allow selection of alternative FPGAs at commandline

diff --git a/examples/soc.py b/examples/soc.py
index 8b856481fdb0361e61b6315150e15ef31996405f..c688e08f51eac9c86bcb2cec7bad942112b05400 100644 (file)
--- a/examples/soc.py
+++ b/examples/soc.py
@@ -26,10 +26,15 @@ from gram.modules import MT41K256M16
 from gram.frontend.wishbone import gramWishbone
 
 from nmigen_boards.versa_ecp5 import VersaECP5Platform
+from nmigen_boards.ulx3s import ULX3S_85F_Platform
+from nmigen_boards.arty_a7 import ArtyA7_100Platform
 from nmigen_boards.test.blinky import Blinky
+
 from uartbridge import UARTBridge
 from crg import ECPIX5CRG
 
+import sys
+
 
 class DDR3SoC(SoC, Elaboratable):
     def __init__(self, *,
@@ -140,14 +145,29 @@ class DDR3SoC(SoC, Elaboratable):
 
 
 if __name__ == "__main__":
-    platform =  VersaECP5Platform()
 
+    # create a platform selected from the toolchain. defaults to VERSA_ECP5
+    fpga = "versa_ecp5"
+    if len(sys.argv) == 2:
+        fpga = sys.argv[1]
+    platform_kls =  {'versa_ecp5': VersaECP5Platform,
+                     'ulx3s': ULX3S_85F_Platform,
+                     'arty_a7': ArtyA7_100Platform,
+                    }[fpga]
+    toolchain = {'arty_a7': "yosys_nextpnr",
+                 'versa_ecp5': 'Trellis',
+                 'ulx3s': 'Trellis'
+                }.get(fpga, None)
+    platform = platform_kls(toolchain=toolchain)
+
+    # get DDR and UART resource pins
     ddr_pins = platform.request("ddr3", 0,
                                 dir={"dq":"-", "dqs":"-"},
                                 xdr={"clk":4, "a":4, "ba":4, "clk_en":4,
                                      "odt":4, "ras":4, "cas":4, "we":4})
     uart_pins = platform.request("uart", 0)
 
+    # set up the SOC
     soc = DDR3SoC(ddrphy_addr=0xff000000, # DRAM firmware init base
                   dramcore_addr=0x80000000,
                   ddr_addr=0x10000000,
@@ -155,4 +175,5 @@ if __name__ == "__main__":
                   uart_pins=uart_pins,
                   fw_addr=None)
 
+    # build and upload it
     platform.build(soc, do_program=True)