After initially rejecting it, Apple has approved the first PC emulator for iOS

Original Article ↗ Hacker News Discussion ↗

Apple’s approval of the UTM SE PC emulator for iOS allows users to run operating systems like Linux and even legacy Windows on iPhones and iPads, but without JIT compilation the performance is limited and often barely usable. Commenters see it as a symbolic breakthrough for device openness driven largely by EU regulatory pressure, reigniting long-running arguments over Apple’s tight control, security justifications, and whether phones and tablets should function as general-purpose computers.

What UTM SE Enables

  • Lets iOS/iPadOS devices run full PC operating systems (Windows, various Linux distros) without bundling them.
  • People note this finally allows “real” Linux, legacy Windows, and even old Flash runtimes on non‑jailbroken iPhones/iPads.
  • Several see this as much more interesting for iPads than for phones, especially with keyboard/mouse.

Performance and JIT Limitations

  • iOS’s ban on JIT and native virtualization means UTM SE relies on interpretation-only emulation.
  • Reports vary:
    • On some devices (e.g., M1 iPad Pro with Debian ARM + lightweight desktop), users find it “surprisingly usable.”
    • Others find x86 Linux installs effectively unusable (multi‑minute boots, laggy input) and very heavy on battery.
  • Many say the app is currently more of a proof‑of‑concept than a practical daily tool on iOS.

Technical Notes (QEMU TCTI and Interpreters)

  • Discussion of QEMU’s TCTI backend: a “threaded code” interpreter that amortizes decode overhead via jump tables, improving speed without JIT.
  • Some argue that even highly optimized interpreters top out around 15–20% of native speed; others call that “very fast for an interpreter but still very slow” compared to JIT.

Apple’s Control, Security, and Regulation

  • Strong debate over whether Apple’s JIT ban is:
    • A necessary security measure within iOS’s current design, or
    • A pretext to preserve App Store control and revenue.
  • DMA discussion:
    • One side claims JIT bans won’t survive the EU’s “strictly necessary and proportionate” standard, pointing to Android’s JIT as evidence.
    • Others counter that Android has more malware and that different OS designs justify different constraints.
  • Broader argument about whether iPhones/iPads should be treated as general‑purpose computers versus tightly managed appliances, and whether regulation (EU, DMA, right‑to‑repair) is appropriate.

Ownership, Repairability, and Philosophy

  • Some insist that once bought, devices should be fully under user control, including OS choice and side‑loading.
  • Others argue Apple clearly markets a locked‑down ecosystem; dissatisfied users should “buy something else” rather than legislate changes.
  • Tangents on lost service manuals/DIY repair culture, anti‑theft kill switches, and how security/anti‑theft features trade off against hackability and repair.