- fix incorrect parsing of whitespace in command.c (thanks to Magnus Lundin)

[openocd.git] / src / jtag / jtag.c

diff --git a/src/jtag/jtag.c b/src/jtag/jtag.c
index 263eed1a931d9ed47b799cfacad79abd75d3ccef..cc9f8dc4502368b3e68cc964c033f44ae01738fc 100644 (file)
--- a/src/jtag/jtag.c
+++ b/src/jtag/jtag.c
@@ -115,6 +115,10 @@ int jtag_verify_capture_ir = 1;
 int jtag_nsrst_delay = 0; /* default to no nSRST delay */
 int jtag_ntrst_delay = 0; /* default to no nTRST delay */ 
 
+/* maximum number of JTAG devices expected in the chain
+ */
+#define JTAG_MAX_CHAIN_SIZE 20 
+
 /* callbacks to inform high-level handlers about JTAG state changes */
 jtag_event_callback_t *jtag_event_callbacks;
 
@@ -597,8 +601,7 @@ int jtag_add_dr_scan(int num_fields, scan_field_t *fields, enum tap_state state)
                        /* if a device is listed, the BYPASS register must not be selected */
                        if (jtag_get_device(i)->bypass)
                        {
-                               ERROR("BUG: scan data for a device in BYPASS");
-                               exit(-1);
+                               WARNING("scan data for a device in BYPASS");
                        }
                }
        }
@@ -1116,6 +1119,93 @@ void jtag_sleep(u32 us)
        usleep(us);
 }
 
+/* Try to examine chain layout according to IEEE 1149.1 §12
+ */
+int jtag_examine_chain()
+{
+       scan_field_t field;
+       u8 idcode_buffer[JTAG_MAX_CHAIN_SIZE * 4];
+       int i;
+       int bit_count;
+       int device_count = 0;
+       u8 valid = 0x0;
+       
+       field.device = 0;
+       field.num_bits = sizeof(idcode_buffer) * 8;
+       field.out_value = idcode_buffer;
+       field.out_mask = NULL;
+       field.in_value = idcode_buffer;
+       field.in_check_value = NULL;
+       field.in_check_mask = NULL;
+       field.in_handler = NULL;
+       field.in_handler_priv = NULL;
+       
+       for (i = 0; i < JTAG_MAX_CHAIN_SIZE; i++)
+       {
+               buf_set_u32(idcode_buffer, 0, 32, 0x000000FF);
+       }
+       
+       jtag_add_plain_dr_scan(1, &field, TAP_TLR);
+       jtag_execute_queue();
+       
+       for (i = 0; i < JTAG_MAX_CHAIN_SIZE * 4; i++)
+       {
+               valid |= idcode_buffer[i];
+       }
+       
+       /* if there wasn't a single non-zero bit, the scan isn't valid */
+       if (!valid)
+       {
+               ERROR("JTAG communication failure, check connection, JTAG interface, target power etc.");
+               exit(-1);
+       }
+       
+       for (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 */
+                       device_count++;
+                       
+                       bit_count += 1;
+               }
+               else
+               {
+                       u32 manufacturer;
+                       u32 part;
+                       u32 version;
+                       
+                       if (idcode == 0x000000FF)
+                       {
+                               /* End of chain (invalid manufacturer ID) */
+                               break;
+                       }
+                       
+                       device_count++;
+                       
+                       manufacturer = (idcode & 0xffe) >> 1;
+                       part = (idcode & 0xffff000) >> 12;
+                       version = (idcode & 0xf0000000) >> 28;
+
+                       DEBUG("JTAG device found: 0x%8.8x (Manufacturer: 0x%3.3x, Part: 0x%4.4x, Version: 0x%1.1x", 
+                               idcode, manufacturer, part, version);
+                       
+                       bit_count += 32;
+               }
+       }
+       
+       /* see if number of discovered devices matches configuration */
+       if (device_count != jtag_num_devices)
+       {
+               ERROR("number of discovered devices in JTAG chain (%i) doesn't match configuration (%i)", 
+                       device_count, jtag_num_devices);
+               exit(-1);
+       }
+       
+       return ERROR_OK;
+}
+
 int jtag_validate_chain()
 {
        jtag_device_t *device = jtag_devices;
@@ -1244,6 +1334,8 @@ int jtag_init(struct command_context_s *cmd_ctx)
                                jtag_add_statemove(TAP_TLR);
                                jtag_execute_queue();
                                
+                               jtag_examine_chain();
+                               
                                jtag_validate_chain();
                                
                                return ERROR_OK;