Initial revision

disk/i386/pc/partition.c

@@ -0,0 +1,248 @@
+/*
+ *  PUPA  --  Preliminary Universal Programming Architecture for GRUB
+ *  Copyright (C) 2002 Yoshinori K. Okuji <okuji@enbug.org>
+ *
+ *  PUPA 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 PUPA; if not, write to the Free Software
+ *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <pupa/machine/partition.h>
+#include <pupa/disk.h>
+#include <pupa/mm.h>
+#include <pupa/misc.h>
+
+/* Parse the partition representation in STR and return a partition.  */
+static pupa_partition_t
+pupa_partition_parse (const char *str)
+{
+  pupa_partition_t p;
+  char *s = (char *) str;
+  
+  p = (pupa_partition_t) pupa_malloc (sizeof (*p));
+  if (! p)
+    return 0;
+
+  /* Initialize some of the fields with invalid values.  */
+  p->bsd_part = p->dos_type = p->bsd_type = p->index = -1;
+
+  /* Get the DOS partition number.  */
+  p->dos_part = pupa_strtoul (s, &s, 0);
+  
+  if (pupa_errno)
+    {
+      /* Not found. Maybe only a BSD label is specified.  */
+      p->dos_part = -1;
+      pupa_errno = PUPA_ERR_NONE;
+    }
+  else if (*s == ',')
+    s++;
+
+  if (*s)
+    {
+      if (*s >= 'a' && *s <= 'h')
+	{
+	  p->bsd_part = *s - 'a';
+	  s++;
+	}
+
+      if (*s)
+	goto fail;
+    }
+
+  if (p->dos_part == -1 && p->bsd_part == -1)
+    goto fail;
+
+  return p;
+  
+ fail:
+  pupa_free (p);
+  pupa_error (PUPA_ERR_BAD_FILENAME, "invalid partition");
+  return 0;
+}
+
+pupa_err_t
+pupa_partition_iterate (pupa_disk_t disk,
+			int (*hook) (const pupa_partition_t partition))
+{
+  struct pupa_partition p;
+  struct pupa_partition_mbr mbr;
+  struct pupa_partition_disk_label label;
+  struct pupa_disk raw;
+
+  /* Enforce raw disk access.  */
+  raw = *disk;
+  raw.partition = 0;
+  
+  p.offset = 0;
+  p.ext_offset = 0;
+  p.dos_part = -1;
+  
+  while (1)
+    {
+      int i;
+      struct pupa_partition_entry *e;
+      
+      /* Read the MBR.  */
+      if (pupa_disk_read (&raw, p.offset, 0, sizeof (mbr), (char *) &mbr))
+	goto finish;
+
+      /* Check if it is valid.  */
+      if (mbr.signature != pupa_cpu_to_le16 (PUPA_PARTITION_SIGNATURE))
+	return pupa_error (PUPA_ERR_BAD_PART_TABLE, "no signature");
+
+      /* Analyze DOS partitions.  */
+      for (p.index = 0; p.index < 4; p.index++)
+	{
+	  e = mbr.entries + p.index;
+	  
+	  p.start = p.offset + pupa_le_to_cpu32 (e->start);
+	  p.len = pupa_le_to_cpu32 (e->length);
+	  p.bsd_part = -1;
+	  p.dos_type = e->type;
+	  p.bsd_type = -1;
+
+	  /* If this partition is a normal one, call the hook.  */
+	  if (! pupa_partition_is_empty (e->type)
+	      && ! pupa_partition_is_extended (e->type))
+	    {
+	      p.dos_part++;
+	      
+	      if (hook (&p))
+		goto finish;
+
+	      /* Check if this is a BSD partition.  */
+	      if (pupa_partition_is_bsd (e->type))
+		{
+		  /* Check if the BSD label is within the DOS partition.  */
+		  if (p.len <= PUPA_PARTITION_BSD_LABEL_SECTOR)
+		    return pupa_error (PUPA_ERR_BAD_PART_TABLE,
+				       "no space for disk label");
+
+		  /* Read the BSD label.  */
+		  if (pupa_disk_read (&raw,
+				      (p.start
+				       + PUPA_PARTITION_BSD_LABEL_SECTOR),
+				      0,
+				      sizeof (label),
+				      (char *) &label))
+		    goto finish;
+
+		  /* Check if it is valid.  */
+		  if (label.magic
+		      != pupa_cpu_to_le32 (PUPA_PARTITION_BSD_LABEL_MAGIC))
+		    return pupa_error (PUPA_ERR_BAD_PART_TABLE,
+				       "invalid disk label magic");
+
+		  for (p.bsd_part = 0;
+		       p.bsd_part < pupa_cpu_to_le16 (label.num_partitions);
+		       p.bsd_part++)
+		    {
+		      struct pupa_partition_bsd_entry *be
+			= label.entries + p.bsd_part;
+
+		      p.start = pupa_le_to_cpu32 (be->offset);
+		      p.len = pupa_le_to_cpu32 (be->size);
+		      p.bsd_type = be->fs_type;
+		      
+		      if (be->fs_type != PUPA_PARTITION_BSD_TYPE_UNUSED)
+			if (hook (&p))
+			  goto finish;
+		    }
+		}
+	    }
+	  else if (p.dos_part < 4)
+	    /* If this partition is a logical one, shouldn't increase the
+	       partition number.  */
+	    p.dos_part++;
+	}
+
+      /* Find an extended partition.  */
+      for (i = 0; i < 4; i++)
+	{
+	  e = mbr.entries + i;
+	  
+	  if (pupa_partition_is_extended (e->type))
+	    {
+	      p.offset = p.ext_offset + pupa_le_to_cpu32 (e->start);
+	      if (! p.ext_offset)
+		p.ext_offset = p.offset;
+
+	      break;
+	    }
+	}
+
+      /* If no extended partition, the end.  */
+      if (i == 4)
+	break;
+    }
+
+ finish:
+  return pupa_errno;
+}
+
+pupa_partition_t
+pupa_partition_probe (pupa_disk_t disk, const char *str)
+{
+  pupa_partition_t p;
+  auto int find_func (const pupa_partition_t partition);
+
+  int find_func (const pupa_partition_t partition)
+    {
+      if ((p->dos_part == partition->dos_part || p->dos_part == -1)
+	  && p->bsd_part == partition->bsd_part)
+	{
+	  pupa_memcpy (p, partition, sizeof (*p));
+	  return 1;
+	}
+      
+      return 0;
+    }
+  
+  p = pupa_partition_parse (str);
+  if (! p)
+    return 0;
+
+
+  if (pupa_partition_iterate (disk, find_func))
+    goto fail;
+
+  if (p->index < 0)
+    {
+      pupa_error (PUPA_ERR_BAD_DEVICE, "no such partition");
+      goto fail;
+    }
+
+  return p;
+
+ fail:
+  pupa_free (p);
+  return 0;
+}
+
+char *
+pupa_partition_get_name (const pupa_partition_t p)
+{
+  char *name;
+
+  name = pupa_malloc (13);
+  if (! name)
+    return 0;
+
+  if (p->bsd_part < 0)
+    pupa_sprintf (name, "%d", p->dos_part);
+  else
+    pupa_sprintf (name, "%d,%c", p->dos_part, p->bsd_part + 'a');
+
+  return name;
+}