Google Pixel 4a

Overview

codename sunfish	⚙️	🛡️
Flavor (?):	Pro	Slim
Android:	15	15
First released:	2024-01-16 (A13) 2026-02-10 (A15)	2025-02-05 (A13) 2026-02-11 (A15)
Firmware:	included	included
Encryption (?):	FBEv1	FBEv1
Relockable:	yes	yes
VerifiedBoot/AVB (?):	v2.0	v2.0
Patchlevel (?):	Platform + Kernel	Platform + Kernel
Verified & tested by:	The AXP.OS team	The AXP.OS community
State:	stable	stable

Installation guide

You want to switch between flavors or coming from DivestOS?

Please read this first: All about AXP.OS flavors If you miss a flavor you can request it here.

Known issues

AXP.OS - Known Issues
Issue tracker - won’t fix

Boot modes

Each device has its own method to access special boot modes.
See: sunfish (@LineageOS wiki)

Firmware

AXP.OS for the Google Pixel 4a includes the appropriate bootloader and modem firmware for the corresponding Android version provided.

Important

Unfortunately, some manufacturers enable so-called “Anti-Rollback Protection” (ARB), which in the worst-case scenario can even take effect within the bootloader (notable examples include various LG models, as well as Samsung and even some Google Pixel devices).

In these cases, special caution must be exercised, as this can often result in a hard brick, which may be unreparable depending on the manufacturer and model. This is not a problem with AXP.OS itself, but affects all custom OSes for such devices.

If you are unsure, please check with the support room before flashing AXP.OS.

Install / Upgrade

Install (Pixel devices)

Setup AXP.OS

Follow Setup

Re-locking the bootloader

Follow Bootloader-Lock

Fingerprint information

On boot you may see a fingerprint/ID verifying AVB trust.
Some devices show only 8 chars, others full digest.
See more details here.

This fingerprint is unique per device and flavor.

If you see a different ID, immediately request support.

Pro build

BOOTLOADER minimal ID
      2357DB9E

BOOTLOADER full ID:
      2357DB9EBF8090F9
      908E9BBC0B353CC9
      CA11015AC588001D
      0AB9A80BD8AA5906

Slim build

BOOTLOADER minimal ID
        B49112D3

BOOTLOADER full ID:
        B49112D3DD534A21
        AD3FC088B8977377
        4004899D7B181996
        15E6F074099EA3E0

XDA thread

See here

Debugging

DEVICE-BOOT-DEBUG-PATH: /mnt/vendor/persist
See Logs

Download

All downloads have a GPG signed sha512sum file which should be used to verify the download & file integrity.
Details how to make use out of it can be found here.

💡 The hashsum of new builds are also send in the sfX Automation channel. This gives you a second and independent option for comparison if the download server is compromised.

Flavor (what's this?)	OS zip	Recovery image	FACTORY zip	AVB key (what's this?)	Release key (what's this?)
Pro ⚙️	(click)	(click)	(click)	(click)	(right click, save-as)
	(click)	(click)	(click)	(right click, save-as) click here for info
Slim 🛡️	(click)	(click)	(click)	(click)	(right click, save-as)
	(click)	(click)	(click)	(right click, save-as) click here for info

Last updated on 2026-04-02

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