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

[Heinrich Schuchardt]

On 10/10/2017 02:23 PM, 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;
> +	}
> +
>   	/* we don't support much: */
>   	env_set("efi_8be4df61-93ca-11d2-aa0d-00e098032b8c_OsIndicationsSupported",
>   		"{ro,boot}(blob)0000000000000000");
> diff --git a/include/efi_api.h b/include/efi_api.h
> index 9610d03d47..07b2af7020 100644
> --- a/include/efi_api.h
> +++ b/include/efi_api.h
> @@ -299,8 +299,16 @@ struct efi_mac_addr {
>   } __packed;
>   
>   #define DEVICE_PATH_TYPE_HARDWARE_DEVICE	0x01
> +#  define DEVICE_PATH_SUB_TYPE_MEMORY		0x03
>   #  define DEVICE_PATH_SUB_TYPE_VENDOR		0x04
>   
> +struct efi_device_path_memory {
> +	struct efi_device_path dp;
> +	u32 memory_type;
> +	u64 start_address;
> +	u64 end_address;
> +} __packed;
> +
>   struct efi_device_path_vendor {
>   	struct efi_device_path dp;
>   	efi_guid_t guid;
> diff --git a/include/efi_loader.h b/include/efi_loader.h
> index fa4e1cdb1c..db805e898f 100644
> --- a/include/efi_loader.h
> +++ b/include/efi_loader.h
> @@ -269,6 +269,9 @@ struct efi_device_path *efi_dp_from_part(struct blk_desc *desc, int part);
>   struct efi_device_path *efi_dp_from_file(struct blk_desc *desc, int part,
>   					 const char *path);
>   struct efi_device_path *efi_dp_from_eth(void);
> +struct efi_device_path *efi_dp_from_mem(uint32_t mem_type,
> +					uint64_t start_address,
> +					uint64_t end_address);
>   void efi_dp_split_file_path(struct efi_device_path *full_path,
>   			    struct efi_device_path **device_path,
>   			    struct efi_device_path **file_path);
> diff --git a/lib/efi_loader/efi_device_path.c b/lib/efi_loader/efi_device_path.c
> index 5d5c3b3464..f6e368e029 100644
> --- a/lib/efi_loader/efi_device_path.c
> +++ b/lib/efi_loader/efi_device_path.c
> @@ -538,6 +538,30 @@ struct efi_device_path *efi_dp_from_eth(void)
>   }
>   #endif
>   
> +/* Construct a device-path for memory-mapped image */
> +struct efi_device_path *efi_dp_from_mem(uint32_t memory_type,
> +					uint64_t start_address,
> +					uint64_t end_address)
> +{
> +	struct efi_device_path_memory *mdp;
> +	void *buf, *start;
> +
> +	start = buf = dp_alloc(sizeof(*mdp) + sizeof(END));
> +
> +	mdp = buf;
> +	mdp->dp.type = DEVICE_PATH_TYPE_HARDWARE_DEVICE;
> +	mdp->dp.sub_type = DEVICE_PATH_SUB_TYPE_MEMORY;
> +	mdp->dp.length = sizeof(*mdp);
> +	mdp->memory_type = memory_type;
> +	mdp->start_address = start_address;
> +	mdp->end_address = end_address;
> +	buf = &mdp[1];
> +
> +	*((struct efi_device_path *)buf) = END;
> +
> +	return start;
> +}
> +
>   /*
>    * Helper to split a full device path (containing both device and file
>    * parts) into it's constituent parts.
> diff --git a/lib/efi_loader/efi_device_path_to_text.c b/lib/efi_loader/efi_device_path_to_text.c
> index 1a5ef3919b..62771338f0 100644
> --- a/lib/efi_loader/efi_device_path_to_text.c
> +++ b/lib/efi_loader/efi_device_path_to_text.c
> @@ -24,6 +24,15 @@ static char *dp_unknown(char *s, struct efi_device_path *dp)
>   static char *dp_hardware(char *s, struct efi_device_path *dp)
>   {
>   	switch (dp->sub_type) {
> +	case DEVICE_PATH_SUB_TYPE_MEMORY: {
> +		struct efi_device_path_memory *mdp =
> +			(struct efi_device_path_memory *)dp;
> +		s += sprintf(s, "/MemoryMapped(0x%x,0x%llx,0x%llx)",
> +			     mdp->memory_type,
> +			     mdp->start_address,
> +			     mdp->end_address);
> +		break;
> +	}
>   	case DEVICE_PATH_SUB_TYPE_VENDOR: {
>   		struct efi_device_path_vendor *vdp =
>   			(struct efi_device_path_vendor *)dp;
> 

Providing a dummmy device path for bootefi hello and bootefi selftest is 
reasonable.

Acked-by: Heinrich Schuchardt <xypron.glpk at gmx.de>