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 --- 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;