fdt: ARM: Add device tree control of U-Boot (CONFIG_OF_CONTROL)

This adds a device tree pointer to the global data. It can be set by
board code. A later commit will add support for making a device
tree binary blob available to U-Boot for run-time configuration.

Signed-off-by: Simon Glass <sjg@chromium.org>

diff --git a/README b/README
index 2dde066..d618957 100644 (file)
--- a/README
+++ b/README
@@ -816,6 +816,17 @@ The following options need to be configured:
 
                XXX - this list needs to get updated!
 
+- Device tree:
+               CONFIG_OF_CONTROL
+               If this variable is defined, U-Boot will use a device tree
+               to configure its devices, instead of relying on statically
+               compiled #defines in the board file. This option is
+               experimental and only available on a few boards. The device
+               tree is available in the global data as gd->fdt_blob.
+
+               U-Boot needs to get its device tree from somewhere. This will
+               be enabled in a future patch.
+
 - Watchdog:
                CONFIG_WATCHDOG
                If this variable is defined, it enables watchdog

diff --git a/arch/arm/include/asm/global_data.h b/arch/arm/include/asm/global_data.h
index fac98d5..c3ff789 100644 (file)
--- a/arch/arm/include/asm/global_data.h
+++ b/arch/arm/include/asm/global_data.h
@@ -76,6 +76,7 @@ typedef       struct  global_data {
 #if !(defined(CONFIG_SYS_ICACHE_OFF) && defined(CONFIG_SYS_DCACHE_OFF))
        unsigned long   tlb_addr;
 #endif
+       const void      *fdt_blob;      /* Our device tree, NULL if none */
        void            **jt;           /* jump table */
        char            env_buf[32];    /* buffer for getenv() before reloc. */
 #if defined(CONFIG_POST) || defined(CONFIG_LOGBUFFER)