Bolt

Bolt Kernel Flasher

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What’s This?

Bolt Kernel Flasher is an Android application for flashing compatible AnyKernel ZIPs on rooted devices. It uses Kotlin, Jetpack Compose and Material 3.

Features

• Copylefted application source (GPLv3.0); bundled runtime provenance documented below
• Kotlin and Jetpack Compose
• Material 3 Design
• Jetpack Compose UI
• Reviewed kernel operations with automatic recovery snapshots and retained logs
• Supports script-based AnyKernel ZIPs with the original installer
• Pinned BusyBox runtime for ARM64, ARM32, x86 and x86-64 (current source release build: approximately 5 MiB)
• Verified manifest-based backups and restores for discovered supported partitions
• Application-wide operation ownership, explicit partial outcomes and interrupted-job recovery
• Cockpit overview, compact recovery bundles and a separate restart/health feedback record
• Thor’s Asgardian light/dark palette, Outfit/Fira Code typography and persistent appearance settings

Flashing, backup and recovery

Root is required for privileged work. Imported/shared ZIPs require a separate review; Bolt does not execute them automatically. Pre-flash snapshots cover discovered active and shared kernel recovery targets, and cannot guarantee rollback of every change an installer may make. Legacy backups without a complete manifest cannot be restored.

See operation and recovery behavior, runtime provenance and release requirements, and tests and pending device validation.

Appearance settings offer System, Light and Dark modes, AMOLED backgrounds, Android 12+ dynamic colors, and Asgard or system fonts. See appearance and font provenance.

Download and website

Download the latest published APK. Bolt is distributed through GitHub; there is no Play Store listing. The landing page is live at https://bolt.trinadhthatakula.com; see web setup and owner-managed hosting.

Bolt 1.02.0: the Cockpit is available in the signed release, with changelogs and verified corresponding BusyBox source/build inputs. Check release notes for the features included in a downloaded APK.

Screenshots

Actual app screens captured on a rooted emulator. Recovery bundles and provider logs use sample data; no kernel was flashed for these captures. See screenshot provenance.

Listing resources and local validation include the descriptions, icon, feature graphic and screenshots for Bolt 1.02.0.

Signed release builds

Bolt uses the same signing setup as Thor. Copy jks.properties.example to jks.properties in the repository root and replace all four placeholders with your keystore path, store password, key alias and key password. Use an absolute keystore path; relative paths resolve from app/. Java properties require literal backslashes to be escaped as \\ (forward slashes also work in paths).

cp jks.properties.example jks.properties
# Fill in jks.properties with your keystore details before building.
./gradlew :app:assembleRelease :app:bundleRelease

Signed APKs are written to app/build/outputs/apk/release/; signed app bundles go to app/build/outputs/bundle/release/. Local jks.properties, *.jks and *.keystore files are ignored by Git; only the placeholder template is tracked.

For CI, set Thor’s KEY_ALIAS, KEY_PASSWORD, KEYSTORE_PASSWORD and KEYSTORE_FILE_PATH environment variables instead. The path defaults to app/release.jks when omitted. Complete local credentials take precedence over the environment. Missing, incomplete or unchanged local placeholders leave release artifacts unsigned unless all required environment credentials are available. Debug builds keep Android’s normal debug signing.

Warnings

• Use at your own risk. Flashing kernels can potentially brick your device.
• Highly recommended: Always back up your data and current boot image before proceeding.
• Check compatibility: Ensure the kernel format and boot image compression match your device requirements. Mismatches may cause your device to be stuck in a bootloop.
• Device warranty: Flashing custom kernels may void your device warranty.
• Data loss: Incorrect usage can result in data loss or device malfunction.
• No liability: The developers are not responsible for any damage caused by using this tool.

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License

This project is licensed under the GNU General Public License v3.0 (GPL-3.0). See the LICENSE file for more details.