Minimal patch of init for 64-bits and squashfs+cloop

[Capricorny]

I have tried to find the minimal set of modifications to minirt init to achieve

1. Full 64-bits handling
2. Use of cloop and squashfs transparently for end users

There are quite a few potential and actual problems with full 64-bits systems, as many details have clearly not been fully handled yet. And the main init tool, busybox, behaves like a somewhat erratically moving target in this respect: I can successfully use vs 1.17 from the Debian package, but neither 1.18 precompiled nor custom compiled seems to work for init.

The major modifications to minirt are

• Use 64-bits busybox - 1.17 from deb package (installed in /bin/busybox)
• Copy over 64-bits dev from running system
• Patch init script as needed

The main problem with 64 vs 32 bits init, is that no busybox version has been able to run programs adequately off /UNIONFS, and standard 6.4.4 init simply chains into /sbin/init. This hasn't been possible with the available busyboxes, but chroot works relatively fine.

Handling squashfs, while keeping the multi-mount option for KNOPPIX[0-7] and the same numbering scheme as the cloops, necessitates that the KNOPPIX-DATA mount be moved from /dev/loop0 to somewhere else. It seems that we may have problems with loops above 9, so I moved it to /dev/loop8 and reduced the multi-mount options for KNOPPIX from 0-7 accordingly. (It's still possible to create an odd crash in a corner case, but anyone getting there should know the way out..)

By adding the cheatcode "squashfs", squashfs will be mounted, and it is possible to have cloop (KNOPPIX) and squashfs (KNOPPIX.sq) images in the same KNOPPIX directory, if one wants to. But any booting will use only one of the types.

I have tried out a "uni-minirt" common for 32- and 64-bits, but so far, it seems like the best thing to do is keep them separate. From past confusion, I have learnt to name each minirt.gz version separately, the attached init. for example belongs to a version called minirt_sq_2.gz, compressed from a directory called 64patch_1.

Here is the diff of original and patched init. mountknoppix() is thoroughly changed, and findknoppix() is modified to look for KNOPPIX.sq.

diff init init644.org > patch_64_squash.txt
156c156
<   if [ -r /mnt-system/"$knoppix_dir"/KNOPPIX$knoppix_ext ]; then
---
>   if [ -r /mnt-system/"$knoppix_dir"/KNOPPIX ]; then
316,324d315
< 
< # Setup extension for squashfs
< if checkbootparam "squashfs" ; then 
<   knoppix_ext=".sq" ; usecloop=0 ;
< else
<   usecloop=1   
< fi     
< 
< 
586c577
<  [ -b /dev/loop8 ]    || mknod -m 755 /dev/loop8 b 7 8
---
>  [ -b /dev/loop0 ]    || mknod -m 755 /dev/loop0 b 7 0
606,608c597,599
<   losetup -d /dev/loop8 2>/dev/null
<   runknoppixlib /sbin/losetup -p 0 -e aes -k 256 /dev/loop8 /mnt-system/"$knoppix_dir"/knoppix-data.aes </tmp/knoppix.pw; rc="$?"; rm -f /tmp/knoppix.pw
<   runknoppixlib /sbin/mke2fs -F -m 0 /dev/loop8
---
>   losetup -d /dev/loop0 2>/dev/null
>   runknoppixlib /sbin/losetup -p 0 -e aes -k 256 /dev/loop0 /mnt-system/"$knoppix_dir"/knoppix-data.aes </tmp/knoppix.pw; rc="$?"; rm -f /tmp/knoppix.pw
>   runknoppixlib /sbin/mke2fs -F -m 0 /dev/loop0
610c601
<   mount -t ext2 -o rw /dev/loop8 /KNOPPIX-DATA && return 0
---
>   mount -t ext2 -o rw /dev/loop0 /KNOPPIX-DATA && return 0
627c618
<    [ -b /dev/loop8 ]    || mknod -m 755 /dev/loop8 b 7 8
---
>    [ -b /dev/loop0 ]    || mknod -m 755 /dev/loop0 b 7 0
642c633
<       if runknoppixlib /sbin/losetup -e aes -k 256 /dev/loop8 "$img"; then
---
>       if runknoppixlib /sbin/losetup -e aes -k 256 /dev/loop0 "$img"; then
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<        runknoppixlib /sbin/e2fsck -y /dev/loop8 >/dev/null 2>&1
<        mount -t ext2 -o rw /dev/loop8 /KNOPPIX-DATA && return 0
---
>        runknoppixlib /sbin/e2fsck -y /dev/loop0 >/dev/null 2>&1
>        mount -t ext2 -o rw /dev/loop0 /KNOPPIX-DATA && return 0
648c639
<       losetup -d /dev/loop8 >/dev/null 2>&1
---
>       losetup -d /dev/loop0 >/dev/null 2>&1
655c646
<      losetup -d /dev/loop8 >/dev/null 2>&1
---
>      losetup -d /dev/loop0 >/dev/null 2>&1
665d655
< 
668,670c658,659
<  if [[ $usecloop = 1 ]]; then
<    grep -q cloop /proc/devices || insmod /mnt-system/"$knoppix_dir"/modules/cloop.ko preload=32 || return 2
<  fi
---
>  [ -b /dev/cloop ] || mknod -m 644 /dev/cloop b 240 0
>  grep -q cloop /proc/devices     || insmod /mnt-system/"$knoppix_dir"/modules/cloop.ko preload=32 || return 2
672,674c661,663
<  for k in /mnt-system/"$knoppix_dir"/[Kk][Nn][Oo][Pp][Pp][Ii][Xx]$knoppix_ext \
<           /mnt-system/"$knoppix_dir"/[Kk][Nn][Oo][Pp][Pp][Ii][Xx][0-7]$knoppix_ext; do
<   [[ -r "$k" ]] || continue
---
>  for k in /mnt-system/"$knoppix_dir"/[Kk][Nn][Oo][Pp][Pp][Ii][Xx] \
>           /mnt-system/"$knoppix_dir"/[Kk][Nn][Oo][Pp][Pp][Ii][Xx][0-9]; do
>   [ -r "$k" ] || continue
676,682c665,666
<   if [[ $count = 0 ]]; then
<     dir=/KNOPPIX
<     if [[ $usecloop = 1 ]]; then
<       dev=/dev/cloop ; 
<     else
<       dev=/dev/loop0 ; 
<     fi
---
>   if [ $count = 0 ]; then
>    dev=/dev/cloop ; dir=/KNOPPIX
684,689c668,670
<     dir=/KNOPPIX$count
<     if [[ $usecloop = 1 ]]; then
<       dev=/dev/cloop$count ;  
<     else
<       dev=/dev/loop$count ; 
<     fi
---
>    dev=/dev/cloop$count ; dir=/KNOPPIX$count
>    [ -b $dev ] || mknod -m 644 $dev b 240 $count
>    [ -d $dir ] || mkdir -m 755 $dir
691,703c672
< #  Set up and mount
<   [[ -d $dir ]] || mkdir -m 755 $dir ; mntsuccess=1;
<   if [[ $usecloop = 1 ]]; then
<     [[ -b $dev ]] || mknod -m 644 $dev b 240 $count 
<     (losetup  $dev $k >/dev/null 2>&1 && mount -r -t iso9660 $dev $dir >/dev/null 2>&1)||mntsuccess=0
<     echo "mntsuccess cloop: $mntsuccess"
<   else
<     [[ -b $dev ]] || mknod -m 755 $dev b 7 $count    
<     (losetup  $dev $k >/dev/null 2>&1 && mount -r -t squashfs $dev $dir >/dev/null 2>&1)||mntsuccess=0
<     echo "mntsuccess squashfs: $mntsuccess"
<   fi
< # Something went wrong, we unmount all loop-mounts
<   if [[ $mntsuccess = 0 ]]; then
---
>   if ! losetup $dev $k >/dev/null 2>&1 || ! mount -r -t iso9660 $dev $dir >/dev/null 2>&1; then
705c674
<    echo -n -e "\n\r${RED}${BROKENIMAGE}: $k ${ON} "; mount | grep /mnt-system; dmesg | tail | grep 'c*loop'; echo -n "${NORMAL}"
---
>    echo -n -e "\n\r${RED}${BROKENIMAGE}: $k ${ON} "; mount | grep /mnt-system; dmesg | tail | grep cloop; echo -n "${NORMAL}"
707c676
<    for dev in /dev/cloop* /dev/loop*; do
---
>    for dev in /dev/cloop*; do
718,719d686
< 
< 
764c731
< mount --bind /UNIONFS/home /home
---
> /bin/mount --bind /UNIONFS/home /home
813,818c780
< 
< for d in mnt-system KNOPPIX-DATA ramdisk; do
<         [ -d /UNIONFS/"$d" ] ||  mkdir /UNIONFS/"$d"
<         mount --bind /"$d" /UNIONFS/"$d"
< done
< exec chroot /UNIONFS /sbin/init "$@" </dev/console >/dev/console 2>&1
---
> exec /sbin/init "$@" </dev/console >/dev/console 2>&1