diff --git a/include/libkernelflinger/lib.h b/include/libkernelflinger/lib.h
index b6bb170..eb5ba7f 100644
--- a/include/libkernelflinger/lib.h
+++ b/include/libkernelflinger/lib.h
@@ -200,6 +200,8 @@ void qsort(void *base, size_t num, size_t width,
            int (*compare)(const void *, const void *))
     __attribute__((weak));
 
+INTN StrcaseCmp(CHAR16 *s1, CHAR16 *s2);
+
 /*
  * misc
  */
diff --git a/include/libkernelflinger/uefi_utils.h b/include/libkernelflinger/uefi_utils.h
index 6506690..9f75b25 100644
--- a/include/libkernelflinger/uefi_utils.h
+++ b/include/libkernelflinger/uefi_utils.h
@@ -57,5 +57,10 @@ EFI_STATUS uefi_create_directory_root(EFI_FILE_IO_INTERFACE *io, CHAR16 *dirname
 EFI_STATUS uefi_rename_file(EFI_FILE_IO_INTERFACE *io, CHAR16 *oldname, CHAR16 *newname);
 EFI_STATUS verify_image(EFI_HANDLE handle, CHAR16 *path);
 EFI_STATUS uefi_bios_update_capsule(EFI_HANDLE root_dir, CHAR16 *name);
+EFI_STATUS uefi_enter_binary(EFI_HANDLE part_handle, CHAR16 *path,
+		BOOLEAN delete, UINT32 load_options_size, VOID *load_options);
+EFI_STATUS uefi_check_upgrade(EFI_LOADED_IMAGE *loaded_image,
+		CHAR16 *partition, CHAR16 *upgrade_file,
+		CHAR16 *self_path1, CHAR16 *bak_path1, CHAR16 *self_path2, CHAR16 *bak_path2);
 
 #endif /* __UEFI_UTILS_H__ */
diff --git a/kernelflinger.c b/kernelflinger.c
index 4e96b10..eaba2a6 100644
--- a/kernelflinger.c
+++ b/kernelflinger.c
@@ -830,57 +830,6 @@ static EFI_STATUS load_boot_image(
 }
 #endif
 
-/* Chainload another EFI application on the ESP with the specified path,
- * optionally deleting the file before entering
- */
-static EFI_STATUS enter_efi_binary(CHAR16 *path, BOOLEAN delete, UINT32 load_options_size, VOID *load_options)
-{
-	EFI_DEVICE_PATH *edp;
-	EFI_STATUS ret;
-	EFI_HANDLE image;
-	EFI_LOADED_IMAGE *loaded_image;
-
-
-	edp = FileDevicePath(g_disk_device, path);
-	if (!edp) {
-		error(L"Couldn't generate a path");
-		return EFI_INVALID_PARAMETER;
-	}
-
-	ret = uefi_call_wrapper(BS->LoadImage, 6, FALSE, g_parent_image,
-			edp, NULL, 0, &image);
-	if (EFI_ERROR(ret)) {
-		efi_perror(ret, L"BS->LoadImage '%s'", path);
-	} else {
-		if (delete) {
-			ret = file_delete(g_disk_device, path);
-			if (EFI_ERROR(ret))
-				efi_perror(ret, L"Couldn't delete %s", path);
-		}
-		if (load_options_size > 0) {
-			// Set the command line option
-			ret = uefi_call_wrapper(BS->OpenProtocol, 6, image,
-					&LoadedImageProtocol, (VOID **)&loaded_image,
-					image, NULL, EFI_OPEN_PROTOCOL_GET_PROTOCOL);
-			if (EFI_ERROR(ret)) {
-				efi_perror(ret, L"OpenProtocol: LoadedImageProtocol");
-				return ret;
-			}
-			if (loaded_image == NULL) {
-				error(L"LoadedImageProtocol, but return image is NULL");
-				return EFI_INVALID_PARAMETER;
-			}
-			loaded_image->LoadOptionsSize = load_options_size;
-			loaded_image->LoadOptions = load_options;
-		}
-		ret = uefi_call_wrapper(BS->StartImage, 3, image, NULL, NULL);
-		uefi_call_wrapper(BS->UnloadImage, 1, image);
-	}
-	FreePool(edp);
-	return ret;
-}
-
-
 #define OEMVARS_MAGIC           "#OEMVARS\n"
 #define OEMVARS_MAGIC_SZ        9
 
@@ -1260,99 +1209,6 @@ static void flash_bootloader_policy(__attribute__((__unused__)) UINT8 boot_state
 }
 #endif
 
-EFI_STATUS check_kf_upgrade(void)
-{
-	EFI_STATUS ret;
-	EFI_FILE_IO_INTERFACE *io = NULL;
-	EFI_GUID SimpleFileSystemProtocol = SIMPLE_FILE_SYSTEM_PROTOCOL;
-	EFI_HANDLE esp_handle = NULL;
-	CHAR16 *self_path = BOOTLOADER_FILE;
-	CHAR16 *bak_path = BOOTLOADER_FILE_BAK;
-
-	ret = gpt_get_partition_handle(BOOTLOADER_LABEL, LOGICAL_UNIT_USER,
-			&esp_handle);
-	if (EFI_ERROR(ret)) {
-		efi_perror(ret, L"Failed to get ESP partition");
-		goto out;
-	}
-
-	ret = handle_protocol(esp_handle, &SimpleFileSystemProtocol,
-		(void **)&io);
-	if (EFI_ERROR(ret)) {
-		efi_perror(ret, L"HandleProtocol for ESP partition failed");
-		goto out;
-	}
-
-	if (!uefi_exist_file_root(io, KFUPDATE_FILE)) {
-		debug(L"Kernelflinger upgrade file is not exist");
-		goto out;
-	}
-	debug(L"Kernelflinger upgrade file is exist");
-
-	ret = verify_image(esp_handle, KFUPDATE_FILE);
-	if (EFI_ERROR(ret)) {
-		efi_perror(ret, L"Verify upgrade image failed");
-		uefi_delete_file(io, KFUPDATE_FILE);
-		goto out;
-	}
-	debug(L"Success to verify the upgrade image");
-
-	if (g_loaded_image != NULL
-			&& g_loaded_image->FilePath != NULL
-			&& g_loaded_image->FilePath->Type == MEDIA_DEVICE_PATH
-			&& g_loaded_image->FilePath->SubType == MEDIA_FILEPATH_DP) {
-		debug(L"Self path name: %s", ((FILEPATH_DEVICE_PATH *)(g_loaded_image->FilePath))->PathName);
-		self_path = ((FILEPATH_DEVICE_PATH *)(g_loaded_image->FilePath))->PathName;
-		if (StriCmp(self_path, BOOTLOADER_FILE)) {
-			if (StriCmp(self_path, KFSELF_FILE)) {
-				error(L"Skip check the upgrade file");
-				goto out;
-			}
-			bak_path = KFBACKUP_FILE;
-		}
-	} else {
-		// maybe loaded by the "fastboot boot" command, or the BIOS not support
-		// Use the default value
-		error(L"Loaded image or FilePath is NULL");
-	}
-
-	// Verify it again
-	if (!uefi_exist_file_root(io, self_path)) {
-		error(L"Can't find file %s", self_path);
-		ret = EFI_NOT_FOUND;
-		goto out;
-	}
-
-	if (uefi_exist_file_root(io, bak_path)) {
-		ret = uefi_delete_file(io, bak_path);
-		if (EFI_ERROR(ret)) {
-			efi_perror(ret, L"Failed to delete %s", bak_path);
-			goto out;
-		}
-		debug(L"Success to delete old %s", bak_path);
-	}
-	ret = uefi_rename_file(io, self_path, bak_path);
-	if (EFI_ERROR(ret)) {
-		efi_perror(ret, L"Failed to rename the %s to %s", self_path, bak_path);
-		goto out;
-	}
-	debug(L"Success rename file %s to %s", self_path, bak_path);
-	ret = uefi_rename_file(io, KFUPDATE_FILE, self_path);
-	if (EFI_ERROR(ret)) {
-		efi_perror(ret, L"Failed to rename the upgrade file %s to %s", KFUPDATE_FILE, self_path);
-		goto out;
-	}
-	debug(L"Success rename the upgrade file %s to %s", KFUPDATE_FILE, self_path);
-
-	error(L"I am about to load the new boot loader after upgrade it");
-	if (g_loaded_image != NULL)
-		enter_efi_binary(self_path, FALSE, g_loaded_image->LoadOptionsSize, g_loaded_image->LoadOptions);
-	reboot(NULL, EfiResetCold);
-
-out:
-	return ret;
-}
-
 EFI_STATUS efi_main(EFI_HANDLE image, EFI_SYSTEM_TABLE *sys_table)
 {
 	EFI_STATUS ret;
@@ -1408,7 +1264,8 @@ EFI_STATUS efi_main(EFI_HANDLE image, EFI_SYSTEM_TABLE *sys_table)
 
 	uefi_bios_update_capsule(g_disk_device, FWUPDATE_FILE);
 
-	check_kf_upgrade();
+	uefi_check_upgrade(g_loaded_image, BOOTLOADER_LABEL, KFUPDATE_FILE,
+			BOOTLOADER_FILE, BOOTLOADER_FILE_BAK, KFSELF_FILE, KFBACKUP_FILE);
 
 #ifdef USE_TPM
 	if (!is_boot_device_removable()) {
@@ -1518,7 +1375,7 @@ EFI_STATUS efi_main(EFI_HANDLE image, EFI_SYSTEM_TABLE *sys_table)
 		debug(L"entering EFI binary");
 		if (!target_path)
 			return EFI_INVALID_PARAMETER;
-		ret = enter_efi_binary(target_path, oneshot, 0, NULL);
+		ret = uefi_enter_binary(g_disk_device, target_path, oneshot, 0, NULL);
 		if (EFI_ERROR(ret)) {
 			efi_perror(ret, L"EFI Application exited abnormally");
 			pause(3);
diff --git a/libkernelflinger/lib.c b/libkernelflinger/lib.c
index 04fa3b1..a867333 100644
--- a/libkernelflinger/lib.c
+++ b/libkernelflinger/lib.c
@@ -1143,6 +1143,34 @@ VOID __stack_chk_fail()
         panic(L"stack-protector: kernelflinger stack is corrupted");
 }
 
+INTN StrcaseCmp(CHAR16 *s1, CHAR16 *s2)
+{
+        CHAR16 *p1 = s1;
+        CHAR16 *p2 = s2;
+        CHAR16 c1, c2;
+
+        if (s1 == NULL)
+                return (s2 == NULL) ? 0 : -1;
+        if (s2 == NULL)
+                return 1;
+
+        while (*p1 != 0) {
+                c1 = *p1;
+                if (c1 >= L'A' && c1 <= L'Z')
+                        c1 += L'a' - L'A';
+                c2 = *p2;
+                if (c2 >= L'A' && c2 <= L'Z')
+                        c2 += L'a' - L'A';
+                if (c1 > c2)
+                        return 1;
+                if (c1 < c2)
+                        return -1;
+                p1++;
+                p2++;
+        }
+
+        return (*p2 == 0) ? 0 : -1;
+}
+
 /* vim: softtabstop=8:shiftwidth=8:expandtab
  */
-
diff --git a/libkernelflinger/uefi_utils.c b/libkernelflinger/uefi_utils.c
index 42f2f14..b1cf97c 100644
--- a/libkernelflinger/uefi_utils.c
+++ b/libkernelflinger/uefi_utils.c
@@ -38,6 +38,7 @@
 #include <gpt.h>
 #include "protocol.h"
 #include "uefi_utils.h"
+#include "options.h"
 
 /* GUID for ESP partition on gmin */
 const EFI_GUID esp_ptn_guid = { 0x2568845d, 0x2332, 0x4675,
@@ -498,3 +499,181 @@ EFI_STATUS uefi_bios_update_capsule(EFI_HANDLE root_dir, CHAR16 *name)
 
 	return ret;
 }
+
+/* Chainload another EFI application on the ESP with the specified path,
+ * optionally deleting the file before entering
+ */
+EFI_STATUS uefi_enter_binary(EFI_HANDLE part_handle, CHAR16 *path,
+		BOOLEAN delete, UINT32 load_options_size, VOID *load_options)
+{
+	EFI_DEVICE_PATH *edp;
+	EFI_STATUS ret;
+	EFI_HANDLE image;
+	EFI_LOADED_IMAGE *loaded_image;
+
+	edp = FileDevicePath(part_handle, path);
+	if (!edp) {
+		error(L"Couldn't generate a path");
+		return EFI_INVALID_PARAMETER;
+	}
+
+	ret = uefi_call_wrapper(BS->LoadImage, 6, FALSE, g_parent_image,
+			edp, NULL, 0, &image);
+	FreePool(edp);
+	if (EFI_ERROR(ret)) {
+		efi_perror(ret, L"BS->LoadImage '%s'", path);
+		return ret;
+	}
+	if (delete) {
+		ret = file_delete(part_handle, path);
+		if (EFI_ERROR(ret))
+			efi_perror(ret, L"Couldn't delete %s", path);
+	}
+	if (load_options_size > 0) {
+		// Set the command line option
+		ret = uefi_call_wrapper(BS->OpenProtocol, 6, image,
+				&LoadedImageProtocol, (VOID **)&loaded_image,
+				image, NULL, EFI_OPEN_PROTOCOL_GET_PROTOCOL);
+		if (EFI_ERROR(ret)) {
+			efi_perror(ret, L"OpenProtocol: LoadedImageProtocol");
+			goto out;
+		}
+		if (loaded_image == NULL) {
+			error(L"LoadedImageProtocol, but return image is NULL");
+			ret = EFI_INVALID_PARAMETER;
+			goto out;
+		}
+		loaded_image->LoadOptionsSize = load_options_size;
+		loaded_image->LoadOptions = load_options;
+	}
+	ret = uefi_call_wrapper(BS->StartImage, 3, image, NULL, NULL);
+
+out:
+	uefi_call_wrapper(BS->UnloadImage, 1, image);
+
+	return ret;
+}
+
+EFI_STATUS uefi_check_upgrade(EFI_LOADED_IMAGE *loaded_image,
+		CHAR16 *partition, CHAR16 *upgrade_file,
+		CHAR16 *self_path1, CHAR16 *bak_path1, CHAR16 *self_path2, CHAR16 *bak_path2)
+{
+	EFI_STATUS ret;
+	EFI_FILE_IO_INTERFACE *io = NULL;
+	EFI_GUID SimpleFileSystemProtocol = SIMPLE_FILE_SYSTEM_PROTOCOL;
+	EFI_HANDLE part_handle = NULL;
+	CHAR16 *self_path = NULL;
+	UINTN self_path_len;
+	CHAR16 efi_full_path[512];
+	CHAR16 *bak_path = NULL;
+	UINTN argc;
+	CHAR16 **argv;
+
+	if (loaded_image == NULL
+			|| loaded_image->FilePath == NULL
+			|| loaded_image->FilePath->Type != MEDIA_DEVICE_PATH
+			|| loaded_image->FilePath->SubType != MEDIA_FILEPATH_DP) {
+		// maybe loaded by the "fastboot boot" command, or the BIOS not support
+		debug(L"Loaded image or FilePath is NULL");
+		return EFI_INVALID_PARAMETER;
+	}
+
+	self_path = ((FILEPATH_DEVICE_PATH *)(loaded_image->FilePath))->PathName;
+	ret = get_argv(loaded_image, &argc, &argv);
+	if (EFI_ERROR(ret))
+		goto out;
+	if (argc > 0 && argv[0][0] != L'-') {
+		// If load from EFI shell, then the loaded_image->FilePath is the working directory of shell,
+		// and argv[0] is the efi application path.
+		// If load from BIOS boot manager, or other EFI application, then the loaded_image->FilePath
+		// is the full path of efi application path.
+		self_path_len = StrLen(self_path);
+		if (self_path_len > 0) {
+			// Build the full path of efi application path.
+			if (self_path[self_path_len - 1] == L'\\') {
+				// Loaded from EFI shell root directory, ended with '\'.
+				SPrint(efi_full_path, sizeof(efi_full_path), L"%s%s", self_path, argv[0]);
+				self_path = efi_full_path;
+			} else if (self_path_len <= 4 || StrcaseCmp(self_path + self_path_len - 4, L".EFI")) {
+				// Loaded from EFI shell and not root directory, need add '\'.
+				SPrint(efi_full_path, sizeof(efi_full_path), L"%s\\%s", self_path, argv[0]);
+				self_path = efi_full_path;
+			}
+		} else
+			self_path = argv[0];
+	}
+	FreePool(argv);
+	debug(L"EFI path: %s", self_path);
+
+	if (!StrcaseCmp(self_path, self_path1))
+		bak_path = bak_path1;
+	else if (!StrcaseCmp(self_path, self_path2))
+		bak_path = bak_path2;
+	else {
+		debug(L"Unsupported running path for check upgrade");
+		goto out;
+	}
+
+	ret = gpt_get_partition_handle(partition, LOGICAL_UNIT_USER, &part_handle);
+	if (EFI_ERROR(ret)) {
+		if (ret != EFI_NOT_FOUND)
+			efi_perror(ret, L"Failed to find partition %s", partition);
+		goto out;
+	}
+
+	ret = handle_protocol(part_handle, &SimpleFileSystemProtocol, (void **)&io);
+	if (EFI_ERROR(ret)) {
+		efi_perror(ret, L"HandleProtocol for FAT in partition %s failed", partition);
+		goto out;
+	}
+
+	if (!uefi_exist_file_root(io, upgrade_file)) {
+		debug(L"Upgrade file %s is not exist", upgrade_file);
+		goto out;
+	}
+	debug(L"Upgrade file %s is exist", upgrade_file);
+
+	ret = verify_image(part_handle, upgrade_file);
+	if (EFI_ERROR(ret)) {
+		efi_perror(ret, L"Verify upgrade image failed");
+		uefi_delete_file(io, upgrade_file);
+		goto out;
+	}
+	debug(L"Success to verify the upgrade image");
+
+	// Verify it again
+	if (!uefi_exist_file_root(io, self_path)) {
+		error(L"Can't find file %s", self_path);
+		ret = EFI_NOT_FOUND;
+		goto out;
+	}
+
+	if (uefi_exist_file_root(io, bak_path)) {
+		ret = uefi_delete_file(io, bak_path);
+		if (EFI_ERROR(ret)) {
+			efi_perror(ret, L"Failed to delete %s", bak_path);
+			goto out;
+		}
+		debug(L"Success to delete old %s", bak_path);
+	}
+	ret = uefi_rename_file(io, self_path, bak_path);
+	if (EFI_ERROR(ret)) {
+		efi_perror(ret, L"Failed to rename the %s to %s", self_path, bak_path);
+		goto out;
+	}
+	debug(L"Success rename file %s to %s", self_path, bak_path);
+	ret = uefi_rename_file(io, upgrade_file, self_path);
+	if (EFI_ERROR(ret)) {
+		efi_perror(ret, L"Failed to rename the upgrade file %s to %s", upgrade_file, self_path);
+		goto out;
+	}
+	debug(L"Success rename the upgrade file %s to %s", upgrade_file, self_path);
+
+	error(L"I am about to load the new boot loader after upgrade it");
+	if (loaded_image != NULL)
+		uefi_enter_binary(part_handle, self_path, FALSE, loaded_image->LoadOptionsSize, loaded_image->LoadOptions);
+	reboot(NULL, EfiResetCold);
+
+out:
+	return ret;
+}