console over SWD

uses customized SEGGER RTT

Makefile

@@ -456,6 +456,12 @@ ifeq ($(USE_TERMINAL),1)
   WRAPPERSOURCES += libs/graphics/jswrap_terminal.c
 endif
 
+ifeq ($(USE_SWDCON),1)
+  DEFINES += -DUSE_SWDCON
+  WRAPPERSOURCES += libs/swdcon/jswrap_swdcon.c
+# directly included so not needed SOURCES += libs/swdcon/SEGGER_RTT_custom.c
+endif
+
 endif
 
 ifeq ($(USE_USB_HID),1)

boards/BANGLEJS2.py

@@ -38,6 +38,7 @@
      'CRYPTO','SHA256','SHA512',
      'LCD_MEMLCD',
      'TENSORFLOW',
+#     'SWDCON', RTT console over SWD
      'JIT' # JIT compiler enabled
    ],
    'makefile' : [

libs/swdcon/jswrap_swdcon.c

@@ -0,0 +1,183 @@
+/*
+ * This file is part of Espruino, a JavaScript interpreter for Microcontrollers
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * ----------------------------------------------------------------------------
+ * This file is designed to be parsed during the build process
+ *
+ * Contains JavaScript SWD console
+ * ----------------------------------------------------------------------------
+ */
+#include "jsvariterator.h"
+#include "jsinteractive.h"
+
+#ifdef NRF5X
+#include "app_util_platform.h"
+#endif
+#ifndef CRITICAL_REGION_ENTER
+#define CRITICAL_REGION_ENTER jshInterruptOff 
+#endif
+#ifndef CRITICAL_REGION_EXIT
+#define CRITICAL_REGION_EXIT jshInterruptOn 
+#endif
+
+// "SWDCON RTT" header instead of default "SEGGER RTT"
+// #define CUSTOM_RTT_HEADER_BACKWARDS "TTR NOCDWS"
+
+// stuff from removed SEGGER_RTT_Conf.h
+#define SEGGER_RTT_MAX_NUM_UP_BUFFERS   (1) 
+#define SEGGER_RTT_MAX_NUM_DOWN_BUFFERS (1)     // Max. number of down-buffers (H->T) available on this target  (Default: 3)
+#define BUFFER_SIZE_UP                  (128)  // Size of the buffer for terminal output of target, up to host (Default: 1k)
+#define BUFFER_SIZE_DOWN                (32)    // Size of the buffer for terminal input to target from host (Usually keyboard input) (Default: 16)
+#define SEGGER_RTT_MODE_DEFAULT         SEGGER_RTT_MODE_NO_BLOCK_SKIP // Mode for pre-initialized terminal channel (buffer 0)
+#define SEGGER_RTT_LOCK()               CRITICAL_REGION_ENTER()
+#define SEGGER_RTT_UNLOCK()             CRITICAL_REGION_EXIT()
+//#include "SEGGER_RTT_Conf.h"
+#include "SEGGER_RTT_custom.c"
+
+// possibly dynamically allocated from variables?
+static char swdconUpBuffer[BUFFER_SIZE_UP];
+static char swdconDownBuffer[BUFFER_SIZE_DOWN];
+const char swdconBufferName[] ="SWDCON"; // visible in "rtt channels" openocd command, SEGGER default for channel 0 is "Terminal"
+// Forward function declarations
+
+
+// console data structures
+
+#define MODE_OFF 0    // console is off
+#define MODE_ON  1    // console is on
+
+static uint8_t      srvMode = MODE_OFF;    ///< current mode 
+
+/*JSON{
+  "type" : "object",
+  "name" : "SWDCON",
+  "instanceof" : "Serial",
+  "ifdef" : "USE_SWDCON"
+}
+In memory serial I/O device accessible via SWD debugger.
+uses SEGGER RTT so it can be used with openocd and other SEGGER compatible tools.   
+*/
+
+
+/*JSON{
+  "type"     : "init",
+  "generate" : "jswrap_swdcon_init"
+}
+*/
+void jswrap_swdcon_init(void) {
+  SEGGER_RTT_Init();
+  SEGGER_RTT_ConfigDownBuffer(0, swdconBufferName, swdconDownBuffer, sizeof(swdconDownBuffer), SEGGER_RTT_MODE_DEFAULT);
+  SEGGER_RTT_ConfigUpBuffer(0, swdconBufferName, swdconUpBuffer, sizeof(swdconUpBuffer), SEGGER_RTT_MODE_DEFAULT);
+  srvMode = MODE_ON; // hardcoded for now
+}
+
+/*JSON{
+  "type"     : "kill",
+  "generate" : "jswrap_swdcon_kill"
+}
+*/
+void jswrap_swdcon_kill(void) {
+  srvMode = MODE_OFF;
+}
+
+/*JSON{
+  "type"     : "idle",
+  "generate" : "jswrap_swdcon_idle"
+}
+*/
+bool swdconActivate();
+bool swdconRecv();
+
+bool jswrap_swdcon_idle(void) {
+
+  if (srvMode == MODE_OFF) {
+    return false;
+  }
+
+  if (SEGGER_RTT_HasKey()) swdconActivate();
+  bool active = false;
+  active |= swdconRecv();
+   // prevent sleep if SWD console is active, we probably have power attached anyway
+   // sleeping would work if SWD debugger would trigger interrupt after sending data (it does not)
+   // however it is possible to trigger interrupt in our own SWD RTT host in future
+   // e.g. triggering TIMER1 interrupt vie writing STIR register wakes nrf52 espruino device
+  active |= (jsiGetConsoleDevice() == EV_SWDCON);
+  return active;  
+}
+
+//===== Internal functions
+bool wasForced=false;
+IOEventFlags oldConsole = EV_NONE;
+// on Bangle 2 looks like console is always forced to something (bluetooth or null)
+// setting to non-programmable forces console to null in .boot0
+// allow to override this case
+#define shouldOverride (console == EV_NONE)
+
+bool swdconActivate() {
+  // if the console is not already us, then change it
+  IOEventFlags console = jsiGetConsoleDevice();
+  if (console != EV_SWDCON) {
+    if (!jsiIsConsoleDeviceForced()) {
+      jsiSetConsoleDevice(EV_SWDCON, false);
+      //jshHadEvent();
+      wasForced=false;
+    } else {
+      if (shouldOverride){
+        wasForced=true;
+        oldConsole=console;
+        jsiSetConsoleDevice(EV_SWDCON, true);
+      }
+    }
+  }
+  return true;
+}
+
+// Close the connection and release the console device
+void swdconRelease() {
+  IOEventFlags console = jsiGetConsoleDevice();
+  // only switch away if the current console is us
+  if (console == EV_SWDCON){
+    if (wasForced){
+      jsiSetConsoleDevice(oldConsole, true); // restore previos forced one back
+      wasForced=false;
+    } else {
+      jsiSetConsoleDevice(jsiGetPreferredConsoleDevice(), false);
+    }
+  }
+}
+
+void swdconSendChar(char ch) {
+  if (srvMode == MODE_OFF) return;
+  int timeout = WAIT_UNTIL_N_CYCLES;
+  while (SEGGER_RTT_GetAvailWriteSpace(0)==0){
+    // same handling as in jshTransmit
+    if (jshIsInInterrupt()) {
+      // if we're printing from an IRQ, don't wait - it's unlikely TX will ever finish
+      jsErrorFlags |= JSERR_BUFFER_FULL;
+      return;
+    }
+    jshBusyIdle();
+    if (--timeout == 0) {
+      // try to switch away if buffer is full and nobody is reading
+      jsiStatus |= JSIS_ECHO_OFF_FOR_LINE; // we are full, no space for "<-" when switching
+      swdconRelease();
+      return;
+    }
+  } 
+  SEGGER_RTT_PutChar(0,ch);
+}
+
+bool swdconRecv() {
+  bool gotChar=false;
+  char c;
+  while(SEGGER_RTT_Read(0, &c, 1) > 0){
+    jshPushIOCharEvent(EV_SWDCON, c);
+    gotChar=true;
+  }
+  if (gotChar) jshHadEvent();
+  return gotChar;
+}

libs/swdcon/jswrap_swdcon.h

@@ -0,0 +1,28 @@
+/*
+ * This file is part of Espruino, a JavaScript interpreter for Microcontrollers
+ *
+ * Copyright (C) 2013 Thorsten von Eicken
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * ----------------------------------------------------------------------------
+ * Contains JavaScript HTTP Functions
+ * ----------------------------------------------------------------------------
+ */
+#ifndef LIBS_SWDCON_H_
+#define LIBS_SWDCON_H_
+
+#include "jsvar.h"
+
+void jswrap_swdcon_setOptions(JsVar *options);
+
+void jswrap_swdcon_init(void);
+void jswrap_swdcon_kill(void);
+
+// Listen, accept, send, and recv on telnet console connections. Returns true if something
+// was done.
+bool jswrap_swdcon_idle(void);
+
+#endif

src/jsdevices.c

@@ -202,6 +202,13 @@ void jshTransmit(
     return;
   }
 #endif
+#ifdef USE_SWDCON
+  if (device==EV_SWDCON) {
+    extern void swdconSendChar(char c);
+    swdconSendChar((char)data);
+    return;
+  }
+#endif
 #ifndef LINUX
 #ifdef USB
   if (device==EV_USBSERIAL && !jshIsUSBSERIALConnected()) {
@@ -613,6 +620,9 @@ const char *jshGetDeviceString(
 #ifdef USE_TELNET
   case EV_TELNET: return "Telnet";
 #endif
+#ifdef USE_SWDCON
+  case EV_SWDCON: return "SWDCON";
+#endif
 #ifdef USE_TERMINAL
   case EV_TERMINAL: return "Terminal";
 #endif
@@ -686,6 +696,9 @@ IOEventFlags jshFromDeviceString(
 #endif
   }
   else if (device[0]=='S') {
+#ifdef USE_SWDCON
+     if (strcmp(&device[1], "WDCON")==0) return EV_SWDCON;
+#endif
 #if ESPR_USART_COUNT>0
   if (device[1]=='e' && device[2]=='r' && device[3]=='i' && device[4]=='a' && device[5]=='l' &&
       device[6]>='1' && (device[6]-'1')<ESPR_USART_COUNT &&

src/jsdevices.h

@@ -44,6 +44,9 @@ typedef enum {
 #ifdef USE_TELNET
   EV_TELNET,
 #endif
+#ifdef USE_SWDCON
+  EV_SWDCON, /// console over in memory buffer accessible via SWD
+#endif
 #ifdef USE_TERMINAL
   EV_TERMINAL, // Built-in VT100 terminal
 #endif