X-Git-Url: https://review.openocd.org/gitweb?a=blobdiff_plain;f=src%2Fjtag%2Fjtag.c;h=96565d949e97c8761a5ae4ee029de20dce614731;hb=b550f70100794d8dfa91d2760324041828836f82;hp=292aa55aaecf557033cef348c148a4ade0b27587;hpb=861f52ff16417bf3077a236b866d906636424d2c;p=openocd.git

diff --git a/src/jtag/jtag.c b/src/jtag/jtag.c
index 292aa55aae..96565d949e 100644
--- a/src/jtag/jtag.c
+++ b/src/jtag/jtag.c
@@ -946,109 +946,168 @@ void jtag_sleep(u32 us)
 #define EXTRACT_PART(X) (((X) & 0xffff000) >> 12)
 #define EXTRACT_VER(X)  (((X) & 0xf0000000) >> 28)
 
-/* Try to examine chain layout according to IEEE 1149.1 §12
- */
-static int jtag_examine_chain(void)
+static int jtag_examine_chain_execute(u8 *idcode_buffer, unsigned num_idcode)
+{
+	scan_field_t field = {
+			.tap = NULL,
+			.num_bits = num_idcode * 32,
+			.out_value = idcode_buffer,
+			.in_value = idcode_buffer,
+		};
+
+	// initialize to the end of chain ID value
+	for (unsigned i = 0; i < JTAG_MAX_CHAIN_SIZE; i++)
+		buf_set_u32(idcode_buffer, i * 32, 32, 0x000000FF);
+
+	jtag_add_plain_dr_scan(1, &field, TAP_RESET);
+	return jtag_execute_queue();
+}
+
+static bool jtag_examine_chain_check(u8 *idcodes, unsigned count)
 {
-	jtag_tap_t *tap;
-	scan_field_t field;
-	u8 idcode_buffer[JTAG_MAX_CHAIN_SIZE * 4];
-	int i;
-	int bit_count;
-	int device_count = 0;
 	u8 zero_check = 0x0;
 	u8 one_check = 0xff;
 
-	field.tap = NULL;
-	field.num_bits = sizeof(idcode_buffer) * 8;
-	field.out_value = idcode_buffer;
-
-	field.in_value = idcode_buffer;
+	for (unsigned i = 0; i < count * 4; i++)
+	{
+		zero_check |= idcodes[i];
+		one_check &= idcodes[i];
+	}
 
+	/* if there wasn't a single non-zero bit or if all bits were one,
+	 * the scan is not valid */
+	if (zero_check == 0x00 || one_check == 0xff)
+	{
+		LOG_ERROR("JTAG communication failure: check connection, "
+			"JTAG interface, target power etc.");
+		return false;
+	}
+	return true;
+}
 
+static void jtag_examine_chain_display(enum log_levels level, const char *msg,
+		const char *name, u32 idcode)
+{
+	log_printf_lf(level, __FILE__, __LINE__, __FUNCTION__,
+			"JTAG tap: %s %16.16s: 0x%08x "
+			"(mfg: 0x%3.3x, part: 0x%4.4x, ver: 0x%1.1x)",
+		name, msg, idcode,
+		EXTRACT_MFG(idcode), EXTRACT_PART(idcode), EXTRACT_VER(idcode) );
+}
 
+static bool jtag_idcode_is_final(u32 idcode)
+{
+		return idcode == 0x000000FF || idcode == 0xFFFFFFFF;
+}
 
-	for (i = 0; i < JTAG_MAX_CHAIN_SIZE; i++)
+/**
+ * This helper checks that remaining bits in the examined chain data are
+ * all as expected, but a single JTAG device requires only 64 bits to be
+ * read back correctly.  This can help identify and diagnose problems
+ * with the JTAG chain earlier, gives more helpful/explicit error messages.
+ */
+static void jtag_examine_chain_end(u8 *idcodes, unsigned count, unsigned max)
+{
+	bool triggered = false;
+	for ( ; count < max - 31; count += 32)
 	{
-		buf_set_u32(idcode_buffer, i * 32, 32, 0x000000FF);
+		u32 idcode = buf_get_u32(idcodes, count, 32);
+		// do not trigger the warning if the data looks good
+		if (!triggered && jtag_idcode_is_final(idcode))
+			continue;
+		LOG_WARNING("Unexpected idcode after end of chain: %d 0x%08x",
+				count, idcode);
+		triggered = true;
 	}
+}
 
-	jtag_add_plain_dr_scan(1, &field, TAP_RESET);
-	jtag_execute_queue();
+static bool jtag_examine_chain_match_tap(const struct jtag_tap_s *tap)
+{
+	if (0 == tap->expected_ids_cnt)
+	{
+		/// @todo Enable LOG_INFO to ask for reports about unknown TAP IDs.
+#if 0
+		LOG_INFO("Uknown JTAG TAP ID: 0x%08x", tap->idcode)
+		LOG_INFO("Please report the chip name and reported ID code to the openocd project");
+#endif
+		return true;
+	}
 
-	for (i = 0; i < JTAG_MAX_CHAIN_SIZE * 4; i++)
+	/* Loop over the expected identification codes and test for a match */
+	u8 ii;
+	for (ii = 0; ii < tap->expected_ids_cnt; ii++)
 	{
-		zero_check |= idcode_buffer[i];
-		one_check &= idcode_buffer[i];
+		if (tap->idcode == tap->expected_ids[ii])
+			break;
 	}
 
-	/* if there wasn't a single non-zero bit or if all bits were one, the scan isn't valid */
-	if ((zero_check == 0x00) || (one_check == 0xff))
+	/* If none of the expected ids matched, log an error */
+	if (ii != tap->expected_ids_cnt)
 	{
-		LOG_ERROR("JTAG communication failure, check connection, JTAG interface, target power etc.");
-		return ERROR_JTAG_INIT_FAILED;
+		LOG_INFO("JTAG Tap/device matched");
+		return true;
+	}
+	jtag_examine_chain_display(LOG_LVL_ERROR, "got",
+			tap->dotted_name, tap->idcode);
+	for (ii = 0; ii < tap->expected_ids_cnt; ii++)
+	{
+		char msg[32];
+		snprintf(msg, sizeof(msg), "expected %hhu of %hhu",
+				ii + 1, tap->expected_ids_cnt);
+		jtag_examine_chain_display(LOG_LVL_ERROR, msg,
+				tap->dotted_name, tap->expected_ids[ii]);
 	}
+	return false;
+}
+
+/* Try to examine chain layout according to IEEE 1149.1 §12
+ */
+static int jtag_examine_chain(void)
+{
+	u8 idcode_buffer[JTAG_MAX_CHAIN_SIZE * 4];
+	int device_count = 0;
+
+	jtag_examine_chain_execute(idcode_buffer, JTAG_MAX_CHAIN_SIZE);
+
+	if (!jtag_examine_chain_check(idcode_buffer, JTAG_MAX_CHAIN_SIZE))
+		return ERROR_JTAG_INIT_FAILED;
 
 	/* point at the 1st tap */
-	tap = jtag_tap_next_enabled(NULL);
-	if( tap == NULL ){
+	jtag_tap_t *tap = jtag_tap_next_enabled(NULL);
+	if (tap == NULL)
+	{
 		LOG_ERROR("JTAG: No taps enabled?");
 		return ERROR_JTAG_INIT_FAILED;
 	}
 
-	for (bit_count = 0; bit_count < (JTAG_MAX_CHAIN_SIZE * 32) - 31;)
+	for (unsigned bit_count = 0; bit_count < (JTAG_MAX_CHAIN_SIZE * 32) - 31;)
 	{
 		u32 idcode = buf_get_u32(idcode_buffer, bit_count, 32);
 		if ((idcode & 1) == 0)
 		{
 			/* LSB must not be 0, this indicates a device in bypass */
 			LOG_WARNING("Tap/Device does not have IDCODE");
-			idcode=0;
+			idcode = 0;
 
 			bit_count += 1;
 		}
 		else
 		{
-			u32 manufacturer;
-			u32 part;
-			u32 version;
-
-			/* some devices, such as AVR will output all 1's instead of TDI
-			input value at end of chain. */
-			if ((idcode == 0x000000FF)||(idcode == 0xFFFFFFFF))
+	 		/*
+			 * End of chain (invalid manufacturer ID) some devices, such
+			 * as AVR will output all 1's instead of TDI input value at
+			 * end of chain.
+			 */
+			if (jtag_idcode_is_final(idcode))
 			{
-				int unexpected=0;
-				/* End of chain (invalid manufacturer ID)
-				 *
-				 * The JTAG examine is the very first thing that happens
-				 *
-				 * A single JTAG device requires only 64 bits to be read back correctly.
-				 *
-				 * The code below adds a check that the rest of the data scanned (640 bits)
-				 * are all as expected. This helps diagnose/catch problems with the JTAG chain
-				 *
-				 * earlier and gives more helpful/explicit error messages.
-				 */
-				for (bit_count += 32; bit_count < (JTAG_MAX_CHAIN_SIZE * 32) - 31;bit_count += 32)
-				{
-					idcode = buf_get_u32(idcode_buffer, bit_count, 32);
-					if (unexpected||((idcode != 0x000000FF)&&(idcode != 0xFFFFFFFF)))
-					{
-						LOG_WARNING("Unexpected idcode after end of chain! %d 0x%08x", bit_count, idcode);
-						unexpected = 1;
-					}
-				}
-
+				jtag_examine_chain_end(idcode_buffer,
+						bit_count + 32, JTAG_MAX_CHAIN_SIZE * 32);
 				break;
 			}
 
-			manufacturer = EXTRACT_MFG(idcode);
-			part = EXTRACT_PART(idcode);
-			version = EXTRACT_VER(idcode);
-
-			LOG_INFO("JTAG tap: %s tap/device found: 0x%8.8x (Manufacturer: 0x%3.3x, Part: 0x%4.4x, Version: 0x%1.1x)",
-					 ((tap != NULL) ? (tap->dotted_name) : "(not-named)"),
-				idcode, manufacturer, part, version);
+			jtag_examine_chain_display(LOG_LVL_INFO, "tap/device found",
+					tap ? tap->dotted_name : "(not-named)",
+					idcode);
 
 			bit_count += 32;
 		}
@@ -1058,56 +1117,21 @@ static int jtag_examine_chain(void)
 
 		tap->idcode = idcode;
 
-		if (0 == tap->expected_ids_cnt)
-		{
-			// @todo Enable LOG_INFO to ask for reports about unknown TAP IDs.
-#if 0
-			LOG_INFO("Uknown JTAG TAP ID: 0x%08x", tap->idcode)
-			LOG_INFO("Please report the chip name and reported ID code to the openocd project");
-#endif
-			tap = jtag_tap_next_enabled(tap);
-			continue;
-		}
-			/* Loop over the expected identification codes and test for a match */
-		u8 ii;
-		for (ii = 0; ii < tap->expected_ids_cnt; ii++) {
-			if (tap->idcode == tap->expected_ids[ii]) {
-				break;
-			}
-		}
+		// ensure the TAP ID does matches what was expected
+ 		if (!jtag_examine_chain_match_tap(tap))
+			return ERROR_JTAG_INIT_FAILED;
 
-		/* If none of the expected ids matched, log an error */
-		if (ii != tap->expected_ids_cnt)
-		{
-			LOG_INFO("JTAG Tap/device matched");
-			tap = jtag_tap_next_enabled(tap);
-			continue;
-		}
-		LOG_ERROR("JTAG tap: %s             got: 0x%08x (mfg: 0x%3.3x, part: 0x%4.4x, ver: 0x%1.1x)",
-				tap->dotted_name,
-				idcode,
-				EXTRACT_MFG( tap->idcode ),
-				EXTRACT_PART( tap->idcode ),
-				EXTRACT_VER( tap->idcode ) );
-		for (ii = 0; ii < tap->expected_ids_cnt; ii++) {
-			LOG_ERROR("JTAG tap: %s expected %hhu of %hhu: 0x%08x (mfg: 0x%3.3x, part: 0x%4.4x, ver: 0x%1.1x)",
-					tap->dotted_name,
-					ii + 1,
-					tap->expected_ids_cnt,
-					tap->expected_ids[ii],
-					EXTRACT_MFG( tap->expected_ids[ii] ),
-					EXTRACT_PART( tap->expected_ids[ii] ),
-					EXTRACT_VER( tap->expected_ids[ii] ) );
-		}
-		return ERROR_JTAG_INIT_FAILED;
+		tap = jtag_tap_next_enabled(tap);
 	}
 
 	/* see if number of discovered devices matches configuration */
 	if (device_count != jtag_tap_count_enabled())
 	{
-		LOG_ERROR("number of discovered devices in JTAG chain (%i) doesn't match (enabled) configuration (%i), total taps: %d",
-				  device_count, jtag_tap_count_enabled(), jtag_tap_count());
-		LOG_ERROR("check the config file and ensure proper JTAG communication (connections, speed, ...)");
+		LOG_ERROR("number of discovered devices in JTAG chain (%i) "
+				"does not match (enabled) configuration (%i), total taps: %d",
+				device_count, jtag_tap_count_enabled(), jtag_tap_count());
+		LOG_ERROR("check the config file and ensure proper JTAG communication"
+				" (connections, speed, ...)");
 		return ERROR_JTAG_INIT_FAILED;
 	}