sim/testsuite/d30v-elf/tick.s

   1         .globl _start
   2         #
   3         # NOTE: Registers r10-r11 are reserved for the interrupt handler
   4         #       while the others can be used by the main loop/start code.
   5
   6 _start:
   7         # patch the external interrupt handlers entry
   8         add r1, r0, handler
   9         ldw r2, @(r1, 0)
  10         ldw r3, @(r1, 4)
  11         add r1, r0, 0xfffff138
  12         stw r2, @(r1, 0)
  13         stw r3, @(r1, 4)
  14
  15         # enable external interrupts - cr0 == PSW
  16         mvfsys r2, cr0
  17         or r2, r0, 0x04000000
  18         mvtsys cr0, r2
  19
  20
  21         # wait for flag to be set
  22 loop:
  23         add r2, r0, flag
  24         ldw r3, @(r2, 0)
  25         bratzr r3, loop
  26
  27         # clear the flag
  28         stw r0, @(r2, 0)
  29
  30         add r2, r0, tick
  31         # putstr
  32         .long 0x0e000001, 0x00f00000
  33
  34         bra loop
  35
  36         # finished
  37         add r2, r0, r0 || nop
  38         .long 0x0e000004, 0x00f00000
  39
  40
  41 handler:
  42         jmp real_handler
  43 real_handler:
  44         add r10, r0, 1
  45         add r11, r0, flag
  46         stb r10, @(r11,0)
  47         reit
  48
  49
  50 flag:   .long 0
  51 tick:   .ascii "Tick\r\n"