minimal changes to do EFI boot on x86_64

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index 801df7c..1e28f31 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -1823,7 +1823,7 @@
 
 module = {
   name = linux;
-  x86 = loader/i386/linux.c;
+  x86_64_efi = loader/efi/linux.c;
   i386_xen_pvh = loader/i386/linux.c;
   xen = loader/i386/xen.c;
   i386_pc = lib/i386/pc/vesa_modes_table.c;
diff --git a/grub-core/kern/efi/mm.c b/grub-core/kern/efi/mm.c
index 3705b8b..99c5e7c 100644
--- a/grub-core/kern/efi/mm.c
+++ b/grub-core/kern/efi/mm.c
@@ -654,7 +654,7 @@
   grub_mm_add_region_fn = grub_efi_mm_add_regions;
 }
 
-#if defined (__aarch64__) || defined (__arm__) || defined (__riscv)
+#if defined (__aarch64__) || defined (__arm__) || defined (__riscv) || defined(__x86_64__)
 grub_err_t
 grub_efi_get_ram_base(grub_addr_t *base_addr)
 {
diff --git a/grub-core/loader/efi/linux.c b/grub-core/loader/efi/linux.c
index 15e0686..ac612f5 100644
--- a/grub-core/loader/efi/linux.c
+++ b/grub-core/loader/efi/linux.c
@@ -125,6 +125,7 @@
   return GRUB_ERR_NONE;
 }
 
+#ifndef __x86_64__
 static grub_err_t
 finalize_params_linux (void)
 {
@@ -169,6 +170,7 @@
   grub_fdt_unload();
   return grub_error(GRUB_ERR_BAD_OS, "failed to install/update FDT");
 }
+#endif
 
 grub_err_t
 grub_arch_efi_linux_boot_image (grub_addr_t addr, grub_size_t size, char *args)
@@ -231,8 +233,10 @@
 static grub_err_t
 grub_linux_boot (void)
 {
+#ifndef __x86_64__
   if (finalize_params_linux () != GRUB_ERR_NONE)
     return grub_errno;
+#endif
 
   return (grub_arch_efi_linux_boot_image((grub_addr_t)kernel_addr,
                                           kernel_size, linux_args));
@@ -253,7 +257,9 @@
   if (kernel_addr)
     grub_efi_free_pages ((grub_addr_t) kernel_addr,
 			 GRUB_EFI_BYTES_TO_PAGES (kernel_size));
+#ifndef __x86_64__
   grub_fdt_unload ();
+#endif
 
   if (initrd_lf2_handle != NULL)
     {
diff --git a/include/grub/efi/api.h b/include/grub/efi/api.h
index b4c4646..b0d76e1 100644
--- a/include/grub/efi/api.h
+++ b/include/grub/efi/api.h
@@ -1229,7 +1229,7 @@
   (*install_configuration_table) (grub_efi_guid_t *guid, void *table);
 
   grub_efi_status_t
-  (*load_image) (grub_efi_boolean_t boot_policy,
+  (__grub_efi_api *load_image) (grub_efi_boolean_t boot_policy,
 		 grub_efi_handle_t parent_image_handle,
 		 grub_efi_device_path_t *file_path,
 		 void *source_buffer,
@@ -1237,7 +1237,7 @@
 		 grub_efi_handle_t *image_handle);
 
   grub_efi_status_t
-  (*start_image) (grub_efi_handle_t image_handle,
+  (__grub_efi_api *start_image) (grub_efi_handle_t image_handle,
 		  grub_efi_uintn_t *exit_data_size,
 		  grub_efi_char16_t **exit_data);
 
@@ -1315,7 +1315,7 @@
 		      void **protocol_interface);
 
   grub_efi_status_t
-  (*install_multiple_protocol_interfaces) (grub_efi_handle_t *handle, ...);
+  (__grub_efi_api *install_multiple_protocol_interfaces) (grub_efi_handle_t *handle, ...);
 
   grub_efi_status_t
   (*uninstall_multiple_protocol_interfaces) (grub_efi_handle_t handle, ...);
diff --git a/include/grub/efi/efi.h b/include/grub/efi/efi.h
index 444bf5b..c56abfb 100644
--- a/include/grub/efi/efi.h
+++ b/include/grub/efi/efi.h
@@ -112,6 +112,8 @@
 
 #if defined(__arm__) || defined(__aarch64__) || defined(__riscv)
 void *EXPORT_FUNC(grub_efi_get_firmware_fdt)(void);
+#endif
+#if defined(__arm__) || defined(__aarch64__) || defined(__riscv) || defined(__x86_64__)
 grub_err_t EXPORT_FUNC(grub_efi_get_ram_base)(grub_addr_t *);
 #include <grub/file.h>
 grub_err_t grub_arch_efi_linux_load_image_header(grub_file_t file,