3.0 KiB
A CPU that aims to be binary compatible with the 8086 ISA, focused on optimisation and flexibility.
Progress
- 8086
- Executing code
- Is Turing complete
- Can boot up MS-DOS / FreeDOS
- Is completely binary compatible
- Is pipelined
- Is Out of Order
- Is superscalar
- Has been successfully synthesized
- Has a comprehensive testing framework
Simulating it
Both Verilator and Icarus Verilog can be used for simulation. You can select which one you want with the SIM variable on ./common.mk. This list shows the software needed and the versions used during development :
- Icarus Verilog : version 12.0 OR (preferred) Verilator : 5.016
- bin86 : 0.16.21
- GNU Make : 4.4.1
- xxd : 2022-01-14
- POSIX coreutils : GNU coreutils 9.4
After that you can run make on the top level directory and it should build everything and start the simulation
Synthesis and bitstream creation ( for FPGAs )
Synthesis is based on Yosys. You need to set FPGA_BOARD in ./common.mk to the name of a directory inside ./system/fpga_config/. You should also check inside your board directory for config.mk for further board-specific configuration options. Then you can run make upload in the top level directory and it should create the bitstream and upload it.
These are the currently supported fpga boards:
- OrangeCrab r0.2.1
This list shows the software needed and the versions used during development :
- yosys : 0.35
- bin86 : 0.16.21
- GNU Make : 4.4.1
- xxd : 2022-01-14
- POSIX coreutils : GNU coreutils 9.4
Additionally, for ECP5 FPGAs:
- prjtrellis : 1.4 ( database commit 4dda149b9e4f1753ebc8b011ece2fe794be1281a )
- nextpnr : 0.6
Additionally, for FPGAs using the foboot bootloader
- dfu-util : 0.11
High level design overview
License and Copyright
All parts of this project and files in this repository are licensed under the GNU General Public License version 3 or later
Efthymios Kritikos is the copyright owner for all files except the following:
| File | Copyright owner | Original license |
|---|---|---|
| system/fpga_config/OrangeCrab_r0.2.1/pin_constraint.pcf | Greg Davill | MIT |
Version names
The version name consist of three numbers:
- The CPU that this version aims to be compatible with
- The specific milestone
- Patch level
For example v1.3.2 aims to support 80186 code, is on the fourth milestone and has 2 bug fixes since the milestone was reached. A "-dev" suffix denotes that the code is in the process to become that version, so in-between that and the previous.