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+fw_env.config configuration file
+================================
+
+This is the configuration file for fw_(printenv/setenv) utility.
+Up to two entries are valid, in this case the redundant
+environment sector is assumed present.
+Notice, that the "Number of sectors" is not required on NOR and SPI-dataflash.
+Futhermore, if the Flash sector size is omitted, this value is assumed to
+be the same as the Environment size, which is valid for NOR and SPI-dataflash
+Device offset must be prefixed with 0x to be parsed as a hexadecimal value.
+
+Structure of the file
+---------------------
+
+Entries must be separated by spaces or tab
+
+
+| device name | Device offset|Env. size|Flash sector size|Number of sectors|Disable lock mechanism|
+|-----------------|--------------|---------|-----------------|-----------------|----------------------|
+| | | | | | |
+
+- device name: device or file where env is stored (mandatory)
+- offset : offset from start of file or device (mandatory)
+- env size : size of environment
+- Flash sector size : (optional) if not set, it is read from kernel
+- Number of sectors: (optional) number of sectors for environment (mainly used with raw NAND)
+- Disable lock mechanism : (optional), 0|1, default=0 (LOCK enable)
+
+NOR example
+-----------
+| device name | Device offset|Env. size|Flash sector size|Number of sectors|Disable lock mechanism|
+|-----------------|--------------|---------|-----------------|-----------------|----------------------|
+|/dev/mtd1 | 0x0000 | 0x4000 | 0x4000 | | |
+|/dev/mtd2 | 0x0000 | 0x4000 | 0x4000 | | |
+
+MTD SPI-dataflash example
+---------------------------
+| device name | Device offset|Env. size|Flash sector size|Number of sectors|Disable lock mechanism|
+|-----------------|--------------|---------|-----------------|-----------------|----------------------|
+|/dev/mtd5 | 0x4200 | 0x4000 | | | |
+|/dev/mtd6 | 0x4200 | 0x4000 | | | |
+
+NAND example
+-----------
+| device name | Device offset|Env. size|Flash sector size|Number of sectors|Disable lock mechanism|
+|-----------------|--------------|---------|-----------------|-----------------|----------------------|
+|/dev/mtd0 | 0x4000 | 0x4000 | 0x20000 | 2 | |
+
+Block device example
+--------------------
+On a block device a negative offset is treated as a backwards offset from the
+end of the device/partition, rather than a forwards offset from the start.
+
+
+| device name | Device offset|Env. size|Flash sector size|Number of sectors|Disable lock mechanism|
+|-----------------|--------------|---------|-----------------|-----------------|----------------------|
+|/dev/mmcblk0 | 0xc0000 | 0x20000 | | | |
+|/dev/mmcblk0 | -0x20000 | 0x20000 | | | |
+
+VFAT example
+------------
+
+| device name | Device offset|Env. size|Flash sector size|Number of sectors|Disable lock mechanism|
+|-----------------|--------------|---------|-----------------|-----------------|----------------------|
+|/boot/uboot.env | 0x00000 | 0x4000 | | | |
+
+UBI volume
+------------
+
+| device name | Device offset|Env. size|Flash sector size|Number of sectors|Disable lock mechanism|
+|-----------------|--------------|---------|-----------------|-----------------|----------------------|
+|/dev/ubi0_0 | 0x0 | 0x1f000 | 0x1f000 | | |
+|/dev/ubi0_1 | 0x0 | 0x1f000 | 0x1f000 | | |
+
+UBI volume by name
+------------------
+
+| device name | Device offset|Env. size|Flash sector size|Number of sectors|Disable lock mechanism|
+|-----------------|--------------|---------|-----------------|-----------------|----------------------|
+|/dev/ubi0:env | 0x0 | 0x1f000 | 0x1f000 | | |
+|/dev/ubi0:redund | 0x0 | 0x1f000 | 0x1f000 | | |
Signed-off-by: Stefano Babic <sbabic@denx.de> --- docs/fw_env_config.md | 81 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 81 insertions(+) create mode 100644 docs/fw_env_config.md