Need CONFIG_DEBUG_INFO=y in kernel configuration for the following to work.

Magic numbers:

• 0x80000000 – here the kernel is loaded
• 0x80008000 – here we jump after it's been decompressed
• 0x80027000 – 'arm-linux-gnu-objdump -x vmlinux' says that .text starts here (if .text.head is at 0x80008000)

Script for gdb session:

target remote 127.0.0.1:1234
break *0x80008000

To debug compression-related stuff from the very beginning (start, arch/arm/boot/compressed/head.S) till start_kernel:

add-symbol-file ~/ws/osll/omap/20090610/linux-omap-2.6/arch/arm/boot/compressed/vmlinux 0x80000000

To debug kernel from stext (arch/arm/kernel/head.S) until MMU is active:

add-symbol-file ~/ws/osll/omap/20090610/linux-omap-2.6/vmlinux 0x80027000 -s .text.head 0x80008000

To debug kernel from start_kernel (init/main.c):

add-symbol-file ~/ws/osll/omap/20090610/linux-omap-2.6/vmlinux 0xc0027000