 'partitions' corresponding to each image in the table, enable
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this option.
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You will still need the parsing functions to be called by the driver
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for your particular device. It won't happen automatically. The
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SA1100 map driver (CONFIG_MTD_SA1100) has an option for this, for
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example.
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if MTD_REDBOOT_PARTS
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config MTD_REDBOOT_DIRECTORY_BLOCK
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int "Location of RedBoot partition table"
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default "-1"
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---help---
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This option is the Linux counterpart to the
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CYGNUM_REDBOOT_FIS_DIRECTORY_BLOCK RedBoot compile time
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option.
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The option specifies which Flash sectors holds the RedBoot
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partition table. A zero or positive value gives an absolute
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erase block number. A negative value specifies a number of
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sectors before the end of the device.
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For example "2" means block number 2, "-1" means the last
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block and "-2" means the penultimate block.
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config MTD_REDBOOT_PARTS_UNALLOCATED
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bool "Include unallocated flash regions"
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help
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If you need to register each unallocated flash region as a MTD
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'partition', enable this option.
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config MTD_REDBOOT_PARTS_READONLY
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bool "Force read-only for RedBoot system images"
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help
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If you need to force read-only for 'RedBoot', 'RedBoot Config' and
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'FIS directory' images, enable this option.
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endif # MTD_REDBOOT_PARTS
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config MTD_CMDLINE_PARTS
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tristate "Command line partition table parsing"
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depends on MTD
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---help---
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Allow generic configuration of the MTD partition tables via the kernel
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command line. Multiple flash resources are supported for hardware where
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different kinds of flash memory are available.
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You will still need the parsing functions to be called by the driver
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for your particular device. It won't happen automatically. The
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SA1100 map driver (CONFIG_MTD_SA1100) has an option for this, for
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example.
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The format for the command line is as follows:
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mtdparts=<mtddef>[;<mtddef]
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<mtddef> := <mtd-id>:<partdef>[,<partdef>]
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<partdef> := <size>[@offset][<name>][ro]
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<mtd-id> := unique id used in mapping driver/device
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<size> := standard linux memsize OR "-" to denote all
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remaining space
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<name> := (NAME)
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Due to the way Linux handles the command line, no spaces are
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allowed in the partition definition, including mtd id's and partition
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names.
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Examples:
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1 flash resource (mtd-id "sa1100"), with 1 single writable partition:
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mtdparts=sa1100:-
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Same flash, but 2 named partitions, the first one being read-only:
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mtdparts=sa1100:256k(ARMboot)ro,-(root)
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If unsure, say 'N'.
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config MTD_AFS_PARTS
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tristate "ARM Firmware Suite partition parsing"
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depends on ARM
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---help---
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The ARM Firmware Suite allows the user to divide flash devices into
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multiple 'images'. Each such image has a header containing its name
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and offset/size etc.
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If you need code which can detect and parse these tables, and
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register MTD 'partitions' corresponding to each image detected,
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enable this option.
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You will still need the parsing functions to be called by the driver
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for your particular device. It won't happen automatically. The
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'physmap' map driver (CONFIG_MTD_PHYSMAP) does this, for example.
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config MTD_OF_PARTS
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tristate "OpenFirmware partitioning information support"
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default y
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depends on OF
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help
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This provides a partition parsing function which derives
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the partition map from the children of the flash node,
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as described in Documentation/devicetree/booting-without-of.txt.
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config MTD_AR7_PARTS
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tristate "TI AR7 partitioning support"
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---help---
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TI AR7 partitioning support
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config MTD_BCM63XX_PARTS
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tristate "BCM63XX CFE partitioning support"
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depends on BCM63XX
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select CRC32
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help
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This provides partions parsing for BCM63xx devices with CFE
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bootloaders.
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config MTD_BCM47XX_PARTS
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tristate "BCM47XX partitioning support"
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depends on BCM47XX
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help
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This provides partitions parser for devices based on BCM47xx
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boards.
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comment "User Modules And Translation Layers"
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config MTD_BLKDEVS
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tristate "Common interface to block layer for MTD 'translation layers'"
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depends on BLOCK
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default n
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config MTD_BLOCK
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tristate "Caching block device access to MTD devices"
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depends on BLOCK
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select MTD_BLKDEVS
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---help---
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Although most flash chips have an erase size too large to be useful
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as block devices, it is possible to use MTD devices which are based
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on RAM chips in this manner. This block device is a user of MTD
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devices performing that function.
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At the moment, it is also required for the Journalling Flash File
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System(s) to obtain a handle on the MTD device when it's mounted
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(although JFFS and JFFS2 don't actually use any of the functionality
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of the mtdblock device).
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Later, it may be extended to perform read/erase/modify/write cycles
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on flash chips to emulate a smaller block size. Needless to say,
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this is very unsafe, but could be useful for file systems which are
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almost never written to.
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You do not need this option for use with the DiskOnChip devices. For
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those, enable NFTL support (CONFIG_NFTL) instead.
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config MTD_BLOCK_RO
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tristate "Readonly block device access to MTD devices"
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depends on MTD_BLOCK!=y && BLOCK
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select MTD_BLKDEVS
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help
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This allows you to mount read-only file systems (such as cramfs)
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from an MTD device, without the overhead (and danger) of the caching
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driver.
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You do not need this option for use with the DiskOnChip devices. For
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those, enable NFTL support (CONFIG_NFTL) instead.
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config FTL
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tristate "FTL (Flash Translation Layer) support"
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depends on BLOCK
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select MTD_BLKDEVS
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---help---
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This provides support for the original Flash Translation Layer which
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is part of the PCMCIA specification. It uses a kind of pseudo-
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file system on a flash device to emulate a block device with
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512-byte sectors, on top of which you put a 'normal' file system.
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You may find that the algorithms used in this code are patented
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unless you live in the Free World where software patents aren't
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legal - in the USA you are only permitted to use this on PCMCIA
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hardware, although under the terms of the GPL you're obviously
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permitted to copy, modify and distribute the code as you wish. Just
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not use it.
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config NFTL
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tristate "NFTL (NAND Flash Translation Layer) support"
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depends on BLOCK
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select MTD_BLKDEVS
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---help---
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This provides support for the NAND Flash Translation Layer which is
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used on M-Systems' DiskOnChip devices. It uses a kind of pseudo-
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file system on a flash device to emulate a block device with
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512-byte sectors, on top of which you put a 'normal' file system.
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You may find that the algorithms used in this code are patented
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unless you live in the Free World where software patents aren't
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legal - in the USA you are only permitted to use this on DiskOnChip
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hardware, although under the terms of the GPL you're obviously
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permitted to copy, modify and distribute the code as you wish. Just
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not use it.
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config NFTL_RW
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bool "Write support for NFTL"
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depends on NFTL
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help
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Support for writing to the NAND Flash Translation Layer, as used
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on the DiskOnChip.
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config INFTL
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tristate "INFTL (Inverse NAND Flash Translation Layer) support"
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depends on BLOCK
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select MTD_BLKDEVS
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---help---
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This provides support for the Inverse NAND Flash Translation
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Layer which is used on M-Systems' newer DiskOnChip devices. It
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uses a kind of pseudo-file system on a flash device to emulate
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a block device with 512-byte sectors, on top of which you put
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a 'normal' file system.
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You may find that the algorithms used in this code are patented
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unless you live in the Free World where software patents aren't
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legal - in the USA you are only permitted to use this on DiskOnChip
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hardware, although under the terms of the GPL you're obviously
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permitted to copy, modify and distribute the code as you wish. Just
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not use it.
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config RFD_FTL
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tristate "Resident Flash Disk (Flash Translation Layer) support"
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depends on BLOCK
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select MTD_BLKDEVS
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---help---
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This provides support for the flash translation layer known
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as the Resident Flash Disk (RFD), as used by the Embedded BIOS
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of General Software. There is a blurb at:
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http://www.gensw.com/pages/prod/bios/rfd.htm
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config SSFDC
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tristate "NAND SSFDC (SmartMedia) read only translation layer"
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depends on BLOCK
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select MTD_BLKDEVS
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help
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This enables read only access to SmartMedia formatted NAND
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flash. You can mount it with FAT file system.
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config SM_FTL
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tristate "SmartMedia/xD new translation layer"
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depends on BLOCK
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select MTD_BLKDEVS
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select MTD_NAND_ECC
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help
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This enables EXPERIMENTAL R/W support for SmartMedia/xD
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FTL (Flash translation layer).
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Write support is only lightly tested, therefore this driver
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isn't recommended to use with valuable data (anyway if you have
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valuable data, do backups regardless of software/hardware you
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use, because you never know what will eat your data...)
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If you only need R/O access, you can use older R/O driver
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(CONFIG_SSFDC)
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config MTD_OOPS
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tristate "Log panic/oops to an MTD buffer"
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help
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This enables panic and oops messages to be logged to a circular
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buffer in a flash partition where it can be read back at some
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later point.
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config MTD_SWAP
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tristate "Swap on MTD device support"
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depends on MTD && SWAP
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select MTD_BLKDEVS
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help
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Provides volatile block device driver on top of mtd partition
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suitable for swapping. The mapping of written blocks is not saved.
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The driver provides wear leveling by storing erase counter into the
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OOB.
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source "drivers/mtd/chips/Kconfig"
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source "drivers/mtd/maps/Kconfig"
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source "drivers/mtd/devices/Kconfig"
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source "drivers/mtd/nand/Kconfig"
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source "drivers/mtd/onenand/Kconfig"
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source "drivers/mtd/lpddr/Kconfig"
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source "drivers/mtd/ubi/Kconfig"
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endif # MTD
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