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authorSimon Glass2011-10-24 19:15:34 +0000
committerWolfgang Denk2011-10-26 21:40:16 +0200
commiteea63e05d0b7f54e7aa39725015483972c71cb3c (patch)
tree6efe7cc0f7dc4eea53b04fc1ac02e35b552af8d4
parentf5437ad141e13ff03dccb24707e8100d2b0295fd (diff)
fdt: ARM: Add fdtcontroladdr to set device tree address in environment
This adds support for a new environment variable called 'fdtcontroladdr'. If defined, the hex address is used as the address of the control fdt for U-Boot. Note: I have not changed CONFIG_PRAM section as I already have an outstanding patch on that. Signed-off-by: Simon Glass <sjg@chromium.org>
-rw-r--r--README4
-rw-r--r--arch/arm/lib/board.c3
-rw-r--r--doc/README.fdt-control12
3 files changed, 19 insertions, 0 deletions
diff --git a/README b/README
index 558f0111ffc..a3b62e14dbb 100644
--- a/README
+++ b/README
@@ -3499,6 +3499,10 @@ List of environment variables (most likely not complete):
add the information it needs into it, and the memory
must be accessible by the kernel.
+ fdtcontroladdr- if set this is the address of the control flattened
+ device tree used by U-Boot when CONFIG_OF_CONTROL is
+ defined.
+
i2cfast - (PPC405GP|PPC405EP only)
if set to 'y' configures Linux I2C driver for fast
mode (400kHZ). This environment variable is used in
diff --git a/arch/arm/lib/board.c b/arch/arm/lib/board.c
index bd6d4e319ad..bae2892373e 100644
--- a/arch/arm/lib/board.c
+++ b/arch/arm/lib/board.c
@@ -286,6 +286,9 @@ void board_init_f(ulong bootflag)
/* FDT is at end of image */
gd->fdt_blob = (void *)(_end_ofs + _TEXT_BASE);
#endif
+ /* Allow the early environment to override the fdt address */
+ gd->fdt_blob = (void *)getenv_ulong("fdtcontroladdr", 16,
+ (uintptr_t)gd->fdt_blob);
for (init_fnc_ptr = init_sequence; *init_fnc_ptr; ++init_fnc_ptr) {
if ((*init_fnc_ptr)() != 0) {
diff --git a/doc/README.fdt-control b/doc/README.fdt-control
index 3f8bb5a6701..85bda035043 100644
--- a/doc/README.fdt-control
+++ b/doc/README.fdt-control
@@ -144,6 +144,18 @@ and then flash image.bin onto your board.
You cannot use both 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"
+
Limitations
-----------