Attached is a small patch to grub 0.91 (I can't get into CVS from here).
This patch allows the "configfile" and "root" commands to be embedded
in a configfile.
The patch also prevents "open_preset_menu" from returning true more than
once (comments in stage2.c suggest that this cannot happen, but the
"open_preset_menu" function did not behave as noted).
Note: Embedding "configfile" and "root" commands in a configfile allow
for run-time determination of boot image based on external configuration
files. In my case, I'm looking to load the "configfile" from a tftp
server. The initial configfile (loaded from the local drive) configures
the network card & tftp server (we don't support bootp or dhcp), then
issues a configfile <nd>/..../configfile command to continue the boot
process. Alternate config files may be selected depending on which tftp
servers are accessible.
diff -urN grub-0.91/stage2/builtins.c grub-0.91.patched/stage2/builtins.c
--- grub-0.91/stage2/builtins.c Wed Jan 2 18:23:30 2002
+++ grub-0.91.patched/stage2/builtins.c Wed Feb 27 16:38:55 2002
@@ -751,7 +751,7 @@
{
"configfile",
configfile_func,
- BUILTIN_CMDLINE,
+ BUILTIN_MENU | BUILTIN_CMDLINE,
"configfile FILE",
"Load FILE as the configuration file."
};
@@ -3030,7 +3030,7 @@
{
"root",
root_func,
- BUILTIN_CMDLINE,
+ BUILTIN_MENU | BUILTIN_CMDLINE,
"root [DEVICE [HDBIAS]]",
"Set the current \"root device\" to the device DEVICE, then"
" attempt to mount it to get the partition size (for passing the"
diff -urN grub-0.91/stage2/stage2.c grub-0.91.patched/stage2/stage2.c
--- grub-0.91/stage2/stage2.c Mon Jan 7 21:56:45 2002
+++ grub-0.91.patched/stage2/stage2.c Mon Mar 4 13:00:28 2002
@@ -35,14 +35,17 @@
static int
open_preset_menu (void)
{
+/* Preset menu can only be used on initial entry... we must force this */
+static int preset_used=0;
#ifdef GRUB_UTIL
/* Unless the user explicitly requests to use the preset menu,
always opening the preset menu fails in the grub shell. */
if (! use_preset_menu)
return 0;
#endif /* GRUB_UTIL */
-
preset_menu_offset = 0;
+ if (preset_used) return 0;
+ preset_used=1;
return preset_menu != 0;
}
