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path: root/drivers/mtd/Makefile
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2007-08-23Merge branch 'master' of ↵David Woodhouse
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
2007-08-03[MTD] Makefile fix for mtdsuperSatyam Sharma
We want drivers/mtd/{mtdcore, mtdsuper, mtdpart}.c to be built and linked into the same mtd.ko module. Fix the Makefile to ensure this, and remove duplicate MODULE_ declarations in mtdpart.c, as mtdcore.c already has them. Signed-off-by: Satyam Sharma <satyam@infradead.org> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2007-06-28[MTD] oops and panic message logging to MTD deviceRichard Purdie
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>
2007-05-11[MTD] generalise the handling of MTD-specific superblocksDavid Howells
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>
2007-04-27UBI: Unsorted Block ImagesArtem B. Bityutskiy
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>
2006-11-29[MTD] add MTD_BLKDEVS Kconfig optionJosh Boyer
Add a MTD_BLKDEVS Kconfig option to cleanup the makefile a bit Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com> Signed-off-by: Artem Bityutskiy <dedekind@infradead.org>
2006-09-22[MTD] Add SSFDC (SmartMedia) read-only translation layerClaudio Lanconelli
Signed-off-by: Claudio Lanconelli <lanconelli.claudio@eptar.com> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2005-11-06[MTD] Add initial support for OneNAND flash chipsKyungmin Park
OneNAND is a new flash technology from Samsung with integrated SRAM buffers and logic interface. Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2005-11-06[MTD] Add Resident Flash Disk (RFD) supportSean Young
This type of flash translation layer (FTL) is used by the Embedded BIOS by General Software. It is known as the Resident Flash Disk (RFD), see: http://www.gensw.com/pages/prod/bios/rfd.htm Signed-off-by: Sean Young <sean@mess.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!