> Do you have a test binary (plus qemu command line) you > can send me?
sure: https://dl.dropboxusercontent.com/u/78151643/minimal.elf for reference, when running the code with Bechus (2.1.1), the result is: ilg-mbp:build ilg$ /Users/ilg/bin/qemu-system-arm -machine stm32-p103 -nographic -monitor null -serial null -semihosting -m 513M -kernel qemu_osx_aep_gcc_minimal_Debug/minimal.elf LED Off os::diag::Trace::Trace() @20000854 livius.net / Minimal v1.1.1, Oct 27 2014 19:57:45 uOS++ v5.1.7631, GCC 4.8.3 20131129 (release) [ARM/embedded-4_8-branch revision 205641] QEMU Processor Emulator Synthetic ARM Cortex-M3 Cooperative scheduler, 1000 ticks/second. ... exactly the same binary, with 2.1.50: ilg-mbp:build ilg$ /Users/ilg/Work/NoBackup/qemu/qemu.git/arm-softmmu/qemu-system-arm -machine lm3s6965evb -nographic -monitor null -serial null -semihosting -m 513M -kernel qemu_osx_aep_gcc_minimal_Debug/minimal.elf qemu: Unsupported SemiHosting SWI 0x00 R00=00000000 R01=00000000 R02=00000000 R03=00000000 R04=00000000 R05=00000000 R06=00000000 R07=200ffed8 R08=00000000 R09=00000000 R10=00000000 R11=00000000 R12=00000000 R13=200ffed8 R14=000022c5 R15=0000157c PSR=60000173 -ZC- T svc32 Abort trap: 6 regards, Liviu