doc: document u-boot, mmc-env-offset and u-boot, mmc-env-offset-redund

Adding documentation on the new config properties:
       'u-boot,mmc-env-offset' - overrides CONFIG_ENV_OFFSET
       'u-boot,mmc-env-offset-redundant'
                               - overrides CONFIG_ENV_OFFSET_REDUND

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>

diff --git a/doc/device-tree-bindings/config.txt b/doc/device-tree-bindings/config.txt
index d4bc1df5531ead399f8017fcdc2b8c9165d308d2..fe0e04af92b8dc50335ccdd434f1254d032e58bf 100644 (file)
--- a/doc/device-tree-bindings/config.txt
+++ b/doc/device-tree-bindings/config.txt
@@ -21,6 +21,18 @@ u-boot,efi-partition-entries-offset
 
        This setting will override any values configured via Kconfig.
 
+u-boot,mmc-env-offset
+u-boot,mmc-env-offset-redundant
+       If present, the values of the 'u-boot,mmc-env-offset' and/or
+       of the u-boot,mmc-env-offset-redundant' properties overrides
+       CONFIG_ENV_OFFSET and CONFIG_ENV_OFFSET_REDUND, respectively,
+       for SD/MMC devices.
+
+       Values are interpreted as the offset from the start of the
+       device, specified in bytes.  It is assumed that the setting
+       will point at the beginning of a LBA and values that are not
+       LBA-aligned will be rounded up to the next LBA address.
+
 u-boot,spl-payload-offset
        If present (and SPL is controlled by the device-tree), this allows
        to override the CONFIG_SYS_SPI_U_BOOT_OFFS setting using a value