--- DiscoBSD 2.7 RELEASED ---

DiscoBSD 2.7 Released

August 11, 2026

DiscoBSD 2.7 is released.

This is the eighth official release of DiscoBSD, the multi-platform 2.11BSD-based Unix-like operating system for microcontrollers.

DiscoBSD 2.7 offers ports to two different microcontroller platforms:

• DiscoBSD/stm32 - STM32F4 family of 32-bit Arm Cortex-M4 microcontrollers from STMicroelectronics
• DiscoBSD/pic32 - PIC32MX7 family of 32-bit MIPS32 M4K microcontrollers from Microchip

DiscoBSD/stm32, unique only to DiscoBSD, offers a familiar BSD environment on the many available STM32F4 development boards.

DiscoBSD/pic32, inherited from RetroBSD, offers a familiar BSD environment on the many available PIC32MX7 development boards, as well as full use with the included VirtualMIPS PIC32 simulator.

A nearly-complete development environment is included in DiscoBSD.

There are: various text editors and compilers, a MIPS assembler and MIPS linker, and many more programming languages in addition to C and asm, such as Scheme, BASIC, Forth, RetroForth, lex, yacc, and TCL. Examples are provided in the file system at /usr/share/examples.

As a descendant of 2.11BSD, DiscoBSD inherits its strong BSD heritage. The userland is powerful, full-featured, and comfortable to competent UNIX users, as it is derived from the rich 4.3BSD-Tahoe userland, modern implementations of classic utilities, and improvements along the way.

Install, build, and debug instructions can be found in the README files.

Significant Changes and Improvements

New Features in this Release

• Kernel source tree follows 4.4BSD hierarchy, to facilitate future ports.
• Import TinyUSB V0.20.0, Device CDC, DWC2; currently unused.
• Refresh of kernel compile Configs and Makefiles for pic32 and stm32.
• KNF style(9) and ANSI cleanup in kernel, ports, and userland.
• Clarity, bugfixes, and improvements in documentation.

Filesystem

• Add pointer types and max constants to sys/stdint.h.
• Symlink sys/sys/std{int,bool}.h headers to /usr/include.

Build System

Continuing the overhaul of the build system.

• Both BSD make and GNU make are fully supported.
• FreeBSD's version of BSD make requires MAKESYSPATH set.
• Remove '-D' option from /tools install(1) and manual page.
• Releases now include ANNOUNCEMENT.md, maintained in tree.
• Add back many SCCS version tags from 2.11BSD.

Kernel Specific Improvements

• Fixed double free of script inode bug when exec an interpreter.

DiscoBSD/stm32 Specific Improvements

• Support for DevEBox STM32F4VE development board.
• Support for WeAct Studio STM32F446RET6 Core development board.
• Support for STMicroelectronics NUCLEO-F446RE development board.
• Enable uart6 on STM32F412G-DISCO board; true multi-user.
• Added sys/stdint.h for kernel; now compiles with -nostdinc.
• Remove libgcc.a from ${LDADD}; it is now not needed nor used.
• Added -z noexecstack to ${LDFLAGS} for no executable stack.
• Rename linker files based on microcontroller and its flash size.
• Added makeoptions to set DEBUG in Config.

DiscoBSD/pic32 Specific Improvements

• Added makeoptions to set DEBUG in Config.
• KNF and ANSI in dev/usb_uart.[ch] to prepare for TinyUSB CDC.

Documentation, Bugfixes, and Corrections

• Documentation to set up a Linux host development environment.
• Releases are documented in ANNOUNCEMENT.md, maintained in tree.
• Steady improvements and corrections in documentation.
• Manual page fixes and improvements.

Host Development Environment

While DiscoBSD is primarily developed and tested on OpenBSD, Linux and FreeBSD are also supported as host environments.

These host development environments have been tested:

OpenBSD 7.6

• Host compiler Clang 16.0.6
• Host compiler GCC 11.2.0
• Host compiler Clang 17.0.6
• BSD make and GNU make
• DiscoBSD/stm32
• Custom port of arm-none-eabi-gcc 12.2.0 (rmprofile)
• OpenBSD package of arm-none-eabi-binutils 2.40
• Custom port of arm-none-eabi-gdb 12.1
• OpenBSD package of OpenOCD 0.11.0
• Custom port of ST-Link 1.8.0
• DiscoBSD/pic32
• Custom port of mips-elf-gcc 12.2.0
• Custom port of mips-elf-binutils 2.40

Ubuntu 24.04 (Zorin OS 18 Core)

• Host compiler GCC 13.2.0
• Host compiler Clang 18.1.3
• BSD make and GNU make
• DiscoBSD/stm32
• arm-none-eabi-gcc 13.2.1
• arm-none-eabi-binutils 2.42
• DiscoBSD/pic32
• Untested

FreeBSD 13.2

• Host compiler GCC 12.2.0
• Host compiler Clang 14.0.5
• BSD make (with MAKESYSPATH set) and GNU make
• DiscoBSD/stm32
• arm-none-eabi-gcc 10.3.1 (gcc-arm-embedded)
• arm-none-eabi-binutils 2.40
• DiscoBSD/pic32
• Untested

Release Build Environment

DiscoBSD distribution releases are cross-built on OpenBSD.

The release build environment is configured as below:

OpenBSD 7.6

• Host compiler Clang 16.0.6
• BSD make
• DiscoBSD/stm32
• Custom port of arm-none-eabi-gcc 12.2.0 (rmprofile)
• OpenBSD package of arm-none-eabi-binutils 2.40
• DiscoBSD/pic32
• Custom port of mips-elf-gcc 12.2.0
• Custom port of mips-elf-binutils 2.40

Developers and Contributors this Release

• @chettrick
• @ramangopalan
• @Sch-LikA

Full Changelog

https://github.com/chettrick/discobsd/compare/DISCOBSD_2_6...DISCOBSD_2_7