johnsonjh/cpm386
CP/M-386: CP/M for 386 protected mode, derived from CP/M-68K - johnsonjh/cpm386
14 stars · 0 forks · 1 watchers
README
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)
BIG.386 Multi‑extent loading test executable
CLEARTPA.386 Clears (zeros) and optionally verifies the TPA
CLS.386 Clear screen (BDOS 221)
DELAY.386 Delay test (BDOS 141)
DEMO.SUB SUBMIT demonstration
DUMPDIR.386 Directory entry dump utility (BDOS 17/18)
DUMPFCB.386 File control block dump utility (BDOS 15)
ENV.DAT Environment data file
FPARSE.386 F_PARSE test (BDOS 152)
GETSN.386 Display serial number (BDOS 107)
GFXTEST.386 Graphics and framebuffer demo (BDOS 229/230/231/233)
HD.386 Hex dump utility
HELLO.386 Hello world (the very first CP/M‑386 program!)
ILLEGAL.386 Ring‑3 protection and exception handler test
IOTEST.386 File I/O BDOS tests
JULIA.386 Draw a Julia set fractal (terminal version)
LRBC.386 Query and/or set Last Record Byte Count
LS.386 List files (with sizes)
MANDEL.386 Draw a Mandelbrot set fractal (terminal version)
ALVTST.386 Get Allocation Vector test (BDOS 27)
MEM.386 Memory map utility (BDOS 227/228)
MORE.386 UNIX more‑style pager
OD.386 Octal dump utility
PAUSE.386 Wait for keypress
PRINTENV.386 Print environment and system data
PRNG.386 PRNG test and demo utility (BDOS 253/254)
PROFILE.SUB SUBMIT script (automatically executed at boot)
RC.386 Return code test and query (BDOS 108)
README.TXT Sample text file
REBOOT.386 Reboot utility (BDOS 220)
RM.386 UNIX rm‑like interactive file deletion utility
SEROFF.386 Disable serial console (BDOS 223)
SERON.386 Enable serial console (BDOS 223)
STAT.386 STAT (A port of Zilog CP/M‑Z8000 STAT v1.0C 01/03/84)
SYNC.386 Synchronize disks (BDOS 48)
TEST211.386 Numeric format test (BDOS 211)
TEXTMODE.386 Query and set the console text mode (BDOS 229/230/231)
TICKS.386 High‑resolution timer tests (BDOS 225/226)
TOD.386 Get (and set) Time of Day clock (BDOS 104/105)
TOUCH.386 Create an empty file
TRUNCATE.386 File truncation utility (LRBC aware)
TRUNCTST.386 Truncation tests (BDOS 99)
TSEC.386 Get date and time (BDOS 155)
VER.386 Display OS version (BDOS 163)
VGAFONT.386 Load a text console font or restore the ROM font (BDOS 232)
VGAOFF.386 Disable VGA text console (BDOS 222)
VGAON.386 Enable VGA text console (BDOS 222)
VGATEXT.386 VGA text direct access demo (BDOS 224)
Contributing
Do not open pull requests with large amounts of LLM‑generated code. These will be immediately rejected. There is currently no AI‑generated code in the operating system at this time (though there are some AI tests, comments, and analysis), as the project is intended to be as much of a learning experience for me as it is a useful OS port. Usage of AI (artificial intelligence) tools by contributors is currently permitted, subject to the same terms and conditions as the LLVM AI Tool Use Policy, but this permission may be withdrawn at any time and without notice.
Future plans See FUTURE.md. Code statistics
Language Files Lines Blank Comment Code Complexity Bytes Uloc C 65 31160 6146 4379 20635 4356 730364 10665 C Header 22 3054 551 1233 1270 13 111663 1558 Makefile 2 1570 300 201 1069 331 52823 773 Assembly 6 1351 235 266 850 1 31040 700 Markdown 2 478 58 0 420 0 21907 378 Linker Script 2 169 34 0 135 0 3923 82 YAML 1 80 6 15 59 0 3196 63 Total 100 37862 7330 6094 24438 4701 954916 14146
Mirrors
The canonical home of this software is https://gitlab.com/johnsonjh/cpm386, with a mirror on GitHub.
License
CP/M‑386 is distributed under the terms of the permissive MIT License. Bryan W. Sparks of DRDOS, Inc. dba DeviceLogics LLC, successor in interest to Digital Research, Inc.’s CP/M assets, explicitly grants an unlimited authorization to use, distribute, modify, enhance, and otherwise make available CP/M technology, including the CP/M operating systems and their derivatives.