Compiler Flags for Building Custom Newlib - Compiler Flags for Building Custom Newlib Description “Common BSP Tasks” in the Nios II Software Build Tools chapter of the Nios II Software Developer’s Handbook describes how to compile a custom version of the newlib library. However, it does not list the compiler flags that must be selected to generate the correct library. Resolution The missing information is as follows: The Nios II EDS provides a number of precompiled newlib implementations. The provided libraries are precompiled with every viable combination of the GCC compiler flags shown in . When you create a BSP with a precompiled newlib, the Nios II SBT selects the newlib matching your BSP’s compiler settings. When you create a custom newlib, you must ensure that the compiler flags listed in match your BSP’s settings. GCC Compiler Options for Newlib Option Name Purpose -pg Link for profiling with gprof -EB Generate big-endian code -mstack-check Enable stack checking -mno-hw-mul Disable use of the mul family of instructions -mhw-mulx Enable use of the mulx family of instructions -mcustom-fpu-cfg Use a floating point custom instruction The Nios II-specific compiler flag -mcustom-fpu-cfg requires the Nios II processor core to be implemented with the floating-point custom instruction as specified in the flag argument. The compiler flag can have one of the following two argument values: -mcustom-fpu-cfg=60-1 --Use the Nios II floating-point custom instruction without divider -mcustom-fpu-cfg=60-2 --Use the Nios II floating-point custom instruction with divider For details about the Nios II-specific compiler flags -mstack-check , -mno-hw-mul , and -mhw-mulx , refer to “Altera Nios II Options” in Using the GNU Compiler Collection (GCC) , installed with the Nios II EDS. For details about the -pg compiler flag, refer to “Compiling a Program for Profiling” in GNU Profiler , installed with the Nios II EDS. To find the installed documentation, on the Windows Start menu, click Programs > Altera > Nios II EDS <version> > Nios II <version> Documentation , and then click Literature . Custom Fields values: ['novalue'] Troubleshooting novalue True ['Nios® II (Classic) Processor', 'Nios® II Processor'] ['FPGA Dev Tools Quartus II Software'] novalue 10.0 ['Programmable Logic Devices'] ['Nios® II Embedded Design Suite (EDS)'] ['novalue'] ['novalue']