[arm-gnu] Cortex-M3 and Floating Point Problems

[Carlos O'Donell]

On 6/22/2012 9:53 AM, Mark Mulrooney wrote:
> I hate to say this, but I think I may have spoken too soon. Yesterday
> after Paul's suggestion that it has to be on an 8 byte boundary, I
> put the following on all the stacks: __attribute__ ((align (8))). I
> compiled it, ran the system, and it immediately printed out the
> correct answer. Thinking that solved the problem I moved on to make
> some changes in another part of the system and now the printf no
> longer works again. I backed out those changes and the printf still
> does not work so I don't think it was anything I added. I have seen
> it before where it works every once in a blue moon and that's why I
> was convinced it was the 8 byte boundary problem.

So this sounds like something is breaking the stack boundary requirements.

Can you look at the stack alignment at entry to several functions?
 
> Carlos: You had mentioned there was a bug in printf with regards to
> %f, does this sound at all like that bug?

No, I was just generically stating that there could be an unfound 
bug, but I don't know of any.

> Also I was wondering if anyone knows of a good alternative
> printf/scanf library to use.

What about the one in the STM32 Firmware Library?

Cheers,
Carlos.
-- 
Carlos O'Donell
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