Bump default stack size for target pico to 8kb from 2kb

[scottfeldman]

The pico-w wifi driver needs a minimum of 8kb stack size. The default stack size for pico (and pico-w) is 2kb, so -stack-size=8kb is needed when working with wifi driver. Unfortunately, developers working on the wifi driver forget to specify -stack-size=8kb when testing, resulting in the wifi driver lockup during initialization. Hours (or days) pass before we realize our mistake, and then HAND smacks HEAD and we specify --stack-size=8kb.

This RP sets the default stack size to 8kb for pico (and pico-w). This will help developers who forget -stack-size=8kb, and will help users once the pico-w wifi driver is available.

[soypat]

This catches me off way too often when working in a project I left in the backburner that requires it. I don't think it would be strictly necessary if there was a panic message for stack overflow. Sadly it just crashes and prints out nothing.

[sago35]

@scottfeldman
Shouldn't we create a pico-w.json that includes different definitions for machine.BUTTON, even if it's just in json? Of course, I also think that changing the pico to 8kb is not a bad thing.

[scottfeldman]

@scottfeldman Shouldn't we create a pico-w.json that includes different definitions for machine.BUTTON, even if it's just in json? Of course, I also think that changing the pico to 8kb is not a bad thing.

That makes sense to me. Would the correct approach be to make pico-w.json inherit from pico.json?

pico-w.json:

{
"inherits": [
"pico"
],
"default-stack-size": 8192,
}

[scottfeldman]

Hmmm...there's probably a lot more to change when adding a new target. What machine things are different compared with pico? machine.LED must be diff since the LED goes thru the wifi chip on pico-w. What else? Maybe it's too early for this PR...but darn it, getting burned forgetting -stack-size is a time-waster.

[sago35]

I think the pico-w.json you mentioned earlier should work fine. Just make sure not to forget to set -target pico-w, and that should be good enough.

[sago35]

I think it's better to add machine/board_pico_w.go later.

[deadprogram]

Thanks for adding this @scottfeldman and to @sago35 and @soypat for review. Now merging.