small_jtag_test/main.cpp

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #include <unistd.h>
   5 #include <sys/select.h>
   6 #include <sys/types.h>
   7 #include <sys/socket.h>
   8 #include <netinet/in.h>
   9 #include <arpa/inet.h>
  10 #include <sys/fcntl.h>
  11 #include <netinet/in.h>
  12 #include <netinet/tcp.h>
  13
  14 #include <iostream>
  15 #include "add.cpp"
  16
  17 using namespace std;
  18
  19 extern "C" {
  20
  21 /* reads from a socket if it is ready (a single byte) and returns 1 if success
  22  */
  23 int read_handler(int fdread, char *buffer)
  24 {
  25     ssize_t read_len;
  26     fd_set read_fds;
  27     FD_ZERO(&read_fds);
  28     struct   timeval tv;
  29     FD_SET(fdread, &read_fds);
  30     int status;
  31
  32     tv.tv_sec = 0;
  33     tv.tv_usec = 1;
  34
  35     status = select(fdread+1, &read_fds, NULL, NULL, &tv);
  36     switch (status)
  37     {
  38         case -1:
  39             printf("Error reading on socket\n");
  40             exit(status); // error
  41             return 0;
  42         case 0:
  43             return 0; // timeout (nothing read)
  44         default:
  45             return read(fdread, buffer, 1);
  46     }
  47 }
  48
  49 /* nothing sophisticated: wait for an incoming connection
  50  */
  51 int get_connection()
  52 {
  53         int listenfd = 0, connfd = 0;
  54     int flag = 1;
  55         struct sockaddr_in serv_addr;
  56
  57         listenfd = socket(AF_INET, SOCK_STREAM, 0);
  58         memset(&serv_addr, '0', sizeof(serv_addr));
  59
  60         serv_addr.sin_family = AF_INET;
  61         serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
  62         serv_addr.sin_port = htons(5000);
  63
  64         bind(listenfd, (struct sockaddr*)&serv_addr, sizeof(serv_addr));
  65
  66         listen(listenfd, 1);
  67
  68     connfd = accept(listenfd, (struct sockaddr*)NULL, NULL);
  69     close(listenfd);
  70
  71     setsockopt(connfd, IPPROTO_TCP, TCP_NODELAY, (char *) &flag, sizeof(int));
  72     return connfd;
  73 }
  74
  75 } // extern "C"
  76
  77 /* main function which polls the socket and talks openocd jtagremote protocol.
  78    dead simple: incoming number 0-7 sets TCK, TMS and TDK.  request "R"
  79    indicates that receiver wants to know the status of TDO.
  80    "Q" means "quit socket".
  81 */
  82 void read_openocd_jtagremote(cxxrtl_design::p_add &top, int sock)
  83 {
  84     char c;
  85     if (read_handler(sock, &c) != 1) {
  86         return;
  87     }
  88     printf ("read %c\n", c);
  89     if ((c >= '0') && (c <= '7'))
  90     {
  91         top.p_tck.set<bool>(((c - '0') >> 2) & 1);
  92         top.p_tms.set<bool>(((c - '0') >> 1) & 1);
  93         top.p_tdi.set<bool>((c - '0')  & 1);
  94     }
  95     if (c == 'R')
  96     {
  97         uint8_t val = top.p_tdo.get<uint8_t>() + '0';
  98         if(-1 == write(sock, &val, 1))
  99         {
 100             printf("Error writing on socket\n");
 101             exit(-1);
 102         }
 103     }
 104     if (c == 'Q') {
 105         printf("disconnect request\n");
 106         exit(-1);
 107     }
 108 }
 109
 110 int main()
 111 {
 112     cxxrtl_design::p_add top;
 113
 114     int sock = get_connection();
 115
 116     top.step();
 117     while (true) {
 118
 119         top.p_clk.set<bool>(false);
 120         top.step();
 121         top.p_clk.set<bool>(true);
 122         top.step();
 123
 124         /* read and process incoming jtag */
 125         read_openocd_jtagremote(top, sock);
 126
 127         // quick check that the output is correct (it's an adder: go figure)
 128         /*
 129         top.p_a.set<uint8_t>(5);
 130         top.p_b.set<uint8_t>(3);
 131         uint32_t f    = top.p_f.get<uint32_t>();
 132
 133         cout << "f " << f << endl;
 134         */
 135     }
 136 }
 137