main: add option to specify device index

README.md

@@ -163,31 +163,35 @@ openFPGALoader --help
 Usage: openFPGALoader [OPTION...] BIT_FILE
 openFPGALoader -- a program to flash FPGA
 
-      --bitstream arg     bitstream
+      --bitstream arg       bitstream
-  -b, --board arg         board name, may be used instead of cable
+  -b, --board arg           board name, may be used instead of cable
-  -c, --cable arg         jtag interface
+  -c, --cable arg           jtag interface
-      --ftdi-serial arg   FTDI chip serial number
+      --ftdi-serial arg     FTDI chip serial number
-      --ftdi-channel arg  FTDI chip channel number (channels 0-3 map to A-D)
+      --ftdi-channel arg    FTDI chip channel number (channels 0-3 map to
-  -d, --device arg        device to use (/dev/ttyUSBx)
+                            A-D)
-      --detect            detect FPGA
+  -d, --device arg          device to use (/dev/ttyUSBx)
-      --file-type arg     provides file type instead of let's deduced by
+      --detect              detect FPGA
-                          using extension
+      --file-type arg       provides file type instead of let's deduced by
-      --freq arg          jtag frequency (Hz)
+                            using extension
-  -f, --write-flash       write bitstream in flash (default: false, only for
+      --fpga-part arg       fpga model flavor + package
-                          Gowin and ECP5 devices)
+      --freq arg            jtag frequency (Hz)
-      --list-boards       list all supported boards
+  -f, --write-flash         write bitstream in flash (default: false, only
-      --list-cables       list all supported cables
+                            for Gowin and ECP5 devices)
-      --list-fpga         list all supported FPGA
+      --index-chain arg     device index in JTAG-chain
-  -m, --write-sram        write bitstream in SRAM (default: true, only for
+      --list-boards         list all supported boards
-                          Gowin and ECP5 devices)
+      --list-cables         list all supported cables
-  -o, --offset arg        start offset in EEPROM
+      --list-fpga           list all supported FPGA
-      --pins arg          pin config (only for ft232R) TDI:TDO:TCK:TMS
+  -m, --write-sram          write bitstream in SRAM (default: true, only for
-      --quiet             Produce quiet output (no progress bar)
+                            Gowin and ECP5 devices)
-  -r, --reset             reset FPGA after operations
+  -o, --offset arg          start offset in EEPROM
-      --spi               SPI mode (only for FTDI in serial mode)
+      --pins arg            pin config (only for ft232R) TDI:TDO:TCK:TMS
-  -v, --verbose           Produce verbose output
+      --probe-firmware arg  firmware for JTAG probe (usbBlasterII)
-  -h, --help              Give this help list
+      --quiet               Produce quiet output (no progress bar)
-  -V, --Version           Print program version
+  -r, --reset               reset FPGA after operations
+      --spi                 SPI mode (only for FTDI in serial mode)
+  -v, --verbose             Produce verbose output
+  -h, --help                Give this help list
+  -V, --Version             Print program version
 
 Mandatory or optional arguments to long options are also mandatory or optional
 for any corresponding short options.

src/main.cpp

@@ -64,6 +64,7 @@ struct arguments {
 	string file_type;
 	string fpga_part;
 	string probe_firmware;
+	int index_chain;
 };
 
 int parse_opt(int argc, char **argv, struct arguments *args, jtag_pins_conf_t *pins_config);
@@ -79,7 +80,7 @@ int main(int argc, char **argv)
 	/* command line args. */
 	struct arguments args = {0, false, false, 0, "", "", "-", "", -1, 6000000, "-",
 			false, false, false, false, Device::WR_SRAM, false, false, "",
-			"", ""};
+			"", "", 0};
 	/* parse arguments */
 	try {
 		if (parse_opt(argc, argv, &args, &pins_config))
@@ -274,19 +275,30 @@ int main(int argc, char **argv)
 	}
 
 	if (found != 0) {
-		for (int i = 0; i < found; i++) {
+		if (args.index_chain == -1) {
-			if (fpga_list.find(listDev[i]) != fpga_list.end()) {
+			for (int i = 0; i < found; i++) {
-				index = i;
+				if (fpga_list.find(listDev[i]) != fpga_list.end()) {
-				if (idcode != -1) {
+					index = i;
-					printError("Error: currently only one device is supported");
+					if (idcode != -1) {
-					for (int i = 0; i < found; i++)
+						printError("Error: more than one FPGA found");
-						printf("0x%08x\n", listDev[i]);
+						printError("Use --index-chain to force selection");
-					delete(jtag);
+						for (int i = 0; i < found; i++)
-					return EXIT_FAILURE;
+							printf("0x%08x\n", listDev[i]);
-				} else {
+						delete(jtag);
-					idcode = listDev[i];
+						return EXIT_FAILURE;
+					} else {
+						idcode = listDev[i];
+					}
 				}
 			}
+		} else {
+			index = args.index_chain;
+			if (index > found || index < 0) {
+				printError("wrong index for device in JTAG chain");
+				delete(jtag);
+				return EXIT_FAILURE;
+			}
+			idcode = listDev[index];
 		}
 	} else {
 		printError("Error: no device found");
@@ -296,6 +308,9 @@ int main(int argc, char **argv)
 
 	jtag->device_select(index);
 
+	/* check if selected device is supported
+	 * mainly used in conjunction with --index-chain
+	 */
 	if (fpga_list.find(idcode) == fpga_list.end()) {
 		cerr << "Error: device " << hex << idcode << " not supported" << endl;
 		delete(jtag);
@@ -413,6 +428,8 @@ int parse_opt(int argc, char **argv, struct arguments *args, jtag_pins_conf_t *p
 			("freq",        "jtag frequency (Hz)", cxxopts::value<string>(freqo))
 			("f,write-flash",
 				"write bitstream in flash (default: false, only for Gowin and ECP5 devices)")
+			("index-chain",  "device index in JTAG-chain",
+				cxxopts::value<int>(args->index_chain))
 			("list-boards", "list all supported boards",
 				cxxopts::value<bool>(args->list_boards))
 			("list-cables", "list all supported cables",