[PATCH v7 2/2] efi_loader: Improve disk image detection in efi_bootmgr

[Javier Tia]

Enhances the process for identifying disk images within the EFI boot
manager. Utilize part_driver_lookup_type() to verify the validity of a
downloaded file as a disk image, rather than depending on file
extensions.

part_driver_lookup_type() is now used in the prepare_loaded_image()
function in the EFI boot manager to detect partitions on a block device
created from a downloaded image. This allows the boot manager to boot
from any disk image that can be recognized by a partition driver, not
just ISO and IMG images.

Update prepare_loaded_image() to create the ramdisk block device
internally, obtain the blk_desc and use part_driver_lookup_type() to
detect a valid partition table.

In try_load_from_uri_path(), try prepare_loaded_image() first to detect
disk images, and fall back to PE-COFF detection only if that fails.

Signed-off-by: Javier Tia <javier.tia at linaro.org>
---
 include/part.h               |  6 ++---
 lib/efi_loader/efi_bootmgr.c | 51 +++++++++++++++++++++++++-----------
 2 files changed, 39 insertions(+), 18 deletions(-)

diff --git a/include/part.h b/include/part.h
index 52fd3d534e0..715900a7ac7 100644
--- a/include/part.h
+++ b/include/part.h
@@ -471,9 +471,6 @@ ulong disk_blk_erase(struct udevice *dev, lbaint_t start, lbaint_t blkcnt);
 #define part_get_info_ptr(x)	x
 #endif
 
-static inline struct part_driver *part_driver_lookup_type(struct blk_desc *desc)
-{ return NULL; }
-
 /**
  * struct part_driver - partition driver
  */
@@ -752,6 +749,9 @@ struct part_driver *part_driver_lookup_type(struct blk_desc *desc);
 static inline int part_driver_get_count(void)
 { return 0; }
 
+static inline struct part_driver *part_driver_lookup_type(struct blk_desc *desc)
+{ return NULL; }
+
 static inline struct part_driver *part_driver_get_first(void)
 { return NULL; }
 
diff --git a/lib/efi_loader/efi_bootmgr.c b/lib/efi_loader/efi_bootmgr.c
index 662993fb809..9ae11d4ebf0 100644
--- a/lib/efi_loader/efi_bootmgr.c
+++ b/lib/efi_loader/efi_bootmgr.c
@@ -17,6 +17,7 @@
 #include <log.h>
 #include <malloc.h>
 #include <net.h>
+#include <part.h>
 #include <efi_loader.h>
 #include <efi_variable.h>
 #include <asm/unaligned.h>
@@ -347,6 +348,9 @@ static efi_status_t fill_default_file_path(struct udevice *blk,
  * @dp:		pointer to default file device path
  * @blk:	pointer to created blk udevice
  * Return:	status code
+ *
+ * This function handles device creation internally and performs cleanup
+ * on error paths.
  */
 static efi_status_t prepare_loaded_image(u16 *label, ulong addr, ulong size,
 					 struct efi_device_path **dp,
@@ -355,10 +359,31 @@ static efi_status_t prepare_loaded_image(u16 *label, ulong addr, ulong size,
 	u64 pages;
 	efi_status_t ret;
 	struct udevice *ramdisk_blk;
+	struct blk_desc *desc;
+	struct part_driver *part_drv;
 
+	/* Create the ramdisk block device internally */
 	ramdisk_blk = mount_image(label, addr, size);
-	if (!ramdisk_blk)
-		return EFI_LOAD_ERROR;
+	if (!ramdisk_blk) {
+		log_err("Failed to create ramdisk block device\n");
+		return EFI_DEVICE_ERROR;
+	}
+
+	/* Get the block descriptor and detect partitions */
+	desc = dev_get_uclass_plat(ramdisk_blk);
+	if (!desc) {
+		log_err("Failed to get block descriptor\n");
+		ret = EFI_DEVICE_ERROR;
+		goto err;
+	}
+
+	/* Use part_driver_lookup_type for comprehensive partition detection */
+	part_drv = part_driver_lookup_type(desc);
+	if (!part_drv) {
+		log_err("Image is not a valid disk image\n");
+		ret = EFI_INVALID_PARAMETER;
+		goto err;
+	}
 
 	ret = fill_default_file_path(ramdisk_blk, dp);
 	if (ret != EFI_SUCCESS) {
@@ -389,7 +414,6 @@ static efi_status_t prepare_loaded_image(u16 *label, ulong addr, ulong size,
 err:
 	if (blkmap_destroy(ramdisk_blk->parent))
 		log_err("Destroying blkmap failed\n");
-
 	return ret;
 }
 
@@ -407,7 +431,7 @@ static efi_status_t efi_bootmgr_release_uridp(struct uridp_context *ctx)
 	if (!ctx)
 		return ret;
 
-	/* cleanup for iso or img image */
+	/* cleanup for disk image */
 	if (ctx->ramdisk_blk_dev) {
 		ret = efi_add_memory_map(ctx->image_addr, ctx->image_size,
 					 EFI_CONVENTIONAL_MEMORY);
@@ -452,6 +476,7 @@ static void EFIAPI efi_bootmgr_http_return(struct efi_event *event,
 	EFI_EXIT(ret);
 }
 
+
 /**
  * try_load_from_uri_path() - Handle the URI device path
  *
@@ -466,7 +491,6 @@ static efi_status_t try_load_from_uri_path(struct efi_device_path_uri *uridp,
 {
 	char *s;
 	int err;
-	int uri_len;
 	efi_status_t ret;
 	void *source_buffer;
 	efi_uintn_t source_size;
@@ -516,18 +540,15 @@ static efi_status_t try_load_from_uri_path(struct efi_device_path_uri *uridp,
 	image_size = ALIGN(image_size, SZ_2M);
 
 	/*
-	 * If the file extension is ".iso" or ".img", mount it and try to load
-	 * the default file.
-	 * If the file is PE-COFF image, load the downloaded file.
+	 * Check if the downloaded file is a disk image or PE-COFF image.
+	 * Try disk image detection first using prepare_loaded_image().
 	 */
-	uri_len = strlen(uridp->uri);
-	if (!strncmp(&uridp->uri[uri_len - 4], ".iso", 4) ||
-	    !strncmp(&uridp->uri[uri_len - 4], ".img", 4)) {
-		ret = prepare_loaded_image(lo_label, image_addr, image_size,
-					   &loaded_dp, &blk);
-		if (ret != EFI_SUCCESS)
-			goto err;
 
+	/* First, try to treat the image as a disk image */
+	ret = prepare_loaded_image(lo_label, image_addr, image_size,
+				   &loaded_dp, &blk);
+	if (ret == EFI_SUCCESS) {
+		/* Image is a disk image, set up for disk boot */
 		source_buffer = NULL;
 		source_size = 0;
 	} else if (efi_check_pe((void *)image_addr, image_size, NULL) == EFI_SUCCESS) {
-- 
2.51.0