[U-Boot] [PATCH 1/2] efi_loader: Pass fdt address directly to bootefi cmd

[Stephen Warren]

On 04/13/2016 03:22 PM, Alexander Graf wrote:
> The bootefi cmd today fetches its device tree pointer from either the
> location appointed by "fdt addr" with a fallback to the U-Boot control
> fdt.
>
> This integration is unusual for U-Boot and diverges from the way we
> usually handle parameters to boot commands. So let's pass the fdt
> directly into the bootefi command instead and move the control fdt
> logic into the distro boot script.

> diff --git a/cmd/bootefi.c b/cmd/bootefi.c

> @@ -155,13 +154,7 @@ static unsigned long do_bootefi_exec(void *efi)
>   	 */
>   	efi_save_gd();
>
> -	/* Update system table to point to our currently loaded FDT */
> -
> -	/* Fall back to included fdt if none was manually loaded */
> -	if (!fdt && gd->fdt_blob)
> -		fdt = (void *)gd->fdt_blob;
> -
> -	if (fdt) {
> +	if (fdt && !fdt_check_header(fdt)) {
>   		/* Prepare fdt for payload */
>   		fdt = copy_fdt(fdt);
>
> @@ -185,7 +178,7 @@ static unsigned long do_bootefi_exec(void *efi)
>   		efi_add_memory_map(fdt_start, fdt_pages,
>   				   EFI_BOOT_SERVICES_DATA, true);
>   	} else {
> -		printf("WARNING: No device tree loaded, expect boot to fail\n");
> +		printf("WARNING: Invalid device tree, expect boot to fail\n");

I'm not familiar with this code, so I'm not really sure what the 
implication of this if/else is.

Still, this looks like it's a move in the right direction. I do agree 
the FDT address parameter likely should be optional, and if not 
specified by the user default to whatever other bootz/booti default too 
(I suspect $fdt_addr_r).

Thanks for fixing this up so quickly.