52 KiB
52 KiB
[> Changes since 2024.08
[> Fixed
--------
[> Added
--------
- cpu/zynqmp : Added SGMII support via PL andoptional PTP (#2095).
- liteeth/phy : Improved 1000BaseX/2500BaseX PCS/PHYs (https://github.com/enjoy-digital/liteeth/pull/174).*
- cpu/urv : Added uRV CPU support (RISC-V CPU use in White Rabbit project).
[> Changed
----------
[> 2024.08, released on September 27th 2024
[> Fixed
--------
- cpu/zynq7000 : Fixed AXI version to AXI3.
- build/vhd2v_converter : Fixed instance replace robustness.
- tools/litex_json2renode : Corrected VexRiscv variants (#1984).
- software/liblitespi : Fixed xor-used-pow bug (#2001).
- soc : Fixed AHB2Wishbone bridge creation (#1998).
- soc : Fixed parameters propagation for AXI data-width conversion (#1997).
- soc/cores/clock/colognechip : Fixed and reworked locked signal handling.
- litesdcard : Fixed data_i sampling (https://github.com/enjoy-digital/litesdcard/pull/34).
- litespi/mmap : Fixed dummy bits (https://github.com/litex-hub/litespi/pull/71).
- sim/verilator : Fixed .fst empty dump with short simulation.
[> Added
--------
- cpu/vexiiriscv : Added initial support (#1923).
- builder : Added default generation of exports with default names to output_dir (#1978).
- litex.gen : Added byte size definitions and use them in targets/json2dts.
- litepcie : Added external QPLL support/sharing for Xilinx Artix7.
- cores/zynq7000/mp : Improved integration, added peripherals supports (#1994).
- software/bios : Generalized IRQ handling approach between CPUs.
- cores/video : Added fifo_depth parameter to add_video_framebuffer (#1931).
- gen/common : Added byte size definitions (KILOBYTE, MEGABYTE, GIGABYTE).
- tools/litex_json2dts_linux : Simplified CPU architecture/RISC-V ISA.
- soc : Added add_spi_master method (#1985).
- tools/litex_json2dts_zephyr : Added spimaster/spiflash handlers (#1985).
- tools/litex_json2renode : Added .elf bios option (#1984).
- cores : Added Watchdog core and Zephyr support (#1996).
- soc : Added add_spi_ram method (#2028).
- build : Added initial Apicula (Gowin) Platform support (#2036).
- build : Added initial Agilex5 support.
- liteeth/mac : Improved broadcast filtering logic in Hybrid Mode (https://github.com/enjoy-digital/liteeth/pull/165).
- soc/cores/hyperbus : Rewritten HyperRAM core to enhance performance and add new features (#2053).
- litedram : Added bank_byte_alignement parameter for improvded address mapping (https://github.com/enjoy-digital/litedram/pull/360).
- build/efinix : Added support for more primitives and improved clocking support. (#2060, #2075).
- software/bios : Added spiram support (#2058).
- liteeth/etherbone : Added 64-bit support to Etherbone.
- liteeth/liteeth_gen : Added XGMII support (PHY handled externally).
- soc/interconnect/stream : Added optional CSR to Multiplexer/Demultiplexer and Crossbar module.
- tools/litex_json2dts_zephyr : Improved support/update ((#1974).
- soc/cores/jtag : Added Spartan7 support (#2076).
- liteeth/phy : Added 1000BASEX support for Virtex7 (https://github.com/enjoy-digital/liteeth/pull/171).
- liteeth/phy : Improved RGMII support on Efinix Titanium/Trion (https://github.com/enjoy-digital/liteeth/pull/168).
- liteiclink/serdes : Added GTH/Virtex7 support (https://github.com/enjoy-digital/liteeth/pull/23).
- litespi/phy : Improved logic and cleanup (https://github.com/litex-hub/litespi/pull/73).
- litespi/mmap : Added write support for SPIRAM devices (https://github.com/litex-hub/litespi/pull/70).
- build/efinix : Improved name elaboration for Signals/Clocks to simplify user design.
[> Changed
----------
- integration/builder : Changed export behavior to now generate csr.csv and csr.json by default to output_dir.
- csr_bus : Added .re signal (#1999).
[> 2024.04, released on June 5th 2024
[> Fixed
--------
- integration/soc : Fixed typo in cpu mem_bus axi-via-wb downconvert
- interconnect/ahb/AHB2Wishbone : Fixed size check that was too restrictive.
- liteeth/phy/gw5rgmii : Fixed Clk assignments.
- build/efinix/programmer : Updated for compatibility with latest Efinity versions.
- litespi/software: : Fixed SPI Flash Clk Divider computation when with L2 Cache.
- litepcie/us(p)pciephy : Fixed x8 / 256-bit wide case.
- litex_sim/serial2console : Fixed RX backpressure handling.
- litedram/frontend/avalon : Fixed and cleaned-up.
- litex_sim/video : Fixed pixel format to RGBA.
- build/xilinx/common : Fixed missing clk parameter on XilinxSDRTristateImpl.
- soc/interconnect : Fixed CSR/LiteXModule issue on WishboneSRAM/AXILiteSRAM.
[> Added
--------
- build/openfpgaloader : Added kwargs support to flash for specific/less common cases.
- cpu/gowin_emcu : Improved/Cleaned-up.
- interconnect/ahb : Added data_width/address_width parameters.
- interconnect/ahb : Added proper byte/sel support to AHB2Wishbone.
- cpu/gowin_ae350 : Added initial support.
- cpu/naxriscv : Updated arch definition and added rvc configuration parameters.
- cpu/vexriscv_smp : Added csr/clint/plic base address configuration parameters.
- liteeth/phy : Added 7-Series/Ultrascale(+) 2500BaseX PHYs.
- litespi/sdrphy: : Allowed flash parameter to be None.
- litespi/integration : Improved integration and simplifications.
- export/builder : Added import/merge of Sub-SoCs .json files.
- cpu/vexriscv_smp : Added reset_address/vector support.
- litex_sim : Added jtagremote support.
- soc/add_master : Added region support to allow/limit access to a specific region.
- litex_json2dts_linux : Added ip= bootarg when local/remote ips are defined.
- cores/jtag : Added JTAGBone support for Zynq.
- cores/ram/lattice_nx : Improved timings.
- liteeth_gen : Added QPLL/BUFH/BUFG parameters for A7 1000BaseX PHY.
- litex_sim : Added Video Color Bar support.
- cpu/neorv32 : Updated to v1.9.7.
- cores/hyperbus : Added latency configuration and variable latency support.
- cpu/cv32e41p : Added ISR support.
- litesdcard : Improved SDPHYClocker (Timings).
- cpu/vexriscv_smp : Added baremetal IRQ support.
- cpu/naxriscv : Added baremetal IRQ support.
- cpu/zynqmp : Added Ethernet, UART, I2C support and improved AXI Master.
- build/efinix : Added reconfiguration interface support.
- build/efinix : Added tx_output_load configuration support.
- cpu/eos_s3 : Updated qlal4s3b_cell_macro clock and reset signals.
- build/quicklogic : Updated f4pga Makefile.
- build/microsemi : Updated libero_soc toolchain.
[> Changed
----------
[> 2023.12, released on December 25th 2023
[> Fixed
--------
- liteeth/arp : Fixed response on table update.
- litesata/us(p)sataphy : Fixed data_width=32 case.
- clock/lattice_ecp5 : Fixed phase calculation.
- interconnect/axi : Fixed AXILite2CSR read access (1 CSR cycle instead of 2).
[> Added
--------
- cpu/naxriscv : Added SMP support.
- cpu/neorv32 : Added Debug support and update core complex.
- cpu/vexriscv_smp : Added hardware breakpoints support.
- build/colognechip : Added initial support.
- soc/cores/video : Added VTG/DMA synchronization stage to VideoFramebuffer.
- litepcie/dma : Improved LitePCIeDMADescriptorSplitter timings.
- interconnect/wishbone : Added linear burst support to DownConverter.
- integration/SoC : Added with_jtagbone/with_uartbone support.
- soc/cores : Added Ti60F100 HyperRAM support.
- build/xilinx : Added initial OpenXC7 support (and improved Yosys-NextPnr).
- build/efinix : Added JTAG-UART/JTAGBone support.
- interconnect/wishbone : Added byte/word addressing support.
- cores/uart : Added 64-bit addressing support to Stream2Wishbone.
- tools : Added 64-bit addressing support to litex_server/client.
- cores/cpu : Added 64-bit support to CPUNone.
- cores/cpu : Added KianV (RV32IMA) initial support.
- litedram : Added initial GW5DDRPHY (compiles but not yet working).
- build/gowin : Added GowinTristate implementation.
- litepcie : Simplify/Cleanup Ultrascale(+) integration and allow .xci generation from .tcl.
- litepcie : Initial 64-bit DMA suppport.
- bios : Added bios_format / --bios-format to allow enabling float/double printf.
- soc/cores/clock : Added proper clock feedback support on Efinix TRIONPLL/TITANIUMPLL.
- liteiclink/phy : Added Efinix support/examples on Trion/Titanium.
- liteiclink/serwb : Reused Etherbone from LiteEth to avoid code duplication.
- interconnect : Added 64-bit support to Wishbone/AXI-Lite/AXI.
- jtag : Fixed firmware upload over JTAG-UART.
- jtag : Improved speed (~X16) on JTABone/JTAGUART on all supported devices (Xilinx, Altera, Efinix, etc...)
- litesata/phy : Added GTHE4 support on Ultrascale+.
- litex_boards : Added Machdyne's Mozart with the Sechzig ML1 module support.
- liteiclink : Added clk_ratio of 1:2, 1:4 on Efinix/SerWB to make clocking more flexible.
[> Changed
----------
- build/osfpga : Removed initial support (would need feedbacks/updates).
- python3 : Updated minimum python3 version to 3.7 (To allow more than 255 arguments in functions).
[> 2023.08, released on September 14th 2023
[> Fixed
--------
- lattice/programmer : Fixed ECPDAP frequency specification.
- soc/add_spi_sdcard : Fixed Tristate build.
- csr/fields : Fixed access type checks.
- software/liblitespi : Fixed support with debug.
- cpu/vexriscv_smp : Fixed compilation with Gowin toolchain (ex for Tang Nano 20K Linux).
- liteiclink/serwb : Fixed 7-Series initialization corner cases.
- liteeth/core/icmp : Fixed length check on LiteEthICMPEcho before passing data to buffer.
- LiteXModule/CSR : Fixed CSR collection order causing CSR clock domain to be changed.
- litepcie/US(P) : Fixed root cause of possible MSI deadlock.
- soc/add_uart : Fixed stub behavior (sink/source swap).
- build/efinix : Fixed AsyncFIFO issues (Minimum of 2 buffer stages).
- software/gcc : Fixed Ubuntu 22.04 GCC compilation issues.
- build/efinix : Fixed hardcoded version.
- litedram/gw2ddrphy : Fixed latencies and tested on Tang Primer 20K.
[> Added
--------
- soc/cores/video : Added low resolution video modes.
- interconnect : Added initial AvalonMM support.
- soc/interconnect/packet : Avoided bypass of dispatcher with a single slave.
- build/add_period_constraints : Improved generic platform and simplify specific platforms.
- gen/fhdl/verilog : Added parameter to avoid register initialization (required for ASIC).
- litedram : Added clamshell topology support.
- stream/Pipeline : Added dynamic pipeline creation capability.
- build/xilinx/vivado : Added project commands to allow adding commands just after project creation.
- soc/software : Moved helpers to hw/common.h.
- tools/litex_json2dts_linux : Added sys_clk to device tree and fixed dts warning.
- tools/litex_json2dts_zephyr : Added LiteSD defines.
- build/yosys : Added quiet capability.
- build/efinix : Improved Titanium support (PLL, DRIVE_STRENGTH, SLEW).
- build/openfpgaloader : Added -fpga-part and -index-chain support.
- soc/add_spi_flash : Added software_debug support.
- software/liblitespi : Added read_id support.
- litex_boards : Added QMtech XC7K325T, VCU128, SITLINV_STVL7325_V2, Enclustra XU8/PE3 support.
- liteeth : Added Ultrascale+ GTY/GTH SGMII/1000BaseX PHYs.
- soc/add_pcie : Added msi_type parameter to select MSI, MSI-Multi-Vector or MSI-X.
- soc/add_pcie : Added msi_width parameter to select MSI width.
- litepcie : Added 7-Series MSI-X capability/integration.
- liteiclink : Improved GTH3/GTH4 support and similarity with Wizard's generated code.
- liteeth_gen : Added SGMII/1000BaseX PHYs support.
- litesata/dma : Added multi-sector support.
- liteeth/mac : Added TX Slots write-only mode for improved resource usage when software does not read buffer.
- liteeth/core : Added DHCP support for CPU-less hardware stack.
- liteeth/core/icmp : Added fifo_depth parameter on LiteEthICMPEcho.
- gen/fhdl/verilog : Improved signal sort by name instead of duid to improve reproducibility.
- litedram/frontend/dma : Added last generation on end of DMA for LiteDRAMDMAReader.
- litepcie/frontend/dma : Added optional integrated data-width converter and data_width parameters to simplify integration/user logic.
- soc/add_uartbone/sata/sdcard : Added support for multiple instances in gateware as for the other cores.
- liteeth_gen : Added raw UDP port support.
- build/vivado : Added .dcp generation also after synthesis and placement.
- gen: : Added initial LiteXContext to easily get build properties (platform, device, toolchain, etc...)
- litepcie/endpoint/tlp : Added optional Configuration/PTM TLP support to Packetizer/Depacketizer.
- liteth/arp : Added proper multi-entries ARP table.
- liteiclink/serdes : Added tx/rx_clk sharing capabilities on Xilinx transceivers.
- soc/cores/spi : Added new SPIMMAP core allowing SPI accesses through MMAP.
- soc/interconnect/stream : Added pipe_valid/pipe_ready parameters to BufferizeEndpoints.
- soc/cores/clock : Added initial GW5A support.
- build/efinix : Added initial EfinixDDROutput/Input and simplified IOs exclusion.
- soc/interconnect : Improved DMA Bus to use the same Bus Standard than the CPU DMA Bus.
- liteeth/phy : Added Artix7 2500BASE-X PHY.
- liteeth/phy : Added Gowin Arora V RGMII PHY (GW5RGMII).
- liteeth/phy : Added Titanium RGMII PHY (Tested with Ti60 F225 + RGMII adapter board).
- build/io : Added ClkInput/Ouput IO abstraction to simplify some Efinix designs.
[> Changed
----------
- litex/gen : Added local version of genlib.cdc/misc to better decouple with Migen and prepare Amaranth's compat use.
- soc/add_uartbone : Renamed name parameter to uart_name (for consistency with other cores).
[> 2023.04, released on May 8th 2023
[> Fixed
--------
- build/xilinx/vivado : Fixed Verilog include path.
- builder/meson : Fixed version comparison.
- liblitedram : Fixed write leveling with x4 modules.
- integration/soc : Fixed alignment of origin on size.
- litex_sim : Fixed ram_init.
- libbase/i2c : Fixed various issues.
- integration/soc : Fixed/Removed soc_region_cls workaround.
- cores/gpio : Fixed IRQ generation.
- litex_sim : Fixed --with-etherbone.
- build/efinix : Fixed iface.py execution order.
- cpu/Vex/NaxRiscv : Fixed IRQ numbering (0 reserved).
- cpu/rocket : Fixed compilation with newer binutils.
- cpu/soc : Fixed CPU IRQ reservation.
- litepcie/software : Fixed compilation with DMA_CHECK_DATA commented.
- litedram/dma : Fixed rdata connection (omit list update since LiteX AXI changes).
- litepcie/US(P) : Fixed possible MSI deadlock.
- cores/usb_ohci : Fixed build issue (usb_clk_freq wrapped as int).
[> Added
--------
- clock/intel : Added StratixVPLL.
- cores/dma : Added FIFO on WishboneDMAReader to pipeline reads and allow bursting.
- liblitedram : Improved SPD read with sdram_read_spd function.
- bios/liblitedram : Added utils and used them to print memory sizes.
- build/parser : Added a method to search default value for an argument.
- litex_setup : Added Arch Linux RISC-V/OR1K/POWER-PC GCC toolchain install.
- cores/pwm : Added reset signal (to allow external reset/synchronization).
- cpu/cva6 : Updated.
- cores/prbs : Improved timings.
- litex_sim : Allowed enabling SDRAM BIST.
- liblitedram : Refactored BIST functions and added sdram_hw_test.
- soc/software : Added extern C (required to link with cpp code).
- cpu/VexRiscv-SMP : Avoided silent generation failure.
- cores/spi_flash : Added Ultrascale support.
- clock/gowin_gw1n : Fixed simulation warnings.
- liblitedram : Various improvements/cleanups.
- cpu/Naxriscv : Exposed FPU parameter.
- cores/xadc : Refactored/Cleaned up.
- cores/dna : Added initial Ultrascale(+) support and reduced default clk_divider to 2.
- cores/usb_ohci : Added support for multiple ports.
- litex_cli : Added binary support for register dump.
- cpu/NaxRiscv : Enabled FPU in crt0.S.
- core/icap : Added initial Ultrascale(+) support and clk_divider parameter.
- litex_sim : Added initial video support.
- soc/add_video : Added framebuffer region definition.
- litex_term : Avoided use of multiprocessing.
- cores/esc : Added initial ESC core with DSHOT 150/300/600 support.
- litex_json2dts : Allowed/Prepared Rocket support and made it more generic.
- gen/common : Added Open/Unsigned/Signed signal definition and updated cores to use it.
- global : Added initial list of sponsors/partners.
- build/xilinx : Improved Xilinx US/US+ support.
- build/platform : Added get_bitstream_extension method.
- cpu/VexRiscvSMP : Added standard variant.
- cpu/cva6 : Added 32-bit variant support and various improvements.
- clock/gowin : Added GW2AR support.
- build/efinix : Added option to select active/passive SPI mode.
- cores/bitbang : Added documentation.
- litex_term : Improved connection setup.
- clock/gowin : Improved VCO config computation and added CLKOUTP/CLKOUTD/CLKOUTD3 support.
- cpu/rocket : Reworked variants.
- liblitesdcard : Avoided use of stop transmission for writes when only one block.
- installation : Simplified/Improved ci.yml/MANIFEST.in/setup.py.
- cores/pwm : Added MultiChannelPWM support.
- soc/add_pcie : Exposed more DMA parameters.
- litepcie/dma : Improved LitePCIeDMAStatus timings.
- litepcie_gen : Exposed 64-bit support.
- litepcie/dma : Better configuration decoupling between DMAWriter/Reader.
- litepcie/dma : Allowed software to get DMA status.
- litepcie/phy : Replaced Xilinx generated core on 7-series Verilog with Migen/LiteX code.
- litepcie/msi : Improved MSI filtering.
- litepcie_gen : Added MSI rate limiting on Ultrascale(+) to avoid stall issues.
- liteiclink/prbs : Improved PRBS RX timings.
- liteiclink/gty/gth : Added power-down signal on GTYQuadPLL and GTHQuadPLL.
- litelclink/gty/gth : Integrated 7-series improvements.
- litelclink/gty/gth : Added DRP interface on QuadPLL.
- litedram/bist : Ensured proper completion of writes.
- litedram/bist : Replicated data for large data-width.
- litedram/ci : Allowed tests to run in parallel.
- litedram/gw2ddrphy : Improvements to remove warnings in simulation.
- liblitespi/spiflash : Add erasee and write functions.
- liblitespi/Spiflash : Add write from sdcard file function.
[> Changed
----------
- builder/export : Added soc-csv/-json/--svd arguments (in addition to csr-xy).
- litepcie/phy : Retained only Gen3/4 support and removed Gen2.
[> 2022.12, released on January 2th 2023
[> Fixed
--------
- bios : Fix missing CONFIG_BIOS_NO_DELAYS update.
- axi/AXIDownConverter : Fix unaligned accesses.
- cpu/rocket : Fix fulld/fullq variants typos.
- cores/video : Fix red/blue channel swap (and apply similar changes to litex_boards).
- software/demo : Fix compilation with Nix.
- cpu/cv32e41p : Fix IRQs.
- interconnect/csr : Allow CSR collection at the top-level.
- interconnect/csr : Fix CSR with 64-bit bus width.
- build/sim : Disable more useless warnings (-Wno-COMBDLY and -Wno-CASEINCOMPLETE).
- intel : Fix constraints issues preventing the build with some boards/versions.
- axi/axi_lite : Fix combinatorial loop on ax.valid/ax.ready.
- soc/cores/video/VideoS7GTPHDMIPHY : Fix typo.
- integration/export : Fix CSR base address definition when with_csr_base_define=False.
[> Added
--------
- soc : Add new "x" (executable) mode to SoCRegion.
- cpu/NaxRiscv : Update to latest and add parameters.
- soc : Propagate address_width on dynamically created interfaces.
- get_mem_data : Add data_width support.
- cores/dma : Allow defining ready behavior on idle.
- axi : Improvements/Simplifications.
- axi_stream : Improvements/Simplifications.
- yosys_nextpnr : Add flow3 option to abc9 mode.
- yosys_nextpnr : Refactor args.
- vivado : Allow directive configuration.
- jtag : Add Efinix JTAG support.
- clock/intel : Improve pll calculation.
- stream/ClockDomainCrossing : Expose buffered parameter.
- tools/remote : Add Etherbone packets retransmisson.
- build : Add VHDL2VConverter to simplify GHDL->Verilog conversion.
- cpu/microwatt : Switch to VHDL2VConverter.
- cpu/neorv32 : Switch to VHDL2VConverter.
- axi : Differentiate AXI3/AXI4.
- stream/Monitor : Add packet count and add reset/latch control from logic.
- spi : Create spi directory and integrate SPIBone + improvements.
- interconnect/csr : Add optional fixed CSR mapping.
- fhdl/verilog : Improve code presentation/attribute generation.
- gen/common : Add new LiteXModule to simplify user designs and avoid some Migen common issues.
- soc/SoCBusHandler : Integrate interconnect code to simplify reuse.
- gen/common : Add reduction functions.
- vhd2v : Use GHDL directly (Instead of GHDL + Yosys).
- cpu/openc906 : Update, add more peripherals to mem_map and add debug variant.
- soc/software/i2c : Add non 8bit i2c mem address support.
- gen/fhdl : Add LiteXHierarchyExplorer to generate SoC hierarchy.
- gen/fhd : Add timescale generation.
- build : Add LitexArgumentParser to customize/simplify argument parsing.
- json2renode : Update.
- logging : Allow logging level to be configured from user scripts.
- soc/cores/cpu : Allow enabling/disabling reset address check.
- integration/export : Directly generate extract/replace mask from Python.
- cpu/zync7000 : Add axi_gp_slave support.
[> Changed
----------
- ci : Bump to Ubutu 22.04.
- soc_core : Move add_interrupt/add_wb_master/add_wb_slave/register_mem/register_rom to compat.
- software : Do not build software as PIE.
- ci : Add microwatt/neorv32 test + requirements (GHDL).
- ci : Switch GCC toolchain installs to distro install.
[> 2022.08, released on September 12th 2022
[> Fixed
--------
- cpu/vexriscv: Fix compilation with new binutils.
- soc/LiteXSocArgumentParser: Fix --cpu-type parsing.
- litex_sim: Fix --with-ethernet.
- liblitesdcard: Fix SDCard initialization corner cases.
- liblitedram: Enable sdram_init/mr_write for SDRAM.
- export/get_memory_x: Replace SPIFlash with ROM.
- soc/cores/video: Fix operation with some monitors (set data to 0 during blanking).
- tools/remote/comm_usb: Fix multi-word reads/writes.
- build/lattice/oxide: Fix ES posfix on device name.
- interconnect/axi: Fix AXIArbiter corner case.
- litex_server/client: Fix remapping over CommPCIe.
- LitePCIe: Fix LiteUART support with multi-boards.
[> Added
--------
- litex_setup: Add -tag support for install/update.
- tools: Add initial LiteX standalone SoC generator.
- cores/ram: Add Xilinx's FIFO_SYNC_MACRO equivalent.
- LitePCIe: Always use 24-bit depth fields on LitePCIeBuffering to simplify software.
- gen/fhdl: Integrate Migen namer to give us more flexibility.
- fhdl/memory: Prefix memory files with build name to simplify reuse/integration.
- cpu/rocket: Add more variants.
- cores/video: Enable driving both + and - diff outs to compensate hardware issues.
- build: Add intial OSFPGA Foedag/Raptor build backend.
- cpu/cva5: Add initial CVA5 CPU support (ex Taiga).
- LiteSATA: Add IRQ and Identify support.
- clock/intel: Improve to find the best PLL config.
- cpu/cva6: Add initial CVA6 CPU support (ex Ariane).
- bios: Improve config flags.
- tools: Add I2s/MMCM support to litex_json2dts_zephyr.
- clock/gowin: Add GW2A support.
- bios: Disable LTO (does not work in all cases, needs to be investigated).
- CI: Test more RISC-V CPUs and OpenRisc CPUs in CI.
- bios: Add CONFIG_NO_BOOT to allow disabling boot sequence.
- export: Allow disabling CSR_BASE define in csr.h.
- build/openocd: Update for compatibility with upstream OpenOCD.
- cpu/openc906: Add initial OpenC906 support (open version of the Allwinner's D1 chip).
- soc: Add automatic bridging between AXI <-> AXI-Lite <-> Wishbone.
- soc: Add AXI-Full bus support.
- interconnect: Add AXI DownConverted and Interconnect/Crossbar.
- interconnect: Create axi directory and split code.
- soc: Modify SoC finalization order for more flexibility.
- soc: Add --bus-interconnect parameter to select interconect: shared/crossbar.
- valentyusb: Package and install it with LiteX.
- bios/mem_list: Align Mem Regions.
- build: Introduce GenericToolchain to cleanup/simplify build backends.
- soc/etherbone: Expose broadcast capability.
- build/lattice: Add MCLK frequency support.
- cpu/cva6: Add IRQ support.
- cores/clock: Add manual placement support to ECP5PLL.
- cores/leds: Add polarity support.
- cpu/neorv32: Switch to new NeoRV32 LiteX Core Complex and add variants support.
- cores/gpio: Add optional reset value.
- litex_client: Add --host support for remote operation.
- sim/verilator: Add jobs number support (to limit RAM usage with large SoCs/CPUs).
- soc/SocBusHandler Add get_address_width method to simplify peripheral integration.
- bios: Expose BIOS console parameters (to enable/disable history/autocomplete).
- bios: Expose BIOS LTO configuration.
- litex_json2renode: Update.
- build: Introduce YosysNextPNRToolchain to cleanup/simplify Yosys support.
- bios: Add buttons support/command.
- litex_client: Add XADC/Identifier/Leds/Buttons support to GUI.
- cpu/NaxRiscv: Update.
- build/generic_platofrm: Add add_connector methode to allow extending connectors.
- litex_server/client: Add initial information exchange between server/client.
- LitePCIe: Improve 64-bit support.
- interconnect/axi: Add missing optional signals.
- interconnect/wishbone: Improve DownConverter efficiency.
[> Changed
----------
- LiteX-Boards : Remove short import support on platforms/targets.
- tools: Rename litex_gen to litex_periph_gen.
- LiteX-Boards: Only generate SoC/Software headers when --build is set
- Symbiflow: Rename to F4PGA.
- mkmsscimg: Rename to crcfbigen.
[> 2022.04, released on May 3th 2022
[> Fixed
--------
- software/bios/mem_write: Fix write address increment.
- software/liblitedram: Improve calibration corner case on 7-series (SDRAM_PHY_DELAY_JUMP).
- software/liblitedram: Fix delay reconfiguration issue on ECP5/DDR3.
- cores/jtag: Fix chain parameter on XilinxJTAG.
- soc/arguments: Fix l2_size handling.
- cpu/vexriscv_smp: Fix pbus_width when using direct LiteDRAM interface.
- libbase/i2c/i2c_poll: Also check for write in i2c_scan (some chips are write only).
- build/vivado: Fix timing constraints application on nets/ports.
[> Added
--------
- litex_setup: Add minimal/standard/full install configs.
- soc/arguments: Improve default/help, add parser groups.
- LiteSPI/phy: Simplify integration on targets.
- openocd/stream: Simplify ECP5 JTAG-UART/JTAGBone use.
- tools/litex_cli: Allow passing reg name to --read/--write.
- soc/add_spi_sdcard: Allow optional Tristate (useful on ULX3S).
- software/bios: Add new mem_cmd memory comparison command.
- cpu/rocket: Increase IRQ lines to 8.
- cpu/serv: Add MDU support.
- cpu/marocchino: Add initial support.
- cpu/eos_s3: Add LiteX BIOS/Bare Metal software support.
- litex_sim: Add .json support for --rom/ram/sdram-init.
- soc/add_uart: Allow multiple UARTs in the same design.
- cores/cpu: Add out-of-tree support.
- build/xilinx: Add initial Yosys/NextPnr support on Artix7 (and Zynq7000 with Artix7 fabric).
- add_source: Add optional copy to gateware directory.
- cores/jtag: Add initial JTAG-UART/JTAGBone Altera/Intel support.
- LiteScope: Add Samplerate support.
- cores/bitbang: Add optional I2C initialization by CPU.
- libliteeth/tftp: Add blocksize support an increase to 1024 bytes (allow 64MB filesize).
- soc/add_sdram: Make AXI integration more flexible (remove some specific Rocket hardcoding).
- cpu/neorv32: Add initial support (RV32I, VHDL converted to Verilog through GHDL-Yosys-synth).
- cpu/naxriscv: Add initial support (RV32IMA & RV64IMA, already able to run Linux).
- interconnect/axi: Add AXI UpConverter.
- soc/add_sdram: Allow data_width upconversion directly on AXI (avoid switching to Wishbone).
- bios/memtest: Optimize memspeed loop for better accuracy.
- build/sim: Allow custom modules to be in custom path.
- build/OpenFPGA: Add initial OpenFPGA build backend (Currently targeting SOFA chips).
- build/efinix: Add initial MIPI TX/RX support (and test on Trion/Titanium).
- cores/video: VTG improvements to support more Video chips.
- cores/xadc: Improve Zynq Ultrascale+ support.
- LiteScope: Optimize waveform upload speed.
- LitePCIe: Add LTSSM tracer capability to debug PCIe bringup issues.
- cores/hyperbus: Refactor core and improve performances (Automatic burst detection).
- cores/jtag: Add Zynq UltraScale+.
- cores/ram: Add Ultrascale+ HBM2 wrapper.
- litex_json2renode: Improve and add support for more CPUs.
- cores/cpu: Add initial FireV support.
- litex_cli: Add --csr-csv support and minimal GUI (based on DearPyGui).
- litescope_cli: Add minimal GUI (based on DearPyGui).
- build/gowin: Add powershell support.
- LitePCIe: Add initial 64-bit addressing support (Only for 64-bit datapath for now).
- software/bios: Add Main RAM test (when not pre-initialized).
- build/trellis: Enable bitstream compression on ECP5 by default.
- soc/add_etherbone: Increase buffer_depth to 16 (to improve etherbone bursting).
- builder: Add get_bios_filename/get_bitstream_filename methods to simplify targets.
- cpu/vexriscv_smp: Re-integrate Linux-on-LiteX−VexRiscv specific changes/mapping.
- tools/litex_sim: Allow RAM/SDRAM initialization from .json files (similar to hardware).
- soc/cpu: Expose optional CPU configuration parameters to users (ex VexRiscv-SMP/NaxRiscv).
- soc: Improve logs.
- build/Efinix: Add Atmel programmer.
- stream/cdc: Add optional common reset.
- LiteDRAM: Decouple DQ/DQS widths on S7DDRPHY.
- cores/ws2812: Improve timings at low sys_clk_freq.
- soc/builder: Add --no-compile (similar to --no-compile-gateware --no-compile-software).
- software/demo: Add --mem parameter to allow compilation for execution in ROM/RAM.
- cpu/naxrsicv: Add JTAG debug support.
- cores/usb_fifo: Re-implement FT245PHYSYnchronous.
- cores/jtag: Add JTAGBone/JTAG-UART support on Zynq/ZynqMP.
- interconnect/sram: Add SRAM burst support.
- liblitesata: Improve SATA init.
- soc/cpu: Improve command line listing.
- soc/cores/uart: Decouple data/address width on Stream2Wishbone.
[> Changed
----------
- Fully deprecate SoCSDRAM/SPIFlash core (replaced by LiteSPI).
- UART "bridge" name deprecated in favor of "crossover" (already supported).
- "external" CPU class support deprecated (replaced by out-of-tree support).
- lxterm/lxserver/lxsim short names deprecated (used long litex_xy names).
- Deprecate JTAG-Atlantic support (Advantageously replaced by JTAG-UART).
[> 2021.12, released on January 5th 2022
[> Fixed
--------
- software/linker: Fix initialized global variables.
- build/xilinx: Fix Ultrascale SDROutput/Input.
- cpu/rocket/crt0.s: Fix alignements.
- core/video: Fix missing ClockDomainsRenamer in specific DRAM's width case.
- mor1kx: Fix --cpu-type=None --with-ethernet case.
- build/lattice: Fix LatticeiCE40SDROutputImpl.
- soc/interconnect/axi: Fix 4KB bursts.
[> Added
--------
- integration/builder: Check if full software re-build is required when a CPU is used.
- cores/clock: Add Gowin PLL support.
- build/gowin: Add initial HyperRam support.
- build/gowin: Add differential Input/Output support.
- build/lattice: Add DDRTristate support.
- cores/gpio: Add external Tristate support.
- tools/json2dts: Make it more generic (now also used with OpenRisc/Mor1kx).
- cpu/rocket: Add SMP support (up to quad-core).
- software/bios/boot: Allow frame reception to time out (for litex_term auto-calibration).
- tools/litex_term: Add automatic settings calibration and --safe mode.
- build/quicklogic: Add initial support.
- cores/icap/7-Series: Add register read capability.
- cores/video: Add RGB565 support to VideoFrameBuffer.
- soc: Raise custom SoCError Exception and disable traceback/exception.
- soc/add_pcie: Automatically set Endpoint's endianness to PHY's endianness.
- build/efinix: Add initial Trion and Titanium support.
- fhdl/verilog: Cleanup/Simplify verilog generation.
- fhdl/memory: Cleanup/Simplify and add support for Efinix case.
- cpu/ibex: Add interrupt support.
- tools/litex_client: Add --length parameter for MMAP read accesses.
- software/bios/cpu: Add CPU tests in CI.
- litex_sim/xgmii_ethernet: Improve models.
- litex_setup: Cleanup/Simplify and switch to proper "--" commands (with retro-compat).
- cores/jtag: Add ECP5 support.
- cores/led: Add WS2812/NeoPixel core.
- cpu/femtorv: Finish integration and add variants support.
- cpu/eos-s3: Add initial support.
- build/anlogic: Add initial support.
- cpu/microwatt: Add Xilinx multiplier support.
- cpu/vexriscv/cfu: Improve integration.
- soc/interconnect: Add initial AHB support (AHB2Wishbone).
- cpu/gowin_emcu: Add initial Gowin EMCU support.
- cpu/zynq7000: Add initial BIOS/software support.
- cpu/zynq7000: Add TCL support.
- core/prbs: Add error behaviour configuration on saturation.
- software/bios: Add write size option to mem_write cmd.
- LitePCIe/phy: Cleanup 7-Series PHY integration.
- LitePCIe/dma Add LitePCIeDMAStatus module.
- LitePCIe/software: Improve kernel/user-space utilities.
- LiteDRAM/litedram_gen: Improve ECP5 support.
- LiteDRAM/phy: Add initial LPDDR5 support.
- LiteDRAM/frontend: Refactor DRAM FIFO and add optional bypass mode.
- LiteEth/core: Add 32-bit/64-bit datapath support.
- LiteEth/phy: Add 10Gbps / Xilinx XGMII support.
- LiteEth/phy: Add 1Gbps / Efinix RGMII support.
- LiteSPI/phy: Simplify SDR/DDR PHYs.
- LiteHyperBus: Add 16-bit support.
[> Changed
----------
- software: Replace libbase with picolibc (new requirements: meson/ninja).
- amaranth: Switch from nMigen to Amaranth HDL.
[> 2021.08, released on September 15th 2021
[> Fixed
--------
- wishbone/UpConverter: Fix SEL propagation.
- cores/i2s: Fix SYNC sampling.
- BIOS/lib*: Fix GCC warnings.
- cpu/software: Fix stack alignment issues.
- cpu/blackparrot: Fix integration.
- interconnect/axi: Fix valid signal in connect_to_pads for axi lite.
- software/hw/common: Fix _csr_rd_buf/_csr_wr_buf for sizeof(buf[0]) < CSR_DW_BYTES case.
- software/soc.h: Fix interoperability with assembly.
- interconnect/stream: Fix n=1 case on Multiplexer/Demultiplexer.
- interconnect/axi: Fix BURST_WRAP case on AXIBurst2Beat.
- cpu/VexRiscv-SMP: Fix build without a memory bus.
- cpu/software: Fix CLANG detection.
- build/software: Force a fresh software build when cpu-type/variant is changed.
- cores/uart: Fix TX reset level.
- BIOS: Fix PHDR link error.
- BIOS: Fix build-id link error.
- LiteDRAM: Fix Artix7/DDR3 calibraiton at low speed.
[> Added
--------
- cores/video: Add 7-Series HDMI PHY over GTPs.
- cores/jtagbone: Allow JTAG chain selection.
- programmer: Add iCESugar programmer.
- cpu/vexriscv: Add CFU support.
- soc/controller: Add separate SoC/CPU reset fields.
- BIOS/liblitedram: Add debug capabilities, minor improvements.
- cpu/femtoRV: Add initial FemtoRV support.
- cores/uart: Cleaned-up, Add optional TX-Flush.
- cores/usb_ohci: Add initial SpinalHDL's USB OHCI support (integrated in Linux-on-LiteX-Vexriscv).
- stream: Add Gate Module.
- soc/builder: Allow linking external software packages.
- soc/software: Allow registering init functions.
- cores/ram: Add init support to Nexus LRAM.
- cores/spi: Add Manual CS Mode for bulk transfers.
- cores/VexRiscv-SMP: Make [ID]TLB size configurable.
- dts: Add GPIO IRQ support.
- programmer/DFUProg: Allow to specify alt interace and to not reboot.
- cores/clock/ecp5: Add dynamic phase adjustment signals.
- tools/litex_sim: Mode SDRAM settings to LiteDRAM's DFI model.
- build/gowin: Add AsyncResetSynchronizer/DDRInput/DDROutput implementations.
- build/gowin: Add On-Chip-Oscillator support.
- build/gowin: Add initial timing constraints support.
- build/attr_translate: Simplify/Cleanup.
- programmer/OpenFPGALoader: Add cable and freq options.
- interconnect/packet: Improve PacketFIFO to handle payload/param separately.
- clock/ecp5: Add 4-output support.
- LiteSPI: Simplified/Cleaned-up, new MMAP architecture, applied to LiteX-Boards.
- soc: Add LiteSPI integration code.
- LitePCIe: DMA/Controller Simplified/Cleaned-up.
- soc/add_cpu: Add memory mapping overrides to build log and make an exception for the CPUNone case.
- programmer: Add ECPprogProgrammer.
- soc/software: Add Random access option to memtest.
- tools: Add Renode generator script.
- tools: Add Zephyr DTS generator script.
- build/io: Add DDRTristate.
- cpu/VexRiscv: Restructure config flags for dcache/icache presence.
- litex_sim: Improve RAM/SDRAM integration and make it closer to LiteX-Boards targets.
- build/sim: Add ODDR/IDDR/DDRSTristate simulation models.
- litex_sim: Add SPIFlash support.
- LiteSPI: Add DDR support and integration in LiteX (rate=1:1, 1:2).
- build/Vivado: Make pre_synthesis/placement/routing commands similar to platform_commands.
- LiteDRAM: Refactor C code generator.
- LiteDRAM: Improve LPDDR4 support.
- LiteDRAM: Reduce ECC granularity.
[> Changed
----------
- soc_core: --integrated-rom-file argument renamed to --integrated-rom-init.
[> 2021.04, released on May 3th 2021
[> Fixed
--------
- litex_term: Fix Windows/OS-X support.
- soc/USB-ACM: Fix reset clock domain.
- litex_json2dts: Various fixes/improvements.
- cores/clock: Fix US(P)IDELAYCTRL reset sequence.
- cpu/Vexriscv: Fix Lite variant ABI (has multiplier so can use rv32im).
- BIOS: Fix various compiler warnings.
- LiteSDCard: Fix various issues, enable multiblock reads/writes and improve performance.
- CSR: Fix address wrapping within a CSRBank.
- soc/add_etherbone: Fix UDPIPCore clock domain.
- stream/Gearbox: Fix some un-supported cases.
- cpu/VexRiscv-SMP: Fix build on Intel/Altera devices with specific RAM implementation.
- timer: Fix AutoDoc.
- Microwatt/Ethernet: Fix build.
- soc/software: Link with compiler instead of ld.
[> Added
--------
- Lattice-NX: Allow up to 320KB RAMs.
- BIOS: Allow compilation with UART disabled.
- litex_json2dts: Simplify/Improve and allow VexRiscv/Mor1kx support.
- BIOS/i2c: Improve cmd_i2c.
- BIOS/liblitedram: Various improvements for DDR4/LPDDR.
- cores/Timer: Add initial unit test.
- cores: Add initial JTAGBone support on Xilinx FPGAs.
- litex_term: Improve JTAG-UART support.
- litex_server: Add JTAGBone support.
- VexRiscv-SMP: Add --without-out-of-order and --with-wishbone-memory capabilities.
- BIOS: Allow specify TRIPLE with LITEX_ENV_CC_TRIPLE.
- litex_client: Add simple --read/--write support.
- OpenFPGALoader: Add flash method.
- litex_sim: Add GTKWave savefile generator.
- litex_term: Add nios2-terminal support.
- cpu/mor1kx: Add initial SMP support.
- interconnect/axi: Add tkeep support.
- cores/gpio: Add IRQ support to GPIOIn.
- cpu: Add initial lowRISC's Ibex support.
- build/xilinx/Vivado: Allow tcl script to be added as ip.
- cores/uart: Rewrite PHYs to reduce resource usage and improve readability.
- cores/pwm: Add configurable default enable/width/period values.
- cores/leds: Add optional dimming (through PWM).
- soc/add_pcie: Allow disabling MSI when not required.
- export/svd: Add constants to SVD export.
- BIOS: Allow dynamic Ethernet IP address.
- BIOS: Add boot command to boot from memory.
- cores: Add simple VideoOut core with Terminal, ColorBards, Framebuffer + various PHYs (VGA, DVI, HDMI, etc...).
- csr/EventSourceProcess: Add rising edge support and edge selection.
- soc/integration: Cleanup/Simplify soc_core/builder.
- soc/integrated_rom: Add automatic BIOS ROM resize to minimize blockram usage and improve flexibility.
- interconnect/axi: Add AXILite Clock Domain Crossing.
- cores/xadc: Add Ultrascale support.
- soc/add_ethernet: Allow nrxslots/ntxslots configuration.
- cpu/VexRiscv-SMP: Integrate FPU/RVC support.
- soc/add_csr: Add auto-allocation mode and switch to it in LiteX's code base.
- soc/BIOS: Add method to check BIOS requirements during the build and improve error message when not satisfied.
- LiteEth: Add initial timestamping support.
- litex_client: Add optional filter to --regs.
- LiteDRAM: Add LPDDR4 support.
- BIOS/netboot: Allow specifying .json file.
- cores/clock: Add initial Gowin GW1N PLL support.
- LiteSDCard: Add IRQ support.
[> Changed
----------
- platforms/targets: Move all platforms/targets to https://github.com/litex-hub/litex-boards.
- litex_term: Remove flashing capability.
- cores/uart: Disable dynamic baudrate by default (Unused and save resources).
[> 2020.12, released on December 30th 2020
[> Fixed
--------
- fix SDCard writes.
- fix crt0 .data initialize on SERV/Minerva.
- fix Zynq7000 AXI HP Slave integration.
[> Added
--------
- Wishbone2CSR: Add registered version and use it on system with SDRAM.
- litex_json2dts: Add Mor1kx DTS generation support.
- Build: Add initial Radiant support for NX FPGA family.
- SoC: Allow ROM to be optionally writable (for contents overwrite over UARTBone/Etherbone).
- LiteSDCard: Improve BIOS support.
- UARTBone: Add clock domain support.
- Clocking: Uniformize reset on iCE40PLL/ECP5PLL.
- LiteDRAM: Improve calibration and add BIOS debug commands.
- Clocking: Add initial Ultrascale+ support.
- Sim: Allow dynamic enable/disable of tracing.
- BIOS: Improve memtest and report.
- BIOS: Rename/reorganize commands.
- litex_server: Simplify usage with PCIe and add debug parameter.
- LitePCIe: Add Ultrascale(+) support up to Gen3 X16.
- LiteSATA: Add BIOS/Boot integration.
- Add litex_cli to provides common RemoteClient functions: get identifier, dump regs, etc...
- LiteDRAM: Simplify BIST integration.
- Toolchains/Programmers: Improve checks/error reporting.
- BIOS: add leds command.
- SoC: Do a full reset of the SoC on reboot (not only the CPU).
- Etherbone: Improve efficiency/performance.
- LiteDRAM: Improve DDR4/DDR3 calibration.
- Build: Add initial Oxide support for NX FPGA family.
- Clock/RAM: Reorganize for better modularity.
- SPI-OPI: Various improvements for Betrusted.
- litex_json2dts: Improvements to use it with mor1kx and VexRiscv-SMP.
- Microwatt: Add IRQ support.
- BIOS: Add i2c_scan command.
- Builder: Simplify Documentation generation with --doc args on targets.
- CSR: Add documentation to EventManager registers.
- BIOS: Allow disabling timestamp for reproducible builds.
- Symbiflow: Remove workarounds on targets.
- litex_server: Simplify use on PCIe, allow direct CommXY use in scripts to bypass litex_server.
- Zynq7000: Improve PS7 configuration support (now supporting .xci/preset/dict)
- CV32E40P: Improve OBI efficiency.
- litex_term: Improve upload speed with CRC check enabled, deprecate --no-crc (no longer useful).
- BIOS: Add mem_list command to list available memory and use mem_xy commands on them.
- litex_term: Add Crossover and JTAG_UART support.
- Software: Add minimal bare metal demo app.
- UART: Add Crossover+Bridge support.
- VexRiscv-SMP: Integrate AES support.
- LitePCIe: Allow AXI mastering from FPGA (AXI-Lite and Full).
- mor1kx: Add standard+fpu and linux+fpu variants.
[> Changed
----------
- BIOS: commands have been renamed/reorganized.
- LiteDRAM: rdcmdphase/wrcmdphase no longer exposed.
- CSR: change default csr_data_width from 8 to 32.
[> 2020.08, released on August 7th 2020
[> Fixed
--------
- Fix flush_cpu_icache on VexRiscv.
- Fix `.data` section placed in rom (#566)
[> Added
--------
- Properly integrate Minerva CPU.
- Add nMigen dependency.
- Pluggable CPUs.
- BIOS history, autocomplete.
- Improve boards's programmers.
- Add Microwatt CPU support (with GHDL-Yosys-plugin support for FOSS toolchains).
- Speedup Memtest using an LFSR.
- Add LedChaser on boards.
- Improve WishboneBridge.
- Improve Diamond constraints.
- Use InterconnectPointToPoint when 1 master,1 slave and no address translation.
- Add CV32E40P CPU support (ex RI5CY).
- JTAG UART with uart_name=jtag_uart (validated on Spartan6, 7-Series, Ultrascale(+)).
- Add Symbiflow experimental support on Arty.
- Add SDCard (SPI and SD modes) boot from FAT/exFAT filesystems with FatFs.
- Simplify boot with boot.json configuration file.
- Revert to a single crt0 (avoid ctr/xip variants).
- Add otional DMA bus for Cache Coherency on CPU(s) with DMA/Cache Coherency interface.
- Add AXI-Lite bus standard support.
- Add VexRiscv SMP CPU support.
[> Changed
----------
- Add --build --load arguments to targets.
- Deprecate soc.interconnect.wishbone.UpConverter (will be rewritten if useful).
- Deprecate soc.interconnect.wishbone.CSRBank (Does not seem to be used by anyone).
- Move soc.interconnect.wishbone2csr.WB2CSR to soc.interconnect.wishbone.Wishbone2CSR.
- Move soc.interconnect.wishbonebridge.WishboneStreamingBridge to soc.cores.uart.Stream2Wishbone.
- Rename --gateware-toolchain target parameter to --toolchain.
- Integrate Zynq's PS7 as a regular CPU (zynq7000) and deprecate SoCZynq.
[> 2020.04, released on April 28th, 2020
[> Description
--------------
First release of LiteX and the ecosystem of cores!
LiteX is a Migen/MiSoC based Core/SoC builder that provides the infrastructure to easily create
Cores/SoCs (with or without CPU).
The common components of a SoC are provided directly:
- Buses and Streams (Wishbone, AXI, Avalon-ST)
- Interconnect
- Common cores (RAM, ROM, Timer, UART, etc...)
- CPU wrappers/integration
- etc...
And SoC creation capabilities can be greatly extended with the ecosystem of LiteX cores (DRAM,
PCIe, Ethernet, SATA, etc...) that can be integrated/simulated/build easily with LiteX.
It also provides build backends for open-source and vendors toolchains.
[> Fixed
--------
- NA
[> Added
--------
- NA
[> Changed
----------
- https://github.com/enjoy-digital/litex/pull/399: Converting LiteX to use Python modules.