ok, it now works /proc/sys/fs/binfmt_misc/qemu-arm was missing, internet searc told me to look for 'binfmt-support' pkg, however i could not find none for centos6 so as chrooted systems share the same kernel (just need to mount /proc under the chroot dir), I chroot to my wheezy_i686 (i have some chroots for testing other disros), and there i did apt-get install binfmt-support qemu-user-static, and update-binfmts --display
now i have /proc/sys/fs/binfmt_misc/qemu-arm. amd everything works again (i do not know if this is permenent or will require redoing after reboot), but i will check it at next reboot (somthing like in 6 months ;-) thanks erez On Tue, May 20, 2014 at 11:22 AM, Tzafrir Cohen <tzaf...@cohens.org.il> wrote: > On Tue, May 20, 2014 at 09:14:16AM +0300, Erez D wrote: >> I am using centos 6 and developing for an armel platform >> >> i created a rootfs using multistrap/debbootstrap >> >> i copied qemu-arm-static to rootfs/usr/bin/qemu-arm-static > > There's something missing from your description. I suspect you forgot to > mention it: debootstrap's run can be broken to two parts: one that > downloads everything, and the second stage that needs to run inside the > chroot. In that case: > > debootstrap --foreign [--arch=] [rest of parameters] > chroot to/chroot > ./debootstrap --second-stage > > At least in Debian, the package qemu-user-static includes the wrapper > qemu-debootstrap to do just that, and also copy the required > qemu-user-static. > >> >> and i was astonished that doing just 'chroot rootfs' worked, without >> explicitly telling 'chroot' to use qemu-arm-static - somehow it decided >> automatically to run everything under qemu-arm-static without me telling it >> to. >> >> >> after a restart of the server. rootfs does not work anymore automatically, >> i get a "chroot: failed to run command `/bin/bash': Exec format error" >> doing "chroot rootfs /usr/bin/qemu-arm-static /bin/bash" does chroot, but >> i get : "bash: /bin/cat: cannot execute binary file" (although >> rootfs/bin/cat is a perfectly ok armel binary, tested on the armel target). >> i also checked the md5sum of the rootfs/qemu-arm-static binary, and it is ok > > A chroot does not replace the kernel. It's running on your kernel and > that kernel does not natively support the armel binaries. > > In Debian, the package qemu-user-static registers foreign Linux ELF > formats. So maybe you forgot this is needed. Specifically: > > $ cat /proc/sys/fs/binfmt_misc/qemu-arm > enabled > interpreter /usr/bin/qemu-arm-static > flags: > offset 0 > magic 7f454c4601010100000000000000000002002800 > mask ffffffffffffff00fffffffffffffffffeffffff > > -- > Tzafrir Cohen | tzaf...@jabber.org | VIM is > http://tzafrir.org.il | | a Mutt's > tzaf...@cohens.org.il | | best > tzaf...@debian.org | | friend > > _______________________________________________ > Linux-il mailing list > Linux-il@cs.huji.ac.il > http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il _______________________________________________ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
