I'm pretty sure I know what's happening. When certain microops in x86
are executed, they may run into some condition they don't like and call
panic. That's actually wrong. What they *should* do is return a fault
object which, when "invoked", aka committed, will call panic on behalf
of the microop. That way if a microop is executed speculatively with bad
arguments, the CPU has a chance to squash the instruction before commit
and save itself from the panic. Everything works ok in the atomic CPU
because it never executes anything speculatively. I initially
implemented x86 targeting the simple CPU, and at the time I didn't
realize using panic was wrong. I've cleaned up some of the places it's
used, but there are still some left. I'll get the rest at some point
soon (maybe a couple days) and send you a patch.

Gabe

On 02/18/12 08:03, Ankita (Garg) Goel wrote:
> Hi,
>
> When running the detailed mode, this is the error I get:
>
> $ build/X86/gem5.opt  configs/example/fs.py --cpu-type=detailed    
> --kernel=x86_64-vmlinux-2.6.28.4-smp --num-cpus=2 --caches
>
> **** REAL SIMULATION ****
> info: Entering event queue @ 0.  Starting simulation...
> 264721000: system.pc.com_1.terminal: attach terminal 0
> warn: Don't know what interrupt to clear for console.
> warn: instruction 'wbinvd' unimplemented
> ....
> warn: instruction 'fxsave' unimplemented
> warn: Address 0xffffffc0 is outside of physical memory, stopping fetch
> warn: Address 0xffffffc0 is outside of physical memory, stopping fetch
> warn: Address 0xffffffc0 is outside of physical memory, stopping fetch
> warn: instruction 'wbinvd' unimplemented
> panic: Wrdh used with wrong descriptor type!
>  @ cycle 309622856000
> [execute:build/X86/arch/x86/o3_cpu_exec.cc, line 12585]
> Memory Usage: 318880 KBytes
> Program aborted at cycle 309622856000
> Aborted
>
> On the terminal, these were the last boot up messages:
>
> Memory: 119608k/131072k available (4219k kernel code, 1024k absent,
> 10284k reserved, 2101k data, 332k init)
> Calibrating delay loop (skipped) preset value.. 3999.96 BogoMIPS
> (lpj=7999923)
> Mount-cache hash table entries: 256
> CPU: L1 I Cache: 64K (64 bytes/line), D cache 64K (64 bytes/line)
> CPU: L2 Cache: 1024K (64 bytes/line)
> Setting APIC routing to flat
> ..TIMER: vector=0x30 apic1=0 pin1=2 apic2=0 pin2=0
> CPU0: M5 Simulator Fake M5 x86_64 CPU stepping 01
> Booting processor 1 APIC 0x1 ip 0x6000
>
> Any idea what might be going on ?
>
> Thanks for your help!
>
> Regards,
> Ankita
>
> On Fri, Feb 17, 2012 at 10:03 PM, Gabriel Michael Black
> <[email protected] <mailto:[email protected]>> wrote:
>
>     I'm not aware of anybody else having this problem. Does it hang,
>     return an error from gem5, return an error from the kernel on the
>     terminal, or? Did you try building from scratch by deleting the
>     entire build directory? Sometimes stray files can survive longer
>     than they're supposed to and mess up incremental builds. A lot
>     will have changed in your update, so there's a non-zero chance of
>     that happening.
>
>     Gabe
>
>
>     Quoting "Ankita (Garg) Goel" <[email protected]
>     <mailto:[email protected]>>:
>
>         Hi,
>
>         I have been using X86_FS for a while now. Just upgraded to the
>         new version
>         that has combined FS and SE mode. However, now I am unable to
>         boot into
>         Linux. The command I used is:
>
>         # build/X86/gem5.opt  configs/example/fs.py
>          --cpu-type=[detailed|timing]
>         --kernel=x86_64-vmlinux-2.6.28.4-smp --caches
>
>         The kernel does boot up if the cpu-type is the default, ie,
>         atomic. Is this
>         a known issue ?
>
>         --
>         Regards,
>         Ankita
>
>
>
>
>     _______________________________________________
>     gem5-users mailing list
>     [email protected] <mailto:[email protected]>
>     http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users
>
>
>
>
> -- 
> Regards,
> Ankita
>
>
>
> _______________________________________________
> gem5-users mailing list
> [email protected]
> http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users

_______________________________________________
gem5-users mailing list
[email protected]
http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users

Reply via email to