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Singh.Harjit
Senior
November 16, 2019
Question

Is .fpu incorrect in startup_stm32f411xe.s?

  • November 16, 2019
  • 3 replies
  • 3109 views

In startup_stm32f411xe.s, the FPU seems to be incorrectly declared. It is:

.fpu softvfp

Shouldn't it be:

.fpu fpv4-sp-d16

I checked other files in the same family and they also have the softvfp declaration.

3 replies

Tesla DeLorean
Guru
November 17, 2019

Is it throwing a warning at link time?

Do you actually have any FPU instructions in the start-up assembler?

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Singh.Harjit
Senior
November 17, 2019

I'm not getting any warnings.

I don't have any FPU instructions in the startup code.

I do enable and use the FPU in startup code.

I was concerned about declaring incorrect / inconsistent FPU information with the rest of the code base.

Tesla DeLorean
Guru
November 17, 2019

I don't think this is consequential.

If you use FPU instructions in the file you'll need to pick a hardware options that covers the instructions in question, so things like push/pop of the float/double registers don't throw errors, for example.

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Associate II
August 10, 2024

I checked everything today and worked as expected. Thanks.

Just moved from a custom board that used STMG0 to a STM32H723. I am so ecstatic to finally be able to figure out TCM, Cache Write back, and just trying to unlock every bit of performance. Kind of bit more than i can chew with a huge project but it feels like i have injected crack. Its fun.