OK this is the sparc64 part of the dietlibc. It seams to work ONLY with gcc 3 out of the box gcc 2.95.4 needed some heavy commandline option settings. -Wl,-melf64_sparc -Wa,-Av9 -mcpu=v9 -D__arch64__ This __arch64__ define is default in 3.0 but missing in 2.95.4