1/* common.c - miscellaneous shared variables and routines */
2/*
3 *  GRUB  --  GRand Unified Bootloader
4 *  Copyright (C) 1999,2000,2001,2002,2004  Free Software Foundation, Inc.
5 *
6 *  This program is free software; you can redistribute it and/or modify
7 *  it under the terms of the GNU General Public License as published by
8 *  the Free Software Foundation; either version 2 of the License, or
9 *  (at your option) any later version.
10 *
11 *  This program is distributed in the hope that it will be useful,
12 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 *  GNU General Public License for more details.
15 *
16 *  You should have received a copy of the GNU General Public License
17 *  along with this program; if not, write to the Free Software
18 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20
21#include <shared.h>
22
23#ifdef SUPPORT_DISKLESS
24# define GRUB	1
25# include <etherboot.h>
26#endif
27
28/*
29 *  Shared BIOS/boot data.
30 */
31
32struct multiboot_info mbi;
33unsigned long saved_drive;
34unsigned long saved_partition;
35unsigned long cdrom_drive;
36#ifndef STAGE1_5
37unsigned long saved_mem_upper;
38
39/* This saves the maximum size of extended memory (in KB).  */
40unsigned long extended_memory;
41#endif
42
43/*
44 *  Error code stuff.
45 */
46
47grub_error_t errnum = ERR_NONE;
48
49#ifndef STAGE1_5
50
51char *err_list[] =
52{
53  [ERR_NONE] = 0,
54  [ERR_BAD_ARGUMENT] = "Invalid argument",
55  [ERR_BAD_FILENAME] =
56  "Filename must be either an absolute pathname or blocklist",
57  [ERR_BAD_FILETYPE] = "Bad file or directory type",
58  [ERR_BAD_GZIP_DATA] = "Bad or corrupt data while decompressing file",
59  [ERR_BAD_GZIP_HEADER] = "Bad or incompatible header in compressed file",
60  [ERR_BAD_PART_TABLE] = "Partition table invalid or corrupt",
61  [ERR_BAD_VERSION] = "Mismatched or corrupt version of stage1/stage2",
62  [ERR_BELOW_1MB] = "Loading below 1MB is not supported",
63  [ERR_BOOT_COMMAND] = "Kernel must be loaded before booting",
64  [ERR_BOOT_FAILURE] = "Unknown boot failure",
65  [ERR_BOOT_FEATURES] = "Unsupported Multiboot features requested",
66  [ERR_DEV_FORMAT] = "Unrecognized device string",
67  [ERR_DEV_NEED_INIT] = "Device not initialized yet",
68  [ERR_DEV_VALUES] = "Invalid device requested",
69  [ERR_EXEC_FORMAT] = "Invalid or unsupported executable format",
70  [ERR_FILELENGTH] =
71  "Filesystem compatibility error, cannot read whole file",
72  [ERR_FILE_NOT_FOUND] = "File not found",
73  [ERR_FSYS_CORRUPT] = "Inconsistent filesystem structure",
74  [ERR_FSYS_MOUNT] = "Cannot mount selected partition",
75  [ERR_GEOM] = "Selected cylinder exceeds maximum supported by BIOS",
76  [ERR_NEED_LX_KERNEL] = "Linux kernel must be loaded before initrd",
77  [ERR_NEED_MB_KERNEL] = "Multiboot kernel must be loaded before modules",
78  [ERR_NO_DISK] = "Selected disk does not exist",
79  [ERR_NO_DISK_SPACE] = "No spare sectors on the disk",
80  [ERR_NO_PART] = "No such partition",
81  [ERR_NUMBER_OVERFLOW] = "Overflow while parsing number",
82  [ERR_NUMBER_PARSING] = "Error while parsing number",
83  [ERR_OUTSIDE_PART] = "Attempt to access block outside partition",
84  [ERR_PRIVILEGED] = "Must be authenticated",
85  [ERR_READ] = "Disk read error",
86  [ERR_SYMLINK_LOOP] = "Too many symbolic links",
87  [ERR_UNALIGNED] = "File is not sector aligned",
88  [ERR_UNRECOGNIZED] = "Unrecognized command",
89  [ERR_WONT_FIT] = "Selected item cannot fit into memory",
90  [ERR_WRITE] = "Disk write error",
91};
92
93
94/* static for BIOS memory map fakery */
95static struct AddrRangeDesc fakemap[3] =
96{
97  {20, 0, 0, MB_ARD_MEMORY},
98  {20, 0x100000, 0, MB_ARD_MEMORY},
99  {20, 0x1000000, 0, MB_ARD_MEMORY}
100};
101
102/* A big problem is that the memory areas aren't guaranteed to be:
103   (1) contiguous, (2) sorted in ascending order, or (3) non-overlapping.
104   Thus this kludge.  */
105static unsigned long
106mmap_avail_at (unsigned long bottom)
107{
108  unsigned long long top;
109  unsigned long addr;
110  int cont;
111
112  top = bottom;
113  do
114    {
115      for (cont = 0, addr = mbi.mmap_addr;
116	   addr < mbi.mmap_addr + mbi.mmap_length;
117	   addr += *((unsigned long *) addr) + 4)
118	{
119	  struct AddrRangeDesc *desc = (struct AddrRangeDesc *) addr;
120
121	  if (desc->Type == MB_ARD_MEMORY
122	      && desc->BaseAddr <= top
123	      && desc->BaseAddr + desc->Length > top)
124	    {
125	      top = desc->BaseAddr + desc->Length;
126	      cont++;
127	    }
128	}
129    }
130  while (cont);
131
132  /* For now, GRUB assumes 32bits addresses, so...  */
133  if (top > 0xFFFFFFFF)
134    top = 0xFFFFFFFF;
135
136  return (unsigned long) top - bottom;
137}
138#endif /* ! STAGE1_5 */
139
140/* This queries for BIOS information.  */
141void
142init_bios_info (void)
143{
144#ifndef STAGE1_5
145  unsigned long cont, memtmp, addr;
146  int drive;
147#endif
148
149  /*
150   *  Get information from BIOS on installed RAM.
151   */
152
153  mbi.mem_lower = get_memsize (0);
154  mbi.mem_upper = get_memsize (1);
155
156#ifndef STAGE1_5
157  /*
158   *  We need to call this somewhere before trying to put data
159   *  above 1 MB, since without calling it, address line 20 will be wired
160   *  to 0.  Not too desirable.
161   */
162
163  gateA20 (1);
164
165  /* Store the size of extended memory in EXTENDED_MEMORY, in order to
166     tell it to non-Multiboot OSes.  */
167  extended_memory = mbi.mem_upper;
168
169  /*
170   *  The "mbi.mem_upper" variable only recognizes upper memory in the
171   *  first memory region.  If there are multiple memory regions,
172   *  the rest are reported to a Multiboot-compliant OS, but otherwise
173   *  unused by GRUB.
174   */
175
176  addr = get_code_end ();
177  mbi.mmap_addr = addr;
178  mbi.mmap_length = 0;
179  cont = 0;
180
181  do
182    {
183      cont = get_mmap_entry ((void *) addr, cont);
184
185      /* If the returned buffer's length is zero, quit. */
186      if (! *((unsigned long *) addr))
187	break;
188
189      mbi.mmap_length += *((unsigned long *) addr) + 4;
190      addr += *((unsigned long *) addr) + 4;
191    }
192  while (cont);
193
194  if (mbi.mmap_length)
195    {
196      unsigned long long max_addr;
197
198      /*
199       *  This is to get the lower memory, and upper memory (up to the
200       *  first memory hole), into the "mbi.mem_{lower,upper}"
201       *  elements.  This is for OS's that don't care about the memory
202       *  map, but might care about total RAM available.
203       */
204      mbi.mem_lower = mmap_avail_at (0) >> 10;
205      mbi.mem_upper = mmap_avail_at (0x100000) >> 10;
206
207      /* Find the maximum available address. Ignore any memory holes.  */
208      for (max_addr = 0, addr = mbi.mmap_addr;
209	   addr < mbi.mmap_addr + mbi.mmap_length;
210	   addr += *((unsigned long *) addr) + 4)
211	{
212	  struct AddrRangeDesc *desc = (struct AddrRangeDesc *) addr;
213
214	  if (desc->Type == MB_ARD_MEMORY && desc->Length > 0
215	      && desc->BaseAddr + desc->Length > max_addr)
216	    max_addr = desc->BaseAddr + desc->Length;
217	}
218
219      extended_memory = (max_addr - 0x100000) >> 10;
220    }
221  else if ((memtmp = get_eisamemsize ()) != -1)
222    {
223      cont = memtmp & ~0xFFFF;
224      memtmp = memtmp & 0xFFFF;
225
226      if (cont != 0)
227	extended_memory = (cont >> 10) + 0x3c00;
228      else
229	extended_memory = memtmp;
230
231      if (!cont || (memtmp == 0x3c00))
232	memtmp += (cont >> 10);
233      else
234	{
235	  /* XXX should I do this at all ??? */
236
237	  mbi.mmap_addr = (unsigned long) fakemap;
238	  mbi.mmap_length = sizeof (fakemap);
239	  fakemap[0].Length = (mbi.mem_lower << 10);
240	  fakemap[1].Length = (memtmp << 10);
241	  fakemap[2].Length = cont;
242	}
243
244      mbi.mem_upper = memtmp;
245    }
246
247  saved_mem_upper = mbi.mem_upper;
248
249  /* Get the drive info.  */
250  /* FIXME: This should be postponed until a Multiboot kernel actually
251     requires it, because this could slow down the start-up
252     unreasonably.  */
253  mbi.drives_length = 0;
254  mbi.drives_addr = addr;
255
256  /* For now, GRUB doesn't probe floppies, since it is trivial to map
257     floppy drives to BIOS drives.  */
258  for (drive = 0x80; drive < 0x88; drive++)
259    {
260      struct geometry geom;
261      struct drive_info *info = (struct drive_info *) addr;
262      unsigned short *port;
263
264      /* Get the geometry. This ensures that the drive is present.  */
265      if (get_diskinfo (drive, &geom))
266	break;
267
268      /* Clean out the I/O map.  */
269      grub_memset ((char *) io_map, 0,
270		   IO_MAP_SIZE * sizeof (unsigned short));
271
272      /* Disable to probe I/O ports temporarily, because this doesn't
273	 work with some BIOSes (maybe they are too buggy).  */
274#if 0
275      /* Track the int13 handler.  */
276      track_int13 (drive);
277#endif
278
279      /* Set the information.  */
280      info->drive_number = drive;
281      info->drive_mode = ((geom.flags & BIOSDISK_FLAG_LBA_EXTENSION)
282			  ? MB_DI_LBA_MODE : MB_DI_CHS_MODE);
283      info->drive_cylinders = geom.cylinders;
284      info->drive_heads = geom.heads;
285      info->drive_sectors = geom.sectors;
286
287      addr += sizeof (struct drive_info);
288      for (port = io_map; *port; port++, addr += sizeof (unsigned short))
289	*((unsigned short *) addr) = *port;
290
291      info->size = addr - (unsigned long) info;
292      mbi.drives_length += info->size;
293    }
294
295  /* Get the ROM configuration table by INT 15, AH=C0h.  */
296  mbi.config_table = get_rom_config_table ();
297
298  /* Set the boot loader name.  */
299  mbi.boot_loader_name = (unsigned long) "GNU GRUB " VERSION;
300
301  /* Get the APM BIOS table.  */
302  get_apm_info ();
303  if (apm_bios_info.version)
304    mbi.apm_table = (unsigned long) &apm_bios_info;
305
306  /*
307   *  Initialize other Multiboot Info flags.
308   */
309
310  mbi.flags = (MB_INFO_MEMORY | MB_INFO_CMDLINE | MB_INFO_BOOTDEV
311	       | MB_INFO_DRIVE_INFO | MB_INFO_CONFIG_TABLE
312	       | MB_INFO_BOOT_LOADER_NAME);
313
314  if (apm_bios_info.version)
315    mbi.flags |= MB_INFO_APM_TABLE;
316
317#endif /* STAGE1_5 */
318
319  /* Set boot drive and partition.  */
320  saved_drive = boot_drive;
321  saved_partition = install_partition;
322
323  /* Set cdrom drive.  */
324  {
325    struct geometry geom;
326
327    /* Get the geometry.  */
328    if (get_diskinfo (boot_drive, &geom)
329	|| ! (geom.flags & BIOSDISK_FLAG_CDROM))
330      cdrom_drive = GRUB_INVALID_DRIVE;
331    else
332      cdrom_drive = boot_drive;
333  }
334
335  /* Start main routine here.  */
336  cmain ();
337}
338