Commit a0c10dd2 authored by zwelch's avatar zwelch
Browse files

David Brownell <david-b@pacbell.net>:

Extend the internal JTAG event handlers to cover enable/disable,
and use those events to make sure that targets get "examined" if
they were disabled when the scan chain was first set up:

 - Remove "enum jtag_tap_event", merge with "enum jtag_event",
   so C code can now listen for TAP enable/disable events.

 - Report those events so they can trigger callbacks.

 - During startup, make target_examine() register a handler to
   catch ENABLE events for any then-disabled targets.

This fixes bugs like "can't halt target after enabling its TAP".

One class of unresolved bugs:  if the target has an ETM hooked
up to an ETB, nothing activates the ETB.  But starting up the
ETM without access to the ETB registers fails...


git-svn-id: svn://svn.berlios.de/openocd/trunk@2251 b42882b7-edfa-0310-969c-e2dbd0fdcd60
parent 491083a2
......@@ -61,6 +61,8 @@ static int jtag_error = ERROR_OK;
static const char *jtag_event_strings[] =
{
[JTAG_TRST_ASSERTED] = "JTAG controller reset (RESET or TRST)",
[JTAG_TAP_EVENT_ENABLE] = "TAP enabled",
[JTAG_TAP_EVENT_DISABLE] = "TAP disabled",
};
static int jtag_trst = 0;
......
......@@ -201,19 +201,18 @@ extern unsigned jtag_tap_count(void);
* - SRST pulls TRST
* - TRST asserted
*
**/
* TAP activation/deactivation is currently implemented outside the core
* using scripted code that understands the specific router type.
*/
enum jtag_event {
JTAG_TRST_ASSERTED
};
enum jtag_tap_event {
JTAG_TRST_ASSERTED,
JTAG_TAP_EVENT_ENABLE,
JTAG_TAP_EVENT_DISABLE
JTAG_TAP_EVENT_DISABLE,
};
struct jtag_tap_event_action_s
{
enum jtag_tap_event event;
enum jtag_event event;
Jim_Obj* body;
jtag_tap_event_action_t* next;
};
......
......@@ -256,7 +256,7 @@ static int jtag_tap_configure_cmd( Jim_GetOptInfo *goi, jtag_tap_t * tap)
jteap = tap->event_action;
/* replace existing? */
while (jteap) {
if (jteap->event == (enum jtag_tap_event)n->value) {
if (jteap->event == (enum jtag_event)n->value) {
break;
}
jteap = jteap->next;
......@@ -460,7 +460,7 @@ static int jim_newtap_cmd( Jim_GetOptInfo *goi )
return JIM_ERR;
}
static void jtag_tap_handle_event( jtag_tap_t * tap, enum jtag_tap_event e)
static void jtag_tap_handle_event(jtag_tap_t *tap, enum jtag_event e)
{
jtag_tap_event_action_t * jteap;
int done;
......@@ -594,6 +594,8 @@ static int jim_jtag_command( Jim_Interp *interp, int argc, Jim_Obj *const *argv
* - scan chain length grew by one (this)
* - IDs and IR lengths are as expected
*/
jtag_call_event_callbacks(JTAG_TAP_EVENT_ENABLE);
break;
case JTAG_CMD_TAPDISABLE:
if (!t->enabled)
......@@ -606,6 +608,8 @@ static int jim_jtag_command( Jim_Interp *interp, int argc, Jim_Obj *const *argv
* - scan chain length shrank by one (this)
* - IDs and IR lengths are as expected
*/
jtag_call_event_callbacks(JTAG_TAP_EVENT_DISABLE);
break;
}
e = t->enabled;
......
......@@ -478,6 +478,18 @@ int target_examine_one(struct target_s *target)
return target->type->examine(target);
}
static int jtag_enable_callback(enum jtag_event event, void *priv)
{
target_t *target = priv;
if (event != JTAG_TAP_EVENT_ENABLE || !target->tap->enabled)
return ERROR_OK;
jtag_unregister_event_callback(jtag_enable_callback, target);
return target_examine_one(target);
}
/* Targets that correctly implement init+examine, i.e.
* no communication with target during init:
*
......@@ -490,8 +502,12 @@ int target_examine(void)
for (target = all_targets; target; target = target->next)
{
if (!target->tap->enabled)
/* defer examination, but don't skip it */
if (!target->tap->enabled) {
jtag_register_event_callback(jtag_enable_callback,
target);
continue;
}
if ((retval = target_examine_one(target)) != ERROR_OK)
return retval;
}
......
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