arm64: add support for Ka-Ro TXSD-410E

[karo-tx-uboot.git] / doc / README.fdt-control

diff --git a/doc/README.fdt-control b/doc/README.fdt-control
index d8fe4a826f20d41335067b6c3a251d1a12d4dfd8..2913fcb360c7c7bfdc52446348040bd00669c970 100644 (file)
--- a/doc/README.fdt-control
+++ b/doc/README.fdt-control
@@ -33,12 +33,6 @@ the features of each board in the device tree file, and have a single
 generic source base.
 
 To enable this feature, add CONFIG_OF_CONTROL to your board config file.
-It is currently supported on ARM, x86 and Microblaze - other architectures
-will need to add code to their arch/xxx/lib/board.c file to locate the
-FDT. Alternatively you can enable generic board support on your board
-(with CONFIG_SYS_GENERIC_BOARD) if this is available (as it is for
-PowerPC). For ARM, Tegra and Exynos5 have device trees available for
-common devices.
 
 
 What is a Flat Device Tree?
@@ -156,7 +150,10 @@ address of the fdt binary blob, and will override either of the options.
 Be aware that this environment variable is checked prior to relocation,
 when only the compiled-in environment is available. Therefore it is not
 possible to define this variable in the saved SPI/NAND flash
-environment, for example (it will be ignored).
+environment, for example (it will be ignored). After relocation, this
+variable will be set to the address of the newly relocated fdt blob.
+It is read-only and cannot be changed. It can optionally be used to
+control the boot process of Linux with bootm/bootz commands.
 
 To use this, put something like this in your board header file:
 
@@ -171,6 +168,22 @@ After board configuration is done, fdt supported u-boot can be build in two ways
     $ make DEVICE_TREE=<dts-file-name>
 
 
+Configuration Options
+---------------------
+
+A number of run-time configuration options are provided in the /config node
+of the control device tree. You can access these using fdtdec_get_config_int(),
+fdtdec_get_config_bool() and fdtdec_get_config_string().
+
+Available options are:
+
+silent-console
+       If present and non-zero, the console is silenced by default on boot.
+
+no-keyboard
+       Tells U-Boot not to expect an attached keyboard with a VGA console
+
+
 Limitations
 -----------