STM32F405RGTx_FLASH.ld uses unaligned SP

markb · ‎2015-05-31

Posted on June 01, 2015 at 08:51

Hello ST People,

The .ld file that the cube generates for me (STM32F405RGTx_FLASH.ld) contains:

_estack = 0x2001FFFF; /* end of RAM */

but this makes the initial SP unaligned which I only noticed because some floating point numbers were

not getting printed out correctly (I was using vprintf()). I changed it to the following and floats now print OK.

_estack = 0x20020000; /* end of RAM */

I believe that ARM require that the stack is 8 byte aligned.

Cheers,

Mark

stm32cube-t · ‎2015-06-08

Posted on June 08, 2015 at 18:31

Hello,

Can you please indicate which toolchain and STM32CubeMX versions you are using?

Thanks.

Tesla DeLorean · ‎2015-06-08

Posted on June 08, 2015 at 18:56

One of the GNU chains.

It was discussed recently in another thread, can't find it right now.

It should be aligned, at the very least 4-byte to the top of memory, as it predecrements.

ARM has mentioned an 8-byte alignment in the past, not sure that's rigorously enforced, and perhaps more salient in CPU/FPU situations where a 64-bit load/store is used.

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Tesla DeLorean · ‎2015-06-08

Posted on June 08, 2015 at 19:01

Here's one from a year ago

https://my.st.com/public/STe2ecommunities/mcu/Lists/STM32Java/Flat.aspx?RootFolder=https://my.st.com/public/STe2ecommunities/mcu/Lists/STM32Java/STM32Cube%20stack%20alignment%20problem&FolderCTID=0x01200200770978C69A1141439FE559EB459D758000F9A0E3A95BA69146A17C2E80209ADC21&currentviews=179

This perhaps the one I had in mind

https://my.st.com/public/STe2ecommunities/mcu/Lists/cortex_mx_stm32/Flat.aspx?RootFolder=https://my.st.com/public/STe2ecommunities/mcu/Lists/cortex_mx_stm32/Unable%20to%20get%20STM32F103ZE%20chip%20working&FolderCTID=0x01200200770978C69A1141439FE559EB459D7580009C4E14902C3CDE46A77F0FFD06506F5B&curren...

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markb · ‎2015-06-08

Posted on June 08, 2015 at 19:33

Hi,

I am using cube version 4.8.0. I am generating code for SW4STM32 but I am not using that toolchain. Instead I am using

arm-none-eabi-gcc (GNU Tools for ARM Embedded Processors) 4.9.3 20150303 (release).

I think this has been wrong for a while now.

Cheers,

Mark

stm32cube-t · ‎2015-07-01

Posted on July 01, 2015 at 13:43

Hello,

Thank you for your feedback. This problem will be resolved in next CubeMX release 4.9.