[U-Boot] [PATCH 10/11] efi_loader: Add mem-mapped for fallback

[Alexander Graf]

On 10.10.17 14:23, Rob Clark wrote:
> When we don't have a real device/image path, such as 'bootefi hello',
> construct a mem-mapped device-path.
> 
> This fixes 'bootefi hello' after devicepath refactoring.
> 
> Fixes: 95c5553ea2 ("efi_loader: refactor boot device and loaded_image handling")
> Signed-off-by: Rob Clark <robdclark at gmail.com>
> ---
>  cmd/bootefi.c                            | 23 +++++++++++++++++++++++
>  include/efi_api.h                        |  8 ++++++++
>  include/efi_loader.h                     |  3 +++
>  lib/efi_loader/efi_device_path.c         | 24 ++++++++++++++++++++++++
>  lib/efi_loader/efi_device_path_to_text.c |  9 +++++++++
>  5 files changed, 67 insertions(+)
> 
> diff --git a/cmd/bootefi.c b/cmd/bootefi.c
> index 24958ada46..18176a1266 100644
> --- a/cmd/bootefi.c
> +++ b/cmd/bootefi.c
> @@ -128,6 +128,7 @@ static unsigned long do_bootefi_exec(void *efi, void *fdt,
>  {
>  	struct efi_loaded_image loaded_image_info = {};
>  	struct efi_object loaded_image_info_obj = {};
> +	struct efi_device_path *memdp = NULL;
>  	ulong ret;
>  
>  	ulong (*entry)(void *image_handle, struct efi_system_table *st)
> @@ -136,6 +137,20 @@ static unsigned long do_bootefi_exec(void *efi, void *fdt,
>  	const efi_guid_t fdt_guid = EFI_FDT_GUID;
>  	bootm_headers_t img = { 0 };
>  
> +	/*
> +	 * Special case for efi payload not loaded from disk, such as
> +	 * 'bootefi hello' or for example payload loaded directly into
> +	 * memory via jtag/etc:
> +	 */
> +	if (!device_path && !image_path) {
> +		printf("WARNING: using memory device/image path, this may confuse some payloads!\n");
> +		/* actual addresses filled in after efi_load_pe() */
> +		memdp = efi_dp_from_mem(0, 0, 0);
> +		device_path = image_path = memdp;
> +	} else {
> +		assert(device_path && image_path);
> +	}
> +
>  	/* Initialize and populate EFI object list */
>  	if (!efi_obj_list_initalized)
>  		efi_init_obj_list();
> @@ -182,6 +197,14 @@ static unsigned long do_bootefi_exec(void *efi, void *fdt,
>  		goto exit;
>  	}
>  
> +	if (memdp) {
> +		struct efi_device_path_memory *mdp = (void *)memdp;
> +		mdp->memory_type = loaded_image_info.image_code_type;
> +		mdp->start_address = (uintptr_t)loaded_image_info.image_base;
> +		mdp->end_address = mdp->start_address +
> +				loaded_image_info.image_size;
> +	}
> +

memdp gets leaked after bootefi is done. Putting it on the stack would
at least remove that problem ;). We currently expect to only return from
bootefi when a payload was successfully quit.


Alex