diff --git a/grub-core/lib/i386/relocator_common_c.c b/grub-core/lib/i386/relocator_common_c.c
index 7be609b73..c9c5efa72 100644
--- a/grub-core/lib/i386/relocator_common_c.c
+++ b/grub-core/lib/i386/relocator_common_c.c
@@ -26,6 +26,8 @@
 #include <grub/relocator.h>
 #include <grub/relocator_private.h>
 
+#include <grub/i386/memory.h>
+
 extern grub_uint8_t grub_relocator_forward_start;
 extern grub_uint8_t grub_relocator_forward_end;
 extern grub_uint8_t grub_relocator_backward_start;
@@ -41,20 +43,122 @@ extern grub_size_t grub_relocator_forward_chunk_size;
 
 #define RELOCATOR_SIZEOF(x)	(&grub_relocator##x##_end - &grub_relocator##x##_start)
 
-grub_size_t grub_relocator_align = 1;
 grub_size_t grub_relocator_forward_size;
 grub_size_t grub_relocator_backward_size;
+grub_size_t grub_relocator_preamble_size = 0;
 #ifdef __x86_64__
 grub_size_t grub_relocator_jumper_size = 12;
 #else
 grub_size_t grub_relocator_jumper_size = 7;
 #endif
+#if defined(__x86_64__) && defined(GRUB_MACHINE_EFI)
+grub_size_t grub_relocator_align = 4096;
+#else
+grub_size_t grub_relocator_align = 1;
+#endif
+
+#if defined(__x86_64__) && defined(GRUB_MACHINE_EFI)
+
+#define PAGE_PRESENT 1
+#define PAGE_WRITABLE 2
+#define PAGE_USER 4
+#define PAGE_PS 0x80
+#define PAGE_IDX_SIZE 9
+#define PAGE_PS_SHIFT 21
+#define PAGE_NUM_ENTRIES 0x200
+#define PS_PAGE_SIZE 0x200000
+
+static grub_uint64_t max_ram_size;
+
+  /* Helper for grub_get_multiboot_mmap_count.  */
+static int
+max_hook (grub_uint64_t addr,
+	  grub_uint64_t size,
+	  grub_memory_type_t type __attribute__ ((unused)),
+	  void *data __attribute__ ((unused)))
+{
+  max_ram_size = grub_max (max_ram_size, addr + size);
+  return 0;
+}
+
+static grub_uint64_t
+find_max_size (void)
+{
+  if (!max_ram_size)
+    {
+      /* We need to map the first 4GiB of address space as well as all the
+	 available RAM, so start with 4GiB and increase if we see any RAM
+	 above this. */
+      max_ram_size = 1ULL << 32;
+
+      grub_mmap_iterate (max_hook, NULL);
+    }
+
+  return max_ram_size;
+}
+
+void
+grub_cpu_relocator_preamble (void *rels)
+{
+  grub_uint64_t nentries = (find_max_size () + PS_PAGE_SIZE - 1) >> PAGE_PS_SHIFT;
+  grub_uint64_t npt2pages = (nentries + PAGE_NUM_ENTRIES - 1) >> PAGE_IDX_SIZE;
+  grub_uint64_t npt3pages = (npt2pages + PAGE_NUM_ENTRIES - 1) >> PAGE_IDX_SIZE;
+  grub_uint8_t *p = rels;
+  grub_uint64_t *pt4 = (grub_uint64_t *) (p + GRUB_PAGE_SIZE);
+  grub_uint64_t *pt3 = pt4 + PAGE_NUM_ENTRIES;
+  grub_uint64_t *pt2 = pt3 + (npt3pages << PAGE_IDX_SIZE);
+  grub_uint64_t *endpreamble = pt2 + (npt2pages << PAGE_IDX_SIZE);
+  grub_uint64_t i;
+
+  /* movabs $pt4, %rax.  */
+  *p++ = 0x48;
+  *p++ = 0xb8;
+  *(grub_uint64_t *) p = (grub_uint64_t) pt4;
+  p += 8;
+
+  /* mov %rax, %cr3.  */
+  *p++ = 0x0f;
+  *p++ = 0x22;
+  *p++ = 0xd8;
+
+  /* jmp $endpreamble.  */
+  *p++ = 0xe9;
+  *(grub_uint32_t *) p = (grub_uint8_t *) endpreamble - p - 4;
+
+  for (i = 0; i < npt3pages; i++)
+    pt4[i] = ((grub_uint64_t) pt3 + (i << GRUB_PAGE_SHIFT)) | PAGE_PRESENT | PAGE_WRITABLE | PAGE_USER;
+
+  for (i = 0; i < npt2pages; i++)
+    pt3[i] = ((grub_uint64_t) pt2 + (i << GRUB_PAGE_SHIFT)) | PAGE_PRESENT | PAGE_WRITABLE | PAGE_USER;
+
+  for (i = 0; i < (npt2pages << PAGE_IDX_SIZE); i++)
+    pt2[i] = (i << PAGE_PS_SHIFT) | PAGE_PS | PAGE_PRESENT | PAGE_WRITABLE | PAGE_USER;
+}
+
+static void
+compute_preamble_size (void)
+{
+  grub_uint64_t nentries = (find_max_size () + PS_PAGE_SIZE - 1) >> PAGE_PS_SHIFT;
+  grub_uint64_t npt2pages = (nentries + PAGE_NUM_ENTRIES - 1) >> PAGE_IDX_SIZE;
+  grub_uint64_t npt3pages = (npt2pages + PAGE_NUM_ENTRIES - 1) >> PAGE_IDX_SIZE;
+  grub_relocator_preamble_size = (npt2pages + npt3pages + 1 + 1) << GRUB_PAGE_SHIFT;
+}
+
+#else
+void
+grub_cpu_relocator_preamble (void *rels __attribute__((unused)))
+{
+}
+#endif
 
 void
 grub_cpu_relocator_init (void)
 {
   grub_relocator_forward_size = RELOCATOR_SIZEOF (_forward);
   grub_relocator_backward_size = RELOCATOR_SIZEOF (_backward);
+#if defined(__x86_64__) && defined(GRUB_MACHINE_EFI)
+  compute_preamble_size ();
+#endif
 }
 
 void
diff --git a/grub-core/lib/mips/relocator.c b/grub-core/lib/mips/relocator.c
index 773f3b769..9f79b40c8 100644
--- a/grub-core/lib/mips/relocator.c
+++ b/grub-core/lib/mips/relocator.c
@@ -45,6 +45,7 @@ grub_size_t grub_relocator_align = sizeof (grub_uint32_t);
 grub_size_t grub_relocator_forward_size;
 grub_size_t grub_relocator_backward_size;
 grub_size_t grub_relocator_jumper_size = JUMP_SIZEOF + REGW_SIZEOF;
+grub_size_t grub_relocator_preamble_size = 0;
 
 void
 grub_cpu_relocator_init (void)
@@ -53,6 +54,11 @@ grub_cpu_relocator_init (void)
   grub_relocator_backward_size = RELOCATOR_SIZEOF(backward);
 }
 
+void
+grub_cpu_relocator_preamble (void *rels __attribute__ ((unused)))
+{
+}
+
 static void
 write_reg (int regn, grub_uint32_t val, void **target)
 {
diff --git a/grub-core/lib/powerpc/relocator.c b/grub-core/lib/powerpc/relocator.c
index 15aeb0246..559e04b5a 100644
--- a/grub-core/lib/powerpc/relocator.c
+++ b/grub-core/lib/powerpc/relocator.c
@@ -43,6 +43,7 @@ grub_size_t grub_relocator_align = sizeof (grub_uint32_t);
 grub_size_t grub_relocator_forward_size;
 grub_size_t grub_relocator_backward_size;
 grub_size_t grub_relocator_jumper_size = JUMP_SIZEOF + REGW_SIZEOF;
+grub_size_t grub_relocator_preamble_size = 0;
 
 void
 grub_cpu_relocator_init (void)
@@ -51,6 +52,11 @@ grub_cpu_relocator_init (void)
   grub_relocator_backward_size = RELOCATOR_SIZEOF(backward);
 }
 
+void
+grub_cpu_relocator_preamble (void *rels __attribute__((unused)))
+{
+}
+
 static void
 write_reg (int regn, grub_uint32_t val, void **target)
 {
diff --git a/grub-core/lib/relocator.c b/grub-core/lib/relocator.c
index 3306a1bb7..1e1e09704 100644
--- a/grub-core/lib/relocator.c
+++ b/grub-core/lib/relocator.c
@@ -110,7 +110,7 @@ grub_relocator_new (void)
     return NULL;
 
   ret->postchunks = ~(grub_phys_addr_t) 0;
-  ret->relocators_size = grub_relocator_jumper_size;
+  ret->relocators_size = grub_relocator_jumper_size + grub_relocator_preamble_size;
   grub_dprintf ("relocator", "relocators_size=%lu\n",
 		(unsigned long) ret->relocators_size);
   return ret;
@@ -1605,6 +1605,9 @@ grub_relocator_prepare_relocs (struct grub_relocator *rel, grub_addr_t addr,
     grub_free (to);
   }
 
+  grub_cpu_relocator_preamble (rels);
+  rels += grub_relocator_preamble_size;
+
   for (j = 0; j < nchunks; j++)
     {
       grub_dprintf ("relocator", "sorted chunk %p->%p, 0x%lx\n",
diff --git a/include/grub/relocator_private.h b/include/grub/relocator_private.h
index d8e972e01..273add76d 100644
--- a/include/grub/relocator_private.h
+++ b/include/grub/relocator_private.h
@@ -27,6 +27,7 @@ extern grub_size_t grub_relocator_align;
 extern grub_size_t grub_relocator_forward_size;
 extern grub_size_t grub_relocator_backward_size;
 extern grub_size_t grub_relocator_jumper_size;
+extern grub_size_t grub_relocator_preamble_size;
 
 void
 grub_cpu_relocator_init (void);
@@ -39,6 +40,7 @@ void grub_cpu_relocator_forward (void *rels, void *src, void *tgt,
 void grub_cpu_relocator_backward (void *rels, void *src, void *tgt,
 				 grub_size_t size);
 void grub_cpu_relocator_jumper (void *rels, grub_addr_t addr);
+void grub_cpu_relocator_preamble (void *rels);
 
 /* Remark: GRUB_RELOCATOR_FIRMWARE_REQUESTS_QUANT_LOG = 1 or 2
    aren't supported.  */