From 2a2db12fc49ec13929a374dc457927ee66e7bc53 Mon Sep 17 00:00:00 2001
From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Thu, 8 Apr 2021 13:37:22 +0100
Subject: [PATCH] start putting in jtagremote protocol

---
 small_jtag_test/main.cpp | 129 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 129 insertions(+)

diff --git a/small_jtag_test/main.cpp b/small_jtag_test/main.cpp
index 3ffa6a3..63c9cf8 100644
--- a/small_jtag_test/main.cpp
+++ b/small_jtag_test/main.cpp
@@ -4,6 +4,135 @@
 
 using namespace std;
 
+extern "C" {
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/select.h>
+
+/* reads from a socket if it is ready (a single byte) and returns 1 if success
+ */
+int read_handler(int fdread, char *buffer)
+{
+    ssize_t read_len;
+    fd_set read_fds;
+    FD_ZERO(&read_fds);
+    struct   timeval tv;
+    FD_SET(fdread, &read_fds);
+    int status;
+
+    tv.tv_sec = 0;
+    tv.tv_usec = 1;
+
+    status = select(fdread+1, &read_fds, NULL, NULL, &tv);
+    switch (status)
+    {
+        case -1:
+            exit(status); // error
+            return 0;
+        case 0:
+            return 0; // timeout (nothing read)
+        default:
+            return read(fdread, buffer, 1);
+    }
+}
+
+/*
+static void event_handler(int fd, short event, void *arg)
+{
+  if (event & EV_READ)
+    read_handler(fd, event, arg);
+}
+
+static void accept_conn_cb(struct evconnlistener *listener, evutil_socket_t fd, struct sockaddr *address, int socklen,  void *ctx)
+{
+  struct session_s *s = (struct session_s*)ctx;
+  struct timeval tv = {1, 0};
+
+  s->fd = fd;
+  s->ev = event_new(base, fd, EV_READ | EV_PERSIST , event_handler, s);
+  event_add(s->ev, &tv);
+}
+
+static int jtagremote_new(void **sess, char *args)
+{
+  int ret = RC_OK;
+  struct session_s *s = NULL;
+  char *cport = NULL;
+  int port;
+  struct evconnlistener *listener;
+  struct sockaddr_in sin;
+
+  if(!sess) {
+    ret = RC_INVARG;
+    goto out;
+  }
+
+  ret = litex_sim_module_get_args(args, "port", &cport);
+  if(RC_OK != ret)
+    goto out;
+
+  printf("Found port %s\n", cport);
+  sscanf(cport, "%d", &port);
+  free(cport);
+  if(!port) {
+    ret = RC_ERROR;
+    fprintf(stderr, "Invalid port selected!\n");
+    goto out;
+  }
+
+  s=(struct session_s*)malloc(sizeof(struct session_s));
+  if(!s) {
+    ret = RC_NOENMEM;
+    goto out;
+  }
+  memset(s, 0, sizeof(struct session_s));
+
+  memset(&sin, 0, sizeof(sin));
+  sin.sin_family = AF_INET;
+  sin.sin_addr.s_addr = htonl(0);
+  sin.sin_port = htons(port);
+  listener = evconnlistener_new_bind(base, accept_conn_cb, s,  LEV_OPT_CLOSE_ON_FREE|LEV_OPT_REUSEABLE, -1, (struct sockaddr*)&sin, sizeof(sin));
+  if (!listener) {
+    ret=RC_ERROR;
+    eprintf("Can't bind port %d\n!\n", port);
+    goto out;
+  }
+  evconnlistener_set_error_cb(listener, accept_error_cb);
+
+out:
+  *sess=(void*)s;
+  return ret;
+}
+
+  if(s->datalen)
+  {
+	  c = s->databuf[s->data_start];
+
+	  if((c >= '0') && (c <= '7')){
+		  *s->tck = ((c - '0') >> 2) & 1;
+		  *s->tms = ((c - '0') >> 1) & 1;
+		  *s->tdi = (c - '0')  & 1;
+	  }
+	  if(c == 'R'){
+		  val = *s->tdo + '0';
+		  if(-1 == write(s->fd, &val, 1)) {
+			  eprintf("Error writing on socket\n");
+			  ret = RC_ERROR;
+			  goto out;
+		  }
+	  }
+	  s->data_start = (s->data_start + 1) % 2048;
+	  s->datalen--;
+  }
+
+out:
+  return ret;
+*/
+
+} // extern "C"
+
 int main()
 {
     cxxrtl_design::p_add top;
-- 
2.30.2