What CPU are you using? How did you determine this is where it gets stuck? Have you traced execution near there? Does it get stuck in the microcode looping forever, executing the same instruction over and over, etc., or does it stop executing instructions all together, perpetually trying to vector to an exception handler for instance?
My off hand guess to what's going on is that the check that makes sure the selector is ok isn't handling a NULL selector properly. The AMD architecture manal says this: "Null selectors can only be loaded into the DS, ES, FS and GS data-segment registers, and into the LDTR descriptor-table register. A #GP occurs if software attempts to load the CS register with a null selector or if software attempts to load the SS register with a null selector in non 64-bit mode or at CPL 3." It sounds like you've determined that %eax should really be 0 when that instruction executes. With some more information I'll try to look at this sometime in the next week or two. Gabe On 11/28/11 05:16, Anders Handler wrote: > Hi, > > I have the same problem. The last instruction decoded in a kernel > >2.6.32 is > > 8e d0 mov %eax,%ss > > where %eax contains 0 (xor %eax,%eax). > > In 2.6.32 and earlier the segment registers was set to "movl > $__KERNEL_DS,%eax", which in my 2.6.32 kernel was 0x18. > > The code is found in head_64.S in entry point "secondary_startup_64". > > Any clue why the simulator gets stuck here? > > > Best regards > Anders > > 2011/11/28 huangyongbing <[email protected] > <mailto:[email protected]>> > > Hi all, > > I try to run Gem5 using X86_FS and Linux kernel 3.1. The > configuration file I use is downloaded from Gem5 website which > contained in file 'config-x86.tar.gz'. No errors are printed out > by gem5. However, there is also nothing printed out in m5term > console. Using the same configuration file, Linux kernel 2.6.32 is > runnable on Gem5. Thus, what's the problem? > > > 2011-11-28 > ------------------------------------------------------------------------ > -- Yongbing Huang > > _______________________________________________ > gem5-users mailing list > [email protected] <mailto:[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
_______________________________________________ gem5-users mailing list [email protected] http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users
