khalil guibene / SWO

Important changes to repositories hosted on mbed.com

Mbed hosted mercurial repositories are deprecated and are due to be permanently deleted in July 2026.

To keep a copy of this software download the repository Zip archive or clone locally using Mercurial.

It is also possible to export all your personal repositories from the account settings page.

Fork of SWO by Wim Huiskamp

SWO.cpp@4:53de8ef789f3, 2017-08-24 (annotated)

Committer:
wim
Date:
Thu Aug 24 18:15:02 2017 +0000
Revision:
4:53de8ef789f3
Parent:
3:e5af2e131b95 
Added stream claim for stdout, proposed by Pavel Sorejs.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
wim 1:bae4cff278f6 1 /* mbed SWO Library
wim 2:ef928f61a770 2 * Copyright (c) 2014, v01: WH. Ported from Segger example (www.segger.com)
wim 3:e5af2e131b95 3 * v02: WH. Added Class with Stream support
wim 4:53de8ef789f3 4 * 2017, v03: WH,PS. Added stream claim for stdout, proposed by Pavel Sorejs
wim 1:bae4cff278f6 5 *
wim 2:ef928f61a770 6 * Simple implementation for tracing via Serial Wire Output(SWO) for Cortex-M processors.
wim 1:bae4cff278f6 7 * It can be used with Host PC software such as ST-LINK Utility or Segger J-Link SWO viewer.
wim 1:bae4cff278f6 8 * This sample implementation ensures that output via SWO is enabled in order to guarantee
wim 1:bae4cff278f6 9 * that the application does not hang.
wim 1:bae4cff278f6 10 *
wim 1:bae4cff278f6 11 * Permission is hereby granted, free of charge, to any person obtaining a copy
wim 1:bae4cff278f6 12 * of this software and associated documentation files (the "Software"), to deal
wim 1:bae4cff278f6 13 * in the Software without restriction, including without limitation the rights
wim 1:bae4cff278f6 14 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
wim 1:bae4cff278f6 15 * copies of the Software, and to permit persons to whom the Software is
wim 1:bae4cff278f6 16 * furnished to do so, subject to the following conditions:
wim 1:bae4cff278f6 17 *
wim 1:bae4cff278f6 18 * The above copyright notice and this permission notice shall be included in
wim 1:bae4cff278f6 19 * all copies or substantial portions of the Software.
wim 1:bae4cff278f6 20 *
wim 1:bae4cff278f6 21 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
wim 1:bae4cff278f6 22 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
wim 1:bae4cff278f6 23 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
wim 1:bae4cff278f6 24 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
wim 1:bae4cff278f6 25 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
wim 1:bae4cff278f6 26 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
wim 1:bae4cff278f6 27 * THE SOFTWARE.
wim 1:bae4cff278f6 28 */
wim 2:ef928f61a770 29 #include "mbed.h"
wim 0:0fd55660fc26 30 #include "SWO.h"
wim 0:0fd55660fc26 31
wim 3:e5af2e131b95 32 //
wim 3:e5af2e131b95 33 // This the Class implementation
wim 3:e5af2e131b95 34 //
wim 3:e5af2e131b95 35
wim 3:e5af2e131b95 36 /** Create and SWO interface for debugging that supports Stream
wim 3:e5af2e131b95 37 * @brief Currently works on nucleo ST-LINK using ST-Link Utility and other devices that support SWD/SWO using Segger SWO viewer
wim 3:e5af2e131b95 38 */
wim 4:53de8ef789f3 39 SWO_Channel::SWO_Channel (const char *name) : Stream(name) {
wim 3:e5af2e131b95 40 //May want to add initialisation stuff here
wim 3:e5af2e131b95 41 }
wim 4:53de8ef789f3 42
wim 3:e5af2e131b95 43
wim 3:e5af2e131b95 44 /** Write a single character (Stream implementation)
wim 3:e5af2e131b95 45 *
wim 3:e5af2e131b95 46 * @param value character to be displayed
wim 3:e5af2e131b95 47 * @return value
wim 3:e5af2e131b95 48 */
wim 3:e5af2e131b95 49 int SWO_Channel::_putc(int value) {
wim 3:e5af2e131b95 50
wim 3:e5af2e131b95 51 //Use CMSIS_core_DebugFunctions. See core_cm3.h
wim 3:e5af2e131b95 52 ITM_SendChar(value);
wim 3:e5af2e131b95 53
wim 3:e5af2e131b95 54 return value;
wim 3:e5af2e131b95 55 }
wim 3:e5af2e131b95 56
wim 3:e5af2e131b95 57 /** Get a single character (Stream implementation)
wim 3:e5af2e131b95 58 * @return -1 Not supported
wim 3:e5af2e131b95 59 */
wim 3:e5af2e131b95 60 int SWO_Channel::_getc() {
wim 3:e5af2e131b95 61 return -1;
wim 3:e5af2e131b95 62 }
wim 3:e5af2e131b95 63
wim 4:53de8ef789f3 64 /**
wim 4:53de8ef789f3 65 * Claim and redirect a stream to this SWO object
wim 4:53de8ef789f3 66 * Important: A name parameter must have been added when creating the SWO object.
wim 4:53de8ef789f3 67 *
wim 4:53de8ef789f3 68 * @param FILE *stream The stream to redirect (default = stdout)
wim 4:53de8ef789f3 69 * @return true if succeeded, else false
wim 4:53de8ef789f3 70 */
wim 4:53de8ef789f3 71 bool SWO_Channel::claim (FILE *stream) {
wim 4:53de8ef789f3 72 if ( FileBase::getName() == NULL) {
wim 4:53de8ef789f3 73 error("claim requires a name to be given in the instantiator of the SWO instance!\r\n");
wim 4:53de8ef789f3 74 }
wim 4:53de8ef789f3 75
wim 4:53de8ef789f3 76 //Add '/' before name:
wim 4:53de8ef789f3 77 char *path = new char[strlen(FileBase::getName()) + 2];
wim 4:53de8ef789f3 78 sprintf(path, "/%s", FileBase::getName());
wim 4:53de8ef789f3 79
wim 4:53de8ef789f3 80 if (freopen(path, "w", stream) == NULL) {
wim 4:53de8ef789f3 81 // Failed, should not happen
wim 4:53de8ef789f3 82 return false;
wim 4:53de8ef789f3 83 }
wim 4:53de8ef789f3 84
wim 4:53de8ef789f3 85 delete(path);
wim 4:53de8ef789f3 86
wim 4:53de8ef789f3 87 //No buffering
wim 4:53de8ef789f3 88 setvbuf(stream, NULL, _IONBF, 32);
wim 4:53de8ef789f3 89 return true;
wim 4:53de8ef789f3 90 }
wim 4:53de8ef789f3 91
wim 4:53de8ef789f3 92
wim 3:e5af2e131b95 93
wim 3:e5af2e131b95 94 //
wim 3:e5af2e131b95 95 //This is the classic implementation
wim 3:e5af2e131b95 96 //
wim 3:e5af2e131b95 97
wim 1:bae4cff278f6 98 /**
wim 1:bae4cff278f6 99 * Defines for Cortex-M debug unit
wim 1:bae4cff278f6 100 */
wim 3:e5af2e131b95 101 #define ITM_STIM_U32(n) (*(volatile unsigned int*) (0xE0000000+4*n)) // Stimulus Port n Register word access
wim 3:e5af2e131b95 102 #define ITM_STIM_U8(n) (*(volatile unsigned char*)(0xE0000000+4*n)) // Stimulus Port n Register byte access
wim 0:0fd55660fc26 103 //#define ITM_STIM_U32_0 (*(volatile unsigned int*)0xE0000000) // Stimulus Port 0 Register word access
wim 0:0fd55660fc26 104 //#define ITM_STIM_U8_0 (*(volatile char*)0xE0000000) // Stimulus Port 0 Register byte access
wim 0:0fd55660fc26 105 #define ITM_ENA (*(volatile unsigned int*)0xE0000E00) // Trace Enable Ports Register
wim 0:0fd55660fc26 106 #define ITM_TCR (*(volatile unsigned int*)0xE0000E80) // Trace control register
wim 0:0fd55660fc26 107
wim 2:ef928f61a770 108 #define ITM_STIM_FIFOREADY 0x00000001 // FIFO empty
wim 2:ef928f61a770 109
wim 2:ef928f61a770 110 //Stuff below is for documentation and needs further testing
wim 2:ef928f61a770 111 // It seems that the Segger SWO Viewer and the ST-Link Utility do most/all of these
wim 2:ef928f61a770 112 // initialisations on the target before starting the session. This is probably not the case
wim 2:ef928f61a770 113 // when using GDB/OpenOCD.
wim 2:ef928f61a770 114 //
wim 2:ef928f61a770 115 //
wim 2:ef928f61a770 116 #if(0)
wim 2:ef928f61a770 117 #include <libopencm3/stm32/rcc.h>
wim 2:ef928f61a770 118 #include <libopencm3/stm32/gpio.h>
wim 2:ef928f61a770 119
wim 2:ef928f61a770 120 #include <libopencm3/stm32/dbgmcu.h>
wim 2:ef928f61a770 121 #include <libopencm3/cm3/scs.h>
wim 2:ef928f61a770 122 #include <libopencm3/cm3/tpiu.h>
wim 2:ef928f61a770 123 #include <libopencm3/cm3/itm.h>
wim 2:ef928f61a770 124
wim 1:bae4cff278f6 125 /**
wim 2:ef928f61a770 126 * SWO_Setup() Example
wim 1:bae4cff278f6 127 *
wim 2:ef928f61a770 128 * This file is part of the libopencm3 project.
wim 2:ef928f61a770 129 *
wim 2:ef928f61a770 130 * Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
wim 2:ef928f61a770 131 * https://github.com/1divf/libopenstm32/blob/master/examples/stm32/stm32-h103/traceswo/traceswo.c
wim 2:ef928f61a770 132 *
wim 2:ef928f61a770 133 */
wim 2:ef928f61a770 134 void SWO_Setup(void) {
wim 2:ef928f61a770 135 /* Enable trace subsystem (we'll use ITM and TPIU) */
wim 2:ef928f61a770 136 SCS_DEMCR |= SCS_DEMCR_TRCENA;
wim 2:ef928f61a770 137
wim 2:ef928f61a770 138 /* Use Manchester code for asynchronous transmission */
wim 2:ef928f61a770 139 TPIU_SPPR = TPIU_SPPR_ASYNC_MANCHESTER;
wim 2:ef928f61a770 140 TPIU_ACPR = 7;
wim 2:ef928f61a770 141
wim 2:ef928f61a770 142 /* Data width is 1 byte */
wim 2:ef928f61a770 143 TPIU_CSPSR = TPIU_CSPSR_BYTE;
wim 2:ef928f61a770 144
wim 2:ef928f61a770 145 /* Formatter and flush control */
wim 2:ef928f61a770 146 TPIU_FFCR &= ~TPIU_FFCR_ENFCONT;
wim 2:ef928f61a770 147
wim 2:ef928f61a770 148 /* Enable TRACESWO pin for async mode */
wim 2:ef928f61a770 149 DBGMCU_CR = DBGMCU_CR_TRACE_IOEN | DBGMCU_CR_TRACE_MODE_ASYNC;
wim 2:ef928f61a770 150
wim 2:ef928f61a770 151 /* Unlock access to ITM registers */
wim 2:ef928f61a770 152 /* FIXME: Magic numbers... Is this Cortex-M3 generic? */
wim 2:ef928f61a770 153 *((volatile uint32_t*)0xE0000FB0) = 0xC5ACCE55;
wim 2:ef928f61a770 154
wim 2:ef928f61a770 155 /* Enable ITM with ID = 1 */
wim 2:ef928f61a770 156 ITM_TCR = (1 << 16) | ITM_TCR_ITMENA;
wim 2:ef928f61a770 157 /* Enable stimulus port 1 */
wim 2:ef928f61a770 158 ITM_TER[0] = 1;
wim 2:ef928f61a770 159 }
wim 2:ef928f61a770 160
wim 2:ef928f61a770 161 /**
wim 2:ef928f61a770 162 * SWO_Setup() Example
wim 2:ef928f61a770 163 *
wim 2:ef928f61a770 164 * http://forum.segger.com/index.php?page=Thread&threadID=608
wim 2:ef928f61a770 165 *
wim 2:ef928f61a770 166 */
wim 2:ef928f61a770 167 void SWO_Setup_1(void) {
wim 2:ef928f61a770 168 U32 SWOPrescaler;
wim 2:ef928f61a770 169 U32 SWOSpeed;
wim 2:ef928f61a770 170
wim 2:ef928f61a770 171 //<Init PLL, set CPU clock to 72 MHz> // Optional, so I do not pos it here
wim 2:ef928f61a770 172
wim 2:ef928f61a770 173 SWOSpeed = 6000000;
wim 2:ef928f61a770 174 *((volatile unsigned *)0xE000EDFC) = 0x01000000; // "Debug Exception and Monitor Control Register (DEMCR)"
wim 2:ef928f61a770 175 *((volatile unsigned *)0xE0042004) = 0x00000027;
wim 2:ef928f61a770 176 *((volatile unsigned *)0xE00400F0) = 0x00000002; // "Selected PIN Protocol Register": Select which protocol to use for trace output (2: SWO)
wim 2:ef928f61a770 177 SWOPrescaler = (72000000 / SWOSpeed) - 1; // SWOSpeed in Hz
wim 2:ef928f61a770 178 *((volatile unsigned *)0xE0040010) = SWOPrescaler; // "Async Clock Prescaler Register". Scale the baud rate of the asynchronous output
wim 2:ef928f61a770 179 *((volatile unsigned *)0xE0000FB0) = 0xC5ACCE55; // ITM Lock Access Register, C5ACCE55 enables more write access to Control Register 0xE00 :: 0xFFC
wim 2:ef928f61a770 180 *((volatile unsigned *)0xE0000E80) = 0x0001000D; // ITM Trace Control Register
wim 2:ef928f61a770 181 *((volatile unsigned *)0xE0000E40) = 0x0000000F; // ITM Trace Privilege Register
wim 2:ef928f61a770 182 *((volatile unsigned *)0xE0000E00) = 0x00000001; // ITM Trace Enable Register. Enabled tracing on stimulus ports. One bit per stimulus port.
wim 2:ef928f61a770 183 *((volatile unsigned *)0xE0001000) = 0x400003FE; // DWT_CTRL
wim 2:ef928f61a770 184 *((volatile unsigned *)0xE0040304) = 0x00000100; // Formatter and Flush Control Register
wim 2:ef928f61a770 185 }
wim 2:ef928f61a770 186 #endif
wim 2:ef928f61a770 187
wim 2:ef928f61a770 188 /**
wim 1:bae4cff278f6 189 * SWO_PrintChar()
wim 1:bae4cff278f6 190 *
wim 1:bae4cff278f6 191 * @brief
wim 1:bae4cff278f6 192 * Checks if SWO is set up. If it is not, return,
wim 1:bae4cff278f6 193 * to avoid program hangs if no debugger is connected.
wim 1:bae4cff278f6 194 * If it is set up, print a character to the ITM_STIM register
wim 1:bae4cff278f6 195 * in order to provide data for SWO.
wim 1:bae4cff278f6 196 * @param c The Character to be printed.
wim 1:bae4cff278f6 197 * @notes Additional checks for device specific registers can be added.
wim 1:bae4cff278f6 198 */
wim 1:bae4cff278f6 199 void SWO_PrintChar(char c) {
wim 0:0fd55660fc26 200
wim 2:ef928f61a770 201 #if(1)
wim 2:ef928f61a770 202 //Use CMSIS_core_DebugFunctions. See core_cm3.h
wim 2:ef928f61a770 203 ITM_SendChar (c);
wim 2:ef928f61a770 204
wim 2:ef928f61a770 205 #else
wim 2:ef928f61a770 206 //Use Segger example. Basically same as CMSIS
wim 2:ef928f61a770 207
wim 0:0fd55660fc26 208 // Check if ITM_TCR.ITMENA is set
wim 0:0fd55660fc26 209 if ((ITM_TCR & 1) == 0) {
wim 0:0fd55660fc26 210 return;
wim 0:0fd55660fc26 211 }
wim 1:bae4cff278f6 212
wim 0:0fd55660fc26 213 // Check if stimulus port is enabled
wim 0:0fd55660fc26 214 if ((ITM_ENA & 1) == 0) {
wim 0:0fd55660fc26 215 return;
wim 0:0fd55660fc26 216 }
wim 0:0fd55660fc26 217
wim 1:bae4cff278f6 218 // Wait until STIMx FIFO is ready, then send data
wim 2:ef928f61a770 219 // while ((ITM_STIM_U8(0) & 1) == 0);
wim 2:ef928f61a770 220 while (!(ITM_STIM_U8(0) & ITM_STIM_FIFOREADY));
wim 1:bae4cff278f6 221 ITM_STIM_U8(0) = c;
wim 2:ef928f61a770 222
wim 1:bae4cff278f6 223 // while ((ITM_STIM_U32(0) & 1) == 0);
wim 1:bae4cff278f6 224 // ITM_STIM_U32(0) = c;
wim 2:ef928f61a770 225
wim 2:ef928f61a770 226 #endif
wim 0:0fd55660fc26 227 }
wim 0:0fd55660fc26 228
wim 1:bae4cff278f6 229 /**
wim 1:bae4cff278f6 230 * SWO_PrintString()
wim 1:bae4cff278f6 231 *
wim 1:bae4cff278f6 232 * @brief Print a string via SWO.
wim 1:bae4cff278f6 233 * @param *s The string to be printed.
wim 1:bae4cff278f6 234 *
wim 1:bae4cff278f6 235 */
wim 0:0fd55660fc26 236 void SWO_PrintString(const char *s) {
wim 1:bae4cff278f6 237
wim 1:bae4cff278f6 238 // Print out characters until \0
wim 0:0fd55660fc26 239 while (*s) {
wim 0:0fd55660fc26 240 SWO_PrintChar(*s++);
wim 0:0fd55660fc26 241 }
wim 3:e5af2e131b95 242 }
wim 3:e5af2e131b95 243
wim 3:e5af2e131b95 244
wim 3:e5af2e131b95 245