Homebrew Can I increase stack size beyond 65535? (libctru)

[ske2004]

Hello! I'm new to homebrew, sorry if this isn't the right place.

I'm using libctru to run a custom scripting language. At one point it allocates around 64kb of memory onto stack and causes stack smashing.

There's a weak symbol called __stacksize__, so I can set a custom stack size, but it's a uint16, so it's limited to 64kb. Is this an inherent limitation of 3DS or ARM, or limtation chosen by libctru?

(maybe better to move those 64k to heap but they're very temporary >o>)

 

[Jayro]

Probably not, as 65535 seems to be a hard-coded number in a lot of hardware applications.

 

[ske2004]

I saw that in `ExHeader_CodeSetInfo` stack_size is a u32.
(10 minutes later)
It maybe possible! `initSystem` is weak too, that's where the stack is set up.

 

[VinsCool]

Allocating to the Heap at a fixed Address and using it as a Soft Stack to your liking seems to be the most ideal way to do it in my opinion.

 

[ske2004]

Lol, I'm dumb. `word` in arm is 32 bit, not 16 bit.
But it's weird that setting stack size to 0x10000 doesn't work

Post automatically merged: Nov 2, 2025

Oh my god, I'm dumb. When I exported it as `uint16_t __stacksize__ = 0xFFFF` it worked, but when I did `uint32_t __stacksize__ = 0x10000` it didn't. Of course, when I declared it as `uint16_t` it probably took some junk bytes around it and it happened to fit, but `0x10000` just wasn't enough xd

Case closed! thanks everyone!