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Anders Dam Kofoed
Anders Dam Kofoed
Associate II
December 11, 2016
Solved

STM32L0 vs STM32F0 huge difference in base code size

  • December 11, 2016
  • 5 replies
  • 1665 views

Posted on December 11, 2016 at 11:25

HI All,

I am wondering why initial code size differs with a factor of 3 between the STM32F031K6 and the STM32L031K6 - just for making an LED blink.

I use CubeMx to generate the project and GCC (OpenSTM32 AC6 IDE) to compile it. In CubeMX I select the Nucleo-F031K6 and the Nucleo-L031K6 and click the 'Initialize all peripherals with their default mode'. Then I leave everything as default, just enough to make the LD3 blink (PB3).

Compiling the project without any modification gives me the following code size:

== STM32L031K6 ==

arm-none-eabi-size 'TEST-L0.elf'

text data bss dec hex filename

12504 12 1684 14200 3778 TEST-L0.elf

== STM32F031K6 ==

arm-none-eabi-size 'TEST-F0.elf'

text data bss dec hex filename

4536 12 1684 6232 1858 TEST-F0.elf

== Question ==

Why this huge difference in code size between the L0 (12,5 KB) and the F0 (4,5 KB) ?

Kind regards

Anders

This topic has been closed for replies.
Best answer by Tesla DeLorean
Posted on December 12, 2016 at 20:46

Review .LD and .MAP files

The linker script might separate regions leaving holes, the .MAP file should break down what's where. A disassembly listing might also be instructive.

Review optimization setting, and libraries pulled in.

One complaint and possible cause is if one is pulling the floating point code library, vs one not. The code to compute the USART baud rate has some unnecessary floating point computation in one of the HAL releases.

#dogfooding

‌

5 replies

Seb
Seb
ST Employee
December 11, 2016
Posted on December 11, 2016 at 11:56

Most compiler toolchain can generate a MAP file which details for each *.o object file the used memory for constants, code and variables. It should help to analyse the resulting code size.

Good luck!

Tesla DeLorean
Tesla DeLoreanBest answer
Guru
December 12, 2016
Posted on December 12, 2016 at 20:46

Review .LD and .MAP files

The linker script might separate regions leaving holes, the .MAP file should break down what's where. A disassembly listing might also be instructive.

Review optimization setting, and libraries pulled in.

One complaint and possible cause is if one is pulling the floating point code library, vs one not. The code to compute the USART baud rate has some unnecessary floating point computation in one of the HAL releases.

#dogfooding

‌

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Anders Dam Kofoed
Anders Dam KofoedAuthor
Associate II
December 13, 2016
Posted on December 13, 2016 at 16:33

Thanks Cilve,

Yes, disabling the USART driver gave me this:

== STM32L031K6 ==

arm-none-eabi-size 'TEST-L0.elf'

  

text

 

data

   

bss

   

dec

   

hex filename

  

3608

   

12

 

1572

 

5192

 

1448 TEST-L0.elf

== STM32F031K6 ==

arm-none-eabi-size 'TEST-F0.elf'

  

text

 

data

   

bss

   

dec

   

hex filename

  

3296

   

12

 

1572

 

4880

 

1310 TEST-F0.elf

The L0 slightly bigger than the F0. Also you are right in that it seems to include code that does some multiplication or division...

Thanks

Kind regards

Anders

Oliver Beirne
Oliver Beirne
Associate II
December 13, 2016

Posted on December 13, 2016 at 16:24

Hi

Kofoed.Anders_Dam

I have moved this post to the

https://community.st.com/s/topic/0TO0X000000BSqSWAW/

where product related questions are posted.

Thanks

Oli

Tesla DeLorean
Tesla DeLorean
Guru
December 14, 2016
Posted on December 14, 2016 at 21:46

https://community.st.com/0D50X00009XkflfSAB

 

https://community.st.com/0D50X00009XkaFMSAZ

 
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