Arch32

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Reason: please use the first argument of the template to provide a brief explanation. (Discuss in Talk:Arch32#)

Note: 32-bit chroot for a 64-bit Arch is described in Install_bundled_32-bit_system_in_Arch64 in great detail.


First we decide where to place the 32bit system. This variable will be used throughout this page for flexibilty. The given value is just what the author used. If you prefer some other location, this is the time to change it.

ARCH32_ROOT="/opt/arch32"

Now we have to create the directories so that pacman can function and affect changes inside our chroot.

mkdir -p $ARCH32_ROOT/var/{cache/pacman/pkg,lib/pacman}

Below is a helper script which I place in /usr/local/bin/pacman32. It will allow us to run pacman from our 64bit install and it will affect our chroot only. Make sure that if you are not using the default location, to change it here.

#!/bin/bash
ARCH32_ROOT="/opt/arch32"
PACMAN_EXEC="pacman" 


sed -e 's/x86_64/i686/g' /etc/pacman.d/mirrorlist > $ARCH32_ROOT/mirrorlist
sed -e 's@/etc/pacman.d/mirrorlist@/opt/arch32/mirrorlist@g' /etc/pacman.conf > $ARCH32_ROOT/pacman.conf

$PACMAN_EXEC --root $ARCH32_ROOT --cachedir $ARCH32_ROOT/var/cache/pacman/pkg --config $ARCH32_ROOT/pacman.conf "$@"

Now we can sync up our 32bit pacman with the repositories.

/usr/local/bin/pacman32 -Sy

And then we install the bare-minimum that we need to install other 32bit programs and libraries.

/usr/local/bin/pacman32 -S filesystem licenses bash sed coreutils gzip

We now setup some of the meaningful configuration files.

cd $ARCH32_ROOT/etc

ln -f /etc/passwd* 
ln -f /etc/shadow* 
ln -f /etc/group*
ln -f /etc/rc.conf 
ln -f /etc/resolv.conf 
ln -f /etc/localtime 
ln -f /etc/locale.gen 
ln -f /etc/profile.d/locale.sh profile.d
ln -f /etc/vimrc
cp /etc/mtab .

/usr/local/bin/arch32

#!/bin/bash
schroot -p -- "$@"

Alternative Setup (Testing)

This setup is being tested and so far seems to work well. It is based on the above comments and the more detailed description in Install_bundled_32-bit_system_in_Arch64.

Create Folder Structure

Create folder to store and sync 32-bit system (as root):

# mkdir /opt/arch32

Create pacman folder structure inside new location:

# mkdir -p /opt/arch32/var/{cache/pacman/pkg,lib/pacman}

Pacman Configuration

Copy the pacman config files from 64-bit system and edit pacman sync files to work as 32-bit system. These two commands will copy and change /etc/pacman.conf and /etc/pacman.d/mirrorlist to be saved in /opt/arch32.

# sed -e 's/x86_64/i686/g' /etc/pacman.d/mirrorlist > /opt/arch32/mirrorlist
# sed -e 's@/etc/pacman.d/mirrorlist@/opt/arch32/mirrorlist@g' -e 's/Architecture = auto/Architecture = i686/g' /etc/pacman.conf > /opt/arch32/pacman.conf

N.B. Check that both files point to i686 mirrors Line: 'Architecture = i686' in /etc/pacman.conf is correct.

Sync 32-bit System Using 64-bit Pacman Command

Use this pacman command to sync files to correct location in /opt/arch32 from 64-bit system:

# pacman --root /opt/arch32 --cachedir /opt/arch32/var/cache/pacman/pkg --config /opt/arch32/pacman.conf -Sy

Once pacman is synchronised, install minimum packages:

# pacman --root /opt/arch32 --cachedir /opt/arch32/var/cache/pacman/pkg --config /opt/arch32/pacman.conf -S filesystem licenses bash sed coreutils gzip pacman (nano make file gawk grep gcc)

Packages in brackets are useful for compiling packages in 32-bit system, e.g. from AUR

Create links in 32-bit system from useful conf files in 64-bit system (some are optional), first change to /opt/arch32/etc directory:

# cd /opt/arch32/etc

Run these commands, including '.' character (during the testing only those marked with required seem to be important)

ln -f /etc/passwd* . 
ln -f /etc/shadow* . 
ln -f /etc/group* .
ln -f /etc/rc.conf . 
ln -f /etc/resolv.conf .    --> required
ln -f /etc/localtime . 
ln -f /etc/locale.gen .    --> required
ln -f /etc/profile.d/locale.sh profile.d
ln -f /etc/vimrc .
cp /etc/mtab .

Create Chroot Enviroment Scripts

Copy bash script below and save as arch32 in /etc/rc.d/

#!/bin/bash

. /etc/rc.conf
. /etc/rc.d/functions

dirs=(/dev /dev/pts /dev/shm /tmp /home)
case $1 in
   start)
       stat_busy "Starting Arch32 chroot"
       for d in "${dirs[@]}"; do
       mount -o bind $d /opt/arch32/$d
       done
       mount -t proc none /opt/arch32/proc
       mount -t sysfs none /opt/arch32/sys
       add_daemon arch32
       stat_done
       ;;
   stop)
       stat_busy "Stopping Arch32 chroot"
       for (( i = ${#dirs[@]} - 1; i >= 0; i-- )); do
        umount "/opt/arch32${dirs[i]}"
       done
       umount /opt/arch32/{proc,sys}
       rm_daemon arch32
       stat_done
       ;;
   restart)
       $0 stop
       sleep 1
       $0 start
       ;;
   *)
       echo "usage: $0 {start|stop|restart}"
esac
exit 0


Then make script executable

# chmod +x /etc/rc.d/arch32

In the other descriptions, arch32 daemon was added to rc.conf. When this daemon is running from start-up, the 64-bit pacman commands to sync to the 32-bit system above don't seem to work properly. This bash script below to chroot into new 32-bit system gets round that problem.


#!/bin/bash

# Start chroot daemon
sudo /etc/rc.d/arch32 start

# Give users access to Xserver (install xorg-xhost if command not found)
xhost +                    

# Chroot into 32-bit system
sudo chroot /opt/arch32

# To leave chroot type 'exit' then environment is cleaned up..... 
xhost -
sudo /etc/rc.d/arch32 stop

The command:

# xhost + 

seems to work better than:

# xhost +SI:localuser:username

Run bash script arch32.sh to chroot and configure locale

locale-gen

11. a) Uncomment required mirrors in /etc/pacman.d/mirrorlist in chroot

   b) Change architecture entry from auto to i686 in /etc/pacman.conf 

12. Sync repositories

pacman -Sy

13. No need to setup xorg, only install video drivers and possibly copy xorg.conf file over to arch32 systen.