1. 13 6月, 2009 1 次提交
  2. 05 1月, 2009 1 次提交
  3. 10 12月, 2008 1 次提交
  4. 02 8月, 2008 1 次提交
  5. 05 6月, 2008 1 次提交
  6. 23 4月, 2008 1 次提交
  7. 03 2月, 2008 1 次提交
  8. 03 12月, 2007 1 次提交
  9. 29 6月, 2007 1 次提交
    • R
      [MTD] oops and panic message logging to MTD device · 4b23aff0
      Richard Purdie 提交于
      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: NRichard Purdie <rpurdie@openedhand.com>
      Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>
      4b23aff0
  10. 10 5月, 2007 1 次提交
  11. 27 4月, 2007 1 次提交
    • A
      UBI: Unsorted Block Images · 801c135c
      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>
      801c135c
  12. 20 4月, 2007 1 次提交
  13. 29 11月, 2006 1 次提交
  14. 09 10月, 2006 1 次提交
    • A
      [MTD] SSFDC must depend on BLOCK · 1ef93a0f
      Adrian Bunk 提交于
      This patch fixes the following compile error with
      CONFIG_SSFDC=m, CONFIG_BLOCK=n:
      
      <--  snip  -->
      
      ...
        CC [M]  drivers/mtd/mtd_blkdevs.o
      /home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/mtd/mtd_blkdevs.c:40: warning: ‘struct request’ declared inside parameter list
      /home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/mtd/mtd_blkdevs.c:40: warning: its scope is only this definition or declaration, which is probably not what you want
      /home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/mtd/mtd_blkdevs.c: In function ‘do_blktrans_request’:
      /home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/mtd/mtd_blkdevs.c:45: error: dereferencing pointer to incomplete type
      ...
      make[3]: *** [drivers/mtd/mtd_blkdevs.o] Error 1
      
      <--  snip  -->
      
      Bug report by Jesper Juhl.
      
      This patch also removes a pointless "default n" from the SSFDC option.
      Signed-off-by: NAdrian Bunk <bunk@stusta.de>
      Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>
      1ef93a0f
  15. 01 10月, 2006 1 次提交
    • D
      [PATCH] BLOCK: Make it possible to disable the block layer [try #6] · 9361401e
      David Howells 提交于
      Make it possible to disable the block layer.  Not all embedded devices require
      it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require
      the block layer to be present.
      
      This patch does the following:
      
       (*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev
           support.
      
       (*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls
           an item that uses the block layer.  This includes:
      
           (*) Block I/O tracing.
      
           (*) Disk partition code.
      
           (*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS.
      
           (*) The SCSI layer.  As far as I can tell, even SCSI chardevs use the
           	 block layer to do scheduling.  Some drivers that use SCSI facilities -
           	 such as USB storage - end up disabled indirectly from this.
      
           (*) Various block-based device drivers, such as IDE and the old CDROM
           	 drivers.
      
           (*) MTD blockdev handling and FTL.
      
           (*) JFFS - which uses set_bdev_super(), something it could avoid doing by
           	 taking a leaf out of JFFS2's book.
      
       (*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and
           linux/elevator.h contingent on CONFIG_BLOCK being set.  sector_div() is,
           however, still used in places, and so is still available.
      
       (*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and
           parts of linux/fs.h.
      
       (*) Makes a number of files in fs/ contingent on CONFIG_BLOCK.
      
       (*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK.
      
       (*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK
           is not enabled.
      
       (*) fs/no-block.c is created to hold out-of-line stubs and things that are
           required when CONFIG_BLOCK is not set:
      
           (*) Default blockdev file operations (to give error ENODEV on opening).
      
       (*) Makes some /proc changes:
      
           (*) /proc/devices does not list any blockdevs.
      
           (*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK.
      
       (*) Makes some compat ioctl handling contingent on CONFIG_BLOCK.
      
       (*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if
           given command other than Q_SYNC or if a special device is specified.
      
       (*) In init/do_mounts.c, no reference is made to the blockdev routines if
           CONFIG_BLOCK is not defined.  This does not prohibit NFS roots or JFFS2.
      
       (*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return
           error ENOSYS by way of cond_syscall if so).
      
       (*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if
           CONFIG_BLOCK is not set, since they can't then happen.
      Signed-Off-By: NDavid Howells <dhowells@redhat.com>
      Signed-off-by: NJens Axboe <axboe@kernel.dk>
      9361401e
  16. 23 9月, 2006 1 次提交
  17. 22 9月, 2006 1 次提交
  18. 09 6月, 2006 1 次提交
  19. 13 5月, 2006 1 次提交
  20. 07 11月, 2005 3 次提交
  21. 17 4月, 2005 1 次提交
    • L
      Linux-2.6.12-rc2 · 1da177e4
      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!
      1da177e4