s390: specify offset and size of the initrd for booting from CD

The old setup worked fine with an ext2 initrd but fails with an initramfs,
either because autodetection is different for initramfs or because of kernel
changes (I suspect the first).
This means that booting s390 from CD has not worked since sometime during the
Etch release cycle, even though support for booting from CD was only added
early in that cycle - ouch.

For booting with an initramfs initrd we apparently need to specify its
offset and size at specific memory locations.

Change is based on SuSE's CD boot. Many thanks to Adam Thornton, Mark Post
(of Novell) and Bastian Blank for providing the pointers to the missing bits.

This fixes booting from CD using the d390.ins file; tested in Hercules for
both Lenny (31-bit kernel) and Squeeze (64-bit kernel).
Booting from CD using the d390.tdf file may still be broken (if possible at
all) as I have no idea how to test that.

data/lenny/s390/d390.ins

@@ -1,4 +1,6 @@
 * Debian GNU/Linux for S/390 (boot from CD-ROM or FTP-Server)
 linux_vm 0x00000000
+root.off 0x0001040c
+root.siz 0x00010414
 parmfile 0x00010480
 root.bin 0x00800000

data/lenny/s390/d390oco.ins

@@ -1,5 +1,7 @@
 * Debian GNU/Linux for S/390 (boot from CD-ROM or FTP-Server with OCO-Modules)
 linux_vm 0x00000000
+root.off 0x0001040c
+root.siz 0x00010414
 parmfile 0x00010480
 root.bin 0x00800000
 oco.bin 0x00c00000

data/squeeze/s390/d390.ins

@@ -1,4 +1,6 @@
 * Debian GNU/Linux for S/390 (boot from CD-ROM or FTP-Server)
 linux_vm 0x00000000
+root.off 0x0001040c
+root.siz 0x00010414
 parmfile 0x00010480
 root.bin 0x00800000

data/squeeze/s390/d390oco.ins

@@ -1,5 +1,7 @@
 * Debian GNU/Linux for S/390 (boot from CD-ROM or FTP-Server with OCO-Modules)
 linux_vm 0x00000000
+root.off 0x0001040c
+root.siz 0x00010414
 parmfile 0x00010480
 root.bin 0x00800000
 oco.bin 0x00c00000

debian/changelog

@@ -41,6 +41,11 @@ debian-cd (3.1.3) UNRELEASED; urgency=low
   * Fix link in README.html.in for lenny, and update squeeze to match.
     Closes: #542191
 
+  [ Frans Pop ]
+  * s390: Add boot files specifying offset and size of the initrd for booting
+    from CD. Change is based on SuSE's CD boot. Many thanks to Adam Thornton,
+    Mark Post and Bastian Blank for providing the pointers to the missing bits.
+
  -- Frans Pop <fjp@debian.org>  Sun, 23 Aug 2009 08:59:25 +0200
 
 debian-cd (3.1.2) unstable; urgency=low

tools/boot/lenny/boot-s390

@@ -87,6 +87,10 @@ done
 # - d390oco.tdf : same, using object-code-only-modules-ramdisk (example)
 cp $BASEDIR/data/$CODENAME/s390/d390* "$imagedir/"
 
+# Create the files specifying offset and size of the initrd
+perl -e "print pack('N', 0x800000)" >"$imagedir/root.off"
+perl -e "print pack('N', -s '$imagedir/root.bin')" >"$imagedir/root.siz"
+
 # Copy the README file
 cp $BASEDIR/data/$CODENAME/s390/README.boot "boot$N/"
 

tools/boot/squeeze/boot-s390

@@ -87,6 +87,10 @@ done
 # - d390oco.tdf : same, using object-code-only-modules-ramdisk (example)
 cp $BASEDIR/data/$CODENAME/s390/d390* "$imagedir/"
 
+# Create the files specifying offset and size of the initrd
+perl -e "print pack('N', 0x800000)" >"$imagedir/root.off"
+perl -e "print pack('N', -s '$imagedir/root.bin')" >"$imagedir/root.siz"
+
 # Copy the README file
 cp $BASEDIR/data/$CODENAME/s390/README.boot "boot$N/"