ecpix5: add SDCard.

Validated with Linux-on-LiteX-VexRiscv.

litex_boards/platforms/ecpix5.py

@@ -85,6 +85,17 @@ _io = [
         Subsignal("tx_data", Pins("D8 C8 B8 A8")),
         IOStandard("LVCMOS33")
     ),
+
+    # sdcard
+    ("sdcard", 0,
+        Subsignal("data",      Pins("N26 N25 N23 N21"), Misc("PULLMODE=UP")),
+        Subsignal("cmd",       Pins("M24"),             Misc("PULLMODE=UP")),
+        Subsignal("clk",       Pins("P24")),
+        Subsignal("cmd_dir",   Pins("M23")),
+        Subsignal("dat0_dir",  Pins("N24")),
+        Subsignal("dat13_dir", Pins("P26")),
+        IOStandard("LVCMOS33"),
+    ),
 ]
 
 _connectors = []

litex_boards/targets/ecpix5.py

@@ -123,6 +123,7 @@ def main():
     parser = argparse.ArgumentParser(description="LiteX SoC on ECPIX-5")
     parser.add_argument("--build", action="store_true", help="Build bitstream")
     parser.add_argument("--load",  action="store_true", help="Load bitstream")
+    parser.add_argument("--with-sdcard", action="store_true",     help="Enable SDCard support")
     builder_args(parser)
     soc_core_args(parser)
     trellis_args(parser)
@@ -130,6 +131,8 @@ def main():
     args = parser.parse_args()
 
     soc     = BaseSoC(with_ethernet=args.with_ethernet, **soc_core_argdict(args))
+    if args.with_sdcard:
+        soc.add_sdcard()
     builder = Builder(soc, **builder_argdict(args))
     builder.build(**trellis_argdict(args), run=args.build)