ARM's BE8 format introduces yet another amusing variation on endianness, 
in which the data is big-endian while the code is little-endian. The 
bits for binutils went in a while ago, this patch extends GDB. In 
theory, we should change functions like read_memory_unsigned_integer to 
have forms for both code and data; in lieu of such a sweeping change for 
what is rather a narrow use, I introduced macros to swap instruction 
bytes after reading. Fortunately, GDB doesn't often need to examine 
instructions! This was tested by passing --be8 to the linker and running 
under a hacked qemu simulator, no hardware being available yet.

Review-wise, Richard Earnshaw is listed as ARM maintainer, not sure if 
he's active here?

2008-08-04  Stan Shebs  <stan@codesourcery.com>

    ARM BE8 support.
    * disasm.c (gdb_disassemble_info): Set endian_code.
    * gdbarch.sh (gdbarch_info): New field byte_order_for_code.
    * gdbarch.h, gdbarch.c: Regenerate.
    * arch-utils.c (initialize_current_architecture): Set the
    default byte_order_for_code.
    (gdbarch_info_init): Ditto.
    (gdbarch_info_fill): Ditto.
    * arm-tdep.c (SWAP_INT, SWAP_SHORT): New macros.
    (thumb_analyze_prologue): Swap halfword if code endianness is
    different from general endianness.
    (arm_skip_prologue): Similarly.
    (arm_scan_prologue): Ditto.
    (thumb_get_next_pc): Ditto.
    (arm_get_next_pc): Ditto.
    (arm_gdbarch_init): Set byte_order_for_code from BE8 flag,
    choose correct endianness for breakpoints.