On Tue, Jul 30, 2013 at 01:59:29PM +0200, Andre Przywara wrote:
On 07/30/2013 12:02 AM, Christoffer Dall wrote:
On Wed, Jul 10, 2013 at 01:54:18AM +0200, Andre Przywara wrote:
[...]
+_hyp_trap:
- mrs lr, elr_hyp @ for older asm: .byte 0x00, 0xe3, 0x0e, 0xe1
this comment just confuses: either make it intelligent to support an older compiler or just get rid of these byte encodings. You can always disassemble the file and lookup the byte code with a modern compiler to get back to the byte encoding.
Well, I used a Debian 6 cross compiler before, which didn't support these instructions. After your remark I updated the system to Debian 7, but found it not appropriate to ask any user to do the same just to use a fixed, non-parametrized assembly instruction. I have the feeling that there are quite some users out there who cannot and don't want to easily update their compiler. So I decided to leave the workaround in the comment to give a hint to a quick fix.
ok, so if Debian's built-in cross compilers are indeed that old and we want to support those (that's ok with me), then let's fix it properly.
By "making it intelligent" you mean a macro which does some version checking and inserts the .byte sequence if needed? Are there any archetypes of such code?
Yes, see arch/arm/include/asm/opcodes-*.h
-Christoffer