# OpenBSD 8.0 expands kernel address space, adds arm64 hibernate

> **Key takeaway:** OpenBSD 8.0 raises amd64 kernel virtual address space from 4 GB to 512 GB and adds hibernate support on arm64.

**Published:** 2026-10-20T02:18:49+00:00 
**Source:** DistroWatch Weekly & News 
**Category:** distro-news 
**Canonical URL:** https://fosswire.org/news/openbsd-80-expands-kernel-address-space-adds-arm64-hibernate.html 

## Summary
Theo de Raadt announced OpenBSD 8.0, the project's 61st stable release. The version brings platform-specific improvements including a dramatically expanded kernel virtual address space on amd64 and hibernate support on arm64. Swap encryption now uses AES CPU instructions on both amd64 and arm64. The riscv64 port gains CPU extension detection advertised to userland via elf_aux_info(3).

## Platform changes in OpenBSD 8.0
- **amd64**: Kernel virtual address space expanded from 4 GB to 512 GB; pmap(9) direct map placed at random location; swap encryption accelerated with AES CPU instructions
- **arm64**: Hibernate support added; swap encryption uses AES CPU instructions; bounce buffers implemented
- **riscv64**: CPU extensions detected and advertised to userland through elf_aux_info(3) AT_HWCAP and AT_HWCAP2
- **luna88k**: Multiple CMMU register write fixes, extended kernel-mode CMMU fault handling for write protection faults, faster CMMU walk

## Why it matters
The 512 GB kernel address space on amd64 enables OpenBSD to scale significantly on modern high-memory servers. Hibernate on arm64 broadens the operating system's deployment options for embedded and laptop platforms.