[U-Boot] [RFC 3/8] efi_loader: bootmgr: return pointer and size of buffer in loading

[Heinrich Schuchardt]

On 3/5/19 6:53 AM, AKASHI Takahiro wrote:
> We need to know the size of image loaded so as to be able to use
> load_image() API at do_bootefi_exec() in a later patch.
>
> So change the interface of efi_bootmgr_load().
>
> Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
> ---
>  include/efi_loader.h         |  5 +++--
>  lib/efi_loader/efi_bootmgr.c | 41 +++++++++++++++++++++---------------
>  2 files changed, 27 insertions(+), 19 deletions(-)
>
> diff --git a/include/efi_loader.h b/include/efi_loader.h
> index 47a51ddc9406..3f51116155ad 100644
> --- a/include/efi_loader.h
> +++ b/include/efi_loader.h
> @@ -564,8 +564,9 @@ struct efi_load_option {
>
>  void efi_deserialize_load_option(struct efi_load_option *lo, u8 *data);
>  unsigned long efi_serialize_load_option(struct efi_load_option *lo, u8 **data);
> -void *efi_bootmgr_load(struct efi_device_path **device_path,
> -		       struct efi_device_path **file_path);
> +efi_status_t efi_bootmgr_load(struct efi_device_path **device_path,
> +			      struct efi_device_path **file_path,
> +			      void **image, efi_uintn_t *size);
>
>  #else /* CONFIG_IS_ENABLED(EFI_LOADER) */
>
> diff --git a/lib/efi_loader/efi_bootmgr.c b/lib/efi_loader/efi_bootmgr.c
> index 1575c5c09e46..38f3fa15f6ef 100644
> --- a/lib/efi_loader/efi_bootmgr.c
> +++ b/lib/efi_loader/efi_bootmgr.c
> @@ -120,14 +120,17 @@ static void *get_var(u16 *name, const efi_guid_t *vendor,
>   * if successful.  This checks that the EFI_LOAD_OPTION is active (enabled)
>   * and that the specified file to boot exists.
>   */
> -static void *try_load_entry(uint16_t n, struct efi_device_path **device_path,
> -			    struct efi_device_path **file_path)
> +static efi_status_t try_load_entry(u16 n,
> +				   struct efi_device_path **device_path,
> +				   struct efi_device_path **file_path,
> +				   void **image, efi_uintn_t *image_size)
>  {
>  	struct efi_load_option lo;
>  	u16 varname[] = L"Boot0000";
>  	u16 hexmap[] = L"0123456789ABCDEF";
> -	void *load_option, *image = NULL;
> +	void *load_option;
>  	efi_uintn_t size;
> +	efi_status_t ret;
>
>  	varname[4] = hexmap[(n & 0xf000) >> 12];
>  	varname[5] = hexmap[(n & 0x0f00) >> 8];
> @@ -136,18 +139,17 @@ static void *try_load_entry(uint16_t n, struct efi_device_path **device_path,
>
>  	load_option = get_var(varname, &efi_global_variable_guid, &size);
>  	if (!load_option)
> -		return NULL;
> +		return EFI_LOAD_ERROR;
>
>  	efi_deserialize_load_option(&lo, load_option);
>
>  	if (lo.attributes & LOAD_OPTION_ACTIVE) {
>  		u32 attributes;
> -		efi_status_t ret;
>
>  		debug("%s: trying to load \"%ls\" from %pD\n",
>  		      __func__, lo.label, lo.file_path);
>
> -		ret = efi_load_image_from_path(lo.file_path, &image, &size);
> +		ret = efi_load_image_from_path(lo.file_path, image, image_size);
>

This call to efi_load_image_from_path() leads to duplication of logic.

Why don't we simply call EFI_CALL(efi_load_image())) here and if it
succeeds return from efi_bootmgr_load()?

Best regards

Heinrich

>  		if (ret != EFI_SUCCESS)
>  			goto error;
> @@ -164,12 +166,14 @@ static void *try_load_entry(uint16_t n, struct efi_device_path **device_path,
>
>  		printf("Booting: %ls\n", lo.label);
>  		efi_dp_split_file_path(lo.file_path, device_path, file_path);
> +	} else {
> +		ret = EFI_LOAD_ERROR;
>  	}
>
>  error:
>  	free(load_option);
>
> -	return image;
> +	return ret;
>  }
>
>  /*
> @@ -177,12 +181,12 @@ error:
>   * EFI variable, the available load-options, finding and returning
>   * the first one that can be loaded successfully.
>   */
> -void *efi_bootmgr_load(struct efi_device_path **device_path,
> -		       struct efi_device_path **file_path)
> +efi_status_t efi_bootmgr_load(struct efi_device_path **device_path,
> +			      struct efi_device_path **file_path,
> +			      void **image, efi_uintn_t *image_size)
>  {
>  	u16 bootnext, *bootorder;
>  	efi_uintn_t size;
> -	void *image = NULL;
>  	int i, num;
>  	efi_status_t ret;
>
> @@ -201,9 +205,9 @@ void *efi_bootmgr_load(struct efi_device_path **device_path,
>  					(efi_guid_t *)&efi_global_variable_guid,
>  					0, 0, &bootnext));
>  		if (ret == EFI_SUCCESS) {
> -			image = try_load_entry(bootnext,
> -					       device_path, file_path);
> -			if (image)
> +			ret = try_load_entry(bootnext, device_path, file_path,
> +					     image, image_size);
> +			if (ret == EFI_SUCCESS)
>  				goto error;
>  		}
>  	}
> @@ -212,19 +216,22 @@ void *efi_bootmgr_load(struct efi_device_path **device_path,
>  	bootorder = get_var(L"BootOrder", &efi_global_variable_guid, &size);
>  	if (!bootorder) {
>  		printf("BootOrder not defined\n");
> +		ret = EFI_NOT_FOUND;
>  		goto error;
>  	}
>
>  	num = size / sizeof(uint16_t);
>  	for (i = 0; i < num; i++) {
> -		debug("%s: trying to load Boot%04X\n", __func__, bootorder[i]);
> -		image = try_load_entry(bootorder[i], device_path, file_path);
> -		if (image)
> +		debug("%s: trying to load Boot%04X\n", __func__,
> +		      bootorder[i]);
> +		ret = try_load_entry(bootorder[i], device_path, file_path,
> +				     image, image_size);
> +		if (ret == EFI_SUCCESS)
>  			break;
>  	}
>
>  	free(bootorder);
>
>  error:
> -	return image;
> +	return ret;
>  }
>