bootmeth_efi: Support PXE booting

Finish off the implementation so it is possible to boot an EFI app over
a network.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/boot/bootmeth_efi.c b/boot/bootmeth_efi.c
index b745ba8..0c9b4c3 100644
--- a/boot/bootmeth_efi.c
+++ b/boot/bootmeth_efi.c
@@ -210,6 +210,7 @@
 	if (size <= 0)
 		return log_msg_ret("sz", -EINVAL);
 	bflow->size = size;
+	bflow->buf = map_sysmem(addr, size);
 
 	/* bootfile should be setup by dhcp */
 	bootfile_name = env_get("bootfile");
@@ -219,10 +220,6 @@
 	if (!bflow->fname)
 		return log_msg_ret("fi0", -ENOMEM);
 
-	/* do the hideous EFI hack */
-	efi_set_bootdev("Net", "", bflow->fname, map_sysmem(addr, 0),
-			bflow->size);
-
 	/* read the DT file also */
 	fdt_addr_str = env_get("fdt_addr_r");
 	if (!fdt_addr_str)
@@ -296,16 +293,6 @@
 		if (bflow->flags & ~BOOTFLOWF_USE_BUILTIN_FDT)
 			fdt = bflow->fdt_addr;
 
-	} else {
-		/*
-		 * This doesn't actually work for network devices:
-		 *
-		 * do_bootefi_image() No UEFI binary known at 0x02080000
-		 *
-		 * But this is the same behaviour for distro boot, so it can be
-		 * fixed here.
-		 */
-		fdt = env_get_hex("fdt_addr_r", 0);
 	}
 
 	if (efi_bootflow_run(bflow))
diff --git a/lib/efi_loader/efi_bootbin.c b/lib/efi_loader/efi_bootbin.c
index fdde536..10ec5e9 100644
--- a/lib/efi_loader/efi_bootbin.c
+++ b/lib/efi_loader/efi_bootbin.c
@@ -302,6 +302,9 @@
 	media_dev = dev_get_parent(bflow->dev);
 
 	if (!bflow->blk) {
+		if (device_get_uclass_id(media_dev) == UCLASS_ETH)
+			return "Net";
+
 		log_err("Cannot boot EFI app on media '%s'\n",
 			dev_get_uclass_name(media_dev));
 
@@ -342,7 +345,7 @@
 	ret = calculate_paths(dev_name, devnum_str, bflow->fname, &device,
 			      &image);
 	if (ret)
-		return ret;
+		return EFI_UNSUPPORTED;
 
 	if (bflow->flags & BOOTFLOWF_USE_BUILTIN_FDT) {
 		log_debug("Booting with built-in fdt\n");