[PATCH v2] disk: efi_loader: Improve disk image detection in efi_bootmgr
Javier Tia
javier.tia at linaro.org
Fri Aug 8 23:27:07 CEST 2025
Refines the disk image detection mechanism in the EFI boot manager.
Instead of relying on file extensions, the updated code uses the
partition driver lookup function to determine if a downloaded file is a
valid disk image.
The change enhances the robustness of the boot manager by providing a
more accurate disk image detection. Extend prepare_loaded_image() to
accept an optional reuse_blk parameter. When a partition driver is
detected, the existing temporary device is passed to
prepare_loaded_image() instead of being destroyed and recreated.
The partition driver lookup function is also made public to enable its
use in the EFI boot manager. The function documentation is updated
accordingly.
Signed-off-by: Javier Tia <javier.tia at linaro.org>
---
Changes in v2:
- Extend prepare_loaded_image() to accept an optional reuse_blk
parameter. When a partition driver is detected, the existing temporary
device is passed to prepare_loaded_image() instead of being destroyed
and recreated.
- v1 link: https://lore.kernel.org/u-boot/20250805162158.117876-1-javier.tia@linaro.org/
---
disk/part.c | 3 +-
include/part.h | 18 +++++++++
lib/efi_loader/efi_bootmgr.c | 78 +++++++++++++++++++++++++++++-------
3 files changed, 83 insertions(+), 16 deletions(-)
diff --git a/disk/part.c b/disk/part.c
index 66e2b3a7219..adc24976624 100644
--- a/disk/part.c
+++ b/disk/part.c
@@ -63,7 +63,7 @@ static struct part_driver *part_driver_get_type(int part_type)
* @dev_desc: Device descriptor
* Return: Driver found, or NULL if none
*/
-static struct part_driver *part_driver_lookup_type(struct blk_desc *desc)
+struct part_driver *part_driver_lookup_type(struct blk_desc *desc)
{
struct part_driver *drv =
ll_entry_start(struct part_driver, part_driver);
@@ -855,3 +855,4 @@ int part_get_bootable(struct blk_desc *desc)
return 0;
}
+
diff --git a/include/part.h b/include/part.h
index b772fb34c8a..3fc3186f4c4 100644
--- a/include/part.h
+++ b/include/part.h
@@ -727,6 +727,24 @@ int part_get_type_by_name(const char *name);
*/
int part_get_bootable(struct blk_desc *desc);
+/**
+ * part_driver_lookup_type() - Look up the partition driver for a blk device
+ *
+ * If @desc->part_type is PART_TYPE_UNKNOWN, this checks each partition driver
+ * against the blk device to see if there is a valid partition table acceptable
+ * to that driver.
+ *
+ * If @desc->part_type is already set, it just returns the driver for that
+ * type, without testing if the driver can find a valid partition on the
+ * descriptor.
+ *
+ * On success it updates @desc->part_type if set to PART_TYPE_UNKNOWN on entry
+ *
+ * @desc: Device descriptor
+ * Return: Driver found, or NULL if none
+ */
+struct part_driver *part_driver_lookup_type(struct blk_desc *desc);
+
#else
static inline int part_driver_get_count(void)
{ return 0; }
diff --git a/lib/efi_loader/efi_bootmgr.c b/lib/efi_loader/efi_bootmgr.c
index 662993fb809..9c97fd7812d 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>
@@ -346,19 +347,27 @@ static efi_status_t fill_default_file_path(struct udevice *blk,
* @size: image size
* @dp: pointer to default file device path
* @blk: pointer to created blk udevice
+ * @reuse_blk: optional existing block device to reuse (can be NULL)
* Return: status code
*/
static efi_status_t prepare_loaded_image(u16 *label, ulong addr, ulong size,
struct efi_device_path **dp,
- struct udevice **blk)
+ struct udevice **blk,
+ struct udevice *reuse_blk)
{
u64 pages;
efi_status_t ret;
struct udevice *ramdisk_blk;
- ramdisk_blk = mount_image(label, addr, size);
- if (!ramdisk_blk)
- return EFI_LOAD_ERROR;
+ if (reuse_blk) {
+ /* Reuse existing block device */
+ ramdisk_blk = reuse_blk;
+ } else {
+ /* Create new block device */
+ ramdisk_blk = mount_image(label, addr, size);
+ if (!ramdisk_blk)
+ return EFI_LOAD_ERROR;
+ }
ret = fill_default_file_path(ramdisk_blk, dp);
if (ret != EFI_SUCCESS) {
@@ -387,7 +396,8 @@ static efi_status_t prepare_loaded_image(u16 *label, ulong addr, ulong size,
return EFI_SUCCESS;
err:
- if (blkmap_destroy(ramdisk_blk->parent))
+ /* Only destroy if we created it (not reused) */
+ if (!reuse_blk && blkmap_destroy(ramdisk_blk->parent))
log_err("Destroying blkmap failed\n");
return ret;
@@ -407,7 +417,7 @@ 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 +462,20 @@ static void EFIAPI efi_bootmgr_http_return(struct efi_event *event,
EFI_EXIT(ret);
}
+/**
+ * cleanup_temp_blkdev() - Clean up temporary block device
+ *
+ * @temp_bdev: temporary block device to clean up
+ */
+static void cleanup_temp_blkdev(struct udevice *temp_bdev)
+{
+ if (!temp_bdev)
+ return;
+
+ if (blkmap_destroy(temp_bdev->parent))
+ log_err("Destroying temporary blkmap failed\n");
+}
+
/**
* try_load_from_uri_path() - Handle the URI device path
*
@@ -466,7 +490,6 @@ 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;
@@ -516,21 +539,43 @@ 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.
+ * Use partition driver lookup for disk image detection.
*/
- uri_len = strlen(uridp->uri);
- if (!strncmp(&uridp->uri[uri_len - 4], ".iso", 4) ||
- !strncmp(&uridp->uri[uri_len - 4], ".img", 4)) {
+ struct udevice *temp_bdev;
+ struct part_driver *part_drv = NULL;
+
+ /* Create temporary block device from the downloaded image for testing */
+ temp_bdev = mount_image(lo_label, image_addr, image_size);
+ if (!temp_bdev) {
+ log_debug("mount_image() failed, will attempt PE-COFF detection\n");
+ }
+ if (temp_bdev) {
+ struct blk_desc *desc = dev_get_uclass_plat(temp_bdev);
+ if (!desc) {
+ /* Clean up temporary device when dev_get_uclass_plat() returns NULL */
+ cleanup_temp_blkdev(temp_bdev);
+ } else {
+ /*
+ * Use part_driver_lookup_type for comprehensive partition detection
+ */
+ part_drv = part_driver_lookup_type(desc);
+ }
+ }
+
+ if (part_drv) {
+ /* Reuse the temporary device instead of destroying and recreating */
ret = prepare_loaded_image(lo_label, image_addr, image_size,
- &loaded_dp, &blk);
+ &loaded_dp, &blk, temp_bdev);
if (ret != EFI_SUCCESS)
goto err;
source_buffer = NULL;
source_size = 0;
} else if (efi_check_pe((void *)image_addr, image_size, NULL) == EFI_SUCCESS) {
+ /* Clean up temporary device if it was created but not a valid disk image */
+ cleanup_temp_blkdev(temp_bdev);
+
/*
* loaded_dp must exist until efi application returns,
* will be freed in return_to_efibootmgr event callback.
@@ -545,7 +590,10 @@ static efi_status_t try_load_from_uri_path(struct efi_device_path_uri *uridp,
source_buffer = (void *)image_addr;
source_size = image_size;
} else {
- log_err("Error: file type is not supported\n");
+ /* Clean up temporary device if it was created but not a valid disk image */
+ cleanup_temp_blkdev(temp_bdev);
+
+ log_err("Error: disk image is not supported\n");
ret = EFI_UNSUPPORTED;
goto err;
}
--
2.50.1
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