Hi,
This patch lets the grub utility operate on a floppy image in the
filesystem as if it were the disk. Let me know if it needs more work.
Thanks
-John
--- grub-0.5.92/grub/main.c~ Mon Jul 26 07:04:07 1999
+++ grub-0.5.92/grub/main.c Wed Sep 22 03:41:59 1999
@@ -36,6 +36,7 @@
int use_curses = 1;
int verbose = 0;
int read_only = 0;
+char *fake_fd0 = 0;
static int default_boot_drive;
static int default_install_partition;
static char *default_config_file;
@@ -51,6 +52,7 @@
#define OPT_BATCH -10
#define OPT_VERBOSE -11
#define OPT_READ_ONLY -12
+#define OPT_FAKE_FD0 -13
#define OPTSTRING ""
static struct option longopts[] =
@@ -66,6 +68,7 @@
{"batch", no_argument, 0, OPT_BATCH},
{"verbose", no_argument, 0, OPT_VERBOSE},
{"read-only", no_argument, 0, OPT_READ_ONLY},
+ {"fake-fd0", required_argument, 0, OPT_FAKE_FD0},
{0},
};
@@ -90,6 +93,7 @@
--no-config-file do not use the config file\n\
--no-curses do not use curses\n\
--read-only do not write anything to devices\n\
+ --fake-fd0=FILE i/o operations on \"(fd0)\" really affect FILE\n\
--verbose print verbose messages\n\
--version print version information and exit\n\
\n\
@@ -188,7 +192,11 @@
case OPT_VERBOSE:
verbose = 1;
break;
-
+
+ case OPT_FAKE_FD0:
+ fake_fd0 = optarg;
+ break;
+
default:
usage (1);
}
--- grub-0.5.92/grub/asmstub.c~ Tue Jul 13 16:39:44 1999
+++ grub-0.5.92/grub/asmstub.c Wed Sep 22 03:25:55 1999
@@ -132,7 +132,10 @@
memset (device_map, 0, NUM_DISKS * sizeof (char *));
/* Floppies. */
- device_map[0] = strdup ("/dev/fd0");
+ if (fake_fd0)
+ device_map[0] = strdup (fake_fd0);
+ else
+ device_map[0] = strdup ("/dev/fd0");
#ifndef __linux__
/* FIXME: leave linux out for now /dev/fd1 blocks for long time
if there is no second floppy ? */
@@ -576,7 +579,10 @@
{
#ifdef __linux__
struct hd_geometry hdg;
- if (! ioctl (disks[drive].flags, HDIO_GETGEO, &hdg))
+ /* Ask the kernel for the drive geometry, but only if it's
+ a real device. */
+ if (! (drive == 0 && fake_fd0)
+ && ! ioctl (disks[drive].flags, HDIO_GETGEO, &hdg))
{
/* Got the geometry, so save it. */
disks[drive].cylinders = hdg.cylinders;
--- grub-0.5.92/stage2/shared.h~ Tue Jul 13 11:46:28 1999
+++ grub-0.5.92/stage2/shared.h Wed Sep 22 03:28:09 1999
@@ -312,6 +312,8 @@
extern int verbose;
/* The flag for read-only. */
extern int read_only;
+/* Name of the fd0 image file, or 0 if fd0 is really /dev/fd0. */
+extern char *fake_fd0;
#endif
#ifndef STAGE1_5
--- grub-0.5.92/docs/grub.texi~ Mon Jul 26 18:58:10 1999
+++ grub-0.5.92/docs/grub.texi Wed Sep 22 04:08:05 1999
@@ -1235,6 +1235,12 @@
@item --read-only
Disable writing to any disk.
+@item --fake-fd0=@var{file}
+Pretend that @var{file} is the first floppy device (@samp{/dev/fd0}).
+This lets you operate on a floppy image in the filesystem as if it were
+the physical floppy disk. In GRUB commands, @samp{fd0} will refer to
+the image @var{file} instead of the disk.
+
@item --hold
Wait until a debegger will attach. This option is useful when you want
to debug the startup code.
