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>

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>
Simon Glass · Wolfgang Denk
1 parent f5437ad141
Showing 3 changed files with 19 additions and 0 deletions Side-by-side Diff
README
arch/arm/lib/board.c
doc/README.fdt-control
@@ -3499,6 +3499,10 @@
 		  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
@@ -286,6 +286,9 @@
 	/* 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) {
@@ -144,6 +144,18 @@
  
 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
 -----------
...	...	@@ -3499,6 +3499,10 @@
3499	3499	add the information it needs into it, and the memory
3500	3500	must be accessible by the kernel.
3501	3501
	3502	+ fdtcontroladdr- if set this is the address of the control flattened
	3503	+ device tree used by U-Boot when CONFIG_OF_CONTROL is
	3504	+ defined.
	3505	+
3502	3506	i2cfast - (PPC405GP\|PPC405EP only)
3503	3507	if set to 'y' configures Linux I2C driver for fast
3504	3508	mode (400kHZ). This environment variable is used in
...	...	@@ -286,6 +286,9 @@
286	286	/* FDT is at end of image */
287	287	gd->fdt_blob = (void *)(_end_ofs + _TEXT_BASE);
288	288	#endif
	289	+ /* Allow the early environment to override the fdt address */
	290	+ gd->fdt_blob = (void *)getenv_ulong("fdtcontroladdr", 16,
	291	+ (uintptr_t)gd->fdt_blob);
289	292
290	293	for (init_fnc_ptr = init_sequence; *init_fnc_ptr; ++init_fnc_ptr) {
291	294	if ((*init_fnc_ptr)() != 0) {
...	...	@@ -144,6 +144,18 @@
144	144
145	145	You cannot use both of these options at the same time.
146	146
	147	+If you wish to put the fdt at a different address in memory, you can
	148	+define the "fdtcontroladdr" environment variable. This is the hex
	149	+address of the fdt binary blob, and will override either of the options.
	150	+Be aware that this environment variable is checked prior to relocation,
	151	+when only the compiled-in environment is available. Therefore it is not
	152	+possible to define this variable in the saved SPI/NAND flash
	153	+environment, for example (it will be ignored).
	154	+
	155	+To use this, put something like this in your board header file:
	156	+
	157	+#define CONFIG_EXTRA_ENV_SETTINGS "fdtcontroladdr=10000\0"
	158	+
147	159
148	160	Limitations
149	161	-----------