From ad2a07fbc3313de5854654beea04d05032f03953 Mon Sep 17 00:00:00 2001
From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Thu, 8 Apr 2021 14:05:12 +0100
Subject: [PATCH] add jtagremote read/write

---
 small_jtag_test/main.cpp | 64 +++++++++++++++++++++++++---------------
 1 file changed, 40 insertions(+), 24 deletions(-)

diff --git a/small_jtag_test/main.cpp b/small_jtag_test/main.cpp
index d98ae9a..5931804 100644
--- a/small_jtag_test/main.cpp
+++ b/small_jtag_test/main.cpp
@@ -3,8 +3,13 @@
 #include <string.h>
 #include <unistd.h>
 #include <sys/select.h>
+#include <sys/types.h>          /* See NOTES */
+#include <sys/socket.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
+#include <sys/fcntl.h>
+#include <netinet/in.h>
+#include <netinet/tcp.h>
 
 #include <iostream>
 #include "add.cpp"
@@ -31,6 +36,7 @@ int read_handler(int fdread, char *buffer)
     switch (status)
     {
         case -1:
+            printf("Error reading on socket\n");
             exit(status); // error
             return 0;
         case 0:
@@ -45,6 +51,7 @@ int read_handler(int fdread, char *buffer)
 int get_connection()
 {
 	int listenfd = 0, connfd = 0;
+    int flag = 1;
 	struct sockaddr_in serv_addr;
 
 	listenfd = socket(AF_INET, SOCK_STREAM, 0);
@@ -61,6 +68,7 @@ int get_connection()
     connfd = accept(listenfd, (struct sockaddr*)NULL, NULL);
     close(listenfd);
 
+    setsockopt(connfd, IPPROTO_TCP, TCP_NODELAY, (char *) &flag, sizeof(int)); 
     return connfd;
 }
 
@@ -127,33 +135,38 @@ out:
   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"
 
+void read_openocd_jtagremote(cxxrtl_design::p_add &top, int sock)
+{
+    char c;
+    if (read_handler(sock, &c) != 1) {
+        return;
+    }
+    printf ("read %c\n", c);
+    if ((c >= '0') && (c <= '7'))
+    {
+        top.p_tck.set<bool>(((c - '0') >> 2) & 1);
+        top.p_tms.set<bool>(((c - '0') >> 1) & 1);
+        top.p_tdi.set<bool>((c - '0')  & 1);
+    }
+    if (c == 'R')
+    {
+        uint8_t val = top.p_tdo.get<uint8_t>() + '0';
+        if(-1 == write(sock, &val, 1))
+        {
+            printf("Error writing on socket\n");
+            exit(-1);
+        }
+    }
+    if (c == 'Q') {
+        printf("disconnect request\n");
+        exit(-1);
+    }
+}
+
 int main()
 {
     cxxrtl_design::p_add top;
@@ -161,13 +174,16 @@ int main()
     int sock = get_connection();
 
     top.step();
-    for(int cycle=0;cycle<1000;++cycle){
+    while (true) {
 
         top.p_clk.set<bool>(false);
         top.step();
         top.p_clk.set<bool>(true);
         top.step();
 
+        /* read and process incoming jtag */
+        read_openocd_jtagremote(top, sock);
+
         // check that the output is correct
         /*
         top.p_a.set<uint8_t>(5);
-- 
2.30.2