> Hello. > > I need to call fft (fast fourier transform) functions in my rtthreads. I found > in the internet a packet of fft functions called FFTW which I've been using in > normal linux without any problems. FFTW uses math functions so you must be link > your programs with -lm, in addition to -lfftw. > But when I try to call FFTW from rtthreads I get some problems. In inserting the > module y get some unresolved symbols in functions like malloc, fflush, free, > exit, stderr, stdout, fprintf, sprintf. Does this mean that FFTW can't be used > in RTLinux?
fft can be run in linux but dynamik memory allocation is a problem - also some of the other standard C functions you are trying to call are not available in kernel space - so you will have to modify the fft code - you will not be able to just statically link it all into the kernel module (doing this with libm is bad enough...) > Anyway, I can get rid of those unresolved symbols by linking in de C library > -lc. But I get some new unresolved symbols in --udivdi3, --umoddi3 and --moddi3 You might get rid of the compiler errors by linking in libc but it will not work - you can't do fprintf or malloc/free in a rt-thread. > (this last one isn't new). How can I get rid of those? > If the final conclusion is that I can't use FFTW in rtlinux, does anyone know > about some pack of fft functions which will work? > numeric recipes section 12.2 and 12.3 - online at http://www.ulib.org/webRoot/Books/Numerical_Recipes/bookcpdf.html (hope the URL is right...) hofrat -- [rtl] --- To unsubscribe: echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR echo "unsubscribe rtl <Your_email>" | mail [EMAIL PROTECTED] -- For more information on Real-Time Linux see: http://www.rtlinux.org/
