This patch adds 405 platform support to the 440 NDFC driver. The new
AMCC 405EZ PPC is equipped with the same NDFC core as the 440EP(x)
and other will follow soon.
Signed-off-by: Stefan Roese <sr@denx.de>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Stefan Roeseauthored and David Woodhousecommited 2007-06-28 20:33:04 +01:00
Fix the sparse warnings generated by the implicit
dependency of mtd_blkdevs.c and mtd_core.c for the
two symbols mtd_table and mtd_table_mutex. This is
done by adding an local header file mtdcore.h to
define these (including the warning about the
non-proliferation of these symbols).
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Ben Dooksauthored and David Woodhousecommited 2007-06-28 20:24:50 +01:00
Fix sparse warnings generated from cfi_cmdset_0001.c.
drivers/mtd/chips/cfi_cmdset_0001.c:1783:5: warning: symbol 'cfi_intelext_erase_varsize' was not declared. Should it be static?
drivers/mtd/chips/cfi_cmdset_0001.c:2258:43: warning: Using plain integer as NULL pointer
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Ben Dooksauthored and David Woodhousecommited 2007-06-28 20:24:31 +01:00
Make cfi_amdstd_erase_varsize static, as declared at the top
of the file to ensure sparse does not print a warning for an
undeclared function, as so:
drivers/mtd/chips/cfi_cmdset_0002.c:1612:5: warning: symbol 'cfi_amdstd_erase_varsize' was not declared. Should it be static?
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Ben Dooksauthored and David Woodhousecommited 2007-06-28 20:24:19 +01:00
The mtd_blktrans_ops is not defined in any of the headers
and is indeed not used elsewhere in the kernel, so mark it
as static to reduce the warnings from sparse
drivers/mtd/mtd_blkdevs.c:204:32: warning: symbol 'mtd_blktrans_ops' was not declared. Should it be static?
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Ben Dooksauthored and David Woodhousecommited 2007-06-28 20:24:06 +01:00
The nand_base.c driver implicitly casts the uint32_t
eccpos array to 'int *', which is not only not guaranteed
to be the same sign as the source, but is not guaranteed
to be the same size.
Fix by changing nand_base.c to use uint32_t
referencing the eccpos fields.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Ben Dooksauthored and David Woodhousecommited 2007-06-28 20:23:40 +01:00
Kernel oops and panic messages are invaluable when debugging crashes.
These messages often don't make it to flash based logging methods (say a
syslog on jffs2) due to the overheads involved in writing to flash.
This patch allows you to turn an MTD partition into a circular log
buffer where kernel oops and panic messages are written to. The messages
are obtained by registering a console driver and checking
oops_in_progress. Erases are performed in advance to maximise the
chances of a saving messages.
To activate it, add console=ttyMTDx to the kernel commandline (where x
is the mtd device number to use).
Signed-off-by: Richard Purdie <rpurdie@openedhand.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Richard Purdieauthored and David Woodhousecommited 2007-06-28 20:18:02 +01:00
The patch below fixes nand driver for AT91 boards which do not have NAND
R/B signal connected to gpio (rdy_pin is not connected).
Signed-off-by: Ivan Kuten <ivan.kuten@promwad.com>
Acked-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Ivan Kutenauthored and David Woodhousecommited 2007-06-28 20:15:13 +01:00
* git://git.infradead.org/mtd-2.6:
[JFFS2] Fix obsoletion of metadata nodes in jffs2_add_tn_to_tree()
[MTD] Fix error checking after get_mtd_device() in get_sb_mtd functions
[JFFS2] Fix buffer length calculations in jffs2_get_inode_nodes()
[JFFS2] Fix potential memory leak of dead xattrs on unmount.
[JFFS2] Fix BUG() caused by failing to discard xattrs on deleted files.
[MTD] generalise the handling of MTD-specific superblocks
[MTD] [MAPS] don't force uclinux mtd map to be root dev
Fix various bits of obviously-busted code which we're not happening to
compile, due to ifdefs.
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Jan Kara <jack@ucw.cz>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Yoann Padioleauauthored and Linus Torvaldscommited 2007-06-01 08:18:28 -07:00
I have made a tool to parse the kernel that does not pre-process the
source. That means that my parser tries to parse all the code, including
code in the #else branch or code that is not often compiled because the
driver is not very used (or not used at all). So, my parser sometimes
reports parse error not originally detected by gcc. Here is my (first)
patch.
[akpm@linux-foundation.org: fix amd8111e.c]
Signed-off-by: Yoann Padioleau <padator@wanadoo.fr>
Acked-by: Matthew Wilcox <matthew@wil.cx>
Acked-by: Wim Van Sebroeck <wim@iguana.be>
Acked-by: David Woodhouse <dwmw2@infradead.org>
Acked-by: Jeff Garzik <jeff@garzik.org>
Acked-by: James Bottomley <James.Bottomley@steeleye.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Yoann Padioleauauthored and Linus Torvaldscommited 2007-06-01 08:18:27 -07:00
SLAB_CTOR_CONSTRUCTOR is always specified. No point in checking it.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Steven French <sfrench@us.ibm.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@ucw.cz>
Cc: David Chinner <dgc@sgi.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Christoph Lameterauthored and Linus Torvaldscommited 2007-05-17 05:23:04 -07:00
Generalise the handling of MTD-specific superblocks so that JFFS2 and ROMFS
can both share it.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
David Howellsauthored and David Woodhousecommited 2007-05-11 12:14:15 +01:00
The cheesy uclinux mtd maps can be used for more than just the root device, so
I think we should drop the forcing.
Also, I feel like this is a policy decision that shouldnt be in the kernel in
the first place. People who have been lazy and boot with uclinux mtd maps and
dont put root= into their commandline can simply add the appropriate root=
line either into their bootloader or into the compiled in bootargs.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Mike Frysingerauthored and David Woodhousecommited 2007-05-11 11:48:15 +01:00
Add "depends on HAS_IOMEM" to a number of menus to make them
disappear for s390 which does not have I/O memory.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Martin Schwidefskycommited 2007-05-10 15:46:07 +02:00
* git://git.infradead.org/mtd-2.6: (21 commits)
[MTD] [CHIPS] Remove MTD_OBSOLETE_CHIPS (jedec, amd_flash, sharp)
[MTD] Delete allegedly obsolete "bank_size" field of mtd_info.
[MTD] Remove unnecessary user space check from mtd.h.
[MTD] [MAPS] Remove flash maps for no longer supported 405LP boards
[MTD] [MAPS] Fix missing printk() parameter in physmap_of.c MTD driver
[MTD] [NAND] platform NAND driver: add driver
[MTD] [NAND] platform NAND driver: update header
[JFFS2] Simplify and clean up jffs2_add_tn_to_tree() some more.
[JFFS2] Remove another bogus optimisation in jffs2_add_tn_to_tree()
[JFFS2] Remove broken insert_point optimisation in jffs2_add_tn_to_tree()
[JFFS2] Remember to calculate overlap on nodes which replace older nodes
[JFFS2] Don't advance c->wbuf_ofs to next eraseblock after wbuf flush
[MTD] [NAND] at91_nand.c: CMDLINE_PARTS support
[MTD] [NAND] Tidy up handling of page number in nand_block_bad()
[MTD] block2mtd_paramline[] mustn't be __initdata
[MTD] [NAND] Support multiple chips in CAFÉ driver
[MTD] [NAND] Rename cafe.c to cafe_nand.c and remove the multi-obj magic
[MTD] [NAND] Use rslib for CAFÉ ECC
[RSLIB] Support non-canonical GF representations
[JFFS2] Remove dead file histo_mips.h
...
Delete the allegedly obsolete "bank_size" member of struct mtd_info.
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Robert P. J. Dayauthored and David Woodhousecommited 2007-05-09 13:26:52 +01:00
drivers/mtd/maps includes flash maps for the Beech and Arctic PowerPC
405LP based boards. However, the 405LP was discontinued before any
quantity were distributed and those boards no longer have kernel
support in general. Therefore, this patch removes this obsolete code.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
David Gibsonauthored and David Woodhousecommited 2007-05-09 09:43:02 +01:00
Squashes a compiler warning, and provides more useful information in
the case messed up device tree information.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
David Gibsonauthored and David Woodhousecommited 2007-05-09 09:38:48 +01:00
Fix various typos in kernel docs and Kconfigs, 2.6.21-rc4.
Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Matt LaPlanteauthored and Adrian Bunkcommited 2007-05-09 08:58:15 +02:00
Ingo Molnar's semaphore to mutex conversions left some noise on a few
trylock calls. Clean it up.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jean Delvareauthored and Linus Torvaldscommited 2007-05-08 11:15:13 -07:00
This patch adds support for generic platform NAND driver.
Updated after tglx's review/discussion in IRC #mtd channel.
Signed-off-by: Vitaly Wool <vitalywool@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Vitaly Woolauthored and David Woodhousecommited 2007-05-08 00:41:55 +01:00
I have never seen a use of SLAB_DEBUG_INITIAL. It is only supported by
SLAB.
I think its purpose was to have a callback after an object has been freed
to verify that the state is the constructor state again? The callback is
performed before each freeing of an object.
I would think that it is much easier to check the object state manually
before the free. That also places the check near the code object
manipulation of the object.
Also the SLAB_DEBUG_INITIAL callback is only performed if the kernel was
compiled with SLAB debugging on. If there would be code in a constructor
handling SLAB_DEBUG_INITIAL then it would have to be conditional on
SLAB_DEBUG otherwise it would just be dead code. But there is no such code
in the kernel. I think SLUB_DEBUG_INITIAL is too problematic to make real
use of, difficult to understand and there are easier ways to accomplish the
same effect (i.e. add debug code before kfree).
There is a related flag SLAB_CTOR_VERIFY that is frequently checked to be
clear in fs inode caches. Remove the pointless checks (they would even be
pointless without removeal of SLAB_DEBUG_INITIAL) from the fs constructors.
This is the last slab flag that SLUB did not support. Remove the check for
unimplemented flags from SLUB.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Christoph Lameterauthored and Linus Torvaldscommited 2007-05-07 12:12:57 -07:00
Ensure pages are uptodate after returning from read_cache_page, which allows
us to cut out most of the filesystem-internal PageUptodate calls.
I didn't have a great look down the call chains, but this appears to fixes 7
possible use-before uptodate in hfs, 2 in hfsplus, 1 in jfs, a few in
ecryptfs, 1 in jffs2, and a possible cleared data overwritten with readpage in
block2mtd. All depending on whether the filler is async and/or can return
with a !uptodate page.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Nick Pigginauthored and Linus Torvaldscommited 2007-05-07 12:12:51 -07:00
* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild: (38 commits)
kconfig: fix mconf segmentation fault
kbuild: enable use of code from a different dir
kconfig: error out if recursive dependencies are found
kbuild: scripts/basic/fixdep segfault on pathological string-o-death
kconfig: correct minor typo in Kconfig warning message.
kconfig: fix path to modules.txt in Kconfig help
usr/Kconfig: fix typo
kernel-doc: alphabetically-sorted entries in index.html of 'htmldocs'
kbuild: be more explicit on missing .config file
kbuild: clarify the creation of the LOCALVERSION_AUTO string.
kbuild: propagate errors from find in scripts/gen_initramfs_list.sh
kconfig: refer to qt3 if we cannot find qt libraries
kbuild: handle compressed cpio initramfs-es
kbuild: ignore section mismatch warning for references from .paravirtprobe to .init.text
kbuild: remove stale comment in modpost.c
kbuild/mkuboot.sh: allow spaces in CROSS_COMPILE
kbuild: fix make mrproper for Documentation/DocBook/man
kbuild: remove kconfig binaries during make mrproper
kconfig/menuconfig: do not hardcode '.config'
kbuild: override build timestamp & version
...
This patch allows you to specify at91_nand partitions on the
kernel command line using the mtdparts variable, if
CONFIG_MTD_CMDLINE_PARTS is set.
Signed-off-by: Frank Mandarino <fmandarino@endrelia.com>
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Andrew Victorauthored and David Woodhousecommited 2007-05-03 07:40:41 +01:00
Further to the previous patch fixing the calculation of page number,
both branches are using the same result. Clean up the function
accordingly, calculating it (and also masking with pagemask) only in one
place.
Signed-off-by: Thomas Knobloch <knobloch@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Thomas Knoblochauthored and David Woodhousecommited 2007-05-03 07:39:37 +01:00
I noticed that many source files include <linux/pci.h> while they do
not appear to need it. Here is an attempt to clean it all up.
In order to find all possibly affected files, I searched for all
files including <linux/pci.h> but without any other occurence of "pci"
or "PCI". I removed the include statement from all of these, then I
compiled an allmodconfig kernel on both i386 and x86_64 and fixed the
false positives manually.
My tests covered 66% of the affected files, so there could be false
positives remaining. Untested files are:
arch/alpha/kernel/err_common.c
arch/alpha/kernel/err_ev6.c
arch/alpha/kernel/err_ev7.c
arch/ia64/sn/kernel/huberror.c
arch/ia64/sn/kernel/xpnet.c
arch/m68knommu/kernel/dma.c
arch/mips/lib/iomap.c
arch/powerpc/platforms/pseries/ras.c
arch/ppc/8260_io/enet.c
arch/ppc/8260_io/fcc_enet.c
arch/ppc/8xx_io/enet.c
arch/ppc/syslib/ppc4xx_sgdma.c
arch/sh64/mach-cayman/iomap.c
arch/xtensa/kernel/xtensa_ksyms.c
arch/xtensa/platform-iss/setup.c
drivers/i2c/busses/i2c-at91.c
drivers/i2c/busses/i2c-mpc.c
drivers/media/video/saa711x.c
drivers/misc/hdpuftrs/hdpu_cpustate.c
drivers/misc/hdpuftrs/hdpu_nexus.c
drivers/net/au1000_eth.c
drivers/net/fec_8xx/fec_main.c
drivers/net/fec_8xx/fec_mii.c
drivers/net/fs_enet/fs_enet-main.c
drivers/net/fs_enet/mac-fcc.c
drivers/net/fs_enet/mac-fec.c
drivers/net/fs_enet/mac-scc.c
drivers/net/fs_enet/mii-bitbang.c
drivers/net/fs_enet/mii-fec.c
drivers/net/ibm_emac/ibm_emac_core.c
drivers/net/lasi_82596.c
drivers/parisc/hppb.c
drivers/sbus/sbus.c
drivers/video/g364fb.c
drivers/video/platinumfb.c
drivers/video/stifb.c
drivers/video/valkyriefb.c
include/asm-arm/arch-ixp4xx/dma.h
sound/oss/au1550_ac97.c
I would welcome test reports for these files. I am fine with removing
the untested files from the patch if the general opinion is that these
changes aren't safe. The tested part would still be nice to have.
Note that this patch depends on another header fixup patch I submitted
to LKML yesterday:
[PATCH] scatterlist.h needs types.h
http://lkml.org/lkml/2007/3/01/141
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Jean Delvareauthored and Greg Kroah-Hartmancommited 2007-05-02 19:02:35 -07:00
Documentation/modules.txt doesn't exist, but
Documentation/kbuild/modules.txt does.
Signed-off-by: Alexander E. Patrakov
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Alexander E. Patrakovauthored and Sam Ravnborgcommited 2007-05-02 20:58:11 +02:00
block2mtd_paramline[] is used in the non-__init block2mtd_setup()
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Joern Engel <joern@lazybastard.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Adrian Bunkauthored and David Woodhousecommited 2007-05-02 12:33:17 +01:00
The CAFÉ can handle two chip on separate chipselect lines. Hook up the
undocumented chipselect bits in the driver and probe both.
In the case of OLPC, it's not actually two separate devices -- it's a
single '1GiB' package with two 512MiB dies internally. So clear the
NAND_BBT_PERCHIP flag to treat it as a single chip for BBT purposes, and
make life easier for the firmware.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
David Woodhousecommited 2007-05-02 12:26:37 +01:00
These are all the remaining instances of get_property. Simple rename of
get_property to of_get_property.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Stephen Rothwellauthored and Paul Mackerrascommited 2007-05-02 20:04:32 +10:00
This patch converts the pci_module_init() usage to pci_register_driver().
It's currently #if 0'ed, but still not a bad idea to change it.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Adrian Bunkauthored and David Woodhousecommited 2007-04-27 23:34:21 +01:00
This patch provides MTD support for NAND flash devices on CM-x270 modules.
Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Mike Rapoportauthored and David Woodhousecommited 2007-04-27 23:04:32 +01:00
* 'for-linus' of git://git.infradead.org/ubi-2.6:
UBI: remove unused variable
UBI: add me to MAINTAINERS
JFFS2: add UBI support
UBI: Unsorted Block Images
In case that there is no memory based bad block table available the
function nand_block_checkbad() in drivers/mtd/nand/nand_base.c will call
nand_block_bad() directly. When parameter 'getchip' is set to zero,
nand_block_bad() will not right shift the offset to calculate the
correct page number.
Signed-off-by: Thomas Knobloch <knobloch@siemens.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Knobloch, Thomasauthored and David Woodhousecommited 2007-04-27 15:13:53 +01:00
UBI (Latin: "where?") manages multiple logical volumes on a single
flash device, specifically supporting NAND flash devices. UBI provides
a flexible partitioning concept which still allows for wear-levelling
across the whole flash device.
In a sense, UBI may be compared to the Logical Volume Manager
(LVM). Whereas LVM maps logical sector numbers to physical HDD sector
numbers, UBI maps logical eraseblocks to physical eraseblocks.
More information may be found at
http://www.linux-mtd.infradead.org/doc/ubi.html
Partitioning/Re-partitioning
An UBI volume occupies a certain number of erase blocks. This is
limited by a configured maximum volume size, which could also be
viewed as the partition size. Each individual UBI volume's size can
be changed independently of the other UBI volumes, provided that the
sum of all volume sizes doesn't exceed a certain limit.
UBI supports dynamic volumes and static volumes. Static volumes are
read-only and their contents are protected by CRC check sums.
Bad eraseblocks handling
UBI transparently handles bad eraseblocks. When a physical
eraseblock becomes bad, it is substituted by a good physical
eraseblock, and the user does not even notice this.
Scrubbing
On a NAND flash bit flips can occur on any write operation,
sometimes also on read. If bit flips persist on the device, at first
they can still be corrected by ECC, but once they accumulate,
correction will become impossible. Thus it is best to actively scrub
the affected eraseblock, by first copying it to a free eraseblock
and then erasing the original. The UBI layer performs this type of
scrubbing under the covers, transparently to the UBI volume users.
Erase Counts
UBI maintains an erase count header per eraseblock. This frees
higher-level layers (like file systems) from doing this and allows
for centralized erase count management instead. The erase counts are
used by the wear-levelling algorithm in the UBI layer. The algorithm
itself is exchangeable.
Booting from NAND
For booting directly from NAND flash the hardware must at least be
capable of fetching and executing a small portion of the NAND
flash. Some NAND flash controllers have this kind of support. They
usually limit the window to a few kilobytes in erase block 0. This
"initial program loader" (IPL) must then contain sufficient logic to
load and execute the next boot phase.
Due to bad eraseblocks, which may be randomly scattered over the
flash device, it is problematic to store the "secondary program
loader" (SPL) statically. Also, due to bit-flips it may become
corrupted over time. UBI allows to solve this problem gracefully by
storing the SPL in a small static UBI volume.
UBI volumes vs. static partitions
UBI volumes are still very similar to static MTD partitions:
* both consist of eraseblocks (logical eraseblocks in case of UBI
volumes, and physical eraseblocks in case of static partitions;
* both support three basic operations - read, write, erase.
But UBI volumes have the following advantages over traditional
static MTD partitions:
* there are no eraseblock wear-leveling constraints in case of UBI
volumes, so the user should not care about this;
* there are no bit-flips and bad eraseblocks in case of UBI volumes.
So, UBI volumes may be considered as flash devices with relaxed
restrictions.
Where can it be found?
Documentation, kernel code and applications can be found in the MTD
gits.
What are the applications for?
The applications help to create binary flash images for two purposes: pfi
files (partial flash images) for in-system update of UBI volumes, and plain
binary images, with or without OOB data in case of NAND, for a manufacturing
step. Furthermore some tools are/and will be created that allow flash content
analysis after a system has crashed..
Who did UBI?
The original ideas, where UBI is based on, were developed by Andreas
Arnez, Frank Haverkamp and Thomas Gleixner. Josh W. Boyer and some others
were involved too. The implementation of the kernel layer was done by Artem
B. Bityutskiy. The user-space applications and tools were written by Oliver
Lohmann with contributions from Frank Haverkamp, Andreas Arnez, and Artem.
Joern Engel contributed a patch which modifies JFFS2 so that it can be run on
a UBI volume. Thomas Gleixner did modifications to the NAND layer. Alexander
Schmidt made some testing work as well as core functionality improvements.
Signed-off-by: Artem B. Bityutskiy <dedekind@linutronix.de>
Signed-off-by: Frank Haverkamp <haver@vnet.ibm.com>
Artem B. Bityutskiyauthored and Frank Haverkampcommited 2007-04-27 14:23:33 +03:00
The only unfortunate bit here is that the name field of struct map_info
is not const, so for now we put a cast on the assignment of it.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stephen Rothwellauthored and David S. Millercommited 2007-04-26 01:54:27 -07:00
drivers/mtd/maps/plat-ram.c:172: warning: format '%lx' expects type 'long unsigned int', but argument 4 has type 'resource_size_t'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Randy Dunlapauthored and David Woodhousecommited 2007-04-26 07:28:58 +01:00
Stefan Roese
authored and
David Woodhouse
commited 
Ben Dooks
authored and
Richard Purdie
authored and
Ivan Kuten
authored and
Joakim Tjernlund
authored and
Linus Torvalds
commited 
Yoann Padioleau
authored and
Christoph Lameter
authored and
David Howells
authored and
Mike Frysinger
authored and
Martin Schwidefsky
commited 
Robert P. J. Day
authored and
David Gibson
authored and
Matt LaPlante
authored and
Adrian Bunk
commited 
Michael Opdenacker
authored and
Jean Delvare
authored and
Paul Mackerras
commited 
Vitaly Wool
authored and
Nick Piggin
authored and
Andrew Victor
authored and
Thomas Knobloch
authored and
Greg Kroah-Hartman
commited 
Alexander E. Patrakov
authored and
Sam Ravnborg
commited 
Segher Boessenkool
authored and
Stephen Rothwell
authored and
Mike Rapoport
authored and
Artem Bityutskiy
commited 
Artem B. Bityutskiy
authored and
Frank Haverkamp
commited 
David S. Miller
commited 
Randy Dunlap
authored and