Debian 32bit chroot setup question

Oxyacetylene · 11-20-2005, 01:36 PM

I have been starting to set up a 32 bit chroot within my amd64 system so that I can run some 32 bit apps. I am using the how-to on Alioth:
https://alioth.debian.org/docman/vie....html#id271960

My questions is dealing with linking the 32 bit linker. What would be the command to do this? What is this doing? The how-to doesn't give the command and I wasn't sure exactly what it's trying to do.

Que_273 · 11-20-2005, 04:26 PM

If you are trying to run a 32bit program while within the 64bit userspace (ie not in the chroot) then you must be able to find the linker ld.so and any libraries.
The howto showed how to put the chroot library paths into /etc/ld.so.conf and you must also have a symlink in /lib to the ld-linux.so file in your chroot

Code:

hugh@polybius:/lib$ ls -l ld*
-rwxr-xr-x  1 root root 97904 2005-08-31 03:00 ld-2.3.5.so
lrwxrwxrwx  1 root root    32 2005-09-16 15:42 ld-linux.so.2 -> /emul/ceasar/lib/ld-2.3.2.so
lrwxrwxrwx  1 root root    11 2005-09-10 01:44 ld-linux-x86-64.so.2 -> ld-2.3.5.so

In 64bit space if your run "ldd myprog" you should get this linker and any libraries shown. For example:

Code:

hugh@polybius:~/Programs/surf2/bin$ ldd surface
        linux-gate.so.1 =>  (0x00000000)
        libstdc++.so.5 => /emul/ceasar/usr/lib/libstdc++.so.5 (0x55675000)
        libm.so.6 => /emul/ceasar/lib/tls/libm.so.6 (0x5572f000)
        libgcc_s.so.1 => /emul/ceasar/usr/lib/libgcc_s.so.1 (0x55751000)
        libc.so.6 => /emul/ceasar/lib/tls/libc.so.6 (0x5575c000)
        libdl.so.2 => /emul/ceasar/lib/tls/libdl.so.2 (0x560d1000)
        /lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x55555000)

Oxyacetylene · 11-21-2005, 06:54 AM

If I do the first command then I see that I already have the link matching up to the x86-64 linker, but I don't have the 2nd item your output shows (pointing to your emul directory). Do I need to have this also? From looking at mine it seems that debootstrap created the link for me?

Que_273 · 11-21-2005, 07:06 AM

You will need that link if you want to run 32bit apps in 64bit userspace. If you are running programs that are in the chroot (like a 32bit version of mozilla w/ Flash plugin) then it is not necessary because when you run "dchroot -d mozilla" it will change to the 32bit chroot and the linker will be found as if it was a standard installation.

If the programs you are running are not actually in .deb files, installed manually or copied from elsewhere (taking care to keep things separate) you can install the ia32-libs package which gives you a nearly completeset of 32bit libraries (and linker) within your 64bit userspace.

Oxyacetylene · 11-28-2005, 08:01 AM

Thanks for the info. My 32 bit chroot seems to be working well so far.