CP/M-386 – CP/M for 386 protected mode, derived from CP/M‑68K

CP/M-386 CP/M‑386 is CP/M for 386 protected mode, derived from CP/M‑68K. Overview Hardware support CP/M compatibility Build requirements Downloads Compilation Build output QEMU testing QEMU notes Included utilities Contributing Future plans Code statistics Mirrors License Overview CP/M‑386 is currently in the very early development stages. Full 32‑bit protected mode implementation with Ring‑3 TPA. Bootable via 3.5" 1.44MB floppy disk MBR or GRUB Multiboot kernel. Supports VGA text (0xB8000) and/or COM1 serial (9600/N/8/1, 0x3F8) consoles. No floppy/hard disk/CD/USB/network/sound/other drivers (yet). Hardware support Compatible with 386 (and later systems) with 2MB (or more) memory. Systems using either PC BIOS or UEFI (with CSM) are supported. VGA, 8042 PS/2, 8250/16450/16550 UART, CMOS RTC, and 8253/8254 PIT are supported. CP/M compatibility CP/M‑386 should be highly source‑compatible with other implementations: System BDOS coverage CP/M‑68K 1.3 100% CP/M 2.2 100% CP/M‑Plus 71% DOS‑Plus 62% MP/M 2.1 50% The system currently reports BDOS 2.2 to applications. The CP/M‑386 BDOS is at full parity with CP/M‑68K 1.3 and CP/M 2.2. A large majority of the CP/M‑Plus (CP/M 3) BDOS is also supported. More than 60% of the DOS‑Plus additions have been implemented. Approximately half of the MP/M extensions have been completed. The missing functionality is largely the multi‑user, multi‑tasking, message queuing, and process control calls that don't apply to a single‑user CP/M implementation. Unique CP/M‑386‑specific BDOS extensions have been added to accommodate new features like direct video access, high‑resolution timing, PRNG, etc. Build requirements The following dependencies are required to compile CP/M‑386: AWK Cpmtools† GNU Binutils GNU Coreutils GNU GCC or LLVM Clang GNU Make NASM QEMU (required only for testing) †Be sure to use cpmtools version 2.23 or later. Older versions may appear to work but have several known bugs. Downloads Download the current CP/M‑386 build. View the GitLab CI/CD logs. Compilation Building CP/M‑386 is supported on current releases of NetBSD and FreeBSD‡, and most recent Linux distributions. The following are the minimum versions of Linux distributions that have been verified to build CP/M‑386 successfully: CentOS Stream 9, Fedora 36, Debian 12, Ubuntu 18.04 (with gcc-16 from ppa:ubuntu-toolchain-r/test), Ubuntu 22.04, Alpine 3.24, and OpenSUSE Leap 15.4. GCC build (recommended): make -Orecurse -j "$(nproc 2> /dev/null || printf '%s' 1)" make test Clang build: make -Orecurse -j "$(nproc 2> /dev/null || printf '%s' 1)" CC="clang" It is recommended to use GCC as Clang‑compiled i386 code is larger. Be sure to make clean if switching compilers or adjusting compiler flags. 32‑bit support libraries are required to run the test suite (make test). ‡At the time of writing, FreeBSD is shipping non‑functional cpmtools2 packages with broken mkfs.cpm functionality. To successfully build on FreeBSD, you must rebuild cpmtools and ensure it is not linked with libdsk. If you receive a Disc rejected by driver error on FreeBSD from mkfs.cpm, your tools are broken and cannot be used to build CP/M‑386. Build output The build produces two primary artifacts: File Description cpm386.elf Multiboot kernel image floppy.img Bootable 3.5" 1.44MB floppy disk image You can download pre‑compiled binaries above. QEMU testing Multiboot kernel (recommended): qemu-system-i386 -m 2M -serial stdio -monitor none -kernel "cpm386.elf" Floppy MBR loader: qemu-system-i386 -m 2M -serial stdio -monitor none -drive if=floppy,format=raw,file="floppy.img" -boot a QEMU notes Use -nographic -display none -vga none to disable VGA video (and use only serial console). Use -serial none to disable the serial UART (and use only VGA console). Included utilities Program Description ACLOCKDV.386 aclock (VGA text console version) ACLOCKVT.386 aclock (ANSI terminal version)