[PATCH 1/3] ARM: debug: use kconfig choice for selecting DEBUG_LL UART

[Russell King - ARM Linux]

On Sun, Aug 21, 2011 at 04:07:37PM -0400, Nicolas Pitre wrote:
> On Sun, 21 Aug 2011, Russell King - ARM Linux wrote:
> 
> > And further to this, I'll point out that the debugging functions are
> > *explicitly* designed to avoid corrupting any more than just r0-r3
> > and lr.  That's not just the IO functions but also the hex and string
> > printing functions.
> > 
> > And the head*.S code is explicitly written to expect r0-r3 to be
> > corrupted - which basically means that no long-term values are held in
> > those registers.
> 
> Well, not exactly.  I actually have a patch to that effect I made a 
> while ago so all the early code could be unaffected by inserted function 
> call, but held on to it because nothing yet justified its need.  Here it 
> is for reference:

And so this buggers up the ability to insert calls to the debugging code
by placing values into r0-r3.  So that patch will get a nak too.