rpi: always set fdt_addr with firmware-provided FDT address

Raspberry firmware prepares the FDT blob in memory at an address
that depends on both the memory size and the blob size [1].
After commit ade243a211d6 ("rpi: passthrough of the firmware provided FDT
blob") this FDT is passed to kernel through fdt_addr environment variable,
handled in set_fdt_addr() function in board file.

When u-boot environment is persistently saved, if a change happens
in loaded FDT (e.g. for a new overlay applied), firmware produces a FDT
address different from the saved one, but u-boot still use the saved
one because set_fdt_addr() function does not overwrite the fdt_addr
variable. So, for example, if there is a script that uses fdt commands for
e.g. manipulate the bootargs, boot hangs with error

libfdt fdt_check_header(): FDT_ERR_BADMAGIC

Removing the fdt_addr variable in saved environment allows to boot.

With this patch set_fdt_addr() function always overwrite fdt_addr value.

[1] https://www.raspberrypi.org/forums//viewtopic.php?f=107&t=134018

Signed-off-by: Mauro Salvini <m.salvini@koansoftware.com>
Cc: Cédric Schieli <cschieli@gmail.com>
Cc: Matthias Brugger <mbrugger@suse.com>

diff --git a/board/raspberrypi/rpi/rpi.c b/board/raspberrypi/rpi/rpi.c
index 049904b..1b0b664 100644 (file)
--- a/board/raspberrypi/rpi/rpi.c
+++ b/board/raspberrypi/rpi/rpi.c
@@ -359,9 +359,6 @@ static void set_fdtfile(void)
  */
 static void set_fdt_addr(void)
 {
-       if (env_get("fdt_addr"))
-               return;
-
        if (fdt_magic(fw_dtb_pointer) != FDT_MAGIC)
                return;