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        .globl _start

        #

        # NOTE: Registers r10-r11 are reserved for the interrupt handler

        #       while the others can be used by the main loop/start code.

_start:

        # patch the DBT handler

        add r1, r0, handler

        ldw r2, @(r1, 0)

        ldw r3, @(r1, 4)

        # DBT vector address

        add r1, r0, 0xfffff120

        stw r2, @(r1, 0)

        stw r3, @(r1, 4)

        # try out the breakpoint/return

        add r2, r0, 47

        #dbt

        nop

        .long 0x00b00000

        nop

        # exit with what ever the breakpoint hander set r2 to.

        nop

        .long 0x0e000004

        nop

handler:

        jmp real_handler

        # The Breakpoint handler sets r2 to 0 if PSW was set correctly.

real_handler:

        mvfsys r2, cr0

        sub r2, r0, 0x08000000

        #rtd

        nop

        .long 0x00a00000

        nop