Cortex-M3 Yotta's or Mbed-os's target


I’m such a newbie with mbed-os or yotta so please don’t blame me for that.
I have a question, is this possible in Mbed-os or yotta to compile program for only core as a target? I need to compile program for Cortex-M3. Only targets which I noticed is full microcontroller and mostly with Cortex M0 and M4 as a core (especially in yotta). Well maybe somebody knows how to make core as a target for Mbed-os or Yotta?

As I said I’m newbie so if this is impossible or something please tell me
Have a nice day!


Hi Barbara,

What do you expect exactly? You can’t ‘just build for a core’, you’ll always need to build for a target.

Maybe I should describe my issue better. I’m currently working on some driver for cortex-M3 (SD and I2C).

I have simulation Cortex-M3. I need to compile my program for that simulation. So it’s not a microcontroller or something it’s just a core simulation (configurated of course) .
I need to compile program for this.

I’m currently trying to create some target in yotta. My target only has Cortex-M3 and gcc specificated.
I’m curious if that solution makes any sense.

I compiled my simple program already and I got some warning:
“warning: cannot find entry symbol _start; defaulting to 0000000000008000”

So in conclusion:

  • is this possible to compile program with Cortex-M3 as a target?
  • Have you got any idea how to create a target only with Cortex-M3 as a core?
  • Does that warning have any connections with my target?