>> Hello, I'm working with the BeagleBone and gcc-4.5.4 on Gentoo. If I >> try to compile the 3.6 kernel with CONFIG_THUMB2_KERNEL, I get: >> >> arch/arm/boot/compressed/head.S:127: Error: selected processor does >> not support requested special purpose register -- `mrs r2,cpsr' >> arch/arm/boot/compressed/head.S:134: Error: selected processor does >> not support requested special purpose register -- `mrs r2,cpsr' >> arch/arm/boot/compressed/head.S:136: Error: selected processor does >> not support requested special purpose register -- `msr cpsr_c,r2' >> >> This post indicates that mainline gcc does not currently support thumb2: >> >> https://groups.google.com/d/msg/beagleboard/P52fgMDzp8A/vupzuh71vdYJ >> >> However, this indicates that thumb2 has been supported since 4.3: >> >> http://gcc.gnu.org/gcc-4.3/changes.html >> >> Can anyone clear this up? > > The errors are coming from an assembler file that is not part of the > GCC sources. Are those instructions valid for Thumb2? I don't know. > If they are valid, then the issue is with the assembler, which is not > part of GCC; check the version of the GNU binutils that you have > installed. If those instructions are not valid, then you need to > change your source.
Thanks Ian. I'm using binutils-2.22-r1. Do you happen to know which version of binutils should support thumb2? - Grant
