[PATCH v3 2/4] arm64: Add xen_boot module file

[fu.wei@linaro.org]

From: Fu Wei <fu.wei@linaro.org>

grub-core/loader/arm64/xen_boot.c

  - This adds support for the Xen boot on ARM specification for arm64.
  - Introduce xen_hypervisor, xen_linux, xen_initrd and xen_xsm
    to load different binaries for xen boot;
    Introduce xen_module to load common or custom module for xen boot.
  - This Xen boot support is a separated  module for aarch64,
    but reuse the existing code of devicetree in linux module.

Signed-off-by: Fu Wei <fu.wei@linaro.org>
---
 grub-core/Makefile.core.def       |   7 +
 grub-core/loader/arm64/xen_boot.c | 685 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 692 insertions(+)

diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index a6101de..796f7e9 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -1648,6 +1648,13 @@ module = {
 };
 
 module = {
+  name = xen_boot;
+  common = lib/cmdline.c;
+  arm64 = loader/arm64/xen_boot.c;
+  enable = arm64;
+};
+
+module = {
   name = linux;
   x86 = loader/i386/linux.c;
   xen = loader/i386/xen.c;
diff --git a/grub-core/loader/arm64/xen_boot.c b/grub-core/loader/arm64/xen_boot.c
new file mode 100644
index 0000000..33a65dd
--- /dev/null
+++ b/grub-core/loader/arm64/xen_boot.c
@@ -0,0 +1,685 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2014  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/cache.h>
+#include <grub/charset.h>
+#include <grub/command.h>
+#include <grub/err.h>
+#include <grub/file.h>
+#include <grub/fdt.h>
+#include <grub/linux.h>
+#include <grub/list.h>
+#include <grub/loader.h>
+#include <grub/misc.h>
+#include <grub/mm.h>
+#include <grub/types.h>
+#include <grub/cpu/linux.h>
+#include <grub/efi/efi.h>
+#include <grub/efi/pe32.h>	/* required by struct xen_hypervisor_header */
+#include <grub/i18n.h>
+#include <grub/lib/cmdline.h>
+
+GRUB_MOD_LICENSE ("GPLv3+");
+
+#define XEN_HYPERVISOR_NAME  "xen_hypervisor"
+
+#define MODULE_DEFAULT_ALIGN  (0x0)
+#define MODULE_IMAGE_MIN_ALIGN  MODULE_DEFAULT_ALIGN
+#define MODULE_INITRD_MIN_ALIGN  MODULE_DEFAULT_ALIGN
+#define MODULE_XSM_MIN_ALIGN  MODULE_DEFAULT_ALIGN
+#define MODULE_CUSTOM_MIN_ALIGN  MODULE_DEFAULT_ALIGN
+
+/* #define MODULE_IMAGE_COMPATIBLE  "xen,linux-image\0xen,module"
+#define MODULE_INITRD_COMPATIBLE  "xen,linux-image\0xen,module"
+#define MODULE_XSM_COMPATIBLE  "xen,xsm-policy\0xen,module"
+#define MODULE_CUSTOM_COMPATIBLE  "xen,module" */
+#define MODULE_IMAGE_COMPATIBLE  "multiboot,kernel\0multiboot,module"
+#define MODULE_INITRD_COMPATIBLE  "multiboot,ramdisk\0multiboot,module"
+#define MODULE_XSM_COMPATIBLE  "xen,xsm-policy\0multiboot,module"
+#define MODULE_CUSTOM_COMPATIBLE  "multiboot,module"
+
+/* This maximum size is defined in Power.org ePAPR V1.1
+ * https://www.power.org/documentation/epapr-version-1-1/
+ * 2.2.1.1 Node Name Requirements
+ * node-name@unit-address
+ * 31 + 1(@) + 16(64bit address in hex format) + 1(\0) = 49
+ */
+#define FDT_NODE_NAME_MAX_SIZE  (49)
+
+#define ARG_SHIFT(argc, argv) \
+  do { \
+    (argc)--; \
+    (argv)++; \
+  } while (0)
+
+struct compat_string_struct
+{
+  grub_size_t size;
+  const char *compat_string;
+};
+typedef struct compat_string_struct compat_string_struct_t;
+#define FDT_COMPATIBLE(x) {.size = sizeof(x), .compat_string = (x)}
+
+enum module_type
+{
+  MODULE_IMAGE,
+  MODULE_INITRD,
+  MODULE_XSM,
+  MODULE_CUSTOM
+};
+typedef enum module_type module_type_t;
+
+struct fdt_node_info
+{
+  module_type_t type;
+
+  const char *compat_string;
+  grub_size_t compat_string_size;
+};
+
+struct xen_hypervisor_header
+{
+  struct grub_arm64_linux_kernel_header efi_head;
+
+  /* This is always PE\0\0.  */
+  grub_uint8_t signature[GRUB_PE32_SIGNATURE_SIZE];
+  /* The COFF file header.  */
+  struct grub_pe32_coff_header coff_header;
+  /* The Optional header.  */
+  struct grub_pe64_optional_header optional_header;
+};
+
+struct xen_boot_binary
+{
+  struct xen_boot_binary *next;
+  struct xen_boot_binary **prev;
+  const char *name;
+
+  grub_addr_t start;
+  grub_size_t size;
+  grub_size_t align;
+
+  char *cmdline;
+  int cmdline_size;
+
+  struct fdt_node_info node_info;
+};
+
+static grub_dl_t my_mod;
+
+static struct xen_boot_binary *xen_hypervisor;
+static struct xen_boot_binary *module_head;
+static const grub_size_t module_default_align[] = {
+  MODULE_IMAGE_MIN_ALIGN,
+  MODULE_INITRD_MIN_ALIGN,
+  MODULE_XSM_MIN_ALIGN,
+  MODULE_CUSTOM_MIN_ALIGN
+};
+
+static void *xen_boot_fdt;
+static const compat_string_struct_t default_compat_string[] = {
+  FDT_COMPATIBLE (MODULE_IMAGE_COMPATIBLE),
+  FDT_COMPATIBLE (MODULE_INITRD_COMPATIBLE),
+  FDT_COMPATIBLE (MODULE_XSM_COMPATIBLE),
+  FDT_COMPATIBLE (MODULE_CUSTOM_COMPATIBLE)
+};
+
+static __inline grub_addr_t
+xen_boot_address_align (grub_addr_t start, grub_size_t align)
+{
+  return (align ? (ALIGN_UP (start, align)) : start);
+}
+
+/* Parse the option of xen_module command. For now, we support
+   (1) --type <the compatible stream>
+   We also set up the type of module in this function.
+   If there are some "--type" options in the command line,
+   we make a custom compatible stream in this function. */
+static grub_err_t
+set_module_type (grub_command_t cmd, struct xen_boot_binary *module,
+		 int argc, char *argv[], int *file_name_index)
+{
+  char **compat_string_temp_array;
+  grub_size_t total_size = 0;
+  int num_types = 0, i;
+  char *temp = NULL;
+
+  *file_name_index = 0;
+
+  if (!grub_strcmp (cmd->name, "xen_linux"))
+    module->node_info.type = MODULE_IMAGE;
+  else if (!grub_strcmp (cmd->name, "xen_initrd"))
+    module->node_info.type = MODULE_INITRD;
+  else if (!grub_strcmp (cmd->name, "xen_xsm"))
+    module->node_info.type = MODULE_XSM;
+  else if (!grub_strcmp (cmd->name, "xen_module"))
+    module->node_info.type = MODULE_CUSTOM;
+
+  /* if there are some options we need to process. */
+  if (module->node_info.type == MODULE_CUSTOM)
+    {
+      compat_string_temp_array =
+	(char **) grub_zalloc (sizeof (char *) * argc);
+      if (!compat_string_temp_array)
+	return grub_errno;
+      /* the module type is set by "--type"(MODULE_CUSTOM) */
+      while (argc > 2 && !grub_strcmp (argv[0], "--type"))
+	{
+	  module->node_info.type = MODULE_CUSTOM;
+	  ARG_SHIFT (argc, argv);
+	  total_size += grub_strlen (argv[0]) + 1;
+	  compat_string_temp_array[num_types++] = argv[0];
+	  ARG_SHIFT (argc, argv);
+	  (*file_name_index) += 2;
+	}
+
+      if (total_size)
+	{
+	  module->node_info.compat_string = temp =
+	    (char *) grub_zalloc (total_size);
+	  if (!temp)
+	    {
+	      grub_free (compat_string_temp_array);
+	      return grub_errno;
+	    }
+
+	  module->node_info.compat_string_size = total_size;
+	  for (i = 0; num_types > 0; num_types--, i++, temp++)
+	    {
+	      grub_strcpy (temp, compat_string_temp_array[i]);
+	      temp += grub_strlen (compat_string_temp_array[i]);
+	    }
+	}
+      else
+	{
+	  module->node_info.compat_string =
+	    default_compat_string[MODULE_CUSTOM].compat_string;
+	  module->node_info.compat_string_size =
+	    default_compat_string[MODULE_CUSTOM].size;
+	}
+
+      grub_free (compat_string_temp_array);
+    }
+
+  return GRUB_ERR_NONE;
+}
+
+static grub_err_t
+prepare_xen_hypervisor_params (void)
+{
+  int chosen_node = 0;
+  int retval;
+
+  xen_boot_fdt = grub_linux_get_fdt ();
+  if (!xen_boot_fdt)
+    return grub_error (GRUB_ERR_IO, "failed to get FDT");
+
+  chosen_node = grub_fdt_find_subnode (xen_boot_fdt, 0, "chosen");
+  if (chosen_node < 0)
+    chosen_node = grub_fdt_add_subnode (xen_boot_fdt, 0, "chosen");
+  if (chosen_node < 1)
+    return grub_error (GRUB_ERR_IO, "failed to get chosen node in FDT");
+
+  grub_dprintf ("xen_loader",
+		"Xen Hypervisor cmdline : %s @ %p size:%d\n",
+		xen_hypervisor->cmdline, xen_hypervisor->cmdline,
+		xen_hypervisor->cmdline_size);
+
+  retval = grub_fdt_set_prop (xen_boot_fdt, chosen_node, "bootargs",
+			      xen_hypervisor->cmdline,
+			      xen_hypervisor->cmdline_size);
+  if (retval)
+    return grub_error (GRUB_ERR_IO, "failed to install/update FDT");
+
+  return GRUB_ERR_NONE;
+}
+
+static grub_err_t
+prepare_xen_module_params (struct xen_boot_binary *module)
+{
+  int retval, chosen_node = 0, module_node = 0;
+  char module_name[FDT_NODE_NAME_MAX_SIZE];
+
+  retval = grub_snprintf (module_name, FDT_NODE_NAME_MAX_SIZE, "module@%lx",
+			  xen_boot_address_align (module->start,
+						  module->align));
+  grub_dprintf ("xen_loader", "Module node name %s \n", module_name);
+
+  if (retval < (int) sizeof ("module@"))
+    return grub_error (GRUB_ERR_IO, N_("failed to get FDT"));
+
+  chosen_node = grub_fdt_find_subnode (xen_boot_fdt, 0, "chosen");
+  if (chosen_node < 0)
+    chosen_node = grub_fdt_add_subnode (xen_boot_fdt, 0, "chosen");
+  if (chosen_node < 1)
+    return grub_error (GRUB_ERR_IO, "failed to get chosen node in FDT");
+
+  module_node =
+    grub_fdt_find_subnode (xen_boot_fdt, chosen_node, module_name);
+  if (module_node < 0)
+    module_node =
+      grub_fdt_add_subnode (xen_boot_fdt, chosen_node, module_name);
+
+  retval = grub_fdt_set_prop (xen_boot_fdt, module_node, "compatible",
+			      module->node_info.compat_string,
+			      (grub_uint32_t) module->
+			      node_info.compat_string_size);
+  if (retval)
+    return grub_error (GRUB_ERR_IO, N_("failed to update FDT"));
+
+  grub_dprintf ("xen_loader", "Module %s compatible = %s size = 0x%lx\n",
+		module->name, module->node_info.compat_string,
+		module->node_info.compat_string_size);
+
+  retval = grub_fdt_set_reg64 (xen_boot_fdt, module_node,
+			       xen_boot_address_align (module->start,
+						       module->align),
+			       module->size);
+  if (retval)
+    return grub_error (GRUB_ERR_IO, N_("failed to update FDT"));
+
+  if (module->cmdline && module->cmdline_size > 0)
+    {
+      grub_dprintf ("xen_loader",
+		    "Module %s cmdline : %s @ %p size:%d\n", module->name,
+		    module->cmdline, module->cmdline, module->cmdline_size);
+
+      retval = grub_fdt_set_prop (xen_boot_fdt, module_node, "bootargs",
+				  module->cmdline, module->cmdline_size + 1);
+      if (retval)
+	return grub_error (GRUB_ERR_IO, "failed to update FDT");
+    }
+  else
+    {
+      grub_dprintf ("xen_loader", "Module %s has not bootargs!\n",
+		    module->name);
+    }
+
+  return GRUB_ERR_NONE;
+}
+
+static grub_err_t
+install_all_params (void)
+{
+  grub_efi_guid_t fdt_guid = GRUB_EFI_DEVICE_TREE_GUID;
+  grub_efi_boot_services_t *b;
+  grub_efi_status_t status;
+
+  b = grub_efi_system_table->boot_services;
+  status = b->install_configuration_table (&fdt_guid, xen_boot_fdt);
+  if (status != GRUB_EFI_SUCCESS)
+    return grub_error (GRUB_ERR_IO, "failed to install FDT");
+
+  grub_dprintf ("xen_loader",
+		"Installed/updated FDT configuration table @ %p\n",
+		xen_boot_fdt);
+
+  return GRUB_ERR_NONE;
+}
+
+static grub_err_t
+clean_all_params (void)
+{
+  if (xen_boot_fdt)
+    {
+      grub_efi_free_pages ((grub_efi_physical_address_t) xen_boot_fdt,
+			   BYTES_TO_PAGES (grub_fdt_get_totalsize
+					   (xen_boot_fdt)));
+      xen_boot_fdt = NULL;
+    }
+
+  return GRUB_ERR_NONE;
+}
+
+static grub_err_t
+finalize_params_xen_boot (void)
+{
+  struct xen_boot_binary *module;
+
+  if (xen_hypervisor)
+    {
+      if (prepare_xen_hypervisor_params () != GRUB_ERR_NONE)
+	goto fail;
+    }
+  else
+    {
+      grub_dprintf ("xen_loader", "Failed to get Xen Hypervisor info!\n");
+      goto fail;
+    }
+
+  /* Set module params info */
+  FOR_LIST_ELEMENTS (module, module_head)
+  {
+    if (module->start && module->size > 0)
+      {
+	grub_dprintf ("xen_loader", "Module %s @ 0x%lx size:0x%lx\n",
+		      module->name,
+		      xen_boot_address_align (module->start, module->align),
+		      module->size);
+	if (prepare_xen_module_params (module) != GRUB_ERR_NONE)
+	  goto fail;
+      }
+    else
+      {
+	grub_dprintf ("xen_loader", "Module info error: %s!\n", module->name);
+	goto fail;
+      }
+  }
+
+  if (install_all_params () == GRUB_ERR_NONE)
+    return GRUB_ERR_NONE;
+
+fail:
+  clean_all_params ();
+
+  return grub_error (GRUB_ERR_IO, "failed to install/update FDT");
+}
+
+
+static grub_err_t
+xen_boot (void)
+{
+  grub_err_t err = finalize_params_xen_boot ();
+  if (err)
+    return err;
+
+  return grub_arm64_uefi_boot_image (xen_hypervisor->start,
+				     xen_hypervisor->size,
+				     xen_hypervisor->cmdline);
+}
+
+static void
+single_binary_unload (struct xen_boot_binary *binary)
+{
+  if (!binary)
+    return;
+
+  if (binary->start && binary->size > 0)
+    {
+      grub_efi_free_pages ((grub_efi_physical_address_t) binary->start,
+			   BYTES_TO_PAGES (binary->size + binary->align));
+    }
+
+  if (binary->cmdline && binary->cmdline_size > 0)
+    {
+      grub_free (binary->cmdline);
+      grub_dprintf ("xen_loader",
+		    "Module %s cmdline memory free @ %p size: %d\n",
+		    binary->name, binary->cmdline, binary->cmdline_size);
+    }
+
+  if (binary->node_info.type == MODULE_CUSTOM)
+    grub_free ((void *) binary->node_info.compat_string);
+
+  if (grub_strcmp (binary->name, XEN_HYPERVISOR_NAME))
+    grub_list_remove (GRUB_AS_LIST (binary));
+
+  grub_dprintf ("xen_loader",
+		"Module %s struct memory free @ %p size: 0x%lx\n",
+		binary->name, binary, sizeof (binary));
+  grub_free (binary);
+
+  return;
+}
+
+static void
+all_binaries_unload (void)
+{
+  struct xen_boot_binary *binary;
+
+  FOR_LIST_ELEMENTS (binary, module_head)
+  {
+    single_binary_unload (binary);
+  }
+
+  if (xen_hypervisor)
+    single_binary_unload (xen_hypervisor);
+
+  return;
+}
+
+static grub_err_t
+xen_unload (void)
+{
+  grub_linux_set_loaded (0);
+  all_binaries_unload ();
+  clean_all_params ();
+  grub_dl_unref (my_mod);
+
+  return GRUB_ERR_NONE;
+}
+
+static void
+xen_boot_binary_load (struct xen_boot_binary *binary, grub_file_t file,
+		      int argc, char *argv[])
+{
+  binary->size = grub_file_size (file);
+  grub_dprintf ("xen_loader", "Xen_boot %s file size: 0x%lx\n",
+		binary->name, binary->size);
+
+  binary->start = (grub_addr_t) grub_efi_allocate_pages (0,
+							 (BYTES_TO_PAGES
+							  (binary->size +
+							   binary->align)));
+  if (!binary->start)
+    {
+      grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("out of memory"));
+      return;
+    }
+
+  grub_dprintf ("xen_loader", "Xen_boot %s numpages: 0x%lx\n",
+		binary->name, BYTES_TO_PAGES (binary->size + binary->align));
+
+  if (grub_file_read (file, (void *) xen_boot_address_align (binary->start,
+							     binary->align),
+		      binary->size) != (grub_ssize_t) binary->size)
+    {
+      single_binary_unload (binary);
+      grub_error (GRUB_ERR_BAD_OS, N_("premature end of file %s"), argv[0]);
+      return;
+    }
+
+  if (argc > 1)
+    {
+      binary->cmdline_size = grub_loader_cmdline_size (argc - 1, argv + 1);
+      binary->cmdline = grub_zalloc (binary->cmdline_size);
+      if (!binary->cmdline)
+	{
+	  single_binary_unload (binary);
+	  grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("out of memory"));
+	  return;
+	}
+      grub_create_loader_cmdline (argc - 1, argv + 1, binary->cmdline,
+				  binary->cmdline_size);
+      grub_dprintf ("xen_loader",
+		    "Xen_boot %s cmdline @ %p %s, size: %d\n", binary->name,
+		    binary->cmdline, binary->cmdline, binary->cmdline_size);
+    }
+  else
+    {
+      binary->cmdline_size = 0;
+      binary->cmdline = NULL;
+    }
+
+  grub_errno = GRUB_ERR_NONE;
+  return;
+}
+
+static grub_err_t
+grub_cmd_xen_module (grub_command_t cmd, int argc, char *argv[])
+{
+
+  struct xen_boot_binary *module = NULL;
+  int file_name_index = 0;
+  grub_file_t file = 0;
+
+  if (!argc)
+    {
+      grub_error (GRUB_ERR_BAD_ARGUMENT, N_("filename expected"));
+      goto fail;
+    }
+
+  if (!grub_linux_get_loaded ())
+    {
+      grub_error (GRUB_ERR_BAD_ARGUMENT,
+		  N_("you need to load the Xen Hypervisor first"));
+      goto fail;
+    }
+
+  module =
+    (struct xen_boot_binary *) grub_zalloc (sizeof (struct xen_boot_binary));
+  if (!module)
+    return grub_errno;
+
+  /* process all the options and get module type */
+  if (set_module_type (cmd, module, argc, argv, &file_name_index) !=
+      GRUB_ERR_NONE)
+    goto fail;
+  switch (module->node_info.type)
+    {
+    case MODULE_IMAGE:
+    case MODULE_INITRD:
+    case MODULE_XSM:
+      module->node_info.compat_string =
+	default_compat_string[module->node_info.type].compat_string;
+      module->node_info.compat_string_size =
+	default_compat_string[module->node_info.type].size;
+      break;
+
+    case MODULE_CUSTOM:
+      /* we have set the node_info in set_module_type */
+      break;
+
+    default:
+      return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("invalid argument"));
+    }
+  module->name = module->node_info.compat_string;
+  module->align = module_default_align[module->node_info.type];
+
+  grub_dprintf ("xen_loader", "Init %s module and node info:\n"
+		"compatible %s\ncompat_string_size 0x%lx\n",
+		module->name, module->node_info.compat_string,
+		module->node_info.compat_string_size);
+
+  file = grub_file_open (argv[file_name_index]);
+  if (!file)
+    goto fail;
+
+  xen_boot_binary_load (module, file, argc - file_name_index,
+			argv + file_name_index);
+  if (grub_errno == GRUB_ERR_NONE)
+    grub_list_push (GRUB_AS_LIST_P (&module_head), GRUB_AS_LIST (module));
+
+fail:
+  if (file)
+    grub_file_close (file);
+  if (grub_errno != GRUB_ERR_NONE)
+    single_binary_unload (module);
+
+  return grub_errno;
+}
+
+static grub_err_t
+grub_cmd_xen_hypervisor (grub_command_t cmd __attribute__ ((unused)),
+			 int argc, char *argv[])
+{
+  struct xen_hypervisor_header sh;
+  grub_file_t file = NULL;
+
+  grub_dl_ref (my_mod);
+
+  if (!argc)
+    {
+      grub_error (GRUB_ERR_BAD_ARGUMENT, N_("filename expected"));
+      goto fail;
+    }
+
+  file = grub_file_open (argv[0]);
+  if (!file)
+    goto fail;
+
+  if (grub_file_read (file, &sh, sizeof (sh)) != (long) sizeof (sh))
+    goto fail;
+  if (grub_arm64_uefi_check_image
+      ((struct grub_arm64_linux_kernel_header *) &sh) != GRUB_ERR_NONE)
+    goto fail;
+  grub_file_seek (file, 0);
+
+  /* if another module has called grub_loader_set,
+     we need to make sure that another module is unloaded properly */
+  grub_loader_unset ();
+
+  xen_hypervisor =
+    (struct xen_boot_binary *) grub_zalloc (sizeof (struct xen_boot_binary));
+  if (!xen_hypervisor)
+    return grub_errno;
+
+  xen_hypervisor->name = XEN_HYPERVISOR_NAME;
+  xen_hypervisor->align = (grub_size_t) sh.optional_header.section_alignment;
+
+  xen_boot_binary_load (xen_hypervisor, file, argc, argv);
+  if (grub_errno == GRUB_ERR_NONE)
+    {
+      grub_loader_set (xen_boot, xen_unload, 0);
+      grub_linux_set_loaded (1);
+    }
+
+fail:
+  if (file)
+    grub_file_close (file);
+  if (grub_errno != GRUB_ERR_NONE)
+    {
+      grub_linux_set_loaded (0);
+      all_binaries_unload ();
+      grub_dl_unref (my_mod);
+    }
+
+  return grub_errno;
+}
+
+static grub_command_t cmd_xen_hypervisor, cmd_xen_module;
+static grub_command_t cmd_xen_linux, cmd_xen_initrd, cmd_xen_xsm;
+
+GRUB_MOD_INIT (xen_boot)
+{
+  cmd_xen_hypervisor =
+    grub_register_command ("xen_hypervisor", grub_cmd_xen_hypervisor, 0,
+			   N_("Load a xen hypervisor."));
+  cmd_xen_linux =
+    grub_register_command ("xen_linux", grub_cmd_xen_module, 0,
+			   N_("Load a xen linux kernel for dom0."));
+  cmd_xen_initrd =
+    grub_register_command ("xen_initrd", grub_cmd_xen_module, 0,
+			   N_("Load a xen initrd for dom0."));
+  cmd_xen_xsm =
+    grub_register_command ("xen_xsm", grub_cmd_xen_module, 0,
+			   N_("Load a xen security module."));
+  cmd_xen_module =
+    grub_register_command ("xen_module", grub_cmd_xen_module, 0,
+			   N_("Load a xen module."));
+  my_mod = mod;
+}
+
+GRUB_MOD_FINI (xen_boot)
+{
+  grub_unregister_command (cmd_xen_hypervisor);
+  grub_unregister_command (cmd_xen_linux);
+  grub_unregister_command (cmd_xen_initrd);
+  grub_unregister_command (cmd_xen_xsm);
+  grub_unregister_command (cmd_xen_module);
+}
-- 
1.8.3.1