Re: Aborted L4linux due to CLI/STI

I forgot to mention that it also does not support the traditional cmpxchg instructions using the lock line. That is why I disabled it.

Sorry about the multiple emails,
Ramya

Sent from my phone

> On 05 Sep 2014, at 18:16, "Masti  Ramya Jayaram" <[email protected]> wrote:
> 
> Dear all,
> 
> I get an error during L4linux boot when I enter the debugger (using ESC) and resume:
> 
> Aborted L4linux due to CLI/STI at 0x534911. 
> 
> When I disassemble this using gdb:
> 
> (gdb) disassemble 0x534911
> Dump of assembler code for function cmpxchg8b_emu:
>   0x00534910 <+0>:    pushf  
>   0x00534911 <+1>:    cli    
>   0x00534912 <+2>:    cmp    (%esi),%eax
>   0x00534914 <+4>:    jne    0x534922 <cmpxchg8b_emu+18>
>   0x00534916 <+6>:    cmp    0x4(%esi),%edx
>   0x00534919 <+9>:    jne    0x534924 <half_same>
>   0x0053491b <+11>:    mov    %ebx,(%esi)
>   0x0053491d <+13>:    mov    %ecx,0x4(%esi)
>   0x00534920 <+16>:    popf   
>   0x00534921 <+17>:    ret    
>   0x00534922 <+18>:    mov    (%esi),%eax
>   0x00534924 <+0>:    mov    0x4(%esi),%edx
>   0x00534927 <+3>:    popf   
>   0x00534928 <+4>:    ret    
> 
> When I built l4linux, I had to disable CONFIG_X86_CMPXCHG, CONFIG_CMPXCHG_LOCAL and  CONFIG_X86_CMPXCHG64 despite building for the Pentium because my processor does not support PAE (which is the option that enables this). I am guessing This is the reason it tries to emulate the CMPXCHG instructions.
> 
> What is the correct l4linux configuration to use for a machine that does not support any of the atomic instructions like CMPXCHG8, ATOMIC, etc.?
> 
> Thanks,
> ramya
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