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

diff --git a/src/helper/binarybuffer.h b/src/helper/binarybuffer.h
index 6d66c18938aff67132a9673d5a0c44f5dbcd1f27..eef4057ab17cb419262209c69f9b5a899812b4d7 100644 (file)
--- 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 f9ebb3fa6f50d9ed401fb66f11932832f9ae1901..b1d3ca0f1abb107b0aa1d4067ed7b83b79fe9151 100644 (file)
--- 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;