stage2/boot.c

/* boot.c - load and bootstrap a kernel */
/*
 *  GRUB  --  GRand Unified Bootloader
 *  Copyright (C) 1996  Erich Boleyn  <erich@uruk.org>
 *  Copyright (C) 1999  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 "shared.h"

#include "freebsd.h"
#include "imgact_aout.h"
#include "i386-elf.h"

static int cur_addr;
entry_func entry_addr;
static struct mod_list mll[99];


/*
 *  The next two functions, 'load_image' and 'load_module', are the building
 *  blocks of the multiboot loader component.  They handle essentially all
 *  of the gory details of loading in a bootable image and the modules.
 */

kernel_t
load_image (char *kernel, char *arg, kernel_t suggested_type)
{
  int len, i, exec_type = 0, align_4k = 1;
  kernel_t type = KERNEL_TYPE_NONE;
  unsigned long flags = 0, text_len = 0, data_len = 0, bss_len = 0;
  char *str = 0, *str2 = 0;
  union
    {
      struct multiboot_header *mb;
      struct exec *aout;
      Elf32_Ehdr *elf;
    }
  pu;
  /* presuming that MULTIBOOT_SEARCH is large enough to encompass an
     executable header */
  unsigned char buffer[MULTIBOOT_SEARCH];

  /* sets the header pointer to point to the beginning of the
     buffer by default */
  pu.aout = (struct exec *) buffer;

  if (!grub_open (kernel))
    return KERNEL_TYPE_NONE;

  if (!(len = grub_read (buffer, MULTIBOOT_SEARCH)) || len < 32)
    {
      grub_close ();
      
      if (!errnum)
	errnum = ERR_EXEC_FORMAT;

      return KERNEL_TYPE_NONE;
    }

  for (i = 0; i < len; i++)
    {
      if (MULTIBOOT_FOUND ((int) (buffer + i), len - i))
	{
	  flags = ((struct multiboot_header *) (buffer + i))->flags;
	  if (flags & MULTIBOOT_UNSUPPORTED)
	    {
	      grub_close ();
	      errnum = ERR_BOOT_FEATURES;
	      return KERNEL_TYPE_NONE;
	    }
	  type = KERNEL_TYPE_MULTIBOOT;
	  str2 = "Multiboot";
	  break;
	}
    }

  /* ELF loading supported if multiboot, FreeBSD and NetBSD.  */
  if ((type == KERNEL_TYPE_MULTIBOOT
       || grub_strcmp (pu.elf->e_ident + EI_BRAND, "FreeBSD") == 0
       || suggested_type == KERNEL_TYPE_NETBSD)
      && len > sizeof (Elf32_Ehdr)
      && BOOTABLE_I386_ELF ((*((Elf32_Ehdr *) buffer))))
    {
      if (type == KERNEL_TYPE_MULTIBOOT)
	entry_addr = (entry_func) pu.elf->e_entry;
      else
	entry_addr = (entry_func) (pu.elf->e_entry & 0xFFFFFF);

      if (((int) entry_addr) < 0x100000)
	errnum = ERR_BELOW_1MB;

      /* don't want to deal with ELF program header at some random
         place in the file -- this generally won't happen */
      if (pu.elf->e_phoff == 0 || pu.elf->e_phnum == 0
	  || ((pu.elf->e_phoff + (pu.elf->e_phentsize * pu.elf->e_phnum))
	      >= len))
	errnum = ERR_EXEC_FORMAT;
      str = "elf";

      if (type == KERNEL_TYPE_NONE)
	{
	  /* At the moment, there is no way to identify a NetBSD ELF
	     kernel, so rely on the suggested type by the user.  */
	  if (suggested_type == KERNEL_TYPE_NETBSD)
	    {
	      str2 = "NetBSD";
	      type = suggested_type;
	    }
	  else
	    {
	      str2 = "FreeBSD";
	      type = KERNEL_TYPE_FREEBSD;
	    }
	}
    }
  else if (flags & MULTIBOOT_AOUT_KLUDGE)
    {
      pu.mb = (struct multiboot_header *) (buffer + i);
      entry_addr = (entry_func) pu.mb->entry_addr;
      cur_addr = pu.mb->load_addr;
      /* first offset into file */
      grub_seek (i - (pu.mb->header_addr - cur_addr));
      text_len = pu.mb->load_end_addr - cur_addr;
      data_len = 0;
      bss_len = pu.mb->bss_end_addr - pu.mb->load_end_addr;

      if (pu.mb->header_addr < pu.mb->load_addr
	  || pu.mb->load_end_addr <= pu.mb->load_addr
	  || pu.mb->bss_end_addr < pu.mb->load_end_addr
	  || (pu.mb->header_addr - pu.mb->load_addr) > i)
	errnum = ERR_EXEC_FORMAT;

      if (cur_addr < 0x100000)
	errnum = ERR_BELOW_1MB;

      pu.aout = (struct exec *) buffer;
      exec_type = 2;
      str = "kludge";
    }
  else if (len > sizeof (struct exec) && !N_BADMAG ((*(pu.aout))))
    {
      entry_addr = (entry_func) pu.aout->a_entry;

      if (type == KERNEL_TYPE_NONE)
	{
	  /*
	   *  If it doesn't have a Multiboot header, then presume
	   *  it is either a FreeBSD or NetBSD executable.  If so,
	   *  then use a magic number of normal ordering, ZMAGIC to
	   *  determine if it is FreeBSD.
	   *
	   *  This is all because freebsd and netbsd seem to require
	   *  masking out some address bits...  differently for each
	   *  one...  plus of course we need to know which booting
	   *  method to use.
	   */
	  entry_addr = (entry_func) ((int) entry_addr & 0xFFFFFF);
	  
	  if (buffer[0] == 0xb && buffer[1] == 1)
	    {
	      type = KERNEL_TYPE_FREEBSD;
	      cur_addr = (int) entry_addr;
	      str2 = "FreeBSD";
	    }
	  else
	    {
	      type = KERNEL_TYPE_NETBSD;
	      cur_addr = (int) entry_addr & 0xF00000;
	      if (N_GETMAGIC ((*(pu.aout))) != NMAGIC)
		align_4k = 0;
	      str2 = "NetBSD";
	    }
	}

      /* first offset into file */
      grub_seek (N_TXTOFF (*(pu.aout)));
      text_len = pu.aout->a_text;
      data_len = pu.aout->a_data;
      bss_len = pu.aout->a_bss;

      if (cur_addr < 0x100000)
	errnum = ERR_BELOW_1MB;

      exec_type = 1;
      str = "a.out";
    }
  else if ((*((unsigned short *) (buffer + BOOTSEC_SIG_OFFSET))
	    == BOOTSEC_SIGNATURE)
	   && ((data_len
		= (((long) *((unsigned char *)
			     (buffer + LINUX_SETUP_LEN_OFFSET))) << 9))
	       <= LINUX_SETUP_MAXLEN)
	   && ((text_len
		= (((long) *((unsigned short *)
			     (buffer + LINUX_KERNEL_LEN_OFFSET))) << 4)),
	       (data_len + text_len + SECTOR_SIZE) <= ((filemax + 15) & 0xFFFFFFF0)))
    {
      int big_linux = buffer[LINUX_SETUP_LOAD_FLAGS] & LINUX_FLAG_BIG_KERNEL;
      buffer[LINUX_SETUP_LOADER] = 0x70;
      if (! big_linux && text_len > LINUX_KERNEL_MAXLEN)
	{
	  printf (" linux 'zImage' kernel too big, try 'make bzImage'\n");
	  grub_close ();
	  errnum = ERR_WONT_FIT;
	  return KERNEL_TYPE_NONE;
	}

      printf ("   [Linux-%s, setup=0x%x, size=0x%x]\n",
	      (big_linux ? "bzImage" : "zImage"), data_len, text_len);

      if (mbi.mem_lower >= 608)
	{
	  /* Video mode selection support. What a shit!  */
	  {
	    char *vga;

	    /* Find the substring "vga=".  */
	    vga = grub_strstr (arg, "vga=");
	    if (vga)
	      {
		char *value = vga + 4;
		char *vga_end;
		int vid_mode;

		/* Handle special strings.  */
		if (substring ("normal", value) < 1)
		  vid_mode = LINUX_VID_MODE_NORMAL;
		else if (substring ("ext", value) < 1)
		  vid_mode = LINUX_VID_MODE_EXTENDED;
		else if (substring ("ask", value) < 1)
		  vid_mode = LINUX_VID_MODE_ASK;
		else if (safe_parse_maxint (&value, &vid_mode))
		  ;
		else
		  {
		    /* ERRNUM is already set inside the function
		       safe_parse_maxint.  */
		    grub_close ();
		    return KERNEL_TYPE_NONE;
		  }

		/* Set the vid mode to VID_MODE. Note that this can work
		   because i386 architecture is little-endian.  */
		grub_memmove (buffer + LINUX_VID_MODE_OFFSET,
			      (char *) &vid_mode,
			      sizeof (unsigned short));
		
		/* Remove the "vga=...".  */
		vga_end = skip_to (0, vga);
		grub_memmove (vga, vga_end, grub_strlen (vga_end) + 1);
	      }
	  }
		
	  memmove ((char *) LINUX_SETUP, buffer, data_len + SECTOR_SIZE);

	  /* copy command-line plus memory hack to staging area */
	  {
	    char *src = arg;
	    char *dest = (char *) CL_MY_LOCATION;

	    *((unsigned short *) CL_OFFSET) = CL_MY_LOCATION - CL_BASE_ADDR;
	    *((unsigned short *) CL_MAGIC_ADDR) = CL_MAGIC;

	    /* Help Linux to find memory only if more than 64MB are present.
	       Up to that amount it is fairly capable to find by itself, 
	       and at least newer Phoenix BIOSes are known to put a
	       10k hole just before 64MB, but report a proper total.  */
	    if (mbi.mem_upper + 0x400 > 0x10000)
	      {
		grub_memmove ((char *) CL_MY_LOCATION, "mem=", 4);
		dest = (char *) (CL_MY_LOCATION + 4);
		
		dest = convert_to_ascii (dest, 'u', (mbi.mem_upper + 0x400));
		*(dest++) = 'K';
		*(dest++) = ' ';
	      }

	    while (*src && *src != ' ')
	      src++;

	    while (((int) dest) < CL_MY_END_ADDR && (*(dest++) = *(src++)));

	    *dest = 0;
	  }

	  /* offset into file */
	  grub_seek (data_len + SECTOR_SIZE);

	  cur_addr = LINUX_STAGING_AREA + text_len;
	  if (grub_read ((char *) LINUX_STAGING_AREA, text_len)
	      >= (text_len - 16))
	    {
	      grub_close ();

	      /* Sanity check.  */
	      if (suggested_type != KERNEL_TYPE_NONE
		  && ((big_linux && suggested_type != KERNEL_TYPE_BIG_LINUX)
		      || (! big_linux && suggested_type != KERNEL_TYPE_LINUX)))
		{
		  errnum = ERR_EXEC_FORMAT;
		  return KERNEL_TYPE_NONE;
		}
	      
	      return big_linux ? KERNEL_TYPE_BIG_LINUX : KERNEL_TYPE_LINUX;
	    }
	  else if (!errnum)
	    errnum = ERR_EXEC_FORMAT;
	}
      else
	errnum = ERR_WONT_FIT;
    }
  else				/* no recognizable format */
    errnum = ERR_EXEC_FORMAT;

  /* return if error */
  if (errnum)
    {
      grub_close ();
      return KERNEL_TYPE_NONE;
    }

  /* fill the multiboot info structure */
  mbi.cmdline = (int) arg;
  mbi.mods_count = 0;
  mbi.mods_addr = 0;
  mbi.boot_device = (current_drive << 24) | current_partition;
  mbi.flags &= ~(MB_INFO_MODS | MB_INFO_AOUT_SYMS | MB_INFO_ELF_SHDR);
  mbi.syms.a.tabsize = 0;
  mbi.syms.a.strsize = 0;
  mbi.syms.a.addr = 0;
  mbi.syms.a.pad = 0;

  printf ("   [%s-%s", str2, str);

  str = "";

  if (exec_type)		/* can be loaded like a.out */
    {
      if (flags & MULTIBOOT_AOUT_KLUDGE)
	str = "-and-data";

      printf (", loadaddr=0x%x, text%s=0x%x", cur_addr, str, text_len);

      /* read text, then read data */
      if (grub_read ((char *) RAW_ADDR (cur_addr), text_len) == text_len)
	{
	  cur_addr += text_len;

	  if (!(flags & MULTIBOOT_AOUT_KLUDGE))
	    {
	      /* we have to align to a 4K boundary */
	      if (align_4k)
		cur_addr = (cur_addr + 0xFFF) & 0xFFFFF000;
	      else
		printf (", C");

	      printf (", data=0x%x", data_len);

	      if ((grub_read ((char *) RAW_ADDR (cur_addr), data_len)
		   != data_len)
		  && !errnum)
		errnum = ERR_EXEC_FORMAT;
	      cur_addr += data_len;
	    }

	  if (!errnum)
	    {
	      memset ((char *) RAW_ADDR (cur_addr), 0, bss_len);
	      cur_addr += bss_len;

	      printf (", bss=0x%x", bss_len);
	    }
	}
      else if (!errnum)
	errnum = ERR_EXEC_FORMAT;

      if (!errnum && pu.aout->a_syms
	  && pu.aout->a_syms < (filemax - filepos))
	{
	  int symtab_err, orig_addr = cur_addr;

	  /* we should align to a 4K boundary here for good measure */
	  if (align_4k)
	    cur_addr = (cur_addr + 0xFFF) & 0xFFFFF000;

	  mbi.syms.a.addr = cur_addr;

	  *((int *) RAW_ADDR (cur_addr)) = pu.aout->a_syms;
	  cur_addr += sizeof (int);
	  
	  printf (", symtab=0x%x", pu.aout->a_syms);

	  if (grub_read ((char *) RAW_ADDR (cur_addr), pu.aout->a_syms)
	      == pu.aout->a_syms)
	    {
	      cur_addr += pu.aout->a_syms;
	      mbi.syms.a.tabsize = pu.aout->a_syms;

	      if (grub_read ((char *) &i, sizeof (int)) == sizeof (int))
		{
		  *((int *) RAW_ADDR (cur_addr)) = i;
		  cur_addr += sizeof (int);

		  mbi.syms.a.strsize = i;

		  i -= sizeof (int);

		  printf (", strtab=0x%x", i);

		  symtab_err = (grub_read ((char *) RAW_ADDR (cur_addr), i)
				!= i);
		  cur_addr += i;
		}
	      else
		symtab_err = 1;
	    }
	  else
	    symtab_err = 1;

	  if (symtab_err)
	    {
	      printf ("(bad)");
	      cur_addr = orig_addr;
	      mbi.syms.a.tabsize = 0;
	      mbi.syms.a.strsize = 0;
	      mbi.syms.a.addr = 0;
	    }
	  else
	    mbi.flags |= MB_INFO_AOUT_SYMS;
	}
    }
  else
    /* ELF executable */
    {
      int loaded = 0, memaddr, memsiz, filesiz;
      Elf32_Phdr *phdr;

      /* reset this to zero for now */
      cur_addr = 0;

      /* scan for program segments */
      for (i = 0; i < pu.elf->e_phnum; i++)
	{
	  phdr = (Elf32_Phdr *)
	    (pu.elf->e_phoff + ((int) buffer)
	     + (pu.elf->e_phentsize * i));
	  if (phdr->p_type == PT_LOAD)
	    {
	      /* offset into file */
	      grub_seek (phdr->p_offset);
	      filesiz = phdr->p_filesz;
	      
	      if (type == KERNEL_TYPE_FREEBSD || type == KERNEL_TYPE_NETBSD)
		memaddr = RAW_ADDR (phdr->p_paddr & 0xFFFFFF);
	      else
		memaddr = RAW_ADDR (phdr->p_paddr);
	      
	      memsiz = phdr->p_memsz;
	      if (memaddr < RAW_ADDR (0x100000))
		errnum = ERR_BELOW_1MB;
	      /* make sure we only load what we're supposed to! */
	      if (filesiz > memsiz)
		filesiz = memsiz;
	      /* mark memory as used */
	      if (cur_addr < memaddr + memsiz)
		cur_addr = memaddr + memsiz;
	      printf (", <0x%x:0x%x:0x%x>", memaddr, filesiz,
		      memsiz - filesiz);
	      /* increment number of segments */
	      loaded++;

	      /* load the segment */
	      if (memcheck (memaddr, memsiz)
		  && grub_read ((char *) memaddr, filesiz) == filesiz)
		{
		  if (memsiz > filesiz)
		    memset ((char *) (memaddr + filesiz), 0, memsiz - filesiz);
		}
	      else
		break;
	    }
	}

      if (!errnum)
	{
	  if (!loaded)
	    errnum = ERR_EXEC_FORMAT;
	  else
	    {
	      /* FIXME: load ELF symbols */
	    }
	}
    }

  if (!errnum)
    printf (", entry=0x%x]\n", (int) entry_addr);
  else
    {
      putchar ('\n');
      type = KERNEL_TYPE_NONE;
    }

  grub_close ();

  /* Sanity check.  */
  if (suggested_type != KERNEL_TYPE_NONE && suggested_type != type)
    {
      errnum = ERR_EXEC_FORMAT;
      return KERNEL_TYPE_NONE;
    }
  
  return type;
}

int
load_module (char *module, char *arg)
{
  int len;

  /* if we are supposed to load on 4K boundaries */
  cur_addr = (cur_addr + 0xFFF) & 0xFFFFF000;

  if (!grub_open (module))
    return 0;

  len = grub_read ((char *) cur_addr, -1);
  if (! len)
    {
      grub_close ();
      return 0;
    }

  printf ("   [Multiboot-module @ 0x%x, 0x%x bytes]\n", cur_addr, len);

  /* these two simply need to be set if any modules are loaded at all */
  mbi.flags |= MB_INFO_MODS;
  mbi.mods_addr = (int) mll;

  mll[mbi.mods_count].cmdline = (int) arg;
  mll[mbi.mods_count].mod_start = cur_addr;
  cur_addr += len;
  mll[mbi.mods_count].mod_end = cur_addr;
  mll[mbi.mods_count].pad = 0;

  /* increment number of modules included */
  mbi.mods_count++;

  grub_close ();
  return 1;
}

int
load_initrd (char *initrd)
{
  int len;
  unsigned long *ramdisk, moveto;

  if (! grub_open (initrd))
    return 0;

  len = grub_read ((char *) cur_addr, -1);
  if (! len)
    {
      grub_close ();
      return 0;
    }

  moveto = ((mbi.mem_upper + 0x400) * 0x400 - len) & 0x3ffff000;
  /* XXX: Linux 2.3.xx has a bug in the memory range check, so avoid
     the last page.  */
  moveto -= 0x1000;
  memmove ((void *) RAW_ADDR (moveto), (void *) cur_addr, len);

  printf ("   [Linux-initrd @ 0x%x, 0x%x bytes]\n", moveto, len);

  ramdisk = (unsigned long *) (LINUX_SETUP + LINUX_SETUP_INITRD);
  ramdisk[0] = RAW_ADDR (moveto);
  ramdisk[1] = len;

  grub_close ();
  return 1;
}


#ifdef GRUB_UTIL
/* Dummy function to fake the *BSD boot.  */
static void
bsd_boot_entry (int flags, int bootdev, int sym_start, int sym_end,
		int mem_upper, int mem_lower)
{
  stop ();
}
#endif


/*
 *  All "*_boot" commands depend on the images being loaded into memory
 *  correctly, the variables in this file being set up correctly, and
 *  the root partition being set in the 'saved_drive' and 'saved_partition'
 *  variables.
 */


void
bsd_boot (kernel_t type, int bootdev, char *arg)
{
  char *str;
  int clval = 0, i;
  struct bootinfo bi;

#ifdef GRUB_UTIL
  entry_addr = (entry_func) bsd_boot_entry;
#else
  stop_floppy ();
#endif

  while (*(++arg) && *arg != ' ');
  str = arg;
  while (*str)
    {
      if (*str == '-')
	{
	  while (*str && *str != ' ')
	    {
	      if (*str == 'C')
		clval |= RB_CDROM;
	      if (*str == 'a')
		clval |= RB_ASKNAME;
	      if (*str == 'b')
		clval |= RB_HALT;
	      if (*str == 'c')
		clval |= RB_CONFIG;
	      if (*str == 'd')
		clval |= RB_KDB;
	      if (*str == 'h')
		clval |= RB_SERIAL;
	      if (*str == 'r')
		clval |= RB_DFLTROOT;
	      if (*str == 's')
		clval |= RB_SINGLE;
	      if (*str == 'v')
		clval |= RB_VERBOSE;
	      str++;
	    }
	  continue;
	}
      str++;
    }

  if (type == KERNEL_TYPE_FREEBSD)
    {
      clval |= RB_BOOTINFO;

      bi.bi_version = BOOTINFO_VERSION;

      *arg = 0;
      while ((--arg) > (char *) MB_CMDLINE_BUF && *arg != '/');
      if (*arg == '/')
	bi.bi_kernelname = arg + 1;
      else
	bi.bi_kernelname = 0;

      bi.bi_nfs_diskless = 0;
      bi.bi_n_bios_used = 0;	/* this field is apparently unused */

      for (i = 0; i < N_BIOS_GEOM; i++)
	{
	  struct geometry geom;

	  /* XXX Should check the return value.  */
	  get_diskinfo (i + 0x80, &geom);
	  /* FIXME: If HEADS or SECTORS is greater than 255, then this will
	     break the geometry information. That is a drawback of BSD
	     but not of GRUB.  */
	  bi.bi_bios_geom[i] = (((geom.cylinders - 1) << 16)
				+ (((geom.heads - 1) & 0xff) << 8)
				+ (geom.sectors & 0xff));
	}

      bi.bi_size = sizeof (struct bootinfo);
      bi.bi_memsizes_valid = 1;
      bi.bi_bios_dev = saved_drive;
      bi.bi_basemem = mbi.mem_lower;
      bi.bi_extmem = mbi.mem_upper;

      if (mbi.flags & MB_INFO_AOUT_SYMS)
	{
	  bi.bi_symtab = mbi.syms.a.addr;
	  bi.bi_esymtab = mbi.syms.a.addr + 4
	    + mbi.syms.a.tabsize + mbi.syms.a.strsize;
	}
#if 0
      else if (mbi.flags & MB_INFO_ELF_SHDR)
	{
	  /* FIXME: Should check if a symbol table exists and, if exists,
	     pass the table to BI.  */
	}
#endif
      else
	{
	  bi.bi_symtab = 0;
	  bi.bi_esymtab = 0;
	}

      /* call entry point */
      (*entry_addr) (clval, bootdev, 0, 0, 0, ((int) (&bi)));
    }
  else
    {
      /*
       *  We now pass the various bootstrap parameters to the loaded
       *  image via the argument list.
       *
       *  This is the official list:
       *
       *  arg0 = 8 (magic)
       *  arg1 = boot flags
       *  arg2 = boot device
       *  arg3 = start of symbol table (0 if not loaded)
       *  arg4 = end of symbol table (0 if not loaded)
       *  arg5 = transfer address from image
       *  arg6 = transfer address for next image pointer
       *  arg7 = conventional memory size (640)
       *  arg8 = extended memory size (8196)
       *
       *  ...in actuality, we just pass the parameters used by the kernel.
       */

      /* call entry point */
      unsigned long end_mark;

      if (mbi.flags & MB_INFO_AOUT_SYMS)
	end_mark = (mbi.syms.a.addr + 4
		    + mbi.syms.a.tabsize + mbi.syms.a.strsize);
      else
	/* FIXME: it should be mbi.syms.e.size.  */
	end_mark = 0;
      
      (*entry_addr) (clval, bootdev, 0, end_mark,
		     mbi.mem_upper, mbi.mem_lower);
    }
}