doc/README.ubi: Add description of accessing ubi filesystems

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

diff --git a/doc/README.fdt-control b/doc/README.fdt-control
index 3f8bb5a670175088c0147e7d6d57cefc36c1a32d..95a88a7c7bffe8028722015f8f2d2b954b2e110b 100644 (file)
--- a/doc/README.fdt-control
+++ b/doc/README.fdt-control
@@ -49,6 +49,12 @@ 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?
@@ -99,7 +105,8 @@ Then run the compiler (your version will vary):
        *   Bad configuration:  0
        * Strange test result:  0
 
-You will also find a useful ftdump utility for decoding a binary file.
+You will also find a useful fdtdump utility for decoding a binary file, as
+well as fdtget/fdtput for reading and writing properties in a binary file.
 
 
 Where do I get an fdt file for my board?
@@ -142,7 +149,31 @@ join the two:
 
 and then flash image.bin onto your board.
 
-You cannot use both of these options at the same time.
+If CONFIG_OF_HOSTFILE is defined, then it will be read from a file on
+startup. This is only useful for sandbox. Use the -d flag to U-Boot to
+specify the file to read.
+
+You cannot use more than one of these options at the same time.
+
+If you wish to put the fdt at a different address in memory, you can
+define the "fdtcontroladdr" environment variable. This is the hex
+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).
+
+To use this, put something like this in your board header file:
+
+#define CONFIG_EXTRA_ENV_SETTINGS      "fdtcontroladdr=10000\0"
+
+Build:
+
+After board configuration is done, fdt supported u-boot can be build in two ways:
+1)  build the default dts which is defined from CONFIG_DEFAULT_DEVICE_TREE
+    $ make
+2)  build the user specified dts file
+    $ make DEVICE_TREE=<dts-file-name>
 
 
 Limitations