From f64e924ba96d944259b284f8cc517e315e78acde Mon Sep 17 00:00:00 2001
From: dbrownell <dbrownell@b42882b7-edfa-0310-969c-e2dbd0fdcd60>
Date: Sat, 26 Sep 2009 19:18:42 +0000
Subject: [PATCH] Updates to the initial scanchain validation code: - minor
bug fixes - code cleanup - update comments - improve diagnostics -
etc
git-svn-id: svn://svn.berlios.de/openocd/trunk@2759 b42882b7-edfa-0310-969c-e2dbd0fdcd60
---
src/helper/binarybuffer.h | 2 +-
src/jtag/core.c | 53 ++++++++++++++++++++++++++++++---------
2 files changed, 42 insertions(+), 13 deletions(-)
diff --git a/src/helper/binarybuffer.h b/src/helper/binarybuffer.h
index 6d66c1893..eef4057ab 100644
--- a/src/helper/binarybuffer.h
+++ b/src/helper/binarybuffer.h
@@ -86,7 +86,7 @@ extern char* buf_to_str(const uint8_t *buf, int size, int radix);
struct scan_field_s;
extern int buf_to_u32_handler(uint8_t *in_buf, void *priv, struct scan_field_s *field);
-#define CEIL(m, n) ((m + n - 1) / n)
+#define CEIL(m, n) (((m) + (n) - 1) / (n))
/* read a uint32_t from a buffer in target memory endianness */
static inline uint32_t fast_target_buffer_get_u32(const uint8_t *buffer, int little)
diff --git a/src/jtag/core.c b/src/jtag/core.c
index f9ebb3fa6..b1d3ca0f1 100644
--- a/src/jtag/core.c
+++ b/src/jtag/core.c
@@ -847,6 +847,9 @@ void jtag_sleep(uint32_t us)
#define EXTRACT_PART(X) (((X) & 0xffff000) >> 12)
#define EXTRACT_VER(X) (((X) & 0xf0000000) >> 28)
+/* A reserved manufacturer ID is used in END_OF_CHAIN_FLAG, so we
+ * know that no valid TAP will have it as an IDCODE value.
+ */
#define END_OF_CHAIN_FLAG 0x000000ff
static int jtag_examine_chain_execute(uint8_t *idcode_buffer, unsigned num_idcode)
@@ -964,6 +967,7 @@ static bool jtag_examine_chain_match_tap(const struct jtag_tap_s *tap)
}
/* Try to examine chain layout according to IEEE 1149.1 §12
+ * This is called a "blind interrogation" of the scan chain.
*/
static int jtag_examine_chain(void)
{
@@ -1037,7 +1041,12 @@ static int jtag_examine_chain(void)
return ERROR_OK;
}
-int jtag_validate_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.
+ */
+static int jtag_validate_ircapture(void)
{
jtag_tap_t *tap;
int total_ir_length = 0;
@@ -1056,7 +1065,11 @@ int jtag_validate_chain(void)
}
total_ir_length += 2;
+
ir_test = malloc(CEIL(total_ir_length, 8));
+ if (ir_test == NULL)
+ return ERROR_FAIL;
+
buf_set_ones(ir_test, total_ir_length);
field.tap = NULL;
@@ -1082,24 +1095,37 @@ int jtag_validate_chain(void)
break;
}
+ /* Validate the two LSBs, which must be 01 per JTAG spec.
+ * REVISIT we might be able to verify some MSBs too, using
+ * ircapture/irmask attributes.
+ */
val = buf_get_u32(ir_test, chain_pos, 2);
- /* Only fail this check if we have IDCODE for this device */
- if ((val != 0x1)&&(tap->hasidcode))
- {
+ if (val != 1) {
char *cbuf = buf_to_str(ir_test, total_ir_length, 16);
- LOG_ERROR("Could not validate JTAG scan chain, IR mismatch, scan returned 0x%s. tap=%s pos=%d expected 0x1 got %0x", cbuf, jtag_tap_name(tap), chain_pos, val);
- free(cbuf);
- free(ir_test);
- return ERROR_JTAG_INIT_FAILED;
+
+ 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;
+ }
}
chain_pos += tap->ir_length;
}
+ /* verify the '11' sentinel we wrote is returned at the end */
val = buf_get_u32(ir_test, chain_pos, 2);
if (val != 0x3)
{
char *cbuf = buf_to_str(ir_test, total_ir_length, 16);
- LOG_ERROR("Could not validate end of JTAG scan chain, IR mismatch, scan returned 0x%s. pos=%d expected 0x3 got %0x", cbuf, chain_pos, val);
+
+ 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;
@@ -1115,6 +1141,7 @@ void jtag_tap_init(jtag_tap_t *tap)
{
assert(0 != tap->ir_length);
+ /// @todo fix, this allocates one byte per bit for all three fields!
tap->expected = malloc(tap->ir_length);
tap->expected_mask = malloc(tap->ir_length);
tap->cur_instr = malloc(tap->ir_length);
@@ -1132,7 +1159,8 @@ void jtag_tap_init(jtag_tap_t *tap)
LOG_DEBUG("Created Tap: %s @ abs position %d, "
"irlen %d, capture: 0x%x mask: 0x%x", tap->dotted_name,
tap->abs_chain_position, tap->ir_length,
- (unsigned int)(tap->ir_capture_value), (unsigned int)(tap->ir_capture_mask));
+ (unsigned) tap->ir_capture_value,
+ (unsigned) tap->ir_capture_mask);
jtag_tap_add(tap);
}
@@ -1141,6 +1169,7 @@ void jtag_tap_free(jtag_tap_t *tap)
jtag_unregister_event_callback(&jtag_reset_callback, tap);
/// @todo is anything missing? no memory leaks please
+ free((void *)tap->expected);
free((void *)tap->expected_ids);
free((void *)tap->chip);
free((void *)tap->tapname);
@@ -1212,9 +1241,9 @@ static int jtag_init_inner(struct command_context_s *cmd_ctx)
LOG_ERROR("trying to validate configured JTAG chain anyway...");
}
- if (jtag_validate_chain() != ERROR_OK)
+ if (jtag_validate_ircapture() != ERROR_OK)
{
- LOG_WARNING("Could not validate JTAG chain, continuing anyway...");
+ LOG_WARNING("Errors during IR capture, continuing anyway...");
}
return ERROR_OK;
--
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