This build error was fixed by this commit: http://git.qemu.org/qemu.git/commit/?id=02615337ef295443daa03233e492194e289a807e
** Changed in: qemu Status: New => Fix Committed -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/670776 Title: Build errors on TEGRA2(ubuntu), testandset() Status in QEMU: Fix Committed Bug description: Build errors on TEGRA2(ubuntu) /tmp/ccqt9Y5t.s: Assembler messages: /tmp/ccqt9Y5t.s:1899: Error: selected processor does not support Thumb mode 'swp r4, r4, [r2]' /tmp/ccqt9Y5t.s:1974: Error: selected processor does not support Thumb mode 'swp r5, r5, [ip]' make[1]: *** [exec.o Error 1 qemu-lock.h #elif defined(__arm__) static inline int testandset (int *spinlock) { register unsigned int ret; __asm__ __volatile__("swp %0, %1, [%2]" : "=r"(ret) : "0"(1), "r"(spinlock)); return ret; }