Bochs Version 3.1

Bochs v3.1 is an open source IA-32 (x86) PC emulator written in C++, compatible with various platforms. It emulates a range of Intel x86 CPUs and commonly used I/O devices, supporting operating systems like Linux, DOS, and Windows versions up to Vista. Recent updates include the implementation of new CPU extensions, MS-DOS compatibility for x87 FPU exceptions, and support for UEFI/OVMF firmware for booting modern operating systems. Additional features include increased memory support, improved graphics card emulation, and various bug fixes. The project, initially authored by Kevin Lawton, continues to evolve with ongoing developments.

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Bochs v3.1 has been launched. Bochs is a versatile open-source IA-32 (x86) PC emulator developed in C++, compatible with various popular platforms. It emulates the Intel x86 CPU, common I/O devices, and features a custom BIOS. Currently, Bochs can be compiled to emulate a 386, 486, Pentium/Pentium II/Pentium III/Pentium IV or x86-64 CPU, including optional MMX, SSEx, and 3DNow! instructions.

Bochs supports running most Operating Systems within the emulation environment, such as Linux, DOS, Windows® 95/98, and Windows® NT/2000/XP or Windows Vista. Created by Kevin Lawton, Bochs is currently maintained by this project.

Bochs can be compiled and utilized in various modes, some of which are still under development. The common usage of Bochs involves complete x86 PC emulation, encompassing the x86 processor, hardware devices, and memory. This setup enables you to run operating systems and software within the emulator on your workstation, resembling a machine operating within another. For example, if your workstation is a Unix/X11 setup and you wish to execute Win’95 applications, Bochs facilitates running Win 95 and related software on your Unix/X11 system, presenting a window that simulates a PC monitor.

Bochs Changelog:
Brief summary:
– CPU: Introduced FRED, USER_MSR, MOVRS, AMX-FP8 ISA extensions emulation
– CPU: Implemented MS-DOS Compatibility mode for managing x87 FPU exceptions, with external logic handling FERR# and IGNNE# pins if enabled
The ‘extfpuirq’ plugin is now consistently loaded if FPU is present
– CPUDB: Added new Wildcat Lake CPU definition featuring FRED, WRMSRNS, and MSRLIST
– Bug fixes for CPU emulation accuracy
(including crucial fixes for emulating XSAVEC/XSAVES, PKeys, AVX BMI1/BMI2, AVX512, AMX, UINTR, CET, and SVM)
– Increased the maximum supported host memory to 8192 MB (previously 2048 MB)
– Implemented UEFI/OVMF firmware support in Bochs via QEMU-compatible fw_cfg device
This allows booting UEFI operating systems, including Windows Server 2025
and modern Linux distributions equipped with OVMF firmware.
– Basic support for GeForce 3D card emulation added (4 AGP models, 2D nearly
complete, 3D still a work in progress)
– AGP functionality in the i440BX chipset is now nearly thoroughly implemented
– Numerous fixes in device code (PCI, VGA, Voodoo, hard drive, floppy, USB)
– VHDX disk image support introduced
– BIOS updates for PCI/AGP initialization and ACPI tables
– Updated LGPL’d VGABIOS to version 0.9d
– SeaBIOS ROM image updated to the latest version 1.16.0