=== modified file 'grub-core/Makefile.core.def'
--- grub-core/Makefile.core.def	2010-08-30 13:13:38 +0000
+++ grub-core/Makefile.core.def	2010-09-03 23:57:56 +0000
@@ -1064,6 +1064,12 @@
 };
 
 module = {
+  name = pxechain;
+  i386_pc = loader/i386/pc/pxechainloader.c;
+  enable = i386_pc;
+};
+
+module = {
   name = multiboot2;
   cppflags = "-DGRUB_USE_MULTIBOOT2";
 

=== modified file 'grub-core/fs/i386/pc/pxe.c'
--- grub-core/fs/i386/pc/pxe.c	2010-09-02 13:47:03 +0000
+++ grub-core/fs/i386/pc/pxe.c	2010-09-05 23:28:35 +0000
@@ -522,12 +522,17 @@
 void
 grub_pxe_unload (void)
 {
+  struct grub_pxenv_tftp_close c;
+
   if (grub_pxe_pxenv)
     {
       grub_fs_unregister (&grub_pxefs_fs);
       grub_disk_dev_unregister (&grub_pxe_dev);
-
-      grub_pxe_pxenv = 0;
+      if (curr_file != 0)
+	{
+	  grub_pxe_call (GRUB_PXENV_TFTP_CLOSE, &c, pxe_rm_entry);
+	  curr_file = 0;
+	}
     }
 }
 

=== added file 'grub-core/loader/i386/pc/pxechainloader.c'
--- grub-core/loader/i386/pc/pxechainloader.c	1970-01-01 00:00:00 +0000
+++ grub-core/loader/i386/pc/pxechainloader.c	2010-09-05 23:29:09 +0000
@@ -0,0 +1,132 @@
+/* chainloader.c - boot another boot loader */
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2002,2004,2007,2009,2010  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/loader.h>
+#include <grub/file.h>
+#include <grub/err.h>
+#include <grub/device.h>
+#include <grub/disk.h>
+#include <grub/misc.h>
+#include <grub/types.h>
+#include <grub/partition.h>
+#include <grub/dl.h>
+#include <grub/command.h>
+#include <grub/machine/biosnum.h>
+#include <grub/i18n.h>
+#include <grub/video.h>
+#include <grub/mm.h>
+#include <grub/cpu/relocator.h>
+
+static grub_dl_t my_mod;
+static struct grub_relocator *rel;
+static grub_uint32_t edx = 0xffffffff;
+
+static grub_err_t
+grub_pxechain_boot (void)
+{
+  struct grub_relocator16_state state = { 
+    .cs = 0,
+    .ip = 0x7c00,
+    .ds = 0,
+    .es = 0,
+    .fs = 0,
+    .gs = 0,
+    .ss = 0,
+    .sp = 0x7c00,
+    .edx = edx
+  };
+  grub_video_set_mode ("text", 0, 0);
+
+  grub_pxe_unload ();
+
+  return grub_relocator16_boot (rel, state);
+}
+
+static grub_err_t
+grub_pxechain_unload (void)
+{
+  grub_relocator_unload (rel);
+  rel = NULL;
+  grub_dl_unref (my_mod);
+  return GRUB_ERR_NONE;
+}
+
+static grub_err_t
+grub_cmd_pxechain (grub_command_t cmd __attribute__ ((unused)),
+		int argc, char *argv[])
+{
+  grub_file_t file = 0;
+  grub_err_t err;
+  void *image;
+  grub_size_t imagesize;
+
+  if (argc == 0)
+    return grub_error (GRUB_ERR_BAD_ARGUMENT, "no file specified");
+
+  grub_dl_ref (my_mod);
+
+  rel = grub_relocator_new ();
+  if (!rel)
+    goto fail;
+
+  file = grub_file_open (argv[0]);
+  if (! file)
+    goto fail;
+
+
+  edx = grub_get_root_biosnumber ();
+
+  imagesize = grub_file_size (file);
+  {
+    grub_relocator_chunk_t ch;
+    err = grub_relocator_alloc_chunk_addr (rel, &ch, 0x7c00, imagesize);
+    if (err)
+      goto fail;
+    image = get_virtual_current_address (ch);
+  }
+
+  if (grub_file_read (file, image, imagesize) != (grub_ssize_t) imagesize)
+    goto fail;
+ 
+  grub_loader_set (grub_pxechain_boot, grub_pxechain_unload, 1);
+  return GRUB_ERR_NONE;
+
+ fail:
+
+  if (file)
+    grub_file_close (file);
+
+  grub_pxechain_unload ();
+
+  return grub_errno;
+}
+
+static grub_command_t cmd;
+
+GRUB_MOD_INIT(pxechainloader)
+{
+  cmd = grub_register_command ("pxechainloader", grub_cmd_pxechain,
+			       0, N_("Chainload a PXE image."));
+  my_mod = mod;
+}
+
+GRUB_MOD_FINI(pxechainloader)
+{
+  grub_unregister_command (cmd);
+}