2 files changed, 21 insertions, 1 deletions
diff --git a/shim.c b/shim.c
index 32b3ae95..7abbe8b4 100644
--- a/shim.c
+++ b/shim.c
@@ -939,7 +939,8 @@ static EFI_STATUS generate_path(EFI_LOADED_IMAGE *li, CHAR16 *ImagePath,
 	}
 
 	*PathName[0] = '\0';
-	StrCat(*PathName, bootpath);
+	if (StrnCaseCmp(bootpath, ImagePath, StrLen(bootpath)))
+		StrCat(*PathName, bootpath);
 	StrCat(*PathName, ImagePath);
 
 	*grubpath = FileDevicePath(device, *PathName);
diff --git a/ucs2.h b/ucs2.h
index 7c49b09b..03742847 100644
--- a/ucs2.h
+++ b/ucs2.h
@@ -54,4 +54,23 @@ StrCaseCmp(CHAR16 *s0, CHAR16 *s1)
 	return 0;
 }
 
+static inline INTN
+__attribute__((unused))
+StrnCaseCmp(CHAR16 *s0, CHAR16 *s1, int n)
+{
+	CHAR16 c0, c1;
+	int x = 0;
+	while (n > x++) {
+		if (*s0 == L'\0' || *s1 == L'\0')
+			return *s1 - *s0;
+		c0 = (*s0 >= L'a' && *s0 <= L'z') ? *s0 - 32 : *s0;
+		c1 = (*s1 >= L'a' && *s1 <= L'z') ? *s1 - 32 : *s1;
+		if (c0 != c1)
+			return c1 - c0;
+		s0++;
+		s1++;
+	}
+	return 0;
+}
+
 #endif /* SHIM_UCS2_H */