* Pass the path of the stage 2 init script to stage 1 init through the

kernel command line, instead of having a /init symlink.  This allows
  us to switch between configurations.
* Some debug support: adding `debug' to the kernel command line gives
  a stage 1 shell.

svn path=/nixu/trunk/; revision=7107

test/README

@@ -1,3 +1,8 @@
+To get a Stage 1 shell:
+
+Add "debug1" to the kernel command line.
+
+
 Switching to maintenance mode:
 
 $ shutdown now

test/boot-stage-1-init.sh

@@ -32,6 +32,25 @@ mkdir /sys
 mount -t sysfs none /sys
 
 
+# Process the kernel command line.
+stage2Init=@stage2Init@
+for o in $(cat /proc/cmdline); do
+    case $o in
+        init=*)
+            set -- $(IFS==; echo $o)
+            stage2Init=$2
+            ;;
+        debugtrace)
+            # Show each command.
+            set -x
+            ;;
+        debug1)
+            fail
+            ;;
+    esac
+done
+
+
 # Create device nodes in /dev.
 source @makeDevices@
 
@@ -85,6 +104,7 @@ else
 
 fi
 
+
 # Start stage 2.
 # !!! Note: we can't use pivot_root here (the kernel gods have
 # decreed), but we could use run-init from klibc, which deletes all
@@ -94,6 +114,10 @@ mount --move . /
 umount /proc # cleanup
 umount /sys
 
-exec chroot . @stage2Init@
+echo "INIT = $stage2Init"
+
+if test -z "$stage2Init"; then fail; fi
+
+exec chroot . $stage2Init
 
 fail

test/system-configuration.nix

@@ -11,7 +11,7 @@ let
   bootEnv = import ./boot-environment.nix {
     autoDetectRootDevice = false;
     inherit rootDevice;
-    stage2Init = "/init"; # !!! should be bootEnv.bootStage2;
+    stage2Init = ""; # Passed on the command line via Grub.
     readOnlyRoot = false;
   };
 

test/system-configuration.sh

@@ -6,9 +6,8 @@ ln -s $kernel $out/kernel
 ln -s $grub $out/grub
 
 cat > $out/menu.lst << GRUBEND
-title NixOS
-        kernel $kernel selinux=0 apm=on acpi=on
-        initrd $initrd
+kernel $kernel selinux=0 apm=on acpi=on init=$bootStage2
+initrd $initrd
 GRUBEND
 
 ensureDir $out/bin
@@ -20,7 +19,6 @@ export PATH=$coreutils/bin:$gnused/bin:$gnugrep/bin:$diffutils/bin
 if test -n "$grubDevice"; then
     $grubMenuBuilder $out
     $grub/sbin/grub-install "$grubDevice" --no-floppy --recheck
-    ln -sf $bootStage2 /init # !!! fix?
 fi
 EOF