[avr-libc-dev] [RFC] Reorganizing io.h and common registers

[Eric Weddington]

Hello All,

See attached patches for 1.4 branch and HEAD.

This patch reorganizes avr/io.h a bit. A new file is created, avr/common.h.
The purpose of this file is to hold register and symbol definitions that are
common across AVR devices and families. It defines common registers that
have not previously been defined in the individual IO header files (e.g. the
stack pointer and status registers), and it also defines generic names for
some registers that are common across devices and families. avr/common.h is
#included in avr/io.h *after* the individual IO header files. Therefore many
definitions in avr/io.h have been moved to avr/common.h. There have been
some of the assembler files in avr-libc that use common register
definitions, and these have been changed to use the generic symbols defined
now in avr/common.h. Lastly, there is a small change to get avr/io.h back
into the documentation.

The main reason to do all this is to organize this a bit better for future
support of new devices. Also, in the future, generic definitions of
registers where the names are different between devices, such as in
avr/wdt.h, avr/sleep.h, avr/power.h, etc., could be placed in avr/common.h.
These generic definitions are not prefixed with an underscore, with the idea
that they should also be available for public use. However, they are not
currently doxygenified, but could be in the near future. The point is to get
this changed ASAP.

Let me know if anyone sees anything missing, or if something might need to
be added, or rearranged. However, I'm not inclined to quibble over every
detail. These changes are very necessary and I would like to get them in
soon. If there are no significant objections, I will commit these patches on
Friday.

Thanks,
Eric Weddington