Re: Bug#865425: debian-installer-9-netboot-mips64el: mips64el Malta netboot installer finds no installable kernel

Aurelien Jarno <[email protected]> Sat, 24 Jun 2017 19:07:40 +0200

Newsgroups	gmane.linux.debian.ports.mips
Message-ID	<[email protected]>

On 2017-06-24 02:12, Cyril Brulebois wrote:
> Control: reassign -1 libdebian-installer 0.110
> Control: affects -1 debian-installer-9-netboot-mips64el
> 
> Bruno Bierbaumer <[email protected]> (2017-06-21):²
> > Package: debian-installer-9-netboot-mips64el
> > Severity: normal
> > Tags: d-i
> > 
> > Dear Maintainer,
> > 
> > I wanted to install Debian Stretch mips64el in QEMU.
> > It seems that the netboot installer can't find any installable kernel for this architecture.
> > There is definitely linux-images for 5kc-malta in the repo and the same install procedure worked for both mips and mipsel.
> > 
> > Steps to reproduce:
> > 
> > qemu-system-mips64el -M malta -m 256 -cpu MIPS64R2-generic  \
> > -drive file=hda.qcow2,if=virtio,format=qcow2,index=0 \
> > -kernel vmlinux-4.9.0-3-5kc-malta \
> > -initrd initrd.gz \
> > -net user,hostfwd=tcp::22222-:22 \
> > -net nic \
> > -nographic \
> > -append "nokaslr"
> > 
> > The installer will show the error: No installable kernel was found in the defined APT sources
> 
> Some info about this:
> ~ # archdetect 
> mips64el/unknown
> 
> and “unknown” is why base-installer isn't able to pick the right kernel.
> 
> Looking at the hwmap structure in src/system/subarch-mips-linux.c (from
> the libdebian-installer package), where architecture detection happens,
> I initially thought we were missing some MIPS64 pattern there, but that
> doesn't seem the case, as /proc/cpuinfo reports this:
> | system type             : MIPS Malta
> …
> | cpu model               : MIPS GENERIC QEMU V0.0  FPU V0.0
> 
> (Full contents below for reference.)
> 
> and those are the ones which are searched through the hwmap…
> 
> I'm not sure how to fix libdebian-installer here, adding debian-mips@
> and qemu maintainers in copy.
> 
> It might make sense to update the bug report title as well at some
> point, since this is likely an issue on QEMU only?

The current version of subarch-mips-linux.c tries to detect if the CPU
is 32 or 64-bit using the CPU type. It's therefore not prepared for the
"GENERIC QEMU" type returned in /proc/cpuinfo. The code should probably
be modified to use the "isa" field as a fallback if the "cpu model"
field can't be used to determine the flavour.

That said, the quick workaround is to emulate a real CPU in QEMU. For
example you can select the 5KEf CPU which is a MIPS64R2 CPU with FPU.

Aurelien

-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
[email protected]                 http://www.aurel32.net

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