targets: add simple SoC

targets/simple.py

@@ -0,0 +1,25 @@
+from migen.fhdl.std import *
+from migen.bus import wishbone
+
+from misoclib.gensoc import GenSoC
+
+class SimpleSoC(GenSoC):
+	def __init__(self, platform):
+		GenSoC.__init__(self, platform,
+			clk_freq=32*1000000,
+			cpu_reset_address=0,
+			sram_size=4096)
+
+		# We can't use reset_less as LM32 does require a reset signal
+		self.clock_domains.cd_sys = ClockDomain()
+		self.comb += self.cd_sys.clk.eq(platform.request("clk32"))
+		self.specials += Instance("FD", p_INIT=1, i_D=0, o_Q=self.cd_sys.rst, i_C=ClockSignal())
+
+		self.submodules.rom = wishbone.SRAM(32768)
+		self.register_rom(self.rom.bus)
+
+	def init_bios_memory(self, data):
+		self.rom.mem.init = data
+
+def get_default_subtarget(platform):
+	return SimpleSoC