jtag: add '-ignore-version' option

Add a "-ignore-version" to "jtag newtap" which makes the IDCODE
comparison logic optionally ignore version differences.

Update the "scan_chain" command to illustrate this by showing
the "*" character instead of the (ignored) version nibble.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>

doc/openocd.texi

@@ -2763,6 +2763,12 @@ are provided in vendors' chip documentation, usually a technical
 reference manual.  Sometimes you may need to probe the JTAG
 hardware to find these values.
 @xref{Autoprobing}.
+@item @code{-ignore-version}
+@*Specify this to ignore the JTAG version field in the @code{-expected-id}
+option.  When vendors put out multiple versions of a chip, or use the same
+JTAG-level ID for several largely-compatible chips, it may be more practical
+to ignore the version field than to update config files to handle all of
+the various chip IDs.
 @item @code{-ircapture} @var{NUMBER}
 @*The bit pattern loaded by the TAP into the JTAG shift register
 on entry to the @sc{ircapture} state, such as 0x01.

src/jtag/core.c

@@ -958,16 +958,25 @@ static bool jtag_examine_chain_end(uint8_t *idcodes, unsigned count, unsigned ma
 
 static bool jtag_examine_chain_match_tap(const struct jtag_tap *tap)
 {
+	uint32_t idcode = tap->idcode;
+
 	/* ignore expected BYPASS codes; warn otherwise */
-	if (0 == tap->expected_ids_cnt && !tap->idcode)
+	if (0 == tap->expected_ids_cnt && !idcode)
 		return true;
 
+	/* optionally ignore the JTAG version field */
+	uint32_t mask = tap->ignore_version ? ~(0xff << 24) : ~0;
+
+	idcode &= mask;
+
 	/* Loop over the expected identification codes and test for a match */
 	unsigned ii, limit = tap->expected_ids_cnt;
 
 	for (ii = 0; ii < limit; ii++)
 	{
-		if (tap->idcode == tap->expected_ids[ii])
+		uint32_t expected = tap->expected_ids[ii] & mask;
+
+		if (idcode == expected)
 			return true;
 
 		/* treat "-expected-id 0" as a "don't-warn" wildcard */

src/jtag/jtag.h

@@ -156,6 +156,9 @@ struct jtag_tap {
 	/// Number of expected identification codes
 	uint8_t expected_ids_cnt;
 
+	/// Flag saying whether to ignore version field in expected_ids[]
+	bool ignore_version;
+
 	/// current instruction
 	uint8_t* cur_instr;
 	/// Bypass register selected

src/jtag/tcl.c

@@ -454,6 +454,7 @@ static int jim_newtap_expected_id(Jim_Nvp *n, Jim_GetOptInfo *goi,
 #define NTAP_OPT_ENABLED   3
 #define NTAP_OPT_DISABLED  4
 #define NTAP_OPT_EXPECTED_ID 5
+#define NTAP_OPT_VERSION   6
 
 static int jim_newtap_ir_param(Jim_Nvp *n, Jim_GetOptInfo *goi,
 		struct jtag_tap *pTap)
@@ -520,6 +521,7 @@ static int jim_newtap_cmd(Jim_GetOptInfo *goi)
 		{ .name = "-enable"			,	.value = NTAP_OPT_ENABLED },
 		{ .name = "-disable"		,	.value = NTAP_OPT_DISABLED },
 		{ .name = "-expected-id"	,	.value = NTAP_OPT_EXPECTED_ID },
+		{ .name = "-ignore-version"	,	.value = NTAP_OPT_VERSION },
 		{ .name = NULL				,	.value = -1 },
 	};
 
@@ -595,6 +597,9 @@ static int jim_newtap_cmd(Jim_GetOptInfo *goi)
 				return e;
 			}
 			break;
+		case NTAP_OPT_VERSION:
+			pTap->ignore_version = true;
+			break;
 		} /* switch (n->value) */
 	} /* while (goi->argc) */
 
@@ -1013,6 +1018,7 @@ COMMAND_HANDLER(handle_interface_command)
 COMMAND_HANDLER(handle_scan_chain_command)
 {
 	struct jtag_tap *tap;
+	char expected_id[12];
 
 	tap = jtag_all_taps();
 	command_print(CMD_CTX, "     TapName            | Enabled |   IdCode      Expected    IrLen IrCap  IrMask Instr     ");
@@ -1020,25 +1026,39 @@ COMMAND_HANDLER(handle_scan_chain_command)
 
 	while (tap) {
 		uint32_t expected, expected_mask, cur_instr, ii;
+
+		snprintf(expected_id, sizeof expected_id, "0x%08x",
+				(unsigned)((tap->expected_ids_cnt > 0)
+					? tap->expected_ids[0]
+					: 0));
+		if (tap->ignore_version)
+			expected_id[2] = '*';
+
 		expected = buf_get_u32(tap->expected, 0, tap->ir_length);
 		expected_mask = buf_get_u32(tap->expected_mask, 0, tap->ir_length);
 		cur_instr = buf_get_u32(tap->cur_instr, 0, tap->ir_length);
 
 		command_print(CMD_CTX,
-					  "%2d | %-18s |    %c    | 0x%08x | 0x%08x | 0x%02x | 0x%02x | 0x%02x | 0x%02x",
+	"%2d | %-18s |    %c    | 0x%08x | %s | 0x%02x | 0x%02x | 0x%02x | 0x%02x",
 					  tap->abs_chain_position,
 					  tap->dotted_name,
 					  tap->enabled ? 'Y' : 'n',
 					  (unsigned int)(tap->idcode),
-					  (unsigned int)(tap->expected_ids_cnt > 0 ? tap->expected_ids[0] : 0),
+					  expected_id,
 					  (unsigned int)(tap->ir_length),
 					  (unsigned int)(expected),
 					  (unsigned int)(expected_mask),
 					  (unsigned int)(cur_instr));
 
 		for (ii = 1; ii < tap->expected_ids_cnt; ii++) {
-			command_print(CMD_CTX, "   |                    |         |            | 0x%08x |      |      |      |         ",
+			snprintf(expected_id, sizeof expected_id, "0x%08x",
-						  (unsigned int)(tap->expected_ids[ii]));
+					(unsigned) tap->expected_ids[1]);
+			if (tap->ignore_version)
+				expected_id[2] = '*';
+
+			command_print(CMD_CTX,
+	"   |                    |         |            | %s |      |      |      |         ",
+						  expected_id);
 		}
 
 		tap = tap->next_tap;