args: better --offset description (#319)

README.md

@@ -94,7 +94,8 @@ openFPGALoader -- a program to flash FPGA
       --list-cables             list all supported cables
       --list-fpga               list all supported FPGA
   -m, --write-sram              write bitstream in SRAM (default: true)
-  -o, --offset arg              start offset in EEPROM
+  -o, --offset arg              Start address (in bytes) for read/write into
+                                non volatile memory (default: 0)
       --pins arg                pin config TDI:TDO:TCK:TMS
       --probe-firmware arg      firmware for JTAG probe (usbBlasterII)
       --protect-flash arg       protect SPI flash area

src/main.cpp

@@ -761,7 +761,7 @@ int parse_opt(int argc, char **argv, struct arguments *args,
 				cxxopts::value<bool>(args->list_fpga))
 			("m,write-sram",
 				"write bitstream in SRAM (default: true)")
-			("o,offset",  "start offset in EEPROM",
+			("o,offset", "Start address (in bytes) for read/write into non volatile memory (default: 0)",
 				cxxopts::value<unsigned int>(args->offset))
 			("pins", "pin config TDI:TDO:TCK:TMS",
 				cxxopts::value<vector<string>>(pins))