[okl4-developer] [Support.opensynergy] S3C2440A and okl4

[Geoffrey Lee]

On Tue, Aug 19, 2008 at 06:01:32PM +0200, Frank Kaiser wrote:

Hi Frank

Can you let us know how you turned off fastpaths in OKL4?  The
supported way to do this is via the command line, by toggling
enable_fastpaths=True|False.

As for the clzeq instruction, Matt has provided me with a patch
to do the functional equivalent for armv4-based processors.  I have
attached the patch to this mail.  Let us know if this works for you.

	-gl

> Update: Using "IPC_FASTPATH=0" is definitely a NOGO. After moving the
> constant "L4_ANYTHREAD" outside "#ifdef CONFIG_IPC_FASTPATH" the file
> could be assembled, but linking failed: In the #ifdef branch there are
> the two labels IPC_RETURN_USER and IPC_COMPLETE_SWITCH_TO_NOEX which are
> referenced from within the #else branch.
> The only remaining option is to replace the CLZ instructions. The first
> appearance is particularly difficult, because the condition code set by
> the preceding 'cmp/cmpne' must survive the replacement, because it is
> checked a few lines further down by a 'bne' instruction. And moving the
> CLZ replacement before the 'cmp/cmpne' would not help in case the cmpne
> is valid.
> The conclusion is that the ARMv4 build is broken in OKL4, v2.1, which is
> a showstopper for my current project.
> 
> Regards
> Frank
> > -----Original Message-----
> > Hello, Folks
> > 
> > I have to tell you that there are also two CLZ instructions in v2.1 of
> > 'traps.spp': at line 480 and line 494. Since they are in a code
> section led by
> > an "#ifdef CONFIG_IPC_FASTPATH" directive, I tried to compile my
> AT91RM9200
> > platform with the parameter "IPC_FASTPATH=0", but unfortunately this
> breaks
> > the compilation of 'traps.spp': the constant "L4_ANYTHREAD", which is
> defined
> > in line 263 after "#ifdef CONFIG_IPC_FASTPATH", is referred in line
> 1445 which
> > lies after the corresponding #else directive so that it is undefined.
> > So I have the situation that my platform runs into an 'undefined
> instruction'
> > exception with IPC_FASTPATH on, and is not compilable with
> IPC_FASTPATH off.
> > Any suggestions how to proceed?
> > Remy, I think you will face the same problem when you build with
> > "PROJECT=iguana" instead of "PROJECT=l4test".
> > 
> > Regards
> > Frank
> > 
> > _______________________________________________
> > Developer mailing list
> > Developer at okl4.org
> > https://lists.okl4.org/mailman/listinfo/developer
> 
> _______________________________________________
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> 

-- 

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