From 089f0fa4cf1885b2333f4522140ae3747f2e367b Mon Sep 17 00:00:00 2001
From: Megan Wachs <megan@sifive.com>
Date: Tue, 18 Apr 2017 14:34:51 -0700
Subject: debug: move remote_bitbang into riscv

---
 riscv/remote_bitbang.cc | 180 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 180 insertions(+)
 create mode 100644 riscv/remote_bitbang.cc

(limited to 'riscv/remote_bitbang.cc')

diff --git a/riscv/remote_bitbang.cc b/riscv/remote_bitbang.cc
new file mode 100644
index 0000000..75aa8fe
--- /dev/null
+++ b/riscv/remote_bitbang.cc
@@ -0,0 +1,180 @@
+#include <arpa/inet.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <algorithm>
+#include <cassert>
+#include <cstdio>
+
+#include "remote_bitbang.h"
+
+#if 1
+#  define D(x) x
+#else
+#  define D(x)
+#endif
+
+/////////// remote_bitbang_t
+
+remote_bitbang_t::remote_bitbang_t(uint16_t port, jtag_dtm_t *tap) :
+  tap(tap),
+  socket_fd(0),
+  client_fd(0),
+  recv_start(0),
+  recv_end(0)
+{
+  socket_fd = socket(AF_INET, SOCK_STREAM, 0);
+  if (socket_fd == -1) {
+    fprintf(stderr, "remote_bitbang failed to make socket: %s (%d)\n",
+        strerror(errno), errno);
+    abort();
+  }
+
+  fcntl(socket_fd, F_SETFL, O_NONBLOCK);
+  int reuseaddr = 1;
+  if (setsockopt(socket_fd, SOL_SOCKET, SO_REUSEADDR, &reuseaddr,
+        sizeof(int)) == -1) {
+    fprintf(stderr, "remote_bitbang failed setsockopt: %s (%d)\n",
+        strerror(errno), errno);
+    abort();
+  }
+
+  struct sockaddr_in addr;
+  memset(&addr, 0, sizeof(addr));
+  addr.sin_family = AF_INET;
+  addr.sin_addr.s_addr = INADDR_ANY;
+  addr.sin_port = htons(port);
+
+  if (bind(socket_fd, (struct sockaddr *) &addr, sizeof(addr)) == -1) {
+    fprintf(stderr, "remote_bitbang failed to bind socket: %s (%d)\n",
+        strerror(errno), errno);
+    abort();
+  }
+
+  if (listen(socket_fd, 1) == -1) {
+    fprintf(stderr, "remote_bitbang failed to listen on socket: %s (%d)\n",
+        strerror(errno), errno);
+    abort();
+  }
+
+  socklen_t addrlen = sizeof(addr);
+  if (getsockname(socket_fd, (struct sockaddr *) &addr, &addrlen) == -1) {
+    fprintf(stderr, "remote_bitbang getsockname failed: %s (%d)\n",
+        strerror(errno), errno);
+    abort();
+  }
+
+  printf("Listening for remote bitbang connection on port %d.\n",
+      ntohs(addr.sin_port));
+  fflush(stdout);
+}
+
+void remote_bitbang_t::accept()
+{
+  client_fd = ::accept(socket_fd, NULL, NULL);
+  if (client_fd == -1) {
+    if (errno == EAGAIN) {
+      // No client waiting to connect right now.
+    } else {
+      fprintf(stderr, "failed to accept on socket: %s (%d)\n", strerror(errno),
+          errno);
+      abort();
+    }
+  } else {
+    fcntl(client_fd, F_SETFL, O_NONBLOCK);
+  }
+}
+
+void remote_bitbang_t::tick()
+{
+  if (client_fd > 0) {
+    execute_commands();
+  } else {
+    this->accept();
+  }
+}
+
+void remote_bitbang_t::execute_commands()
+{
+  static char send_buf[buf_size];
+  unsigned total_processed = 0;
+  bool quit = false;
+  bool in_rti = tap->state() == RUN_TEST_IDLE;
+  bool entered_rti = false;
+  while (1) {
+    if (recv_start < recv_end) {
+      unsigned send_offset = 0;
+      while (recv_start < recv_end) {
+        uint8_t command = recv_buf[recv_start];
+
+        switch (command) {
+          case 'B': /* fprintf(stderr, "*BLINK*\n"); */ break;
+          case 'b': /* fprintf(stderr, "_______\n"); */ break;
+          case 'r': tap->reset(); break;
+          case '0': tap->set_pins(0, 0, 0); break;
+          case '1': tap->set_pins(0, 0, 1); break;
+          case '2': tap->set_pins(0, 1, 0); break;
+          case '3': tap->set_pins(0, 1, 1); break;
+          case '4': tap->set_pins(1, 0, 0); break;
+          case '5': tap->set_pins(1, 0, 1); break;
+          case '6': tap->set_pins(1, 1, 0); break;
+          case '7': tap->set_pins(1, 1, 1); break;
+          case 'R': send_buf[send_offset++] = tap->tdo() ? '1' : '0'; break;
+          case 'Q': quit = true; break;
+          default:
+                    fprintf(stderr, "remote_bitbang got unsupported command '%c'\n",
+                        command);
+        }
+        recv_start++;
+        total_processed++;
+        if (!in_rti && tap->state() == RUN_TEST_IDLE) {
+          entered_rti = true;
+          break;
+        }
+        in_rti = false;
+      }
+      unsigned sent = 0;
+      while (sent < send_offset) {
+        ssize_t bytes = write(client_fd, send_buf + sent, send_offset);
+        if (bytes == -1) {
+          fprintf(stderr, "failed to write to socket: %s (%d)\n", strerror(errno), errno);
+          abort();
+        }
+        sent += bytes;
+      }
+    }
+
+    if (total_processed > buf_size || quit || entered_rti) {
+      // Don't go forever, because that could starve the main simulation.
+      break;
+    }
+
+    recv_start = 0;
+    recv_end = read(client_fd, recv_buf, buf_size);
+
+    if (recv_end == -1) {
+      if (errno == EAGAIN) {
+        // We'll try again the next call.
+      } else {
+        fprintf(stderr, "remote_bitbang failed to read on socket: %s (%d)\n",
+            strerror(errno), errno);
+        abort();
+      }
+    }
+    
+    if (quit) {
+      fprintf(stderr, "Remote Bitbang received 'Q'\n");
+    }
+    
+    if (recv_end == 0 || quit) {
+      // The remote disconnected.
+      fprintf(stderr, "Received nothing. Quitting.\n");
+      close(client_fd);
+      client_fd = 0;
+      break;
+    }
+  }
+}
-- 
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