Lpc2000

Dear group members,
Have an activation problem with the secondary JTAG interface.
Using the Philips application note AN10255 I tried to convert the 
assembly code of their ARM assembler to the GNU assembler with some 
support of Rowley. The evaluation board is from Olimex (P1).
The code is transferred via JTAG1 to the Flash memory and shows no
errors doing that.
But when changing connector to the JTAG2 interface (secondary) this 
is not activated by the new code.
It seems to be a task of the right checksum. 
But I don't know how to calculate it.

Can somebody explain this to me ?

Here the converted Philips code :

.section .vectors, "ax"
  .code 32
  .align 0

/*********************************************************************
********
 * Exception 
Vectors                                                         *
 
**********************************************************************
*******/
_vectors:
  ldr pc, [pc, #reset_handler_address - . - 8]  /* reset */
  ldr pc, [pc, #undef_handler_address - . - 8]  /* undefined 
instruction */
  ldr pc, [pc, #swi_handler_address - . - 8]    /* swi handler */
  ldr pc, [pc, #pabort_handler_address - . - 8] /* abort prefetch */
  ldr pc, [pc, #dabort_handler_address - . - 8] /* abort data */
#ifdef VECTORED_IRQ_INTERRUPTS
  .word 0xB9205F84                              /* boot loader 
checksum */
  ldr pc, [pc, #-0xFF0]                         /* irq handler */
#else
  .word 0xB8A06F60                              /* boot loader 
checksum */
  ldr pc, [pc, #irq_handler_address - . - 8]    /* irq handler */
#endif
  ldr pc, [pc, #fiq_handler_address - . - 8]    /* fiq handler */

reset_handler_address:
  .word reset_handler
undef_handler_address:
  .word undef_handler
swi_handler_address:
  .word swi_handler
pabort_handler_address:
  .word pabort_handler
dabort_handler_address:
  .word dabort_handler
irq_handler_address:
  .word irq_handler
fiq_handler_address:
  .word fiq_handler

  .section .init, "ax"
  .code 32
  .align 0

/*********************************************************************
*********
 
*                                                                     
       *
 * Default exception 
handlers                                                 *
 
*                                                                     
       *
 
**********************************************************************
********/

reset_handler:
  LDR         R0, JTAG2       /* Load R0 with 0x55400000 */
  LDR         R1, PINSEL1     /* Load R1 with oxE002C004 */
  LDR         R0, [R1]        /* Load PINSEL1 with 0x55400000 */

loop:
  b loop

JTAG2:
  .word         0x55400000
PINSEL1:
  .word         0xE002C004

/*********************************************************************
*********
 
*                                                                     
       *
 * Default exception 
handlers                                                 *
 * These are declared weak symbols so they can be redefined in user 
code.     * 
 
*                                                                     
       *
 
**********************************************************************
********/

undef_handler:
  b undef_handler
  
swi_handler:
  b swi_handler
  
pabort_handler:
  b pabort_handler
  
dabort_handler:
  b dabort_handler
  
irq_handler:
  b irq_handler
  
fiq_handler:
  b fiq_handler

  .weak undef_handler, swi_handler, pabort_handler, dabort_handler, 
irq_handler, fiq_handler
  .end  

Thank's for your help.

Roland