efi_loader: allow unaligned memory access

The UEFI spec mandates that unaligned memory access should be enabled if
supported by the CPU architecture.

This patch adds an empty weak function unaligned_access() that can be
overridden by an architecture specific routine.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>

cmd/bootefi.c

@@ -17,6 +17,7 @@
 #include <memalign.h>
 #include <asm/global_data.h>
 #include <asm-generic/sections.h>
+#include <asm-generic/unaligned.h>
 #include <linux/linkage.h>
 
 DECLARE_GLOBAL_DATA_PTR;
@@ -83,6 +84,15 @@ out:
 }
 
 /*
+ * Allow unaligned memory access.
+ *
+ * This routine is overridden by architectures providing this feature.
+ */
+void __weak allow_unaligned(void)
+{
+}
+
+/*
  * Set the load options of an image from an environment variable.
  *
  * @loaded_image_info:	the image
@@ -370,6 +380,9 @@ static int do_bootefi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 	efi_status_t r;
 	void *fdt_addr;
 
+	/* Allow unaligned memory access */
+	allow_unaligned();
+
 	/* Initialize EFI drivers */
 	r = efi_init_obj_list();
 	if (r != EFI_SUCCESS) {

include/asm-generic/unaligned.h

@@ -20,4 +20,7 @@
 #error invalid endian
 #endif
 
+/* Allow unaligned memory access */
+void allow_unaligned(void);
+
 #endif