Hi Steve,

There's plenty of flash left for the cohpsk modem, we already have the 
entire codec and fdmdv modem fitting in around half the flash.

No need to load any program code - it all runs out of flash.

It's important to test and characterise, hence the porting steps I 
suggested on 24 Sep.

- David

On 25/10/15 12:00, Steve wrote:
> On Sat, Oct 24, 2015 at 7:55 PM, Stuart Longland
> <[email protected]> wrote:
>> On 25/10/15 10:49, Steve wrote:
>>> Added to the language in C99 if I remember right... No problem in GCC.
>>
>> Ahh, figured it was a newer feature.  I sometimes have to deal with K&R C.
>>
>
> The difference of course, is that Variable Length Arrays (VLA) are
> allocated on the stack, rather than the heap, as in the old days.
> Stack space may need to be weighed if you are creating some huge
> arrays.
>
> I'm kind of old fashioned in my C programming. I don't really like
> HEAP or STACK, and tend to favor BSS. The nice thing about BSS
> storage, is it is auto-initialized to zero. This can save a lot of
> code at the initialization step, with loops allocating zero's to
> arrays. Then to, there is no danger of the BSS crashing into the STACK
> or the HEAP, while the later crash all the time out in the wild.
>
> Somewhere along the line someone declared BSS evil (globals are evil)
> and usage waned. Course now in OOP languages it is like making the
> sign of the cross inside a Mosque...
>
> Having looked at the cohpsk modem, it is going to need a ton of
> memory, then too, you'll need to save room for the vocoder.
>
> I think the best bet may be to load the two modems from flash
> separately depending on which modem the user wants. Running both
> probably will run out of memory. The cohpsk modem, for example doesn't
> need all the pilot code and allocated space, but does have some rather
> large filter tables.
>
> Just some thinking out loud...
>
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