Merge branch 'master' of git://www.denx.de/git/u-boot-mmc

[u-boot] / README

diff --git a/README b/README
index ac1ec44d155b06620303a6ccf7672fd2f15e5201..cd0336c3c887a2efdaac7c4c8ed3092f2b08e276 100644 (file)
--- a/README
+++ b/README
@@ -3648,6 +3648,57 @@ but it can not erase, write this NOR flash by SRIO or PCIE interface.
          You will probably want to define these to avoid a really noisy system
          when storing the env in UBI.
 
+- CONFIG_ENV_IS_IN_MMC:
+
+       Define this if you have an MMC device which you want to use for the
+       environment.
+
+       - CONFIG_SYS_MMC_ENV_DEV:
+
+         Specifies which MMC device the environment is stored in.
+
+       - CONFIG_SYS_MMC_ENV_PART (optional):
+
+         Specifies which MMC partition the environment is stored in. If not
+         set, defaults to partition 0, the user area. Common values might be
+         1 (first MMC boot partition), 2 (second MMC boot partition).
+
+       - CONFIG_ENV_OFFSET:
+       - CONFIG_ENV_SIZE:
+
+         These two #defines specify the offset and size of the environment
+         area within the specified MMC device.
+
+         If offset is positive (the usual case), it is treated as relative to
+         the start of the MMC partition. If offset is negative, it is treated
+         as relative to the end of the MMC partition. This can be useful if
+         your board may be fitted with different MMC devices, which have
+         different sizes for the MMC partitions, and you always want the
+         environment placed at the very end of the partition, to leave the
+         maximum possible space before it, to store other data.
+
+         These two values are in units of bytes, but must be aligned to an
+         MMC sector boundary.
+
+       - CONFIG_ENV_OFFSET_REDUND (optional):
+
+         Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
+         hold a redundant copy of the environment data. This provides a
+         valid backup copy in case the other copy is corrupted, e.g. due
+         to a power failure during a "saveenv" operation.
+
+         This value may also be positive or negative; this is handled in the
+         same way as CONFIG_ENV_OFFSET.
+
+         This value is also in units of bytes, but must also be aligned to
+         an MMC sector boundary.
+
+       - CONFIG_ENV_SIZE_REDUND (optional):
+
+         This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
+         set. If this value is set, it must be set to the same value as
+         CONFIG_ENV_SIZE.
+
 - CONFIG_SYS_SPI_INIT_OFFSET
 
        Defines offset to the initial SPI buffer area in DPRAM. The