Currently in do_fat_read() when reading FAT sectors, we have to divide down
LINEAR_PREFETCH_SIZE by the sector size, whereas it's defined as 2 sectors
worth of bytes. In order to avoid redundant multiplication/division, introduce
#define PREFETCH_BLOCKS instead of #define LINEAR_PREFETCH_SIZE.

Signed-off-by: Sergei Shtylyov <sshtylyov@mvista.com>

Apple iPod nanos have sector sizes of 2 or 4 KiB, which crashes U-Boot when it
tries to read the boot sector into 512-byte buffer situated on stack. Make the
FAT code indifferent to the sector size.

Signed-off-by: Sergei Shtylyov <sshtylyov@mvista.com>

The U-Boot code has the following bugs related to the processing of Long File
Name (LFN) entries scattered across several clusters/sectors :

1) get_vfatname() function is designed to gather scattered LFN entries by
cluster chain processing - that doesn't work for FAT12/16 root directory.
In other words, the function expects the following input data:
 1.1) FAT32 directory (which is cluster chain based);
        OR
 1.2) FAT12/16 non-root directory (which is also cluster chain based);
        OR
 1.3) FAT12/16 root directory (allocated as contiguous sectors area), but
 all necessary information MUST be within the input buffer of filesystem cluster
 size (thus cluster-chain jump is never initiated).

In order to accomplish the last condition, root directory parsing code in
do_fat_read() uses the following trick: read-out cluster-size block, process
only first sector (512 bytes), then shift 512 forward, read-out cluster-size
block and so on. This works great unless cluster size is equal to 512 bytes
(in a case you have a small partition), or long file name entries are scattered
across three sectors, see 4) for details.

2) Despite of the fact that get_vfatname() supports FAT32 root directory
browsing, do_fat_read() function doesn't send current cluster number correctly,
so root directory look-up doesn't work correctly.

3) get_vfatname() doesn't gather scattered entries correctly also is the case
when all LFN entries are located at the end of the source cluster, but real
directory entry (which must be returned) is at the only beginning of the
next one. No error detected, the resulting directory entry returned contains
a semi-random information (wrong size, wrong start cluster number and so on)
i.e. the entry is not accessible.

4) LFN (VFAT) allows up to 20 entries (slots) each containing 26 bytes (13
UTF-16 code units) to represent a single long file name i.e. up to 520 bytes.
U-Boot allocates 256 bytes buffer instead, i.e. 10 or more LFN slots record
may cause buffer overflow / memory corruption.
Also, it's worth to mention that 20+1 slots occupy 672 bytes space which may
take more than one cluster of 512 bytes (medium-size FAT32 or small FAT16
partition) - get_vfatname() function doesn't support such case as well.

The patch attached fixes these problems in the following way:
- keep using 256 bytes buffer for a long file name, but safely prevent a
possible buffer overflow (skip LFN processing, if it contains 10 or more
slots).

- explicitly specify FAT12/16 root directory parsing buffer size, instead
of relying on cluster size. The value used is a double sector size (to store
current sector and the next one). This fixes the first problem and increases
performance on big FAT12/16 partitions;

- send current cluster number (FAT32) to get_vfatname() during root
directory processing;

- use LFN counter to seek the real directory entry in get_vfatname() - fixes the
third problem;

- skip deleted entries in the root directory (to prevent bogus buffer
overflow detection and LFN counter steps).

Note: it's not advised to split up the patch, because a separate part may
operate incorrectly.

Signed-off-by: Mikhail Zolotaryov <lebon@lebon.org.ua>

- reformat
- throw out macros like FAT_DPRINT and FAT_DPRINT
- remove dead code

Signed-off-by: Wolfgang Denk <wd@denx.de>

This code contains some non-ascii characters in comment lines and code.
Most editors do not display those characters properly and editing those
files results always in diffs at these places which are usually not required
to be changed at all. This is error prone.

So, remove those weird characters and replace them by normal C-style
equivalents for which the proper defines were already in the header.

Signed-off-by: Remy Bohmer <linux@bohmer.net>

This commit gets rid of a huge amount of silly white-space issues.
Especially, all sequences of SPACEs followed by TAB characters get
removed (unless they appear in print statements).

Also remove all embedded "vim:" and "vi:" statements which hide
indentation problems.

Signed-off-by: Wolfgang Denk <wd@denx.de>

This fixes the cluster size tests in the FAT32 file system.
The current implementation of VFAT support doesn't work if the
referred cluster has an offset > 16bit representation, causing
"fatload" and "fatls" commands etc. to fail.

Signed-off-by: michael trimarchi <trimarchi@gandalf.sssup.it>

Patch by Joachim Jaeger, 18 Nov 2005

  sticks (including FAT / VFAT filesystem support)

* Add SL811 Host Controller Interface driver for USB

* Add CFG_I2C_EEPROM_ADDR_OVERFLOW desription to README

* Patch by Pantelis Antoniou, 19 Apr 2004:
  Allow to use shell style syntax (i. e. ${var} ) with standard parser.
  Minor patches for Intracom boards.

* Patch by Christian Pell, 19 Apr 2004:
  cleanup support for CF/IDE on PCMCIA for PXA25X

  Add support for Picture Elements JSE board

* Patch by Christian Pell, 01 Apr 2004:
  Add CompactFlash support for PXA systems.

  Add support for NET+50 CPU and ModNET50 board

* Patch by Sam Song, 10 Feb 2004:
  Fix typos in cfi_flash.c

* Patch by Leon Kukovec, 10 Feb 2004
  Fixed long dir entry slot id calculation in get_vfatname

* Patch by Robin Gilks, 10 Feb 2004:
  add "itest" command (operators: -eq, -ne, -lt, -gt, -le, -ge, ==,
  !=, <>, <, >, <=, >=)

  - Changed the incorrect FAT12BUFSIZE
  - data_begin in fsdata can be negative. Changed it to be short.
* Code cleanup

  - add a return value for the fpga command
  - add ide_preinit() function called in ide_init if CONFIG_IDE_PREINIT
    is defined. If ide_preinit fails, ide_init is aborted.
  - fix an endianess problem in fat.h

  add FAT support for IDE, SCSI and USB

* Patches by Gleb Natapov, 2 Sep 2003:
  - cleanup of POST code for unsupported architectures
  - MPC824x locks way0 of data cache for use as initial RAM;
    this patch unlocks it after relocation to RAM and invalidates
    the locked entries.

* Patch by Gleb Natapov, 30 Aug 2003:
  new I2C driver for mpc107 bridge. Now works from flash.

* Patch by Dave Ellis, 11 Aug 2003:
  - JFFS2: fix typo in common/cmd_jffs2.c
  - JFFS2: fix CFG_JFFS2_SORT_FRAGMENTS option
  - JFFS2: remove node version 0 warning
  - JFFS2: accept JFFS2 PADDING nodes
  - SXNI855T: add AM29LV800 support
  - SXNI855T: move environment from EEPROM to flash
  - SXNI855T: boot from JFFS2 in NOR or NAND flash

* Patch by Bill Hargen, 11 Aug 2003:
  fixes for I2C on MPC8240
  - fix i2c_write routine
  - fix iprobe command
  - eliminates use of global variables, plus dead code, cleanup.

* Patches by Kyle Harris, 13 Mar 2003:
  - Add FAT partition support
  - Add command support for FAT
  - Add command support for MMC
  ----
  - Add Intel PXA support for video
  - Add Intel PXA support for MMC
  ----
  - Enable MMC and FAT for lubbock board
  - Other misc changes for lubbock board