Subject: Mixed Thumb & Arm Code - msg#00019

I've read through the docs about ARM interworking
found in:

gcc-3.2/gcc/config/arm/README-interworking

and I'm looking for more details, done quite a bit
of searching and can't seem to find anything other then
'how to build a cross compiler' (Which I have working
just fine)

Specifically I have 4 questions:

1) I'd like to know if there is some type of an attribute
that can specify that an external function is thumb
or arm, it might work like this:

#define __thumbfunc __attribute((interfacethumb))
#define __arm32func __attribute((interfacearm32))

extern int __thumbfunc foo(void);
extern int __arm32func bar(void);

WHY? Because - if I turn on Interworking - I seem to
need it turned on for *everything* including all the
libraries that I'm going to use. (I get a slew of
messages Blah supports Interworking - but BlahBlah
does not)

I'd rather have the bulk of my code - all libs and such
compiled as "thumb" - then have a few special routines
(core computationally intensive routines) compiled as ARM

2) Where can I find ASSEMBLER calling conventions for ARM
both in THUMB mode and in ARM32 mode.

There are some routines that I need to write that must
be written in the "other mode" and written in assembler.

Where can I get more information about this.

Yes, I can "gleen" some stuff from the compiler sources
and by using the compiler "-S" option I'd rather find
docs on the subject.

3) Where can I find information about how ARM does
PIC code - ie: I want to write assembler code
that supports this, but can't find any info on it.

4) In NEWLIB - 'setjmp.S' it has a few macros and such
that make it easier to write assembler functions.

Is there another repository of this type of stuff
someplace that I should look for?

Specifically - I'm looking for a doc that might
have this title:

"How to write ARM and THUMB assembler
functions that interface to GCC compiled
C and C++ functions - including examples
of all those .whatever things the assembler
and DEBUGGER requires to make things work."

-Duane


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