debug/programs/interrupt.c

   1 #include "init.h"
   2 #include "encoding.h"
   3
   4 static volatile unsigned interrupt_count;
   5 static volatile unsigned local;
   6
   7 static unsigned delta = 0x100;
   8 void *increment_count(unsigned hartid, unsigned mcause, void *mepc, void *sp)
   9 {
  10     interrupt_count++;
  11     // There is no guarantee that the interrupt is cleared immediately when
  12     // MTIMECMP is written, so stick around here until that happens.
  13     while (csr_read(mip) & MIP_MTIP) {
  14         MTIMECMP[hartid] = MTIME + delta;
  15     }
  16     return mepc;
  17 }
  18
  19 int main()
  20 {
  21     interrupt_count = 0;
  22     local = 0;
  23     unsigned hartid = csr_read(mhartid);
  24
  25     set_trap_handler(increment_count);
  26     MTIMECMP[hartid] = MTIME - 1;
  27     enable_timer_interrupts();
  28
  29     while (1) {
  30         local++;
  31     }
  32 }