--- /dev/null
+/*
+ * GRUB -- GRand Unified Bootloader
+ * Copyright (C) 2011 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/memory.h>
+#include <grub/i386/memory.h>
+#include <grub/file.h>
+#include <grub/err.h>
+#include <grub/dl.h>
+#include <grub/mm.h>
+#include <grub/elfload.h>
+#include <grub/video.h>
+#include <grub/relocator.h>
+#include <grub/i386/relocator.h>
+#include <grub/command.h>
+#include <grub/i18n.h>
+
+GRUB_MOD_LICENSE ("GPLv3+");
+
+static grub_addr_t entry;
+static struct grub_relocator *relocator = NULL;
+
+static grub_err_t
+grub_chain_boot (void)
+{
+ struct grub_relocator32_state state;
+
+ grub_video_set_mode ("text", 0, 0);
+
+ state.eip = entry;
+ return grub_relocator32_boot (relocator, state);
+}
+
+static grub_err_t
+grub_chain_unload (void)
+{
+ grub_relocator_unload (relocator);
+ relocator = NULL;
+
+ return GRUB_ERR_NONE;
+}
+
+static grub_err_t
+grub_chain_elf32_hook (Elf32_Phdr * phdr, grub_addr_t * addr, int *do_load)
+{
+ grub_err_t err;
+ grub_relocator_chunk_t ch;
+
+ if (phdr->p_type != PT_LOAD)
+ {
+ *do_load = 0;
+ return 0;
+ }
+
+ *do_load = 1;
+ err = grub_relocator_alloc_chunk_addr (relocator, &ch,
+ phdr->p_paddr, phdr->p_memsz);
+ if (err)
+ return err;
+
+ *addr = (grub_addr_t) get_virtual_current_address (ch);
+
+ return GRUB_ERR_NONE;
+}
+
+
+static grub_err_t
+grub_cmd_chain (grub_command_t cmd __attribute__ ((unused)),
+ int argc, char *argv[])
+{
+ grub_err_t err;
+ grub_file_t file;
+ grub_elf_t elf;
+
+ if (argc != 1)
+ return grub_error (GRUB_ERR_BAD_ARGUMENT, "filename expected");
+
+ grub_loader_unset ();
+
+ file = grub_file_open (argv[0]);
+ if (!file)
+ return grub_errno;
+
+ relocator = grub_relocator_new ();
+ if (!relocator)
+ {
+ grub_file_close (file);
+ return grub_errno;
+ }
+
+ elf = grub_elf_file (file);
+ if (!elf)
+ {
+ grub_relocator_unload (relocator);
+ relocator = 0;
+ grub_file_close (file);
+ }
+
+ if (!grub_elf_is_elf32 (elf))
+ {
+ grub_relocator_unload (relocator);
+ relocator = 0;
+ grub_elf_close (elf);
+ }
+
+ entry = elf->ehdr.ehdr32.e_entry & 0xFFFFFF;
+
+ err = grub_elf32_load (elf, grub_chain_elf32_hook, 0, 0);
+
+ grub_elf_close (elf);
+ if (err)
+ return err;
+
+ grub_loader_set (grub_chain_boot, grub_chain_unload, 0);
+ return GRUB_ERR_NONE;
+}
+
+static grub_command_t cmd_chain;
+
+GRUB_MOD_INIT (chain)
+{
+ cmd_chain = grub_register_command ("chainloader", grub_cmd_chain,
+ N_("FILE"), N_("Load another payload"));
+}
+
+GRUB_MOD_FINI (chain)
+{
+ grub_unregister_command (cmd_chain);
+ grub_chain_unload ();
+}