Cannot find /bin/bash when chrooting during crossdev

manphiz · n00b Joined: 01 Dec 2021 Posts: 26

Hi,

I've been trying to create a mips64el n32 chroot for loongson2f by following the instructions in https://wiki.gentoo.org/wiki/Cross_build_environment. I've made some progress in creating the crossdev using "crossdev -t mips64el-unknown-linux-gnu", cross-compiling @system under /usr/mips64-unknown-linux-gnu, and compiling most of the essential packages except Python-3.9.9, which AIUI doesn't support cross compiling and needs to be done in chroot.

I've also compiled qemu on the host and the static qemu for mips. One difference is that my Gentoo is using systemd so I followed the instructions in https://wiki.gentoo.org/wiki/Embedded_Handbook/General/Full to create the bits required by systemd so that it can start systemd-binfmt, more specifically I've prepared the binfmt-support for both mips and mipsel under /etc/binfmt.d. When trying to chroot to /usr/mips64el-unknown-linux-gnu I was hit by this error:

mattst88 · Developer Joined: 28 Oct 2004 Posts: 422

Obvious question: is there a /bin/bash in that directory? That is, is there a /usr/mips64el-unknown-linux-gnu/bin/bash?
_________________
My Wiki page

eccerr0r · Posted: Tue Dec 14, 2021 3:21 am Post subject:

And then the next maybe not so obvious question, are /lib/libc.so.6, libtinfo, libtinfow, readline; and the dynamic library loader (ld-linux-mips64el*) there in the chroot?
_________________
Intel Core i7 2700K/Radeon R7 250/24GB DDR3/256GB SSD
What am I supposed watching?

manphiz · n00b Joined: 01 Dec 2021 Posts: 26

NeddySeagoon · Posted: Tue Dec 14, 2021 10:18 pm Post subject:

manphiz,

eccerr0r · Posted: Tue Dec 14, 2021 10:35 pm Post subject:

I'm not sure you can use the host ldd on non native binaries though theoretically qemu should handle it, and the file is too small to be statically linked anyway so it's lying to you.

My guess is you still have qemu problems, binfmt problems, or your ld-linux-* is missing (should have been built with glibc), unfortunately I ran out of string over here...
_________________
Intel Core i7 2700K/Radeon R7 250/24GB DDR3/256GB SSD
What am I supposed watching?

szatox · Advocate Joined: 27 Aug 2013 Posts: 3433

manphiz · n00b Joined: 01 Dec 2021 Posts: 26

manphiz · n00b Joined: 01 Dec 2021 Posts: 26

pingtoo · Posted: Wed Dec 15, 2021 12:10 am Post subject:

manphiz,

please share output for following

manphiz · n00b Joined: 01 Dec 2021 Posts: 26

pingtoo · Posted: Wed Dec 15, 2021 1:14 pm Post subject:

This is bit of beyond me. Let me do some research see if I can find something about this.

NeddySeagoon · Posted: Wed Dec 15, 2021 5:05 pm Post subject:

manphiz,

I'm trying to recreate your problem here.

szatox · Advocate Joined: 27 Aug 2013 Posts: 3433

NeddySeagoon · Posted: Wed Dec 15, 2021 6:26 pm Post subject:

szatox,

That's what the guide says.

The OP said

manphiz · n00b Joined: 01 Dec 2021 Posts: 26

NeddySeagoon · Posted: Thu Dec 16, 2021 10:09 am Post subject:

manphiz,

manphiz · n00b Joined: 01 Dec 2021 Posts: 26

NeddySeagoon · Posted: Thu Dec 16, 2021 4:02 pm Post subject:

manphiz,

Make friends with wgetpaste and put the entire build log onto a pastebin please.

NeddySeagoon · Posted: Thu Dec 16, 2021 9:01 pm Post subject:

manphiz,

Some progress. I was getting

pingtoo · Posted: Thu Dec 16, 2021 10:38 pm Post subject:

manphiz,

I too successful build qemu with mips64el. I am use gcc-10 and build with older qemu-6.0.0-r2. however I doubt those matter since the error happen at early configuration stage. I found a online error report similar to your error, even thought it is not same arch (for m68k) but may indicate your environment have same setup.

qemu emerge command line I used

eccerr0r · Posted: Fri Dec 17, 2021 2:36 am Post subject:

hmm. I tried setting up qemu-arm to auto run binaries and tried to chroot into a raspbian rootfs. Well, didn't work, same outcome as the OP so must be doing something wrong too. If I tried running without chroot, it gives me an error that it can't find the dynamic loader (ld-linux-arm), which is expected as there's only the native ld-linux installed there on root. Not sure how much actually ran there.

now I don't know if there are any static binaries in the raspbian rootfs to play with to see if there's any sign of life...
_________________
Intel Core i7 2700K/Radeon R7 250/24GB DDR3/256GB SSD
What am I supposed watching?

manphiz · n00b Joined: 01 Dec 2021 Posts: 26

Thanks guys! So I figured out that to properly build qemu with USE="static-user static" I need to build all its dependencies with "static-libs". Now I have this

NeddySeagoon · Posted: Fri Dec 17, 2021 11:56 am Post subject:

manphiz,

Lets rewind a little. Your stated objective was to make a

manphiz · n00b Joined: 01 Dec 2021 Posts: 26

Thanks Neddy. It looks to me that maybe qemu doesn't handle mips64el n32 ABI correctly. I'll see whether I can get the old Loongson2f image work in qemu-mips64el.

Also, can you show me which command you used to chroot to "/usr/mips64el-unknown-linux-gcc"? I suspect that my binfmt may not be set up correctly which could explain why my chroot failed.