gcc porting

[Soha Eyal-RM50194 <eyal dot soha at freescale dot com>]

My name is Eyal Soha.  I'm a member of a team of software engineers at Freescale (née Motorola) Semiconductors.  We're considering developing a GCC back end for a new processor.  We have some questions about the development process.

1) The processor has a heap but possibly no stack at all.  Are there any existing GCC ports on processors with no stack?  How do they work?

2) The processor has a general-purpose register that is written to by an outside source but can be accessed as any other GPR.  It can be thought of as a "volatile" register.  We'd like to be able to access the value there in some natural manner.  Is that possible?  Has this been done before?

3) How long might it take to port a back end?  Assume our team is 2-3 software engineers, all with strong backgrounds in c programming, basic knowledge of compiler principles, plenty of experience with using gcc, but no experience with the code of gcc.  Any estimates or accounts of previous similar projects would be helpful!

4) What kind of help is available for writing the port?  Are there experience engineers willing to do work by contract?  What free help is available by way of the GCC community?

5) What are the legal implications of the GPL on the back end?  As I understand, any back end distributed by Freescale would need to include source code or access to the code, but until Freescale starts distributing the back end, it can remain private.  I also read that Freescale could sell gcc with the back end or its source for a profit.  Is all that correct?

I'm sorry that I can't currently be more specific on the details of the processor.  We're still debating the direction of the project and whether or not to use GCC.  If a GCC back end becomes the preferred solution then we should be able to reveal more details as time goes on.

Thanks,

Eyal Soha
Freescale Semiconductors