From: Mauro Salvini <m.salvini@koansoftware.com>
To: u-boot@lists.denx.de
Subject: [PATCH] rpi: always set fdt_addr with firmware-provided FDT address
Date: Wed, 12 May 2021 14:39:45 +0200	[thread overview]
Message-ID: <20210512123945.25649-1-m.salvini@koansoftware.com> (raw)

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: C?dric Schieli <cschieli@gmail.com>
Cc: Matthias Brugger <mbrugger@suse.com>
---
 board/raspberrypi/rpi/rpi.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/board/raspberrypi/rpi/rpi.c b/board/raspberrypi/rpi/rpi.c
index df52a4689f..611013471e 100644
--- a/board/raspberrypi/rpi/rpi.c
+++ b/board/raspberrypi/rpi/rpi.c
@@ -318,9 +318,6 @@ 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;
 
-- 
2.17.1