A CP/M-inspired operating system
What is CP/M Neo?
CP/M Neo is a small CP/M-inspired operating system, designed around simplicity, portability, and a clear separation between the operating system and platform-specific hardware.
It provides a CP/M-style command environment, filesystem, system calls, application SDK, and platform interface for different hardware platforms.
Port Status
| Platform | Architecture | Storage | XIP | Status |
|---|---|---|---|---|
| VEMU | RISC-V | Emulated | Yes | ✅ Done |
| TinyMCU | RISC-V | — | — | ⏳ WIP |
| Blackpill (F411) | ARM | — | — | ⏳ WIP |
Quick Start
CP/M Neo requires a bare-metal cross-compiler toolchain for your target architecture (arch/<isa>/config.sh supplies the toolchain prefix and flags), make, and sh.
make -C sysgen ./sysgen/build/sysgen new --disk-size=2048K --platform=vemu
Everything outputs directly to sysgen/build/:
| File | Purpose |
|---|---|
disk.img |
Final disk image |
bootloader.bin |
Boot image |
core/int/kernel.bin |
kernel binary |
core/int/ccp.bin |
Console Command Processor (CCP) binary |
apps/ |
Bundled Apps |
To clean up the build environment, run:
See the User Guide for the full build and execution walkthrough.
Features
- CP/M-style Console Command Processor (CCP)
- Kernel syscall interface
- BDOS-inspired filesystem
- Hardware-independent architecture
- Application SDK
- sysgen tool for building and managing disk images
The Sysgen Tool
sysgen is the host utility for building and inspecting CP/M Neo disk images. Commands other than new support appending --disk=path to target a specific image; new always writes to sysgen/build/disk.img.
| Command | Description |
|---|---|
new --disk-size=KBK --platform=NAME |
Build the OS and create a disk image (the disk is divided into 1 KB blocks; --disk-size is capped at the useful maximum: 2 MB). NAME is the 8-char max platform id declared by ID= in a platform's config.sh; the platform provides the ISA and RAM_SIZE |
add <file> [--dst=Vn] [--attr=R/W|R/O|SYS] |
Add an external file to an image |
install <folder> [--dst=Vn] [--attr=...] |
Compile a source folder and install the binaries |
dir [Vn] |
List files on a volume |
type <name> [Vn] |
Print a file |
era <name> [Vn] |
Delete a file |
ren <old> <new> [Vn] |
Rename a file |
stat |
Show volume usage and metadata |
Platforms are defined in platform/<name>/: config.sh plus bios.c
implementing the console and storage functions from core/kernel/bios.h.
See the Developer Guide to add your own.
Documentation Library
| Document | Description |
|---|---|
| User Guide | Build, run, and get started |
| CCP Reference | Console Command Processor guide |
| Disk Format | CP/M Neo disk image layout |
| Syscall Reference | Complete syscall API and ABI specifications |
| Bundled Apps | Auto-installed programs |
| Developer Guide | SDK usage, compiling applications, and adding platforms |
| Architecture | Memory layout, boot flow, and build internals |
Contributing
Contributions to CP/M Neo are welcome!
If you'd like to contribute, see CONTRIBUTING.md for more info.
License
CP/M Neo is distributed under the terms of the open-source MIT.