9 axis fusion

Hi,

I am using a MPU9250 and a cortex M0. I would like to port the Motion Driver 6.0 to it but I have less than 4kbytes RAM available to do the Sensor fusion.

It is possible to do a 9 axis fusion with only 4kbytes of RAM?
If it is not, is there a way to use less RAM ? I just want to read quite accurate quaternions.

I also tried to add the librairy libmpllib.a to my project on Keil. I have this error :
"._buildsoundlab.axf: Error: L6366E: quaternion_supervisor.o attributes are not compatible with the provided cpu and fpu attributes .
Object quaternion_supervisor.o contains Build Attributes that are incompatible with the CPU attributes.
Tag_CPU_arch = ARM v7E-M (=13)
Tag_CPU_arch_profile = The microcontroller profile 'M' (e.g. for Cortex M3) (=77)
Tag_THUMB_ISA_use = Thumb2 instructions were permitted (implies Thumb instructions permitted) (=2)
._buildsoundlab.axf: Error: L6242E: Cannot link object quaternion_supervisor.o as its attributes are incompatible with the image attributes.
... wchart-16 clashes with wchart-32.
... packed-enum clashes with enum_is_int."

The librairy should be compatible with CM0. Is there a way to fix this error?

Thanks in advance.