env: export fdt_blob to the environment variable

Export fdt_blob to the environment variable. So that we may
use it to boot Linux.

Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
Acked-by: Simon Glass <sjg@chromium.org>

diff --git a/common/board_r.c b/common/board_r.c
index f8c1baa9496e9f3cc4a932cabdef1b2b301a2de5..0a4dfe49720e41efe2de1474d4af2a0fe628f056 100644 (file)
--- a/common/board_r.c
+++ b/common/board_r.c
@@ -446,6 +446,9 @@ static int initr_env(void)
                env_relocate();
        else
                set_default_env(NULL);
+#ifdef CONFIG_OF_CONTROL
+       setenv_addr("fdtcontroladdr", gd->fdt_blob);
+#endif
 
        /* Initialize from environment */
        load_addr = getenv_ulong("loadaddr", 16, load_addr);

diff --git a/doc/README.fdt-control b/doc/README.fdt-control
index e6d5ed0bb61d664b0c7938c0649262f545d36fad..29fd56a815f8086d28e340f030b5a6e6b1755227 100644 (file)
--- a/doc/README.fdt-control
+++ b/doc/README.fdt-control
@@ -156,7 +156,10 @@ 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: