grub/loader/powerpc/ieee1275/linux.c

/* linux.c - boot Linux */
/*
 *  GRUB  --  GRand Unified Bootloader
 *  Copyright (C) 2003, 2004  Free Software Foundation, Inc.
 *
 *  This program 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 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <grub/machine/loader.h>
#include <grub/machine/ieee1275.h>
#include <grub/elf.h>
#include <grub/loader.h>
#include <grub/dl.h>
#include <grub/mm.h>
#include <grub/rescue.h>
#include <grub/misc.h>

static grub_dl_t my_mod;

static int loaded;
static int vmlinux;

static grub_addr_t initrd_addr;
static grub_size_t initrd_size;

static grub_addr_t linux_addr;
static grub_size_t linux_size;

static char *linux_args;

typedef void (*kernel_entry_t) (void *, unsigned long, intptr_t (void *),
				unsigned long, unsigned long);

static grub_err_t
grub_linux_boot (void)
{
  kernel_entry_t linuxmain;
  grub_ieee1275_phandle_t chosen;
  grub_size_t actual;
  
  struct bi_rec
  {
    unsigned long tag;
    unsigned long size;
    unsigned long data[0];
  };
  
  grub_ieee1275_finddevice ("/chosen", &chosen);
  
  /* Set the command line arguments.  */
  grub_ieee1275_set_property (chosen, "bootargs", linux_args,
			      grub_strlen (linux_args) + 1, &actual);
  
  /* Boot the kernel.  */
  linuxmain = (kernel_entry_t) linux_addr;
  linuxmain ((void *) initrd_addr, initrd_size, grub_ieee1275_entry_fn, 0, 0);

  return GRUB_ERR_NONE;
}

static grub_err_t
grub_linux_release_mem (void)
{
  grub_free (linux_args);
  linux_args = 0;
  
  if (linux_addr && grub_ieee1275_release ((void *) linux_addr, linux_size))
    return grub_error (GRUB_ERR_OUT_OF_MEMORY, "Can not release memory");
  
  linux_addr = 0;
  return GRUB_ERR_NONE;
}

static grub_err_t
grub_linux_unload (void)
{
  grub_err_t err;
  
  err = grub_linux_release_mem ();
  grub_dl_unref (my_mod);
  
  loaded = 0;
  
  return err;
}

void
grub_load_linux (int argc, char *argv[])
{
  grub_file_t file = 0;
  Elf32_Ehdr ehdr;
  Elf32_Phdr *phdrs = 0;
  int i;  
  int offset = 0;
  static grub_addr_t entry;
  int size;
  
  grub_dl_ref (my_mod);

  if (argc == 0)
    {
      grub_error (GRUB_ERR_BAD_ARGUMENT, "no kernel specified");
      goto fail;
    }
  
  file = grub_file_open (argv[0]);
  if (! file)
    goto fail;
  
  if (grub_file_read (file, (char *) &ehdr, sizeof (ehdr)) != sizeof (ehdr))
    {
      grub_error (GRUB_ERR_READ_ERROR, "cannot read the linux elf header");
      goto fail;
    }
  
  if (!((ehdr.e_ident[EI_MAG0] == ELFMAG0) 
	&& (ehdr.e_ident[EI_MAG1] == ELFMAG1)
	&& (ehdr.e_ident[EI_MAG2] == ELFMAG2) 
	&& (ehdr.e_ident[EI_MAG3] == ELFMAG3)
	&& (ehdr.e_ident[EI_CLASS] == ELFCLASS32) 
	&& (ehdr.e_ident[EI_DATA] == ELFDATA2MSB)
	&& (ehdr.e_ident[EI_VERSION] == EV_CURRENT) 
	&& (ehdr.e_type == ET_EXEC) && (ehdr.e_machine == EM_PPC) 
	&& (ehdr.e_version == EV_CURRENT)))
    {
      grub_error (GRUB_ERR_UNKNOWN_OS, "No valid ELF header found");
      goto fail;
    }
  
  if (ehdr.e_type != ET_EXEC)
    {
      grub_error (GRUB_ERR_UNKNOWN_OS,
		  "This ELF file is not of the right type\n");
      goto fail;
    }

  if (ehdr.e_machine != EM_PPC)
    {
      grub_error (GRUB_ERR_UNKNOWN_OS,
		  "This ELF file is not for the PPC32\n");
      goto fail;
    }
  
  if (ehdr.e_version != EV_CURRENT)
    {
      grub_error (GRUB_ERR_UNKNOWN_OS,
		  "Invalid ELF version\n");
      goto fail;
    }

  /* Read the sections.  */
  entry = ehdr.e_entry;
  if (entry == 0xc0000000)
    {
      entry = 0x01400000;
      vmlinux = 1;
    }
  else
    vmlinux = 0;

  phdrs = (Elf32_Phdr *) grub_malloc (ehdr.e_phnum * ehdr.e_phentsize);
  grub_file_read (file, (void *) phdrs, ehdr.e_phnum * ehdr.e_phentsize);
  
  /* Release the previously used memory.  */
  grub_loader_unset ();
  
  /* Determine the amount of memory that is required.  */
  linux_size = 0;
  for (i = 0; i < ehdr.e_phnum; i++)
    {
      Elf32_Phdr *phdr = phdrs + i;
      /* XXX: Is this calculation correct?  */
      linux_size += phdr->p_memsz + phdr->p_filesz;
    }
  
  /* Reserve memory for the kernel.  */
  linux_size += 0x100000;
  
  if (grub_ieee1275_claim ((void *) entry, linux_size, 0, (void *) &linux_addr) == -1)
    {
      grub_error (GRUB_ERR_OUT_OF_MEMORY, "Can not claim memory");
      goto fail;
    }
  
  /* Load every loadable segment in memory.  */
  for (i = 0; i < ehdr.e_phnum; i++)
    {
      Elf32_Phdr *phdr = phdrs + i;

      if (phdr->p_type == PT_LOAD)
	{
	  if (grub_file_seek (file, phdr->p_offset) == -1)
	    {
	      grub_error (GRUB_ERR_BAD_OS, "Invalid offset in program header");
	      goto fail;
	    }
	  
	  if (grub_file_read (file, (void *) (((char *) entry) + offset) , phdr->p_filesz) 
	      != (grub_ssize_t) phdr->p_filesz)
	    goto fail;
	  
	  if (phdr->p_filesz < phdr->p_memsz)
	    grub_memset ((char *) (((char *) entry) + offset) + phdr->p_filesz, 0, 
			 phdr->p_memsz - phdr->p_filesz);

	  offset += phdr->p_filesz;
	}
    }
  
  size = 0;
  for (i = 0; i < argc; i++)
    size += grub_strlen (argv[i]);
  
  linux_args = grub_malloc (size + argc + 1);
  if (!linux_args)
    goto fail;
  
  for (i = 1; i < argc; i++)
    {
      grub_strcat (linux_args, argv[i]);
      grub_strcat (linux_args, " ");
    }
  
 fail:

  if (file)
    grub_file_close (file);
  
  grub_free (phdrs);

  if (grub_errno != GRUB_ERR_NONE)
    {
      grub_linux_release_mem ();
      grub_dl_unref (my_mod);
      loaded = 0;
    }
  else
    {
      grub_loader_set (grub_linux_boot, grub_linux_unload);
      initrd_addr = 0xc0000000;
      loaded = 1;
    }
  
  return;
}


GRUB_MOD_INIT
{
  grub_rescue_register_command ("linux", grub_load_linux,
				"load a linux kernel");
  my_mod = mod;
}

GRUB_MOD_FINI
{
  grub_rescue_unregister_command ("linux");
}

void
grub_linux_init (void)
{
  grub_rescue_register_command ("linux", grub_load_linux,
				"load a linux kernel");
}

void
grub_linux_fini (void)
{
  grub_rescue_unregister_command ("linux");
}