The users's guide that ADI has provided for FreeRTOS says to use this file in a linker directive when linking FreeRTOS projects. The claim is that it prevents default driver libraries from being linked.
I'm trying to figure out how it does that. The file itself contains no comments, and the documentation about this "specs" format is quite complex. Here's the first part.
%{!nostdlib: \
%{!mno-adi-sys-libs: \
%{mproc=ADSP-SC570: apt-sc570.o%s} \
%{mproc=ADSP-SC571: apt-sc571.o%s} \
%{mproc=ADSP-SC572: apt-sc572.o%s} \
%{mproc=ADSP-SC573: apt-sc573.o%s} \
%{mproc=ADSP-SC582: apt-sc582.o%s} \
%{mproc=ADSP-SC583: apt-sc583.o%s} \
%{mproc=ADSP-SC584: apt-sc584.o%s} \
%{mproc=ADSP-SC587: apt-sc587.o%s} \
%{mproc=ADSP-SC589: apt-sc589.o%s} \
%{mproc=ADSP-SC58*: -lfftacc} \
%{mproc=ADSP*: -lssl -losal -lrtadi} \
%{mproc=AD*: -lm} \
} -lc \
}
I think what it is saying is that "IF the -nostdlib flag IS NOT SET *AND* the -no-adi-sys-libs flag IS NOT SET, THEN use these default mmu tables (apt*.o) and use these default libraries".
If I have that right, then there is a problem, because in all these demo projects, neither of these flags are set (nor are we advised to set them), thus the default libraries are getting loaded anyway. Yes, I verified this by looking at a map dump, there is a lot of device code being loaded from libssl, even though I specified all my devices with add-in in the System Configuration Overview.
But maybe it doesn't matter, because the source to the FreeRTOS libraries are effectively linked-in via virtual directory links, and this code will get linked before the linker starts opening libraries. That explains why some of the Demo projects that don't have use the freertos.specs file in their linker settings work just fine.
