Hi Jim, On Fri, Dec 9, 2011 at 10:59 PM, Jim Cromie <jim.cromie@gmail.com> wrote:
hi folks,
out of habit, I build my kernels to a build tree ie use make O=../build-foo just once, then cd ../build-foo, and thereafter run make there
this doesnt play nice with objdump -S --source Display source code intermixed with disassembly, if possible. Implies -d.
it seems its not possible unless the source and obj are in the same file. GDB manages to find the source, whats missing in objdump ?
FWIW, Id love a micro-tutorial on this, anyone know how to display, dissect the obj file, debuginfo etc ? or can recommend some on-line tome that gets into it at some breadth and depth ? many many search hits are for quick Q&A that doesnt get deeper than a puddle.
So I normally do out of tree builds, but I always run make from the source tree and specify the O= option. I'm using 3.0.1, and in menuconfig, I went into "Kernel hacking", enabled "Kernel debugging" and then "Compile the kernel with debug info". The "Compile the kernel with debug info" option enables CONFIG_DEBUG_INFO which cause the kernel source to be compiled with the -g option which adds the debugging information needed to find the source from the objects. I normally cross compile for the ARM, so I then cd'd into my build tree and tried arm-linux-gnueabi-objdump -S on a few object files and they all gave intermingled C and assembler listings. I tried it using your method and it seemed to work fine for me as well. -- Dave Hylands Shuswap, BC, Canada http://www.davehylands.com