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--- avr:usage [2013/09/18 12:56] – sdolt
+++ avr:usage [2014/07/07 16:09] – [Liens utiles] sbolay
@@ Line 137: / Line 137: @@
 ^Description^Liens^
 |Calculateur de fusible|[[http://www.engbedded.com/fusecalc/]]|
+|Comprendre les registres d'entrée/sortie|[[http://iamsuhasm.wordpress.com/tutsproj/avr-gcc-tutorial/]]|
+===== FAQ =====
+see error  "multiple definition of `_floatsisf'"
+look especially to the position of the **-lm** flag
+<code bash>
+$ avr-gcc -mmcu=attiny85 -o main.elf main.c
+/usr/local/CrossPack-AVR-20130212/lib/gcc/avr/4.6.2/../../../../avr/lib/avr25/libc.a(floatsisf.o):../../../libm/fplib/floatsisf.S:46: multiple definition of `__floatsisf'
+/usr/local/CrossPack-AVR-20130212/lib/gcc/avr/4.6.2/avr25/libgcc.a(_si_to_sf.o):/Users/cs/Developer/Repos/Microcontroller/CrossPack-AVR/compile/avr-gcc-4.6.2/build-objects/avr/avr25/libgcc/../../.././gcc/fp-bit.c:1336: first defined here
+collect2: ld returned 1 exit status
+$ avr-gcc -mmcu=attiny85 -lm -o main.elf main.c
+/usr/local/CrossPack-AVR-20130212/lib/gcc/avr/4.6.2/../../../../avr/lib/avr25/libc.a(floatsisf.o):../../../libm/fplib/floatsisf.S:46: multiple definition of `__floatsisf'
+/usr/local/CrossPack-AVR-20130212/lib/gcc/avr/4.6.2/avr25/libgcc.a(_si_to_sf.o):/Users/cs/Developer/Repos/Microcontroller/CrossPack-AVR/compile/avr-gcc-4.6.2/build-objects/avr/avr25/libgcc/../../.././gcc/fp-bit.c:1336: first defined here
+collect2: ld returned 1 exit status
+$ avr-gcc -mmcu=attiny85 -o main.elf main.c -lm
+$
+</code>