HiBig Zero v1.5.0

HiBig Zero v1.5.0

🆕 New managed app: Obtainium

Obtainium joins the APPS tab — install and update apps straight from GitHub releases, with no Play Store and no account.

• Uses the plain release asset (app-arm64-v8a-release.apk), not the F-Droid flavour. They are different packages (dev.imranr.obtainium vs dev.imranr.obtainium.fdroid) signed by different keys, so mixing them would install a second app or fail the signature check on update. Verified against the published asset.
• REQUEST_INSTALL_PACKAGES is granted on install, so Obtainium can actually install what it downloads instead of sitting behind a system "Allow from this source" prompt.

🔋 Sleep clamp measured — results published

The screen-off CPU clamp was finally measured on hardware. Full write-up in docs/SLEEP_CLAMP_TEST.md:

• The clamp works — identical work takes 2.44× longer, verified across 8 legs with CPU frequencies recorded in every sample.
• It only matters while the device is awake with the screen off, where it saves ~10–17 mA (the wake profile pins the little cores at a 900 MHz minimum). While the device is genuinely suspended it saves nothing — the firmware powers the cores down regardless of governor.
• The total-energy figure cannot be measured on this hardware: the battery gauge is unusable below ~10 mA (charge_counter frozen, positive current reported while discharging) and the timing and current instruments contradict each other by ~6×. This is stated rather than papered over.
• Recommendation: the upside is small and bounded while the failure mode is a crippled device, so SLEEP_GOVERNOR_ENABLED=0 is the safer default. Shipped default is unchanged (1), and the failure mode is fully contained by the recovery machinery below.

🛠️ Reliability and hardening (since v1.4.0)

• Self-updater trust boundaries — downloads are restricted to GitHub hosts with every redirect hop re-checked, and the APK must be signed by the same certificate as the running app. A tampered or failed download now fails loudly.
• execRoot liveness — stdout and stderr are read on separate threads (the old sequential read could deadlock permanently when a command filled the stderr pipe), with waitFor(timeout) plus destroyForcibly() so a wedged su can never freeze a caller forever.
• Screen-state durability, three tiers — dynamic receiver for the hot path, reconciliation on every process start, and a non-wakeup ELAPSED_REALTIME watchdog that repairs a stuck clamp within ~2 s of the screen coming on. Previously a process killed while clamped left the device at 400–900 MHz with 4 cores dead permanently; that state was reproduced on-device before being fixed.
• Boot-loop guard — after 3 fast boots the rule pass suspends itself and the header offers RESUME RULES, so a bad rule can't make the device unbootable.
• Boot rule table — the 19 numbered blocks in BootReceiver are now tables plus explicit steps, with behaviour proven identical by diffing 24 real boot commands against the pre-refactor binary. Kills the ON/OFF drift class that had already caused two bugs.
• Config hardening — a package name read from a world-writable file was interpolated into root shell commands at every boot. Closed with 0600 owner-only files plus package-name validation; the injection was demonstrated not to execute afterwards.
• Persistent log — the log is now a real rotating file (/data/local/tmp/hibreak.log) instead of a memory-only list, written by a single batched thread.
• Charge ceiling — the MTK current_cmd switch, with every failure path resuming normal charging.

📥 Install

adb install -r HiBigZero-v1.5.0-release.apk

Same signing key as previous releases, so this upgrades in place. HiBigZero-v1.5.0-release.apk.sha256 is attached for verification.