[U-Boot-Users] Generic ARM Error with respect to usage of r8 in start.S's.

Wolfgang Denk wd at denx.de
Tue Jun 24 20:40:49 CEST 2003

In message <FD2AC9A020DDD51194710008C7089B20053D4CA9 at dlee17.itg.ti.com> you wrote:
> possibly reset....instead it just locked up.  Tracing the code I see that
> the exception code in start.S for all ARM ports uses r8 as a frame pointer.
> This is NOT allowed as r8 is reserved as the global data pointer....given
> the way the ARM code currently operates I don't see why this has to be, but

What is it you don't see? Why we reserve R8 for global data?

> it might be handy if someone was trying to use C before the memory
> controller was up (this is not the case for the ARM code today).

...but may change any day. As soon as there is a little time left for
"nice to have" things.

Best regards,

Wolfgang Denk

Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd at denx.de
Program maintenance is an entropy-increasing process,  and  even  its
most skilfull execution only delays the subsidence of the system into
unfixable obsolescence.       - Fred Brooks, "The Mythical Man Month"

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