Thank you for the feedback.
[quote user="ichlfgang"]1. How do I know the required scratchpad size?[/quote]
You will need to add the largest offset from the __cla_scratchpad_start symbol with the largest offset from the __cla_scratchpad_end symbol. Interrupt functions use offsets from the start of the scratchpad and leaf functions use offsets from the end of the scratchpad. To prevent overlap you need to allocate space for both.
[quote user="ichlfgang"]2. How can I make the linker warn me if the compiler uses more scratchpad memory than assigned by CLA_SCRATCHPAD_SIZE?[/quote]
There is no way to generate a warning from the linker at this time.
[quote user="ichlfgang"]3. Apparently, the first 4 scratchpad memory locations are not used, the lowest reference I see is "__cla_scratchpad_start+4".[/quote]
I will have to look into this further.
[quote user="ichlfgang"]4. Why doesn't the compiler simply allocate space for scratchpad data like it does for all other segments?
This would make it much easier to use, and solve problems 1 und 2 as well.[/quote]
We are already investigating this possibility for the next CLA compiler release. At this time it is not certain that we will add this support, but we will take your feedback into consideration when prioritizing the feature.