[Qemu-devel] openSUSE Buildservice: cross-build using qemu in "User Mode" => qemu issues

[Martin Mohring <martin.mohring@5etech.eu>]

Hi,

my name is Martin Mohring and I am one of the developers of the openSUSE 
Buildservice (part of the openSUSE Projekt opensuse.org, is also 
openSource). I contribute the embedded Support to the distribution and 
also cross-development to the openSUSE Buildservice. OBS Release 1.0 
<http://news.opensuse.org/2008/07/09/opensuse-build-service-10-released> 
is out. I am also the maintainer of the development project which 
engineers the OBS and tests and releases it.

Jan Kiszka told me I should write about the issues found here on the 
qemu-devel mailing list. We are currently implementing a new variant of 
cross-build capability in the OBS using qemu "User Mode" emulation. In 
order to function properly on newer linux distributions for powerpc/arm, 
tls/nptl and 
futex support is beginning to materialize now in "linux-user", as I have 
noticed. Since we also want to use qemu-ppc with new glibc 2.6 or newer 
variants (using futex and tls/nptl syscalls), the changes changes around 
version -r4616 (NPTL host detection and futex syscall passthrough) and 
-r4610 (Implement ARM magic kernel page and TLS register) need to be put 
into powerpc user mode also. If I correctly understood, the change in 
-r4610 would also be needed to get nptl running on powerpc.

I also read in one of the e-mail the very short message "thread safety 
and tls/nptl is under work", I think this e-mail was by paul brook. What 
do you have currently planned wrt. to "User Emulation" mode, especially 
on powerpc? Below you will find some output of qemu-ppc.

Since we are good testers of qemu with many linux distro variants 
(openSUS Buildservice has currently implemented all "big" linux distros 
as build targets), I would also be looking forward to give you more test 
results if you whish.

Martin

PS: Below you will also find the error with which the OBS fails inside 
qemu (at the very bottom). "syscall 221" is futex on powerpc, and I 
think "fork: Invalid argument" is the 
result of USE_NPTL not yet working on powerpc.
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here----------------------------------------------------
....
.init_b_cache/scripts/aaa_base.pre: fork: Invalid argument
running aaa_base postinstall script
.init_b_cache/scripts/aaa_base.post: fork: Invalid argument
initializing rpm db...
qemu: Unsupported syscall: 221
qemu: Unsupported syscall: 221
....
-------------------------------------------------cut 
here----------------------------------------------------