Streamline Capture-IR validation code
- Don't issue needless JTAG resets ... only do them after
errors. Normal exit now leaves every TAP in BYPASS.
- Fix an unlikely memory leak on one fault path.
- Remove the oddball limitation that invalid capture LSBs
trigger errors only for TAPs that support IDCODE.
Re the JTAG reset: there are too many of them, and they can
(and do!) change system state. So the needless ones should
get removed. This one was especially pointless.
---
This is against *latest* SVN head. Works for me in light
testing. I have no idea why the code previously did some of
the strange and nonstandard stuff it did. This could be
tweaked just a bit more, but it's probably not absolutely needed.
src/jtag/core.c | 35 ++++++++++++++++++-----------------
1 file changed, 18 insertions(+), 17 deletions(-)
--- a/src/jtag/core.c
+++ b/src/jtag/core.c
@@ -1046,6 +1046,9 @@ static int jtag_examine_chain(void)
* Validate the date loaded by entry to the Capture-IR state, to help
* find errors related to scan chain configuration (wrong IR lengths)
* or communication.
+ *
+ * Entry state can be anything. On non-error exit, all TAPs are in
+ * bypass mode. On error exits, the scan chain is reset.
*/
static int jtag_validate_ircapture(void)
{
@@ -1054,6 +1057,7 @@ static int jtag_validate_ircapture(void)
uint8_t *ir_test = NULL;
scan_field_t field;
int chain_pos = 0;
+ int retval;
tap = NULL;
total_ir_length = 0;
@@ -1065,12 +1069,14 @@ static int jtag_validate_ircapture(void)
total_ir_length += tap->ir_length;
}
+ /* increase length to add 2 bit sentinel after scan */
total_ir_length += 2;
ir_test = malloc(CEIL(total_ir_length, 8));
if (ir_test == NULL)
return ERROR_FAIL;
+ /* after this scan, all TAPs will capture BYPASS instructions */
buf_set_ones(ir_test, total_ir_length);
field.tap = NULL;
@@ -1078,14 +1084,11 @@ static int jtag_validate_ircapture(void)
field.out_value = ir_test;
field.in_value = ir_test;
+ jtag_add_plain_ir_scan(1, &field, TAP_IDLE);
- jtag_add_plain_ir_scan(1, &field, TAP_IRPAUSE);
- jtag_add_tlr();
-
- int retval;
retval = jtag_execute_queue();
if (retval != ERROR_OK)
- return retval;
+ goto done;
tap = NULL;
chain_pos = 0;
@@ -1107,14 +1110,8 @@ static int jtag_validate_ircapture(void)
LOG_ERROR("%s: IR capture error; saw 0x%s not 0x..1",
jtag_tap_name(tap), cbuf);
- /* Fail only if we have IDCODE for this device.
- * REVISIT -- why not fail-always?
- */
- if (tap->hasidcode) {
- free(cbuf);
- free(ir_test);
- return ERROR_JTAG_INIT_FAILED;
- }
+ free(cbuf);
+ retval = ERROR_JTAG_INIT_FAILED;
}
chain_pos += tap->ir_length;
}
@@ -1128,13 +1125,17 @@ static int jtag_validate_ircapture(void)
LOG_ERROR("IR capture error at bit %d, saw 0x%s not 0x...3",
chain_pos, cbuf);
free(cbuf);
- free(ir_test);
- return ERROR_JTAG_INIT_FAILED;
+ retval = ERROR_JTAG_INIT_FAILED;
+ goto done;
}
+done:
free(ir_test);
-
- return ERROR_OK;
+ if (retval != ERROR_OK) {
+ jtag_add_tlr();
+ jtag_execute_queue();
+ }
+ return retval;
}
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