semantic: 0.197 other: 0.137 device: 0.095 vnc: 0.084 socket: 0.079 network: 0.058 files: 0.052 debug: 0.052 PID: 0.050 permissions: 0.049 performance: 0.044 graphic: 0.044 boot: 0.037 KVM: 0.024 debug: 0.565 files: 0.113 network: 0.065 performance: 0.058 socket: 0.039 other: 0.034 PID: 0.029 device: 0.025 semantic: 0.024 vnc: 0.013 graphic: 0.010 boot: 0.010 permissions: 0.008 KVM: 0.006 qemu-system-arm exits when cortex-m4 floating point used and irq occurs qemu-system-arm exits with "...Secure UsageFault with CFSR.NOCP because NSACR.CP10 prevents stacking FP regs ...taking pending nonsecure exception 3 Taking exception 7 [Breakpoint] qemu: fatal: Lockup: can't escalate 3 to HardFault (current priority -1)" when emulating Cortex-m4, executing at least 1 floating point instruction, and then an irq (e.g. sys tick) occurring. CPACR.CP10 and CPACR.CP11 are set to 0x3 respectively prior to executing the fp instructions. NOTE: NSACR does not appear to be a cortex m4 register. Attached is a simplified elf to repro the issue. The qemu command line is: "qemu-system-arm --gdb tcp::1234 -cpu cortex-m4 -machine lm3s6965evb -nographic -semihosting-config enable=on,target=native -kernel QemuExitWhenUsingFPAndIRQOccurs.elf -d int" I think this patch should fix this bug: https://