io.c

cpu的源码

#include "io.h"

#define ADDR_OUTPUT   0x7FFFFFF8

#define load(address, load) { \
volatile unsigned char *ctrlload = (unsigned char *) address; \
load =  *ctrlload;}

#define store(address,save) { \
volatile unsigned char *ctrlstore = (unsigned char *) address; \
*ctrlstore = save;}

int read(int io, void *buf, int count) {
  /* FIX ME ! */ 

  return 0;
}

int write(int io, const void *buf, int count) {
  int i;
  int addr;

  switch (io) {
  
  case IO_TERM :
    addr = 1;
    break;
    
  case IO_FILE : 
    addr = 2;
    break;
   
  case IO_FD3  :
    addr = ADDR_OUTPUT;
    break;

  case IO_OCP  :
    /* FIX ME ! */ 
    break;
  }

  for (i = 0; i < count; i++) {
    store(addr, *((unsigned char*)buf + i));
  }

  return i;
}