EXTRACT_MFG(idcode), EXTRACT_PART(idcode), EXTRACT_VER(idcode) );
}
+static bool jtag_idcode_is_final(u32 idcode)
+{
+ return idcode == 0x000000FF || idcode == 0xFFFFFFFF;
+}
+
+/**
+ * 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)
+ {
+ 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;
+ }
+}
+
+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;
+ }
+
+ /* 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;
+ }
+
+ /* If none of the expected ids matched, log an error */
+ if (ii != tap->expected_ids_cnt)
+ {
+ 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 ยง12
*/
static int jtag_examine_chain(void)
{
- jtag_tap_t *tap;
u8 idcode_buffer[JTAG_MAX_CHAIN_SIZE * 4];
- int bit_count;
int device_count = 0;
jtag_examine_chain_execute(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
{
- /* 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;
}
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;
- }
- jtag_examine_chain_display(LOG_LVL_ERROR, "got",
- tap->dotted_name, tap->idcode);
- for (ii = 0; ii < tap->expected_ids_cnt; ii++) {
- char msg[20];
- snprintf(msg, 20, "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 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;
}