Overview
An ARM64 JIT-focused fork of Previous, the NeXT Computer emulator. Doing for Previous what macemu-jit did for Basilisk II and SheepShaver: bring over a newer AArch64-capable JIT toolchain, wire it into the emulator cleanly, and build a fast validation loop around it.
How it works
The transplanted uae_cpu_2026 JIT/compiler subtree is vendored under src/cpu/uae_cpu_2026/. A bridge layer initialises the compiler inside Previous's CPU loop. A suite of shell harnesses runs interpreter vs JIT opcode equivalence checks and headless boot smoke tests against a fresh-copied disk image per run. Host ASLR is disabled for deterministic JIT mappings.
Features
Transplanted JIT runtime
uae_cpu_2026 vendored; bridge and runtime scaffolding complete.
Opcode equivalence harness
Interpreter vs JIT comparison across risky and missing opcode families.
Headless boot harness
Fresh disk image per run — clean, reproducible bring-up tests.
Full NeXT hardware emulation
Original 68030 Cube, NeXTcube/station variants, NeXTdimension board.
Experimental build flag
-DENABLE_EXPERIMENTAL_UAE2026_JIT=ON — keeps upstream usable in parallel.
Architecture
Posts
2026-05-11
Notes for May 3-10
2026-05-03
Notes for April 27 – May 3