[U-Boot] p4080ds starts OS with MSR[EE]=1 and DEC armed?

Timur Tabi timur at freescale.com
Tue Mar 15 22:21:02 CET 2011


Jimi Xenidis wrote:
> That is true for "server" and "classic" because they do not necessarily stop at 0.
> for embedded you can just:
> 	/* u-boot leaves decrementer enabled */
> 	mtspr(SPRN_DECAR, 0); /* paranoia */
> 	mtspr(SPRN_DEC, 0);
> 	mtspr(SPRN_TCR, 0);
> 	mtspr(SPRN_TSR, 0);

I think you mean

	mtspr(SPRN_TSR, 0xFFFFFFFF);

since it's write-1-to-clear.  Other than that, this is exactly what I was
talking about.  I just think it makes sense for the boot loader to try to
disable as many interrupt sources as possible, and force the OS to enable the
ones it wants.

On the other hand, Scott's points are completely valid.

-- 
Timur Tabi
Linux kernel developer at Freescale



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