]> git.sur5r.net Git - openocd/blobdiff - src/jtag/bitbang.c
- added mips software breakpoint support
[openocd] / src / jtag / bitbang.c
index 16b5f1918b3fe6f317d3234b8d2c6fe4cc9a92ab..e4191d1487e9a35a65767fee33ca5e084a7b8615 100644 (file)
@@ -2,6 +2,9 @@
  *   Copyright (C) 2005 by Dominic Rath                                    *
  *   Dominic.Rath@gmx.de                                                   *
  *                                                                         *
+ *   Copyright (C) 2007,2008 Øyvind Harboe                                 *
+ *   oyvind.harboe@zylin.com                                               *
+ *                                                                         *
  *   This program is free software; you can redistribute it and/or modify  *
  *   it under the terms of the GNU General Public License as published by  *
  *   the Free Software Foundation; either version 2 of the License, or     *
 #include <stdlib.h>
 #include <unistd.h>
 
-#include <sys/time.h>
-#include <time.h>
+
+static void bitbang_stableclocks(int num_cycles);
+
 
 bitbang_interface_t *bitbang_interface;
 
+/* DANGER!!!! clock absolutely *MUST* be 0 in idle or reset won't work!
+ *
+ * Set this to 1 and str912 reset halt will fail.
+ *
+ * If someone can submit a patch with an explanation it will be greatly
+ * appreciated, but as far as I can tell (ØH) DCLK is generated upon
+ * clk=0 in TAP_IDLE. Good luck deducing that from the ARM documentation!
+ * The ARM documentation uses the term "DCLK is asserted while in the TAP_IDLE
+ * state". With hardware there is no such thing as *while* in a state. There
+ * are only edges. So clk => 0 is in fact a very subtle state transition that
+ * happens *while* in the TAP_IDLE state. "#&¤"#¤&"#&"#&
+ *
+ * For "reset halt" the last thing that happens before srst is asserted
+ * is that the breakpoint is set up. If DCLK is not wiggled one last
+ * time before the reset, then the breakpoint is not set up and
+ * "reset halt" will fail to halt.
+ *
+ */
+#define CLOCK_IDLE() 0
+
 int bitbang_execute_queue(void);
 
-/* The bitbang driver leaves the TCK 0 when in idle */
 
 
+/* The bitbang driver leaves the TCK 0 when in idle */
+
 void bitbang_end_state(enum tap_state state)
 {
        if (tap_move_map[state] != -1)
@@ -56,18 +81,18 @@ void bitbang_end_state(enum tap_state state)
 }
 
 void bitbang_state_move(void) {
-       
+
        int i=0, tms=0;
        u8 tms_scan = TAP_MOVE(cur_state, end_state);
-       
+
        for (i = 0; i < 7; i++)
        {
                tms = (tms_scan >> i) & 1;
                bitbang_interface->write(0, tms, 0);
                bitbang_interface->write(1, tms, 0);
        }
-       bitbang_interface->write(0, tms, 0);
-       
+       bitbang_interface->write(CLOCK_IDLE(), tms, 0);
+
        cur_state = end_state;
 }
 
@@ -90,10 +115,10 @@ void bitbang_path_move(pathmove_command_t *cmd)
                }
                else
                {
-                       LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition", tap_state_strings[cur_state], tap_state_strings[cmd->path[state_count]]);
+                       LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition", jtag_state_name(cur_state), jtag_state_name(cmd->path[state_count]));
                        exit(-1);
                }
-               
+
                bitbang_interface->write(0, tms, 0);
                bitbang_interface->write(1, tms, 0);
 
@@ -101,8 +126,8 @@ void bitbang_path_move(pathmove_command_t *cmd)
                state_count++;
                num_states--;
        }
-       
-       bitbang_interface->write(0, tms, 0);
+
+       bitbang_interface->write(CLOCK_IDLE(), tms, 0);
 
        end_state = cur_state;
 }
@@ -110,41 +135,56 @@ void bitbang_path_move(pathmove_command_t *cmd)
 void bitbang_runtest(int num_cycles)
 {
        int i;
-       
+
        enum tap_state saved_end_state = end_state;
-       
-       /* only do a state_move when we're not already in RTI */
-       if (cur_state != TAP_RTI)
+
+       /* only do a state_move when we're not already in IDLE */
+       if (cur_state != TAP_IDLE)
        {
-               bitbang_end_state(TAP_RTI);
+               bitbang_end_state(TAP_IDLE);
                bitbang_state_move();
        }
-       
+
        /* execute num_cycles */
-       bitbang_interface->write(0, 0, 0);
        for (i = 0; i < num_cycles; i++)
        {
-               bitbang_interface->write(1, 0, 0);
                bitbang_interface->write(0, 0, 0);
+               bitbang_interface->write(1, 0, 0);
        }
-       
+       bitbang_interface->write(CLOCK_IDLE(), 0, 0);
+
        /* finish in end_state */
        bitbang_end_state(saved_end_state);
        if (cur_state != end_state)
                bitbang_state_move();
 }
 
+
+static void bitbang_stableclocks(int num_cycles)
+{
+       int i;
+
+       /* send num_cycles clocks onto the cable */
+       for (i = 0; i < num_cycles; i++)
+       {
+               bitbang_interface->write(1, 0, 0);
+               bitbang_interface->write(0, 0, 0);
+       }
+}
+
+
+
 void bitbang_scan(int ir_scan, enum scan_type type, u8 *buffer, int scan_size)
 {
        enum tap_state saved_end_state = end_state;
        int bit_cnt;
-       
-       if (!((!ir_scan && (cur_state == TAP_SD)) || (ir_scan && (cur_state == TAP_SI))))
+
+       if (!((!ir_scan && (cur_state == TAP_DRSHIFT)) || (ir_scan && (cur_state == TAP_IRSHIFT))))
        {
                if (ir_scan)
-                       bitbang_end_state(TAP_SI);
+                       bitbang_end_state(TAP_IRSHIFT);
                else
-                       bitbang_end_state(TAP_SD);
+                       bitbang_end_state(TAP_DRSHIFT);
 
                bitbang_state_move();
                bitbang_end_state(saved_end_state);
@@ -152,52 +192,50 @@ void bitbang_scan(int ir_scan, enum scan_type type, u8 *buffer, int scan_size)
 
        for (bit_cnt = 0; bit_cnt < scan_size; bit_cnt++)
        {
+               int val=0;
+               int tms=(bit_cnt==scan_size-1) ? 1 : 0;
+               int tdi;
+               int bytec=bit_cnt/8;
+               int bcval=1<<(bit_cnt % 8);
+
                /* if we're just reading the scan, but don't care about the output
                 * default to outputting 'low', this also makes valgrind traces more readable,
                 * as it removes the dependency on an uninitialised value
-                */ 
-               if ((type != SCAN_IN) && ((buffer[bit_cnt/8] >> (bit_cnt % 8)) & 0x1))
-               {
-                       bitbang_interface->write(0, (bit_cnt==scan_size-1) ? 1 : 0, 1);
-                       bitbang_interface->write(1, (bit_cnt==scan_size-1) ? 1 : 0, 1);
-               } else {
-                       bitbang_interface->write(0, (bit_cnt==scan_size-1) ? 1 : 0, 0);
-                       bitbang_interface->write(1, (bit_cnt==scan_size-1) ? 1 : 0, 0);
-               }
-               
+                */
+               tdi=0;
+               if ((type != SCAN_IN) && (buffer[bytec] & bcval))
+                       tdi=1;
+
+               bitbang_interface->write(0, tms, tdi);
+
+               if (type!=SCAN_OUT)
+                       val=bitbang_interface->read();
+
+               bitbang_interface->write(1, tms, tdi);
+
                if (type != SCAN_OUT)
                {
-                       /*
-                       TDO should be sampled on the rising edge, and will change 
-                       on the falling edge. 
-                       
-                       Because there is no way to read the signal exactly at the rising edge,
-                       read after the rising edge.
-
-                       This is plain IEEE 1149 JTAG - nothing specific to the OpenOCD or its JTAG
-                       API. 
-                       */
-                       if (bitbang_interface->read())
-                               buffer[(bit_cnt)/8] |= 1 << ((bit_cnt) % 8);
+                       if (val)
+                               buffer[bytec] |= bcval;
                        else
-                               buffer[(bit_cnt)/8] &= ~(1 << ((bit_cnt) % 8));
+                               buffer[bytec] &= ~bcval;
                }
        }
-       
-       /* TAP_SD & TAP_SI are illegal end states, so we always transition to the pause
+
+       /* TAP_DRSHIFT & TAP_IRSHIFT are illegal end states, so we always transition to the pause
         * state which is a legal stable state from which statemove will work.
-        *  
-        * Exit1 -> Pause 
+        *
+        * Exit1 -> Pause
         */
        bitbang_interface->write(0, 0, 0);
        bitbang_interface->write(1, 0, 0);
-       bitbang_interface->write(0, 0, 0);
-       
+       bitbang_interface->write(CLOCK_IDLE(), 0, 0);
+
        if (ir_scan)
-               cur_state = TAP_PI;
+               cur_state = TAP_IRPAUSE;
        else
-               cur_state = TAP_PD;
-       
+               cur_state = TAP_DRPAUSE;
+
        if (cur_state != end_state)
                bitbang_state_move();
 }
@@ -209,18 +247,18 @@ int bitbang_execute_queue(void)
        enum scan_type type;
        u8 *buffer;
        int retval;
-       
+
        if (!bitbang_interface)
        {
                LOG_ERROR("BUG: Bitbang interface called, but not yet initialized");
                exit(-1);
        }
-       
+
        /* return ERROR_OK, unless a jtag_read_buffer returns a failed check
         * that wasn't handled by a caller-provided error handler
-        */ 
+        */
        retval = ERROR_OK;
-               
+
        if(bitbang_interface->blink)
                bitbang_interface->blink(1);
 
@@ -230,7 +268,7 @@ int bitbang_execute_queue(void)
                {
                        case JTAG_END_STATE:
 #ifdef _DEBUG_JTAG_IO_
-                               LOG_DEBUG("end_state: %i", cmd->cmd.end_state->end_state);
+                               LOG_DEBUG("end_state: %s", jtag_state_name(cmd->cmd.end_state->end_state) );
 #endif
                                if (cmd->cmd.end_state->end_state != -1)
                                        bitbang_end_state(cmd->cmd.end_state->end_state);
@@ -241,21 +279,26 @@ int bitbang_execute_queue(void)
 #endif
                                if ((cmd->cmd.reset->trst == 1) || (cmd->cmd.reset->srst && (jtag_reset_config & RESET_SRST_PULLS_TRST)))
                                {
-                                       cur_state = TAP_TLR;
+                                       cur_state = TAP_RESET;
                                }
                                bitbang_interface->reset(cmd->cmd.reset->trst, cmd->cmd.reset->srst);
                                break;
                        case JTAG_RUNTEST:
 #ifdef _DEBUG_JTAG_IO_
-                               LOG_DEBUG("runtest %i cycles, end in %i", cmd->cmd.runtest->num_cycles, cmd->cmd.runtest->end_state);
+                               LOG_DEBUG("runtest %i cycles, end in %s", cmd->cmd.runtest->num_cycles, jtag_state_name(cmd->cmd.runtest->end_state) );
 #endif
                                if (cmd->cmd.runtest->end_state != -1)
                                        bitbang_end_state(cmd->cmd.runtest->end_state);
                                bitbang_runtest(cmd->cmd.runtest->num_cycles);
                                break;
+
+                       case JTAG_STABLECLOCKS:
+                               bitbang_stableclocks(cmd->cmd.stableclocks->num_cycles);
+                               break;
+
                        case JTAG_STATEMOVE:
 #ifdef _DEBUG_JTAG_IO_
-                               LOG_DEBUG("statemove end in %i", cmd->cmd.statemove->end_state);
+                               LOG_DEBUG("statemove end in %s", jtag_state_name(cmd->cmd.statemove->end_state));
 #endif
                                if (cmd->cmd.statemove->end_state != -1)
                                        bitbang_end_state(cmd->cmd.statemove->end_state);
@@ -263,13 +306,14 @@ int bitbang_execute_queue(void)
                                break;
                        case JTAG_PATHMOVE:
 #ifdef _DEBUG_JTAG_IO_
-                               LOG_DEBUG("pathmove: %i states, end in %i", cmd->cmd.pathmove->num_states, cmd->cmd.pathmove->path[cmd->cmd.pathmove->num_states - 1]);
+                               LOG_DEBUG("pathmove: %i states, end in %s", cmd->cmd.pathmove->num_states,
+                                       jtag_state_name(cmd->cmd.pathmove->path[cmd->cmd.pathmove->num_states - 1]));
 #endif
                                bitbang_path_move(cmd->cmd.pathmove);
                                break;
                        case JTAG_SCAN:
 #ifdef _DEBUG_JTAG_IO_
-                               LOG_DEBUG("%s scan end in %i",  (cmd->cmd.scan->ir_scan) ? "IR" : "DR", cmd->cmd.scan->end_state);
+                               LOG_DEBUG("%s scan end in %s",  (cmd->cmd.scan->ir_scan) ? "IR" : "DR", jtag_state_name(cmd->cmd.scan->end_state) );
 #endif
                                if (cmd->cmd.scan->end_state != -1)
                                        bitbang_end_state(cmd->cmd.scan->end_state);
@@ -295,7 +339,6 @@ int bitbang_execute_queue(void)
        }
        if(bitbang_interface->blink)
                bitbang_interface->blink(0);
-       
+
        return retval;
 }
-