remote_bitbang.cc

   1 #include <arpa/inet.h>
   2 #include <errno.h>
   3 #include <fcntl.h>
   4 #include <stdlib.h>
   5 #include <string.h>
   6 #include <unistd.h>
   7
   8 #include <algorithm>
   9 #include <cassert>
  10 #include <cstdio>
  11
  12 #include "remote_bitbang.h"
  13
  14 #if 1
  15 #  define D(x) x
  16 #else
  17 #  define D(x)
  18 #endif
  19
  20 /////////// remote_bitbang_t
  21
  22 remote_bitbang_t::remote_bitbang_t(uint16_t port, jtag_dtm_t *tap) :
  23   tap(tap),
  24   socket_fd(0),
  25   client_fd(0),
  26   recv_start(0),
  27   recv_end(0)
  28 {
  29   socket_fd = socket(AF_INET, SOCK_STREAM, 0);
  30   if (socket_fd == -1) {
  31     fprintf(stderr, "remote_bitbang failed to make socket: %s (%d)\n",
  32         strerror(errno), errno);
  33     abort();
  34   }
  35
  36   fcntl(socket_fd, F_SETFL, O_NONBLOCK);
  37   int reuseaddr = 1;
  38   if (setsockopt(socket_fd, SOL_SOCKET, SO_REUSEADDR, &reuseaddr,
  39         sizeof(int)) == -1) {
  40     fprintf(stderr, "remote_bitbang failed setsockopt: %s (%d)\n",
  41         strerror(errno), errno);
  42     abort();
  43   }
  44
  45   struct sockaddr_in addr;
  46   memset(&addr, 0, sizeof(addr));
  47   addr.sin_family = AF_INET;
  48   addr.sin_addr.s_addr = INADDR_ANY;
  49   addr.sin_port = htons(port);
  50
  51   if (bind(socket_fd, (struct sockaddr *) &addr, sizeof(addr)) == -1) {
  52     fprintf(stderr, "remote_bitbang failed to bind socket: %s (%d)\n",
  53         strerror(errno), errno);
  54     abort();
  55   }
  56
  57   if (listen(socket_fd, 1) == -1) {
  58     fprintf(stderr, "remote_bitbang failed to listen on socket: %s (%d)\n",
  59         strerror(errno), errno);
  60     abort();
  61   }
  62
  63   socklen_t addrlen = sizeof(addr);
  64   if (getsockname(socket_fd, (struct sockaddr *) &addr, &addrlen) == -1) {
  65     fprintf(stderr, "remote_bitbang getsockname failed: %s (%d)\n",
  66         strerror(errno), errno);
  67     abort();
  68   }
  69
  70   printf("Listening for remote bitbang connection on port %d.\n",
  71       ntohs(addr.sin_port));
  72   fflush(stdout);
  73 }
  74
  75 void remote_bitbang_t::accept()
  76 {
  77   client_fd = ::accept(socket_fd, NULL, NULL);
  78   if (client_fd == -1) {
  79     if (errno == EAGAIN) {
  80       // No client waiting to connect right now.
  81     } else {
  82       fprintf(stderr, "failed to accept on socket: %s (%d)\n", strerror(errno),
  83           errno);
  84       abort();
  85     }
  86   } else {
  87     fcntl(client_fd, F_SETFL, O_NONBLOCK);
  88   }
  89 }
  90
  91 void remote_bitbang_t::tick()
  92 {
  93   if (client_fd > 0) {
  94     execute_commands();
  95   } else {
  96     this->accept();
  97   }
  98 }
  99
 100 void remote_bitbang_t::execute_commands()
 101 {
 102   static char send_buf[buf_size];
 103   unsigned total_processed = 0;
 104   bool quit = false;
 105   bool in_rti = tap->state() == RUN_TEST_IDLE;
 106   bool entered_rti = false;
 107   while (1) {
 108     if (recv_start < recv_end) {
 109       unsigned send_offset = 0;
 110       while (recv_start < recv_end) {
 111         uint8_t command = recv_buf[recv_start];
 112
 113         switch (command) {
 114           case 'B': /* fprintf(stderr, "*BLINK*\n"); */ break;
 115           case 'b': /* fprintf(stderr, "_______\n"); */ break;
 116           case 'r': tap->reset(); break;
 117           case '0': tap->set_pins(0, 0, 0); break;
 118           case '1': tap->set_pins(0, 0, 1); break;
 119           case '2': tap->set_pins(0, 1, 0); break;
 120           case '3': tap->set_pins(0, 1, 1); break;
 121           case '4': tap->set_pins(1, 0, 0); break;
 122           case '5': tap->set_pins(1, 0, 1); break;
 123           case '6': tap->set_pins(1, 1, 0); break;
 124           case '7': tap->set_pins(1, 1, 1); break;
 125           case 'R': send_buf[send_offset++] = tap->tdo() ? '1' : '0'; break;
 126           case 'Q': quit = true; break;
 127           default:
 128                     fprintf(stderr, "remote_bitbang got unsupported command '%c'\n",
 129                         command);
 130         }
 131         recv_start++;
 132         total_processed++;
 133         if (!in_rti && tap->state() == RUN_TEST_IDLE) {
 134           entered_rti = true;
 135           break;
 136         }
 137         in_rti = false;
 138       }
 139       unsigned sent = 0;
 140       while (sent < send_offset) {
 141         ssize_t bytes = write(client_fd, send_buf + sent, send_offset);
 142         if (bytes == -1) {
 143           fprintf(stderr, "failed to write to socket: %s (%d)\n", strerror(errno), errno);
 144           abort();
 145         }
 146         sent += bytes;
 147       }
 148     }
 149
 150     if (total_processed > buf_size || quit || entered_rti) {
 151       // Don't go forever, because that could starve the main simulation.
 152       break;
 153     }
 154
 155     recv_start = 0;
 156     recv_end = read(client_fd, recv_buf, buf_size);
 157
 158     if (recv_end == -1) {
 159       if (errno == EAGAIN) {
 160         // We'll try again the next call.
 161       } else {
 162         fprintf(stderr, "remote_bitbang failed to read on socket: %s (%d)\n",
 163             strerror(errno), errno);
 164         abort();
 165       }
 166     }
 167     if (recv_end == 0 || quit) {
 168       // The remote disconnected.
 169       close(client_fd);
 170       client_fd = 0;
 171       break;
 172     }
 173   }
 174 }