On Sat, 30 Jun 2007 23:36:23 +0100 Simon Pickering <[EMAIL PROTECTED]> wrote:
> The next question is how to implement the undefined instruction > exception handler. Is 0x00000004 (or optionally 0xFFFF0004) writable (I > need to write some test code really) from a user program? Assuming it > is, then it should be reasonably straightforward to write an exception > handler and to use this to branch to some code to handle the > un-implemented Java instructions. If it's not possible to write to this > memory, how do programs like gdb hook exceptions? Have I missed some > unseen stumbling-block here? GDB doesn't handles exceptions because they are mapped as signal at kernel level. This is a posix abstraction. Unexpected ones are handled as 'Segmentation Fault'. Exceptions must be handled at ring0. You should compile a new kernel. No idea if is easy to do the same into a kernel module, but you can directly write assembly in /dev/mem into the interrupt vector and launch these new syscalls to trigger your snippets. I have never hooked an exception on ARM or Linux, so I should probably need to read more kernel :) > I seem to remember seeing a list of those instructions that are handled > by the hardware, does anyone have a link? (though obviously writing a > piece of code to interate through and see which cause exceptions is > quite possible). Take a look here: http://www.gelato.unsw.edu.au/lxr/source/arch/arm/mm/fault.c --pancake _______________________________________________ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
