Assembler error after upgrade to Ver 2.1: bad instruction `rtc ldr sp,=_estack'

erastusC · ‎2026-03-05

Good day,

After I did an upgrade to the latest version when I compile I get this error.

Where can I get documentation on this.

Never did an upgrade without issues.

make -j48 all

arm-none-eabi-gcc -mcpu=cortex-m4 -g3 -DDEBUG -c -x assembler-with-cpp -MMD -MP -MF"Startup/startup_stm32f411ceux.d" -MT"Startup/startup_stm32f411ceux.o" --specs=nano.specs -mfpu=fpv4-sp-d16 -mfloat-abi=hard -mthumb -o "Startup/startup_stm32f411ceux.o" "../Startup/startup_stm32f411ceux.s"

../Startup/startup_stm32f411ceux.s: Assembler messages:

../Startup/startup_stm32f411ceux.s:61: Error: bad instruction `rtc ldr sp,=_estack'

make: *** [Startup/subdir.mk:19: Startup/startup_stm32f411ceux.o] Error 1

Andrew Neil · ‎2026-03-05

Note that everybody can see all posts - there's no need to repeat the same thing in separate replies to each person.

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@erastusC wrote:
I did a search in the C code .

As noted above, it's not in the C code - it's an Assembler error.

The error message tells you this, and identifies the file & line number where the error occurred:

../Startup/startup_stm32f411ceux.s: Assembler messages:

../Startup/startup_stm32f411ceux.s:61: Error: bad instruction `rtc ldr sp,=_estack'

So the file name is startup_stm32f411ceux.s

That file is located in the Startup folder

The :61: is the line number within the file.

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.

View solution in original post

mƎALLEm · ‎2026-03-05

Hello,

@erastusC wrote:

After I did an upgrade to the latest version when I compile I get this error.

last update of what? tool? software package? which one?

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TDK · ‎2026-03-05

Looks like "rtc" was typed somewhere it shouldn't have been. Maybe that window was active when you didn't expect.

Create a new project and copy the startup file to recover.

I don't think this has anything to do with upgrading STM32CubeIDE. The compiler hasn't changed. This is a compiler error. If the file is the same, it will produce the same results.

If you feel a post has answered your question, please click "Accept as Solution".

Andrew Neil · ‎2026-03-05

@TDK wrote:
This is a compiler error. .

Actually, it's an Assembler error:

../Startup/startup_stm32f411ceux.s: Assembler messages:

../Startup/startup_stm32f411ceux.s:61: Error: bad instruction `rtc ldr sp,=_estack'

@TDK wrote:
Looks like "rtc" was typed somewhere it shouldn't have been.

Indeed.

I think the code should be something like this:

Reset_Handler:
 ldr r0, =_estack
 mov sp, r0 /* set stack pointer */

@TDK wrote:
Maybe that window was active when you didn't expect.

Possibly due to this long-running issue: Jumping to random file after pressing Run button

@erastusC - Specifically, this.

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.

TDK · ‎2026-03-05

Thank you for the pedantic correction. I'm not sure it changes the overall message.

If you feel a post has answered your question, please click "Accept as Solution".

erastusC · ‎2026-03-05

I did a search in the C code and there is no error showing or I could not find any place where rtc was incorrectly typed. It gets generated when it gets compiled.

I have no idea to search for it as I did not work in assembler.

erastusC · ‎2026-03-05

I did a search in the C code and there is no error showing or I could not find any place where rtc was incorrectly typed. It gets generated when it gets compiled.

I have no idea to search for it as I did not work in assembler.

TDK · ‎2026-03-05

It's in your "startup_stm32f411ceux.s" file.

If you feel a post has answered your question, please click "Accept as Solution".

Andrew Neil · ‎2026-03-05

Note that everybody can see all posts - there's no need to repeat the same thing in separate replies to each person.

You can mention multiple people in a post using '@'

@erastusC wrote:
I did a search in the C code .

As noted above, it's not in the C code - it's an Assembler error.

The error message tells you this, and identifies the file & line number where the error occurred:

../Startup/startup_stm32f411ceux.s: Assembler messages:

../Startup/startup_stm32f411ceux.s:61: Error: bad instruction `rtc ldr sp,=_estack'

So the file name is startup_stm32f411ceux.s

That file is located in the Startup folder

The :61: is the line number within the file.

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.

erastusC · ‎2026-03-05

Thanks a mil. There was a RTC not sure where that came from.

I copied your software and voila it works.

Many thanks