S5LBox 1.1.0

S5LBox 1.1.0

Browse Legacy Store, manage guest files without leaving S5LBox, and enjoy a more reliable iPhone OS experience.

What's new

• Legacy Store: native browsing, search, artwork, and individual app downloads inside IPA Library. Results are filtered for the guest, with a choice of compatible archived versions. Downloaded IPAs are validated before installation; filtering does not guarantee that every app will run.
• Guest Files: browse Media, preview and export files, import files, create folders, rename items, and delete empty folders or files over virtual USB. Jailbroken guests can also expose the full filesystem.
• AppSync setup: new guest jailbreaks install AppSync for OS 3.1 by default, with an independent opt-out in Advanced settings.
• Home-only interface: a minimal alternative to the Modern and Legacy layouts, with hidden controls available through the screen margin and VoiceOver.
• Firmware import option: Advanced > Firmware can skip stock checksums before an IPSW is imported. Archive integrity, device validation, and kernel safety checks still apply; custom firmware compatibility is not guaranteed.

Fixes and improvements

• Guest date and timezone follow the host iPhone, including after saved-session resume, background pauses, and timezone changes.
• Silent mode is remembered separately for each machine across restarts and resume.
• Audio buffering better handles uneven delivery and recovery without changing guest clocks or pitch. Microphone capture starts only when the guest requests input.
• Home wakes a guest whose display is asleep, even when the rest of the guest is still running.
• IPA and Packages controls become available when boot or restore finishes, without reopening Machine Settings.
• Firmware preparation runs off the UI thread. Force Power Off remains available during startup, saving, and restart, canceling unfinished preparation work.
• First-boot jailbreak setup initializes package dependency records, and Packages waits for setup to finish before offering operations.
• Safe file links inside legacy IPAs are preserved; unsafe paths, cycles, missing targets, and directory links are rejected.
• Cold-boot file connections allow stock AFC pairing to complete. Transfers have clearer state, preserve guest errors, and clean up temporary previews.
• A verified HTTPS CDN fallback handles affected Saurik archive download failures without disabling certificate or archive verification.

Acknowledgements

A huge thanks to everyone who tested S5LBox, reported bugs, and shared suggestions! Your feedback has been incredibly helpful in improving the project, and I really appreciate all the support!

Full changelog · Changes since 1.0.0 · Report an issue

S5LBox 1.0.0

Classic iPhone OS. On your iPhone.

The first public release of S5LBox: the iPhone 3G's iPhone OS 3.1.3 running inside an iOS app. This release is experimental; compatibility and performance are still being improved.

Firmware and first-run setup

• Native first-run setup with progress, cancellation, errors and retry paths.
• Download the supported IPSW directly from Apple using metadata from ipsw.me, with SHA-256 verification before import.
• Import an existing IPSW as an alternative. Selection is handled immediately, without reopening Settings or choosing the file a second time.
• Automatically identify iPhone1,2 / iPhone OS 3.1.3 / build 7E18, resolve its publicly documented keys, decrypt and extract the required components, and validate them before preparing a machine.
• Keep firmware details and manual overrides in Advanced settings. Skip setup once firmware is configured. No Apple firmware is bundled.

Machines, storage and controls

• Create multiple independent machines, with long-press actions to rename, duplicate or delete them.
• Save and resume running sessions, or shut down for a fresh boot. Keep machine files accessible through the Files app.
• Use an 8 GiB virtual disk for new machines by default, with 2 and 4 GiB alternatives under Advanced. Sparse storage avoids allocating the full capacity immediately; guest data and saved sessions still use real storage.
• Modern emulator toolbar and a separate device-controls sheet for Home, sleep/wake, silent mode, volume, pause, restart and Save & close.
• Separate app settings from running-machine settings; keep the legacy interface available in Advanced.
• Pause in the background by default. Provide Force Power Off for guests that cannot complete an ordinary shutdown, including during boot.
• Use guest shutdown confirmation before restarting a running machine. Forced power-off remains an unclean stop and can lose unsaved work.

Guest apps and jailbreak

• A Files-visible IPAs folder and in-app import, with individual app selection and real IPA icons, including supported legacy optimized PNG artwork.
• Install apps while the guest is running through virtual USB, pairing, AFC and the guest's installation_proxy service—not by editing its live disk.
• Installation progress, cancellation, guest verification errors and per-machine pairing identities.
• Guided guest jailbreak with Cydia, centered preparation progress and automatic entry into the machine afterward.
• First-boot setup performs a respring. The completion notice explains that Cydia may appear afterward and Packages may need a guest reboot.
• Packages helper setup is included with jailbreak by default, with an Advanced opt-out and a setup path for existing jailbroken machines.

Built-in Packages

• Native package browsing, categories, search, sources, installed packages and available updates.
• Download and process repository indexes on the host, with dependency planning, conflict checks and package downloads outside the emulated CPU.
• Install, update and remove packages using the running guest's own dpkg and maintainer scripts. Unsupported dependency plans are refused rather than silently applied.
• Handle supported package finish requests for respring or reboot after changes, with progress and connection-recovery feedback.
• First-use helper setup and first-boot waiting are integrated into Packages; missing setup is not treated as a successful connection.

Emulation, networking and audio

• ARMv6 guest execution with a no-JIT shipping path; no host jailbreak or JIT activation is required to run the emulator.
• Experimental MBX graphics enabled by default for new machines, with the existing software-rendering configuration retained for machines that use it.
• Guest internet access enabled by default for new machines, using the host's network connection. Includes guest packet-transfer and repository-processing improvements developed before this release.
• Experimental audio playback and microphone input, guest digital volume/mute, host audio-session handling and saved audio-device state.
• Microphone access enabled by default subject to iOS permission, with an Advanced opt-out. Declining permission does not block setup or boot.
• A firmware-specific software-decoder compatibility path for supported audio playback; this is not emulation of the missing audio accelerator.

Reliability fixes included in 1.0.0

• Fix virtual USB reconnection after Save & close for both Packages and live IPA installation. Wake a sleeping guest for pending service work, and detect controller resets instead of mistaking cleared interrupts for a completed handshake.
• Preserve deadlines for requests waiting for a connection, release canceled requests, and discard stale streams without replaying in-flight installs.
• Improve jailbreak/helper first-boot recovery, stale filesystem metadata handling and protection of referenced disk blocks during supported stopped maintenance operations.
• Preserve sparse disk allocation during maintenance copies and validate disk geometry and firmware identity before applying supported compatibility fixes.
• Fix firmware picker/import state handling, setup progress presentation, retained setup state and the separation of everyday and Advanced controls.
• Include regression coverage for USB transport, installation, storage, firmware preparation, input, audio and package operations.

Compatibility and known limitations

• Host requirement: an arm64 iOS device running iOS 13 or later. Physical-device validation has focused on iPhone 6s Plus with iOS 15.8.5; it does not establish identical behavior on every supported host version or device.
• Supported guest: iPhone 3G (iPhone1,2), iPhone OS 3.1.3, build 7E18. iOS 6 is not included in this release.
• Apps and tweaks must support this guest. Copy-protected IPAs cannot be installed; some otherwise compatible apps require AppSync inside the guest.
• Graphics, audio, input latency and performance remain experimental. Not all hardware, apps, tweaks, media formats or audio routes are supported, and original-device animation speed is not guaranteed.
• Packages is not a complete replacement for every Cydia/APT dependency plan. Unsupported plans may require Cydia. Guest scripts and initial jailbreak configuration can still take time; first boot may need a respring or reboot.
• Back up important machine data before experimenting. An interrupted installation can have an uncertain outcome; reconnecting does not undo it.

Installation

Download S5LBox.ipa from the 1.0.0 release and install it with your preferred IPA installer. The download is ad-hoc signed; on stock iOS, your installer must apply a valid provisioning signature. Keep several gigabytes free, open S5LBox, and choose Download iPhone OS or Import IPSW. Keep the app open while firmware preparation finishes.

Apple firmware, machine disks and test-device data are not part of the release assets.

Full changelog