OpenBSD 8.0

OpenBSD 8.0 introduces numerous enhancements across various platforms and system components. On amd64, the kernel virtual address space has been expanded from 4G to a substantial 512G, enabling the mapping of more than 4GB of VRAM. The pmap(9) direct map has been placed at a random location in the amd64 kernel, improving security. Swap encryption has been accelerated by leveraging AES CPU instructions.

The arm64 architecture now supports hibernate, and swap encryption has seen another speed boost with the use of AES CPU instructions. Bounce buffers have been implemented for better performance.

On the luna88k platform, a critical bug has been fixed, ensuring that the m88k kernel-mode CMMU fault handling can now manage write protection faults. The CPU #0 initialization in non-MP kernels has been optimized for faster CMMU walk functionality.

The riscv64 architecture now detects CPU extensions and makes them available to userland through elf_aux_info(3) AT_HWCAP and AT_HWCAP2 queries. Kernel support for RISC-V Advanced Interrupt Architecture has been added, accompanied by the introduction of imsic(4) and aplic(4) drivers. Support for the Sstc timer extension has been integrated into the kernel.

In sparc64, a bounds check for the sparc64 relocation flags table has been added, while the sparc64 architecture has switched to the LLVM toolchain. Memory alignment on SPARCV9 has been improved.

Several other platforms have seen specific updates, including the luna88k, riscv64, sparc64, and various RISC-V and MIPS bugfixes for LLVM. The fencing of hppa protection bits has also been addressed.

Alongside these platform-specific improvements, OpenBSD 8.0 brings a host of kernel enhancements. Memory size calculation in open_wmemstream(3) has been corrected, and semop(2) semaphore id destruction during context switch has been rectified. Inactive page queue heuristics have been enhanced for pagedaemon swapping pages and freeing memory.

A new getexecpath(3) function has been added to provide a copy of the execution path for the elf(5) program. Efforts are underway for larger disklabel support, and more fixes are being prepared for upcoming disklabel expansion.

A notable addition is the implementation of suspend and hibernate support for qwz(4), ufshci(4) surviving a suspend on Samsung Galaxy Book4 Edge and HONOR MagicBook Art 14 Snapdragon systems, and the cessation of wake-up events when the lid is closed with machdep.lidaction set to 0. A global sleep mode variable has been introduced to distinguish hibernate from normal suspend, and support for qcuart(4) and wakeup interrupts in bytgpio(4) have been added.

Direct Rendering Manager and graphics drivers have been updated to Linux 6.18.53, with added support for Intel Arc A-Series (DG2/Alchemist) graphics cards in inteldrm(4). The kernel virtual address space on amd64 allows the mapping of more than 4GB of VRAM, and a workaround has been implemented for inteldrm(4) GuC timeout errors on some Alder Lake systems.

The VMM/VMD improvements include support for up to 64 VCPUs per guest VM on MP systems, redesigned file management for VM ownership, and the addition of x2apic mode support for guest virtual machines. The implementation of missing lapic/ioapic modes has ensured vmd(8) support for 32-bit Linux guests, and checksum offload for vmd(8) guests has been added.

Various userland features have been enhanced, including the ability of netstat(1) to print interface multicast counters, more specific adjustments to ddb(4) default ps output, mount(8) support for DUIDs with -u, and the preservation of DUID upon file system updates. The midithru ports control has been implemented with sndioctl(1), enabling the addition and removal of list elements dynamically.

Bugfixes and tweaks have been made across the userland, ensuring proper elf(5) header and program header size fitting into shared libraries, addressing leak issues in getpwent(3) yp_next(), solving infinite loops in patch(1), and ensuring proper execv(3) absolute-path execution in various utilities. uaudio(4) now validates reported formats and channel usability, and sndiod(8) has been optimized for better performance.

The hardware support and driver bugfixes have expanded, including touchscreen support on the Samsung Galaxy Book4 Edge, support for the riscv64 K3 PCIe/USB3 combo PHY, and gpioleds(4) on riscv64. Improved error checking for received packets in smte(4), enhanced support for the SpacemiT K3 SoC, and the introduction of new drivers for various hardware components, such as samsabi(4) and sambat(4), have been introduced.

Overall, OpenBSD 8.0 showcases a robust set of features, enhancements, and bugfixes that demonstrate the dedication of its development team to delivering a secure and efficient operating system for a wide range of hardware platforms.