ARM: rpi: set fdt_high in the default environment

The ARM Linux kernel requires the DT to be in memory accessible early
during the boot process. This always happens naturally on the RPi 1,
since the maximum memory size of 512MiB, and additionally some of that
is reserved for use by the GPU. The RPi 2 has 1GiB of RAM (minus some
GPU usage), and so if the DT is relocated to the top of RAM, Linux cannot
access it. Prevent this from happening by setting fdt_high.

Cc: Daniel Stone <daniels@collabora.com>
Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>

diff --git a/include/configs/rpi-common.h b/include/configs/rpi-common.h
index 29510f5c9c926223ca179a5a6d392755cbed1024..48f5fc2d0351fb28b0f4ed06c554d8adb557555f 100644 (file)
--- a/include/configs/rpi-common.h
+++ b/include/configs/rpi-common.h
@@ -172,6 +172,7 @@
  *   for any boot script to be up to 1M, which is hopefully plenty.
  */
 #define ENV_MEM_LAYOUT_SETTINGS \
+       "fdt_high=ffffffff\0" \
        "fdt_addr_r=0x00000100\0" \
        "pxefile_addr_r=0x00100000\0" \
        "kernel_addr_r=0x01000000\0" \