targets: add tinyfpga_bx target (based on icebreaker/fomu targets).

litex_boards/targets/tinyfpga_bx.py

+#!/usr/bin/env python3
+
+#
+# This file is part of LiteX-Boards.
+#
+# Copyright (c) 2020 Florent Kermarrec <florent@enjoy-digital.fr>
+# SPDX-License-Identifier: BSD-2-Clause
+
+import os
+import sys
+import argparse
+
+from migen import *
+
+from litex.build.io import CRG
+
+from litex_boards.platforms import tinyfpga_bx
+
+from litex.soc.cores.spi_flash import SpiFlash
+from litex.soc.integration.soc_core import *
+from litex.soc.integration.soc import SoCRegion
+from litex.soc.integration.builder import *
+from litex.soc.cores.led import LedChaser
+
+kB = 1024
+mB = 1024*kB
+
+# BaseSoC ------------------------------------------------------------------------------------------
+
+class BaseSoC(SoCCore):
+    mem_map = {**SoCCore.mem_map, **{"spiflash": 0x80000000}}
+    def __init__(self, bios_flash_offset, **kwargs):
+        sys_clk_freq = int(16e6)
+        platform = tinyfpga_bx.Platform()
+
+        # Disable Integrated ROM since too large for iCE40.
+        kwargs["integrated_rom_size"]  = 0
+
+        # Set CPU variant / reset address
+        kwargs["cpu_reset_address"] = self.mem_map["spiflash"] + bios_flash_offset
+
+        # SoCCore ----------------------------------------------------------------------------------
+        SoCCore.__init__(self, platform, sys_clk_freq,
+            ident          = "LiteX SoC on TinyFPGA BX",
+            ident_version  = True,
+            **kwargs)
+
+        # CRG --------------------------------------------------------------------------------------
+        self.submodules.crg = CRG(platform.request("clk16"))
+
+        # SPI Flash --------------------------------------------------------------------------------
+        self.add_spi_flash(mode="1x", dummy_cycles=8)
+
+        # Add ROM linker region --------------------------------------------------------------------
+        self.bus.add_region("rom", SoCRegion(
+            origin = self.mem_map["spiflash"] + bios_flash_offset,
+            size   = 32*kB,
+            linker = True)
+        )
+
+        # Leds -------------------------------------------------------------------------------------
+        self.submodules.leds = LedChaser(
+            pads         = platform.request_all("user_led"),
+            sys_clk_freq = sys_clk_freq)
+        self.add_csr("leds")
+
+# Build --------------------------------------------------------------------------------------------
+
+def main():
+    parser = argparse.ArgumentParser(description="LiteX SoC on TinyFPGA BX")
+    parser.add_argument("--build",             action="store_true", help="Build bitstream")
+    parser.add_argument("--bios-flash-offset", default=0x60000,     help="BIOS offset in SPI Flash (default: 0x60000)")
+    builder_args(parser)
+    soc_core_args(parser)
+    args = parser.parse_args()
+
+    soc = BaseSoC(args.bios_flash_offset, **soc_core_argdict(args))
+    builder = Builder(soc, **builder_argdict(args))
+    builder.build(run=args.build)
+
+if __name__ == "__main__":
+    main()