[U-Boot] [PATCH] pxe: detect image format before calling bootm/bootz

[Stephen Warren <swarren@wwwdotorg.org>]

On 07/30/2014 04:54 PM, Bryan Wu wrote:
> Trying bootm for zImage will print out several error message which
> is not necessary for this case. So detect image format firstly, only
> try bootm for legacy and FIT format image then try bootz for others.

> diff --git a/common/cmd_pxe.c b/common/cmd_pxe.c

> @@ -771,11 +772,14 @@ static int label_boot(cmd_tbl_t *cmdtp, struct pxe_label *label)
>   	if (bootm_argv[3])
>   		bootm_argc = 4;
>
> -	do_bootm(cmdtp, 0, bootm_argc, bootm_argv);
>
> +	/* Try bootm for legacy and FIT format image */
> +	if (genimg_get_format(bootm_argv[1]) != IMAGE_FORMAT_INVALID)
> +		do_bootm(cmdtp, 0, bootm_argc, bootm_argv);

This breaks the ability to boot a uImage, since the call to 
genimg_get_format() is incorrect.

genimg_get_format() takes the address of an image itself, not the 
address of a string containing a textual representation of the address.

Also, bootm_argv[1] might not be supplied at all, in which case, 
boot_get_kernel() falls back to using load_addr as the address.

This is further complicated by the fact that for FIT images, the string 
in bootm_argv[1] won't just be the address of the image, but perhaps 
have concatenated information indicating which sub-image to select 
(since FIT images pack multiple files into a single image).

You probably need to pull the start of boot_get_kernel() (in 
common/bootm.c) into a utility function and call that to distinguish 
between zImage/not, so as not to duplicate any of the logic.

(Yes, I failed to notice this when I reviewed this downstream, but I 
just actually tested this patch, using a uImage for pxe booting...)

For the zImage case, this patch certainly does remove the annoying error 
message generated when do_bootm() can't identify the image type. So, I 
think it's worth continuing to work on a solution.

P.S. you didn't CC anyone who might apply this patch.