gateware/platform: Implemented a nextpnr seed specification CLI option

gateware/dragonBoot/__init__.py

@@ -27,6 +27,10 @@ def cli():
 	platforms = listPlatforms()
 	buildAction.add_argument('--target', action = 'store', required = True, choices = platforms.keys())
 
+	# Allow the user to pick a seed if their toolchain is not giving good nextpnr runs
+	buildAction.add_argument('--seed', action = 'store', type = int, default = 0,
+		help = 'The nextpnr seed to use for the gateware build (default 0)')
+
 	# Parse the command line and, if `-v` is specified, bump the logging level
 	args = parser.parse_args()
 	if args.verbose:
@@ -46,5 +50,5 @@ def cli():
 		return 0
 	elif args.action == 'build':
 		platform = platforms[args.target]()
-		platform.build(DragonBoot(), name = 'dragonBoot')
+		platform.build(DragonBoot(), name = 'dragonBoot', pnrSeed = args.seed)
 		return 0

gateware/dragonBoot/platform.py

@@ -150,7 +150,7 @@ def __init__(self, toolchain = 'IceStorm'):
 		self.flash.platform(self)
 
 	def build(self, elaboratable, name = "top", build_dir = "build", do_build = True,
-		program_opts = None, do_program = False, **kwargs
+		program_opts = None, do_program = False, pnrSeed = 0, **kwargs
 	) -> Union[BuildPlan, BuildProducts, None]:
 		""" This is called automatically by the bootloader CLI.
 
@@ -169,7 +169,7 @@ def build(self, elaboratable, name = "top", build_dir = "build", do_build = True
 		"""
 		products : LocalBuildProducts = super().build(
 			elaboratable, name, build_dir, do_build, do_program = False,
-			synth_opts = '-abc9', nextpnr_opts = '--tmg-ripup --seed=0',
+			synth_opts = '-abc9', nextpnr_opts = ['--tmg-ripup', f'--seed={pnrSeed}'],
 			**kwargs
 		)