[PATCH] rpi: always set fdt_addr with firmware-provided FDT address

[Mauro Salvini]

On 12/05/21 14:39, Mauro Salvini wrote:
> 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 at koansoftware.com>
> Cc: Cédric Schieli <cschieli at gmail.com>
> Cc: Matthias Brugger <mbrugger at 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;
>   
> 


Hi all,

kind ping.

Regards

-- 
Mauro Salvini | KOAN sas | Bergamo - Italia
embedded software engineering
http://KoanSoftware.com