Index: stand/efi/loader/main.c
===================================================================
--- stand/efi/loader/main.c
+++ stand/efi/loader/main.c
@@ -408,6 +408,17 @@
 	return (false);
 }
 
+/*
+ * Ensure that preloaded files have 16 byte alignment.  This is required
+ * for early loading of microcode updates.
+ */
+static uint64_t
+efi_loadaddr(u_int type __unused, void *data __unused, uint64_t addr)
+{
+
+	return (roundup2(addr, 16));
+}
+
 static int
 parse_args(int argc, CHAR16 *argv[])
 {
@@ -544,6 +555,7 @@
 	archsw.arch_copyin = efi_copyin;
 	archsw.arch_copyout = efi_copyout;
 	archsw.arch_readin = efi_readin;
+	archsw.arch_loadaddr = efi_loadaddr;
 #ifdef EFI_ZFS_BOOT
 	/* Note this needs to be set before ZFS init. */
 	archsw.arch_zfs_probe = efi_zfs_probe;
Index: stand/i386/loader/main.c
===================================================================
--- stand/i386/loader/main.c
+++ stand/i386/loader/main.c
@@ -69,6 +69,7 @@
 static void		extract_currdev(void);
 static int		isa_inb(int port);
 static void		isa_outb(int port, int value);
+static uint64_t		i386_loadaddr(u_int type, void *data, uint64_t addr);
 void			exit(int code);
 #ifdef LOADER_GELI_SUPPORT
 #include "geliboot.h"
@@ -166,6 +167,7 @@
     archsw.arch_readin = i386_readin;
     archsw.arch_isainb = isa_inb;
     archsw.arch_isaoutb = isa_outb;
+    archsw.arch_loadaddr = i386_loadaddr;
 #ifdef LOADER_ZFS_SUPPORT
     archsw.arch_zfs_probe = i386_zfs_probe;
 
@@ -385,6 +387,17 @@
     outb(port, value);
 }
 
+/*
+ * Ensure that preloaded files have 16 byte alignment.  This is required
+ * for early loading of microcode updates.
+ */
+static uint64_t
+i386_loadaddr(u_int type __unused, void *data __unused, uint64_t addr)
+{
+
+    return (roundup2(addr, 16));
+}
+
 #ifdef LOADER_ZFS_SUPPORT
 static void
 i386_zfs_probe(void)