.text

 .global _start

 _start:

     b reset

     ldr pc, _undefined_instruction

     ldr pc, _software_interrupt

     ldr pc, _prefetch_abort

     ldr pc, _data_abort

     ldr pc, _not_used

     ldr pc, _irq

     ldr pc, _fiq

 _undefined_instruction: .word undefined_instruction

 _software_interrupt:.word software_interrupt

 _prefetch_abort:.word prefetch_abort

 _data_abort:.word data_abort

 _not_used:.word not_used

 _irq:.word irq

 _fiq:.word fiq

 undefined_instruction:

     nop

 software_interrupt:

     nop

 prefetch_abort:

     nop

 data_abort:

     nop

 not_used:

     nop

 irq:

     nop

 fiq:

     nop

 reset:

     bl set_svc

 set_svc:

     mrs r0, cpsr

     bic r0, r0, #0x1f

     orr r0, r0, #0xd3

     msr cpsr, r0