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Mail Archives: djgpp-workers/1999/01/20/15:19:01

From: Martin Str|mberg <ams AT ludd DOT luth DOT se>
Message-Id: <199901202018.VAA21696@father.ludd.luth.se>
Subject: FAT32 step 1
To: djgpp-workers AT delorie DOT com (DJGPP-WORKERS)
Date: Wed, 20 Jan 1999 21:18:33 +0100 (MET)
X-Mailer: ELM [version 2.4ME+ PL15 (25)]
MIME-Version: 1.0
Reply-To: djgpp-workers AT delorie DOT com

Here is a patch I call FAT32 step 1. It lays the foundation to build
on. It breaks out three functions from mntent.c and adds three, which
will be useful.
It compiles, however _is_fat32() is actually untested. The three from
mntent.c did work fine there so they ought to be good now. The two
_get_*() is tested but outside of libc.

Right,

							MartinS
diff -ruN include.org/dos.h include/dos.h
--- include.org/dos.h	Mon Sep  7 18:55:40 1998
+++ include/dos.h	Tue Jan 19 21:08:06 1999
@@ -134,6 +134,12 @@
 
 unsigned short _get_dos_version(int);
 
+int _get_fat_size(const int drive);
+int _get_fs_type(const int drive, char *const result_str);
+int _is_cdrom_drive(const int drive);
+int _is_fat32(const int drive);
+int _is_ram_drive(const int drive);
+int _media_type(const int drive);
 
 int int86(int ivec, union REGS *in, union REGS *out);
 int int86x(int ivec, union REGS *in, union REGS *out, struct SREGS *seg);
diff -ruN src.org/libc/compat/mntent/mntent.c src/libc/compat/mntent/mntent.c
--- src.org/libc/compat/mntent/mntent.c	Sun Nov 15 14:20:56 1998
+++ src/libc/compat/mntent/mntent.c	Sun Jan 17 21:51:34 1999
@@ -368,26 +368,6 @@
 }
 
 /*
- * Return 1 if this drive is a CD-ROM drive, 0 otherwise.  Works
- * with MSCDEX 2.x, but what about other CD-ROM device drivers?
- */
-static int
-is_cdrom_drive(int drive_num)
-{
-  __dpmi_regs r;
-
-  r.x.ax = 0x150b;      /* CD-ROM Drive Check function */
-  r.x.cx = drive_num - 1; /* 0 = A: */
-  __dpmi_int(0x2f, &r);
-
-  /* If MSCDEX installed, BX will hold ADADh; AX will be non-zero
-     if this drive is supported by MSCDEX.  */
-  if (r.x.bx == 0xadad && r.x.ax != 0)
-    return 1;
-  return 0;
-}
-
-/*
  * Return 1 if a CD-ROM drive DRIVE_NUM is ready, i.e. there
  * is a disk in the drive and the tray door is closed.
  */
@@ -445,51 +425,6 @@
   return 0;
 }
 
-/*
- * Detect a RAM disk.  We do this by checking if the number of FAT
- * copies (in the Device Parameter Block) is 1, which is typical of
- * RAM disks.  [This doesn't _have_ to be so, but if it's good
- * enough for Andrew Schulman et al (Undocumented DOS, 2nd edition),
- * we can use this as well.]
- */
-static int
-is_ram_drive(int drive_num)
-{
-  __dpmi_regs r;
-
-  r.h.ah = 0x32;        /* Get Device Parameter Block function */
-  r.h.dl = drive_num;
-  __dpmi_int(0x21, &r);
-
-  if (r.h.al == 0)
-    {
-      /* The pointer to DPB is in DS:BX.  The number of FAT copies is at
-         offset 8 in the DPB.  */
-      char fat_copies = _farpeekb(dos_mem_base, MK_FOFF(r.x.ds, r.x.bx) + 8);
-
-      return fat_copies == 1;
-    }
-  return 0;
-}
-
-/*
- * Check if the media in this disk drive is fixed or removable.
- * Should only be called after we're sure this ain't CD-ROM or
- * RAM disk, since these might fool you with this call.
- */
-static int
-media_type(int drive_num)
-{
-  __dpmi_regs r;
-
-  r.x.ax = 0x4408;
-  r.h.bl = drive_num;
-  __dpmi_int(0x21, &r);
-
-  if (r.x.flags & 1)
-    return -1;
-  return r.x.ax;    /* returns 1 for fixed disks, 0 for removable */
-}
 
 /* Exported library functions.  */
 
@@ -700,11 +635,11 @@
           */
           if (mnt_type[0] == '?')
             {
-              int disk_type = media_type(drive_number);
+              int disk_type = _media_type(drive_number);
 
-              if (is_ram_drive(drive_number))
+              if (_is_ram_drive(drive_number))
                 mnt_type = NAME_ram;
-              else if (is_cdrom_drive(drive_number))
+              else if (_is_cdrom_drive(drive_number))
 		{
 		  /* Empty CD-ROM drives do NOT fail _truename(),
 		     so we must see if there is a disk in the drive.  */
diff -ruN src.org/libc/compat/sys/vfs/statfs.c src/libc/compat/sys/vfs/statfs.c
--- src.org/libc/compat/sys/vfs/statfs.c	Sun Dec 13 13:09:46 1998
+++ src/libc/compat/sys/vfs/statfs.c	Sat Jan 16 19:00:58 1999
@@ -4,6 +4,7 @@
 #include <string.h>
 #include <dpmi.h>
 #include <go32.h>
+#include <dos.h>
 #include <libc/farptrgs.h>
 #include <errno.h>
 #include <unistd.h>
@@ -17,7 +18,9 @@
   __dpmi_regs regs;
   int drive_number;
   int cdrom_calls_used = 0;
-  int blocks = 0;
+  long blocks = 0;
+  long free = 0;
+  long bsize = 0;
 
   /* Get the drive number, including the case of magic
      names like /dev/c/foo.  */
@@ -44,7 +47,7 @@
   if ((regs.x.flags & 1) == 0 && regs.x.bx == 0xadad && regs.x.ax != 0)
   {
     unsigned char request_header[0x14];
-    int status, i = 2, bsize = 0;
+    int status, i = 2;
 
     /* Construct the request header for the CD-ROM device driver.  */
     memset (request_header, 0, sizeof request_header);
@@ -89,9 +92,8 @@
       if (_farpeekw (_dos_ds, __tb + 8) == 0x100
 	  && _farpeekw (_dos_ds, __tb + 5 + 0x12) == 5)
       {
-	regs.x.ax = 1;		/* fake: sectors per cluster */
-	regs.x.cx = bsize;
-	regs.x.bx = 0;		/* no free space: cannot add data to CD-ROM */
+	/* bsize has been set some lines above. */
+	free = 0;		/* no free space: cannot add data to CD-ROM */
 	blocks  = _farpeekl (_dos_ds, __tb + 1);
 	cdrom_calls_used = 1;
       }
@@ -100,26 +102,70 @@
 
   if (!cdrom_calls_used)
   {
-    /* Get free space info from DOS.  */
-    regs.h.ah = 0x36;		/* DOS Get Free Disk Space call */
-    regs.h.dl = drive_number + 1;
-    __dpmi_int(0x21, &regs);
+      /* Get free space info from DOS.  */
+      regs.h.ah = 0x36;		/* DOS Get Free Disk Space call */
+      regs.h.dl = drive_number + 1;
+      __dpmi_int(0x21, &regs);
 
-    /* Check for errors */
-    if ((regs.x.ax & 0xffff) == 0xffff)
+      /* Check for errors */
+      if ((regs.x.ax & 0xffff) == 0xffff)
+      {
+	errno = ENODEV;
+	return -1;
+      }
+      bsize = regs.x.cx * regs.x.ax;
+      free = regs.x.bx;
+      blocks = regs.x.dx;
+#if 0
+      printf("First: bsize = %ld, free = %ld, blocks = %ld.\n"
+	     , bsize
+	     , free
+	     , blocks
+	     );
+#endif
+
+    if( 7 <= (_get_dos_version(1) >> 8) /* Is FAT32 supported? */
+     && _is_fat32(drive_number + 1) /* Is it a FAT32 drive? */
+     && blocks <= free /* Has free maxed out? */
+	)
     {
-      errno = ENODEV;
-      return -1;
+      /* Get free space info from Extended Drive Parameter Block. */
+      regs.x.ax = 0x7302;
+      regs.h.dl = drive_number + 1;
+      regs.x.es = __tb_segment;
+      regs.x.di = __tb_offset;
+      regs.x.cx = 0x100; /* 256 bytes should be enough (RBIL says 0x3f). */
+      __dpmi_int(0x21, &regs);
+
+      /* Errors? */
+      if( regs.x.flags & 1 )
+      {
+	errno = ENODEV;
+	return( -1 );
+      }
+      
+      bsize = _farpeekw (_dos_ds, __tb + 0x2 + 0x2) * 
+	( _farpeekb (_dos_ds, __tb + 0x2 + 0x4) + 1 );
+      free = _farpeekw (_dos_ds, __tb + 0x2 + 0x1f) + 
+	65536 * _farpeekw (_dos_ds, __tb + 0x2 + 0x21);
+      blocks = _farpeekl( _dos_ds, __tb + 0x2 + 0x2d);
+#if 0	
+      printf("Second: bsize = %ld, free = %ld, blocks = %ld.\n"
+	     , bsize
+	     , free
+	     , blocks
+	     );
+#endif
+
     }
-    blocks = regs.x.dx;
   }
 
   /* Fill in the structure */
-  buf->f_bavail = regs.x.bx;
-  buf->f_bfree = regs.x.bx;
+  buf->f_bavail = free;
+  buf->f_bfree = free;
   buf->f_blocks = blocks;
-  buf->f_bsize = regs.x.cx * regs.x.ax;
-  buf->f_ffree = regs.x.bx;
+  buf->f_bsize = bsize;
+  buf->f_ffree = free;
   buf->f_files = blocks;
   buf->f_type = 0;
   buf->f_fsid[0] = drive_number;
diff -ruN src.org/libc/dos/dos/getfatsz.c src/libc/dos/dos/getfatsz.c
--- src.org/libc/dos/dos/getfatsz.c	Thu Jan  1 00:00:00 1970
+++ src/libc/dos/dos/getfatsz.c	Sat Jan  9 13:29:48 1999
@@ -0,0 +1,38 @@
+/*
+ * File getfatsz.c.
+ *
+ * Copyright (C) 1999 Martin Str”mberg <ams AT ludd DOT luth DOT se>.
+ *
+ * This software may be used freely so long as this copyright notice is
+ * left intact. There is no warranty on this software.
+ *
+ */
+
+#include <dpmi.h>
+#include <dos.h>
+
+/* Returns number of bits in FAT; 0 == FAT of unknown size; -1 == error. */
+int 
+_get_fat_size( const int drive /* drive number (1=A:). */
+	      )
+{
+  char s[9];
+  int n;
+  int size;
+
+  if( _get_fs_type( drive, s ) )
+  {
+    if( s[0] == 'F' && s[1] == 'A' && s[2] == 'T' )
+    {
+      size = 0;
+      for(n = 3; n < 8 && ( '0' <= s[n] && s[n] <= '9' ); n++)
+      {
+	size = 10*size + s[n] - '0';
+      }
+      
+      return( size );
+    }
+  }
+  
+  return( -1 );
+}
diff -ruN src.org/libc/dos/dos/getfatsz.txh src/libc/dos/dos/getfatsz.txh
--- src.org/libc/dos/dos/getfatsz.txh	Thu Jan  1 00:00:00 1970
+++ src/libc/dos/dos/getfatsz.txh	Sun Jan 10 19:00:42 1999
@@ -0,0 +1,47 @@
+@node _get_fat_size, file system
+@subheading Syntax
+
+@example
+#include <dos.h>
+
+int _get_fat_size( const int drive );
+@end example
+
+@subheading Description
+
+This function tries to determine the number bits used to enumerate the
+clusters by the FAT on drive number @var{drive}. 1 == A:, 2 == B:,
+etc. 
+
+This function will not succeed on DOS version < 4.
+
+@subheading Return Value
+
+The number of bits used by the FAT (12, 16 or 32). 0 if the drive was
+formatted with FAT but of unknown size (NT reports that on FAT16). -1
+on error. 
+
+@subheading Portability
+
+@portability !ansi, !posix
+
+@subheading Example
+
+@example
+#include <stdio.h>
+#include <dos.h>
+
+int main(void)
+@{
+  int size;
+
+  size = _get_fs_type( 'C' - 'A' + 1 );
+  if( 0 <= size )
+  @{
+    printf("The size of FAT on C: is %d bits.\n", size);
+  @}
+
+  exit(0);
+@}
+
+@end example
diff -ruN src.org/libc/dos/dos/getfstyp.c src/libc/dos/dos/getfstyp.c
--- src.org/libc/dos/dos/getfstyp.c	Thu Jan  1 00:00:00 1970
+++ src/libc/dos/dos/getfstyp.c	Sat Jan  9 13:29:04 1999
@@ -0,0 +1,58 @@
+/*
+ * File getfstyp.c.
+ *
+ * Copyright (C) 1999 Martin Str”mberg <ams AT ludd DOT luth DOT se>.
+ *
+ * This software may be used freely so long as this copyright notice is
+ * left intact. There is no warranty on this software.
+ *
+ */
+
+#include <dos.h>
+#include <go32.h>
+#include <dpmi.h>
+#include <sys/farptr.h>
+
+/* Returns: 0 == error; 1 == result_str filled in. */
+int 
+_get_fs_type( const int drive /* drive number (1=A:). */
+	    , char *const result_str  /* String to put result in. At least 9 chars long. */
+	     )
+{
+  int n;
+  __dpmi_regs r;
+
+  /* Check DOZE version and return -1 if too low. */
+  if( ( _get_dos_version(1) >> 8) < 4 )
+  {
+    return( 0 );
+  }
+
+  /* Call INT21, ax==0x6900 i.e. Get Disk Serial Number (sic!). */
+  r.x.ax = 0x6900;
+  r.h.bl = drive; 
+  r.h.bh = 0;
+  r.x.ds = __tb >> 4;
+  r.x.dx = __tb & 0x0f;
+  __dpmi_int(0x21, &r);
+  if( (r.x.flags & 1) == 0 )
+  {
+    /* Get the file system type. */
+    for(n = 0; n < 8; n++)
+    {
+      result_str[n] = _farpeekb( _dos_ds, __tb + 0x11 + n);
+    }
+    result_str[8] = 0;
+
+    /* Remove terminating spaces. */
+    for(n = 7; n && result_str[n] == ' '; n-- )
+    {
+      result_str[n] = 0;
+    }
+
+    return( 1 );
+  }
+
+  return( 0 );
+
+}
diff -ruN src.org/libc/dos/dos/getfstyp.txh src/libc/dos/dos/getfstyp.txh
--- src.org/libc/dos/dos/getfstyp.txh	Thu Jan  1 00:00:00 1970
+++ src/libc/dos/dos/getfstyp.txh	Sun Jan 10 19:00:46 1999
@@ -0,0 +1,48 @@
+@node _get_fs_type, file system
+@subheading Syntax
+
+@example
+#include <dos.h>
+
+int _get_fs_type( const int drive
+                , char *const result_str
+	         );
+@end example
+
+@subheading Description
+
+This function tries to extract the file system type of the drive
+number @var{drive}, 1 == A:, 2 == B:, etc. If successful the result
+is put in @var{result_str} which must be at least 9 characters long. 
+
+This function will not succeed on DOS version < 4 and is known to have
+trouble detecting the file system type of disks formatted with a later
+version of DOS than on the version it is run on. 
+
+@subheading Return Value
+
+1 if the file system type was extracted successfully; otherwise 0.
+
+@subheading Portability
+
+@portability !ansi, !posix
+
+@subheading Example
+
+@example
+#include <stdio.h>
+#include <dos.h>
+
+int main(void)
+@{
+  char buffer[9];
+
+  if( _get_fs_type( 3, buffer ) )
+  @{
+    printf("The file system on C: is '%s'.\n", buffer);
+  @}
+
+  exit(0);
+@}
+
+@end example
diff -ruN src.org/libc/dos/dos/iscdrom.c src/libc/dos/dos/iscdrom.c
--- src.org/libc/dos/dos/iscdrom.c	Thu Jan  1 00:00:00 1970
+++ src/libc/dos/dos/iscdrom.c	Sun Jan 17 21:08:36 1999
@@ -0,0 +1,20 @@
+/* Copyright (c) 1995-98 Eli Zaretskii <eliz AT is DOT elta DOT co DOT il> */
+
+#include <dpmi.h>
+#include <dos.h>
+
+int
+_is_cdrom_drive(int drive_num)
+{
+  __dpmi_regs r;
+
+  r.x.ax = 0x150b;      /* CD-ROM Drive Check function */
+  r.x.cx = drive_num - 1; /* 0 = A: */
+  __dpmi_int(0x2f, &r);
+
+  /* If MSCDEX installed, BX will hold ADADh; AX will be non-zero
+     if this drive is supported by MSCDEX.  */
+  if (r.x.bx == 0xadad && r.x.ax != 0)
+    return 1;
+  return 0;
+}
diff -ruN src.org/libc/dos/dos/iscdrom.txh src/libc/dos/dos/iscdrom.txh
--- src.org/libc/dos/dos/iscdrom.txh	Thu Jan  1 00:00:00 1970
+++ src/libc/dos/dos/iscdrom.txh	Sun Jan 17 19:57:10 1999
@@ -0,0 +1,45 @@
+@node _is_cdrom_drive, file system
+@subheading Syntax
+
+@example
+#include <dos.h>
+
+int _is_cdrom_drive( const int drive );
+@end example
+
+@subheading Description
+
+This function checks if drive number @var{drive} (1 == A:, 2 == B:,
+etc.) is a CD-ROM drive. Works with MSCDEX 2.x, but what about other
+CD-ROM device drivers? 
+
+@subheading Return Value
+
+1 if the drive is a CDROM drive, otherwise 0.
+
+@subheading Portability
+
+@portability !ansi, !posix
+
+@subheading Example
+
+@example
+#include <stdio.h>
+#include <dos.h>
+
+int main(void)
+@{
+
+  if( _is_cdrom_drive( 'R' - 'A' + 1 ) )
+  @{
+    printf("C: is a CDROM drive.\n");
+  @}
+  else
+  @{
+    printf("C: is not a CDROM drive.\n");
+  @}
+
+  exit(0);
+@}
+
+@end example
diff -ruN src.org/libc/dos/dos/isfat32.c src/libc/dos/dos/isfat32.c
--- src.org/libc/dos/dos/isfat32.c	Thu Jan  1 00:00:00 1970
+++ src/libc/dos/dos/isfat32.c	Sun Jan 17 21:11:56 1999
@@ -0,0 +1,76 @@
+/*
+ * This is the file isfat32.c.
+ *
+ * Copyright (C) 1999 Martin Str”mberg <ams AT ludd DOT luth DOT se>.
+ *
+ * This software may be used freely so long as this copyright notice is
+ * left intact. There is no warranty on this software.
+ *
+ */
+
+#include <dos.h>
+
+static unsigned long checked = 0;
+static unsigned long removable = 0;
+static unsigned long fat32 = 0;
+
+/* Returns 1 if the drive is formatted with FAT32; 0 otherwise. */
+int 
+_is_fat32( const int drive /* drive number (1=A:). */
+	  )
+{
+  unsigned long mask;
+
+  /* Check input. */
+  if( 0 <= drive
+   && drive <= 32
+      )
+  {
+    /* Always check current drive (as we don't know if it's been changed). */
+    if( drive == 0 )
+    {
+      return( _get_fat_size( drive ) == 32 );
+    }
+    else
+    {
+      mask = 1 << ( drive - 1 );
+
+      /* Have we checked this drive for FAT32 yet and it isn't removable? */ 
+      if( checked & mask
+       && !( removable & mask ) )
+      {
+	return( ( fat32 & mask ) != 0 );
+      }
+
+      /* Always recheck removable drives. */
+      if( removable & mask )
+      {
+	return( _get_fat_size( drive ) == 32 );
+      }
+
+      /* Previously untested drive -> update tables. */
+
+      /* Is this a removable drive? (!_is_*_drive for _media_type problems.) */
+      if( !_is_ram_drive( drive )
+       && !_is_cdrom_drive( drive )
+       && _media_type( drive ) == 0 )
+      {
+	removable |= mask;
+	checked |= mask;
+	return( _get_fat_size( drive ) == 32 );
+      }
+
+      if( _get_fat_size( drive ) == 32 )
+      {
+	fat32 |= mask;
+      }
+
+      checked |= mask;
+
+      return( ( fat32 & mask ) != 0 );
+    }
+  }
+
+  /* Drives that don't exist can't be FAT32. */
+  return( 0 );
+}
diff -ruN src.org/libc/dos/dos/isfat32.txh src/libc/dos/dos/isfat32.txh
--- src.org/libc/dos/dos/isfat32.txh	Thu Jan  1 00:00:00 1970
+++ src/libc/dos/dos/isfat32.txh	Sun Jan 17 21:04:52 1999
@@ -0,0 +1,47 @@
+@node _is_fat32, file system
+@subheading Syntax
+
+@example
+#include <dos.h>
+
+int _is_fat32( const int drive );
+@end example
+
+@subheading Description
+
+This function checks if drive number @var{drive} (1 == A:, 2 == B:,
+etc.) is formatted with FAT32. 
+
+For performance reasons the result is cached, hence if a drive is
+reformatted either from or to FAT32 a DJGPP program must be restarted.
+
+@subheading Return Value
+
+1 if the drive is formatted with FAT32, otherwise 0.
+
+@subheading Portability
+
+@portability !ansi, !posix
+
+@subheading Example
+
+@example
+#include <stdio.h>
+#include <dos.h>
+
+int main(void)
+@{
+
+  if( _is_fat32( 'C' - 'A' + 1 ) )
+  @{
+    printf("C: is a FAT32 drive.\n");
+  @}
+  else
+  @{
+    printf("C: is not a FAT32 drive.\n");
+  @}
+
+  exit(0);
+@}
+
+@end example
diff -ruN src.org/libc/dos/dos/isramdri.c src/libc/dos/dos/isramdri.c
--- src.org/libc/dos/dos/isramdri.c	Thu Jan  1 00:00:00 1970
+++ src/libc/dos/dos/isramdri.c	Sun Jan 17 21:36:10 1999
@@ -0,0 +1,33 @@
+/* Copyright (c) 1995-98 Eli Zaretskii <eliz AT is DOT elta DOT co DOT il> */
+
+#include <dpmi.h>
+#include <go32.h>
+#include <sys/farptr.h>
+#include <dos.h>
+
+/* Macro to convert a segment and an offset to a "far offset" suitable
+   for _farxxx() functions of DJGPP.  */
+#ifndef MK_FOFF
+#define MK_FOFF(s,o) ((int)((((unsigned long)(unsigned short)(s)) << 4) + \
+                      (unsigned short)(o)))
+#endif
+
+int
+_is_ram_drive(int drive_num)
+{
+  __dpmi_regs r;
+
+  r.h.ah = 0x32;        /* Get Device Parameter Block function */
+  r.h.dl = drive_num;
+  __dpmi_int(0x21, &r);
+
+  if (r.h.al == 0)
+    {
+      /* The pointer to DPB is in DS:BX.  The number of FAT copies is at
+         offset 8 in the DPB.  */
+      char fat_copies = _farpeekb(_dos_ds, MK_FOFF(r.x.ds, r.x.bx) + 8);
+
+      return fat_copies == 1;
+    }
+  return 0;
+}
diff -ruN src.org/libc/dos/dos/isramdri.txh src/libc/dos/dos/isramdri.txh
--- src.org/libc/dos/dos/isramdri.txh	Thu Jan  1 00:00:00 1970
+++ src/libc/dos/dos/isramdri.txh	Sun Jan 17 19:57:46 1999
@@ -0,0 +1,37 @@
+@node _is_ram_drive, file system
+@subheading Syntax
+
+@example
+#include <dos.h>
+
+int _is_ram_drive( const int drive );
+@end example
+
+@subheading Description
+
+This function checks if drive number @var{drive} (1 == A:, 2 == B:,
+etc.) is a RAM disk.  It is done by checking if the number of FAT
+copies (in the Device Parameter Block) is 1, which is typical of 
+RAM disks.  (This doesn't _have_ to be so, but if it's good enough for
+Andrew Schulman et al (Undocumented DOS, 2nd edition), we can use this
+as well.)
+
+@subheading Return Value
+
+1 if the drive is a RAM drive, otherwise 0.
+
+@subheading Portability
+
+@portability !ansi, !posix
+
+@subheading Example
+
+@example
+#include <stdio.h>
+#include <dos.h>
+
+  int i = 4;
+
+  printf("%c: is a RAM drive: %d.\n",  'A' - 1 + i, _is_ram_drive( i ) )
+
+@end example
diff -ruN src.org/libc/dos/dos/makefile src/libc/dos/dos/makefile
--- src.org/libc/dos/dos/makefile	Sun Jun 18 02:50:38 1995
+++ src/libc/dos/dos/makefile	Sun Jan 17 19:50:06 1999
@@ -10,6 +10,8 @@
 SRC += getdfree.c
 SRC += getdinfo.c
 SRC += getdos_v.c
+SRC += getfatsz.c
+SRC += getfstyp.c
 SRC += getftime.c
 SRC += gettime.c
 SRC += gettimeo.c
@@ -17,6 +19,10 @@
 SRC += int86x.S
 SRC += intdos.c
 SRC += intdosx.c
+SRC += iscdrom.c
+SRC += isfat32.c
+SRC += isramdri.c
+SRC += mediatyp.c
 SRC += osflavor.c
 SRC += osmajor.c
 SRC += osminor.c
diff -ruN src.org/libc/dos/dos/mediatyp.c src/libc/dos/dos/mediatyp.c
--- src.org/libc/dos/dos/mediatyp.c	Thu Jan  1 00:00:00 1970
+++ src/libc/dos/dos/mediatyp.c	Sun Jan 17 21:36:06 1999
@@ -0,0 +1,18 @@
+/* Copyright (c) 1995-98 Eli Zaretskii <eliz AT is DOT elta DOT co DOT il> */
+
+#include <dpmi.h>
+#include <dos.h>
+
+int
+_media_type(int drive_num)
+{
+  __dpmi_regs r;
+
+  r.x.ax = 0x4408;
+  r.h.bl = drive_num;
+  __dpmi_int(0x21, &r);
+
+  if (r.x.flags & 1)
+    return -1;
+  return r.x.ax;    /* returns 1 for fixed disks, 0 for removable */
+}
diff -ruN src.org/libc/dos/dos/mediatyp.txh src/libc/dos/dos/mediatyp.txh
--- src.org/libc/dos/dos/mediatyp.txh	Thu Jan  1 00:00:00 1970
+++ src/libc/dos/dos/mediatyp.txh	Sun Jan 17 18:47:42 1999
@@ -0,0 +1,53 @@
+@node _media_type, file system
+@subheading Syntax
+
+@example
+#include <dos.h>
+
+int _media_type( const int drive );
+@end example
+
+@subheading Description
+
+This function checks if drive number @var{drive} (. 1 == A:, 2 == B:,
+etc.) is fixed or removable.
+
+@code{_media_type} should only be called after you are sure the drive
+isn't a CD-ROM or a RAM disk, since these might fool you with this
+call.  
+
+For performance reasons the result is cached.
+
+@subheading Return Value
+
+1 if the drive is a fixed disk, 0 if it is removable. -1 on error.
+
+@subheading Portability
+
+@portability !ansi, !posix
+
+@subheading Example
+
+@example
+#include <stdio.h>
+#include <dos.h>
+
+Some work is needed here.
+
+
+int main(void)
+@{
+
+  if( _is_fat32( 'C' - 'A' + 1 ) )
+  @{
+    printf("C: is a FAT32 drive.\n");
+  @}
+  else
+  @{
+    printf("C: is not a FAT32 drive.\n");
+  @}
+
+  exit(0);
+@}
+
+@end example


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