STM32 with small flash + HAL + DEBUG + no Optimization...

[LCE]

... leads to "funny" results:

STM32L011 with 16 kB of flash, HAL inits and LED toggle in main, DEBUG, no optimization:

93% of flash used

I had not expected it to be that bad! 😅

Okay, I will probably not use too much HAL, will use Release version with optimization,
but I better select an L01 in the next bigger QFN package (4x4) to get 32 kB of flash.

[MM..1]

Your screenshot show many peripherals , then maybe your LED toggle count bitcoins too ...

[Andrew Neil]

Show the results with "Optimise for Debug" (-Og).

You should also take a look at the map file - is it actually HAL that's using all that space ... ?

🤔

[KnarfB]

The Memory Details tab gives you more insights.

hth

KnarfB

[LCE]

Yes, luckily I know all that - it was just a bad surprise and might deter some complete STM32 beginners.

So, this wasn't actually a call for help, just ... being "amazed" at how things are. Until now I only worked with "bigger" STM32 (G4, F7, H7), and occasionally using HAL or at project start wasn't a problem.

The list file showed mostly the "bloated" HAL inits - I actually forgot about the "Memory Details", thanks @KnarfB .

With release / optimization to size, it drops to 56%.

Record holder is HAL_RCC_Config with 1.15 kB, together with HAL_RCC_ClockConfig and HAL_RCCEx_PeriphCLKConfig taking up even more than 10% of the 16 kB.
These are the HAL setup functions I always use - I guess I have to overcome my laziness in that area.

BTW - RAM: the default CubeMx settings for heap and stack also took up ~90% :D

[MM..1]

In MX you can very easy switch some parts to LL

[LCE]

If this MCU will be used in a product, I will probably throw out the HAL stuff anyway (I don't like the LL either, so direct register settings for me).

I was just really shocked that a basically empty project - except for the inits - with all defaults from CubeMX leads to this memory usage: > 90% for flash and RAM.

[Andrew Neil]

---

@LCE wrote:

I was just really shocked that a basically empty project - except for the inits.

---

Probably, the inits are where 90% of the code lies!

So what do you get if you don't init any peripherals?

And then there's the C runtime support - how much did that amount to?

[LCE]

@Andrew Neil 

> Probably, the inits are where 90% of the code lies!

Definitely!

I just switched to its next big brother with 32 kB SRAM, switched all to LL instead of HAL.

Release with no Opt: 9.57 kB flash

Release with Opt for size: 4.14 kB flash  <- I hadn't expected that with LL

> And then there's the C runtime support - how much did that amount to?

Erm... where's that? Isn't that for memory allocation and stuff like that - which I don't use?

[Andrew Neil]

---

@LCE wrote:

@Andrew Neil 

Erm... where's that? Isn't that for memory allocation and stuff like that - which I don't use?

---

There's a lot more to it than that!