- 27 4月, 2007 1 次提交
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由 Artem B. Bityutskiy 提交于
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: NArtem B. Bityutskiy <dedekind@linutronix.de> Signed-off-by: NFrank Haverkamp <haver@vnet.ibm.com>
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- 09 2月, 2007 1 次提交
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由 Artem Bityutskiy 提交于
Remove unused and broken mtd->ecctype and mtd->eccsize fields from struct mtd_info. Do not remove them from userspace API data structures (don't want to breake userspace) but mark them as obsolete by a comment. Any userspace program which uses them should be half-broken anyway, so this is more about saving data structure size. Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>
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- 26 9月, 2006 1 次提交
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由 David Woodhouse 提交于
Now that we have headers_install, we don't need this crap. Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>
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- 22 9月, 2006 1 次提交
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由 Håvard Skinnemoen 提交于
Introduce the MTD_STUPID_LOCK flag which indicates that the flash chip is always locked after power-up, so all sectors need to be unlocked before it is usable. If this flag is set, and the chip provides an unlock() operation, mtd_add_device will unlock the whole MTD device if it's writeable. This means that non-writeable partitions will stay locked. Set MTD_STUPID_LOCK in fixup_use_atmel_lock() so that these chips will work as expected. Signed-off-by: NHåvard Skinnemoen <hskinnemoen@atmel.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>
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- 19 9月, 2006 1 次提交
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由 David Woodhouse 提交于
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>
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- 29 6月, 2006 1 次提交
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由 Randy Dunlap 提交于
Fix some kernel-doc typos/spellos. Use kernel-doc syntax in places where it was almost used. Correct/add struct, struct field, and function param names where needed. Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net> Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>
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- 18 6月, 2006 1 次提交
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由 David Woodhouse 提交于
This adds the Kbuild files listing the files which are to be installed by the 'headers_install' make target, in generic directories. Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>
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- 15 6月, 2006 1 次提交
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由 David Woodhouse 提交于
Let's not attempt the abolition of mtd->type until/unless it's properly thought through. And certainly, let's not do it by halves. Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>
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- 30 5月, 2006 3 次提交
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由 Joern Engel 提交于
Ram devices get the extra capability of MTD_NO_ERASE - not requiring an explicit erase before writing to it. Currently only mtdblock uses this capability. Rest of the patch is a simple text replacement. Signed-off-by: NJoern Engel <joern@wh.fh-wedel.de>
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由 Joern Engel 提交于
No mtd user should ever check for the device type. Instead, device features should be checked by the flags - if at all. As a first step towards type removal, change MTD_ROM into MTD_GENERIC_TYPE. Signed-off-by: NJoern Engel <joern@wh.fh-wedel.de>
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由 Thomas Gleixner 提交于
The raw read/write access to NAND (without ECC) has been changed in the NAND rework. Expose the new way - setting the file mode via ioctl - to userspace. Also allow to read out the ecc statistics information so userspace tools can see that bitflips happened and whether errors where correctable or not. Also expose the number of bad blocks for the partition, so nandwrite can check if the data fits into the parition before writing to it. Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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- 29 5月, 2006 1 次提交
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由 Thomas Gleixner 提交于
The nand_oobinfo structure is not fitting the newer error correction demands anymore. Replace it by struct nand_ecclayout and fixup the users all over the place. Keep the nand_oobinfo based ioctl for user space compability reasons. Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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- 23 5月, 2006 3 次提交
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由 Joern Engel 提交于
o Add a flag MTD_BIT_WRITEABLE for devices that allow single bits to be cleared. o Replace MTD_PROGRAM_REGIONS with a cleared MTD_BIT_WRITEABLE flag for STMicro and Intel Sibley flashes with internal ECC. Those flashes disallow clearing of single bits, unlike regular NOR flashes, so the new flag models their behaviour better. o Remove MTD_ECC. After the STMicro/Sibley merge, this flag is only set and never checked. Signed-off-by: NJoern Engel <joern@wh.fh-wedel.de>
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由 Joern Engel 提交于
At least two flashes exists that have the concept of a minimum write unit, similar to NAND pages, but no other NAND characteristics. Therefore, rename the minimum write unit to "writesize" for all flashes, including NAND. Signed-off-by: NJoern Engel <joern@wh.fh-wedel.de>
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由 Joern Engel 提交于
Two flags exist to decide whether a device is writeable or not. None of those two flags is checked for independently, so they are clearly redundant, if not an invitation to bugs. This patch removed both of them, replacing them with a single new flag. Signed-off-by: NJoern Engel <joern@wh.fh-wedel.de>
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- 25 4月, 2006 1 次提交
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由 David Woodhouse 提交于
Currently, unifdef removes the comment which starts on the same line as the #ifdef __KERNEL__, but leaves the second line of the comment in place. Move the comment onto a separate line. Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>
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- 17 4月, 2006 2 次提交
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由 Jörn Engel 提交于
Three types are never set or checked for. Remove. Signed-off-by: NJörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>
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由 Jörn Engel 提交于
Several flags are set by some devices, but never checked. Remove them. Signed-off-by: NJörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>
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- 07 11月, 2005 2 次提交
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由 Thomas Gleixner 提交于
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Nicolas Pitre 提交于
This updates the Primary Vendor-Specific Extended Query parsing to version 1.4 in order to get the information about the Configurable Programming Mode regions implemented in the Sibley flash, as well as selecting the appropriate write command code. This flash does not behave like traditional NOR flash when writing data. While mtdblock should just work, further changes are needed for JFFS2 use. Signed-off-by: NNicolas Pitre <nico@cam.org> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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- 23 5月, 2005 4 次提交
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由 Thomas Gleixner 提交于
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Andrew Victor 提交于
For Dataflash, can_mark_obsolete = false and the NAND write buffering code (wbuf.c) is used. Since the DataFlash chip will automatically erase pages when writing, the cleanmarkers are not needed - so cleanmarker_oob = false and cleanmarker_size = 0 DataFlash page-sizes are not a power of two (they're multiples of 528 bytes). The SECTOR_ADDR macro (added in the previous core patch) is replaced with a (slower) div/mod version if CONFIG_JFFS2_FS_DATAFLASH is selected. Signed-off-by: NAndrew Victor <andrew@sanpeople.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Nicolas Pitre 提交于
This is implemented using a ioctl to switch the MTD char device into one of the different OTP "modes", at which point read/write/seek can operate on the selected OTP area. Also some extra ioctls to query for size and lock protection segments or groups. Some example user space utilities are provided. Signed-off-by: NNicolas Pitre <nico@cam.org> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Nicolas Pitre 提交于
This enables support for reading, writing and locking so called "Protection Registers" present on some flash chips. A subset of them are pre-programmed at the factory with a unique set of values. The rest is user-programmable. Signed-off-by: NNicolas Pitre <nico@cam.org> Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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- 17 4月, 2005 1 次提交
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由 Linus Torvalds 提交于
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!
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