speedtest.c

#define _GNU_SOURCE

#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <stdbool.h>
#include <unistd.h>
#include <termios.h>
#include <error.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#include <time.h>

#define BUF_SIZE 1024

int readn (int serial_port, uint8_t *buf, size_t nbytes) {
  uint8_t rxbuf[BUF_SIZE];
  uint8_t *p = buf;
  int rc;
  size_t i = 0, j = 0;
  int escape = 0;
  do {
    rc = read(serial_port, rxbuf, BUF_SIZE);
    if (rc == -1) {
      exit(EXIT_FAILURE);
    }
    for (i = 0; i < rc; i++) {
      if (rxbuf[i] == 0x3a) {
        escape = 1;
      } else {
        if (escape == 1) {
          escape = 0;
          if (rxbuf[i] == 0x3b) {
            buf[j++] = 0x3a;
          } else {
            buf[j++] = rxbuf[i];
          }
        } else {
          buf[j++] = rxbuf[i];
        }
      }
    }
  } while (j < nbytes);
  return 0;
}

int writen(int serial_port, uint8_t *buf, size_t nbytes) {
  uint8_t tbuf[BUF_SIZE];
  int rc;
  size_t i = 0, j = 0;
  tbuf[j++] = 0x3a;
  tbuf[j++] = 0x3c;
  for (i = 0; i < nbytes; i++) {
    tbuf[j++] = buf[i];
    if (buf[i] == 0x3a) {
      tbuf[j++] = 0x3b;
    }
  }
  uint8_t *p = tbuf;
  do {
    rc = write(serial_port, p, j);
    if (rc == -1) {
      perror("");
      exit(EXIT_FAILURE);
    }
    p += rc;
    j -= rc;
  } while (j > 0);
  return 0;
}

int main(int argc, char **argv) {
  int rc;
  int serial_port = open(argv[1], O_RDWR);
  if (serial_port == -1) {
    perror("");
    exit(EXIT_FAILURE);
  }

  struct termios tp;
  if (tcgetattr(serial_port, &tp) != 0) {
    perror("");
    exit(EXIT_FAILURE);
  }
  cfmakeraw(&tp);
  cfsetspeed(&tp, B2500000);
  rc = tcsetattr(serial_port, TCSANOW, &tp);


  uint8_t rbuf[BUF_SIZE];
  uint8_t tbuf[BUF_SIZE];

  size_t i = 0, j = 0;

  /* 1. cmd = 0xff */
  tbuf[j++] = 0xab; /* src */
  tbuf[j++] = 0x00; /* dst */
  tbuf[j++] = 0x1c; /* flags */
  tbuf[j++] = 0xff; /* cmd */
  tbuf[j++] = 0xdb;
  tbuf[j++] = 0xcf;
  tbuf[j++] = 0xc0;
  tbuf[j++] = 0xde;
  tbuf[j++] = 0x27;
  tbuf[j++] = 0x18;
  tbuf[j++] = 0x28;
  tbuf[j++] = 0x18;

  writen(serial_port, tbuf, 12);
  readn(serial_port, rbuf, 15);

  /* 1. cmd = 0xfe */
  tbuf[3] = 0xfe; /* cmd */
  
  tbuf[4] = rbuf[1+4];
  tbuf[5] = rbuf[1+5];
  tbuf[6] = rbuf[1+6];
  tbuf[7] = rbuf[1+7];
  
  tbuf[8] = rbuf[1+8];
  tbuf[9] = rbuf[1+9];
  tbuf[10] = (rbuf[1+10] & 0xf0) | 0x7;
  tbuf[11] = 0x70;
  
  writen(serial_port, tbuf, 12);
  readn(serial_port, rbuf, 15);

  time_t start, stop;
  start = time(NULL);
  size_t memptr;
  for (memptr = 0; memptr < 256*1024; memptr += 4) {
    /* cmd = 0xfc */
    uint32_t a = 0xa0000000 + memptr;
    uint32_t d;
  
    tbuf[1] = 0x77;
    tbuf[3] = 0xfc; /* cmd */
  
    tbuf[4] = (a >> 24) & 0xff;
    tbuf[5] = (a >> 16) & 0xff;
    tbuf[6] = (a >>  8) & 0xff;
    tbuf[7] = (a >>  0) & 0xff;
  
    tbuf[8] = 0;
    tbuf[9] = 0;
    tbuf[10] = 0;
    tbuf[11] = 0;
  
    writen(serial_port, tbuf, 12);
    readn(serial_port, rbuf, 15);

    d = (rbuf[9] << 24) | (rbuf[10] << 16) | (rbuf[11] << 8) | rbuf[12];
    if (0) {
      printf("%08x = %08x\n", a, d);
    }
  }
  stop = time(NULL);
  printf("Total time = %ld s\n", stop - start);
  
  return 0;
}