Re: [avr-gcc-list] an idea: adding serial sram to avr to extend heap storage

[David Kelly]

On Mar 13, 2011, at 9:13 AM, Raymond Moore wrote:

> I am working on several projects that require more sram than most AVRs
> have.  I don't particularly need more processing power but it would be
> nice to have much larger variable storage space.  I can work with a
> serial sram and use it for external storage already but it would be
> nice to have an option to be able to turn that serial sram into heap
> storage.
> 
> Due to the complexity of gcc I am assuming this will be a non-trivial
> task but it is something I would be willing to work on.  My question
> is, where in the gcc source would I look to start redirecting heap
> storage?  Yes, I'm lazy, and I just had this idea about 10 minutes ago
> and haven't started digging into the source yet.


You want to modify gcc to add a new data type which is stored off-chip in a 
serial SRAM rather than on-chip?

Think everyone else simply uses a library to stash or fetch values as needed. 
You should practice that first. Then perhaps investigate how to add new 
intrinsic functions and data types to the compiler.

But for me, I don't go beyond w_ssram() and r_ssram() functions because I think 
it adds readability and understanding to my code for ssram access to be obvious 
where its being used than if it was hidden.

Perhaps this is a job for C++? But that also hits on why I do not use C++, that 
I want to see what is being done, not expect things to be done magically for me.

--
David Kelly N4HHE, address@hidden
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Whom computers would destroy, they must first drive mad.