> some OpenFirmware implementations, such as the one in the PegasosII, > have a 12 MB size limit on kernel images, and no initrd loading > capability. The latter is worked around by merging the initrd into the > image with the "mkvmlinuz" tool, however the generated images are > unbootable if they exceed 12 MB. The attached patch brings vmlinuz from about 13MB to about 9.5MB, which is well under the 12MB limit. Downside is that xz compressing is noticeably slower than currently used gzip, but decompressing speed difference is not noticeable. I've tested it on Pegasos II machine, it boots really fast. Updated mkvmlinuz package is waiting on mentors.debian.net for a willing sponsor for upload. Milan
Index: mkvmlinuz
===================================================================
--- mkvmlinuz (revision 19233)
+++ mkvmlinuz (working copy)
@@ -133,11 +133,6 @@
# if no release was specified, extract it from the kernel image name
if test -z "$release"; then
release=$(echo $kernel | sed s/.*vmlinux-//)
- if echo $release | grep -q '2\.[46]\.[0-9]*'; then
- :
- else
- release=""
- fi
fi
if dpkg --compare-versions $release ge 2.6.16 && test "$arch" != "prep" ; then
@@ -158,6 +153,12 @@
post_2_6_19=
fi
+if dpkg --compare-versions $release ge 2.6.38 && test "$arch" != "prep" ; then
+ post_2_6_38=Yes
+else
+ post_2_6_38=
+fi
+
test -z "$verbose" || echo === Release version seems to be $release.
# if no object file directory was specified, try to find one
@@ -206,6 +207,11 @@
test -z "$verbose" || echo === Doing build in $work.
# utilities
+if test "$post_2_6_38"; then
+ XZ="xz --check=crc32 -8"
+else
+ XZ=false
+fi
if test "$post_2_6_16"; then
ADDNOTE=$objdir/addnote # must be present in mkvmlinuz fallback tools
if test \! -f "$ADDNOTE"; then
@@ -291,22 +297,35 @@
# create the compressed initrd image file
if test -n "$initrd"; then
- test -z "$verbose" || echo === Creating compressed initrd image initrd.gz...
+ test -z "$verbose" || echo === Creating compressed initrd image
if test -z "$compressed"; then
- # Detect if the file was already compressed by gzip.
- if test "`od -A n -c -N 2 $initrd`" = " 037 213"; then
- compressed="Yes"
+ if test "`xxd -p -l2 $initrd`" = "1f8b"; then
+ test -z "$verbose" || echo === $initrd is already gzip compressed
+ do_cmd cp -p $initrd $work/initrd.gz
+ if test -n "$post_2_6_38" && test "$arch" != "prep"; then
+ test -z "$verbose" || echo === recompressing to xz
+ zcat $initrd | $XZ - > $work/initrd.xz
+ fi
+ elif test "`xxd -p -l6 $initrd`" = "fd377a585a00"; then
+ test -z "$verbose" || echo === $initrd is already xz compressed
+ do_cmd cp -p $initrd $work/initrd.xz
else
+ test -z "$verbose" || echo === assuming $initrd was not compressed
compressed="No"
fi
fi
case "$compressed" in
Yes)
do_cmd cp -p $initrd $work/initrd.gz
+ do_cmd ln -s $work/initrd.gz $work/initrd.xz
;;
No)
do_cmd cp -p $initrd $work/initrd
- do_cmd $GZIP $work/initrd
+ if test -n "$post_2_6_38" && test "$arch" != "prep"; then
+ do_cmd $XZ $work/initrd
+ else
+ do_cmd $GZIP $work/initrd
+ fi
;;
esac
fi
@@ -317,7 +336,11 @@
WRAPPER=$objdir/wrapper
vmlinuz=$work/vmlinuz.$arch
if test -n "$initrd"; then
- INITRD="-i $work/initrd.gz"
+ if test "$post_2_6_38"; then
+ INITRD="-i $work/initrd.xz"
+ else
+ INITRD="-i $work/initrd.gz"
+ fi
fi
$WRAPPER -c -o $vmlinuz -p $arch $INITRD -D $objdir -W $work $kernel
else
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