[Pkg-xen-devel] Re: libc6-xen not used on AMD Geode LX system

[Aurelien Jarno]

Jérôme a écrit :
>     Hi,
> 
>     I'm trying to install xen+Debian Etch on a Geode LX system. Xen 
> boots fine, but although the package "libc6-xen" is installed I have a 
> large number of such errors:
>        4gb seg fixup, process syslogd (pid 1878), cs:ip 73:b7f24610
> 
>     All processes triggers it, and from what I've found on the web it's 
> a sign that libc6-xen is not recognized. Indeed:
>     minimo:~:2# ldd /bin/echo
>         linux-gate.so.1 =>  (0xffffe000)
>         libc.so.6 => /lib/tls/libc.so.6 (0xb7e48000)
>         /lib/ld-linux.so.2 (0xb7f82000)
> 
>     It's /lib/tls and not /lib/tls/i686/cmov.
> 
>     I have found on the web references to this issue for FC6, with a fix 
> ("hwcap 0 nosegneg" in a file in /etc/ld.so.conf.d, and put the libs in 
> /lib/tls/i686/cmov/nosegneg, ldconfig) but this does not help here. So 
> it may be a capability issue?
> 
>     When I look at the hardware capabilities needed with "ldconfig -Nv | 
> grep '^/'" I get:
>     lib/tls:        (hwcap: 0x8000000000000000)
>     /usr/lib/i486:        (hwcap:    0x2000000000000)
>     /usr/lib/i686:        (hwcap:    0x8000000000000)
>     /usr/lib/i586:        (hwcap:    0x4000000000000)
>     /lib/tls/i686:        (hwcap: 0x8008000000000000)
>     /usr/lib/i686/cmov:    (hwcap:    0x8000000008000)
>     /lib/tls/i686/cmov:    (hwcap: 0x8008000000008000)
> 
>     0x8000 is CMOV support, which is present on the Geode LX. Here's the 
> whole CPU info:
>     minimo:~:3# cat /proc/cpuinfo
>     processor       : 0
>     vendor_id       : AuthenticAMD
>     cpu family      : 5
>     model           : 10
>     model name      : Geode(TM) Integrated Processor by AMD PCS
>     stepping        : 2
>     cpu MHz         : 499.919
>     cache size      : 128 KB
>     fdiv_bug        : no
>     hlt_bug         : no
>     f00f_bug        : no
>     coma_bug        : no
>     fpu             : yes
>     fpu_exception   : yes
>     cpuid level     : 1
>     wp              : yes
>     flags           : fpu de pse tsc msr cx8 sep pge cmov clflush mmx 
> mmxext 3dnowext 3dnow up
>     bogomips        : 1001.25
> 
>     The upper bit is required for TLS, so it's not the problem as TLS is 
> supported. So it should be the middle bit 0x8000000000000 that is not 
> supported. I found a reference to "MP support" but that seems weird --- 
> why would MP support be required here?

This bit means than you need a 686 CPU. This seems to be the case as you
are using a -686 kernel, but it seems it is not correctly detected by
the kernel. You can try to move the files from /lib/tls/i686/cmov into
/lib/tls/i586/cmov, then run ldconfig and try again. Be aware that it
can crash your system if your CPU really doesn't support 686 instructions.


-- 
  .''`.  Aurelien Jarno	            | GPG: 1024D/F1BCDB73
 : :' :  Debian developer           | Electrical Engineer
 `. `'   aurel32 at debian.org         | aurelien at aurel32.net
   `-    people.debian.org/~aurel32 | www.aurel32.net