The community is in search for former Omnius owners/maintainers to retrieve the source code or SEUS signing process.
@vi0let/lucy: Please release non-functional Omnius server side program w/o database for reverse engineering. should have bought it in 2018…
Basics
I do not intend to create tutorials here. This has been done elsewhere already, also beginner friendly.
Look in the links section yourself. Also see the se-nse archive for beginner friendly tutorials.
See which platform and CID your phone can be, e.g. on topsony.
There is a collection of tutorials here: https://www.akshayy.com/sonyericsson/index/
How to use Setool2-lite for A1 phones: https://sony.yt/topic/3199-setool2-lite-v111-user-guide-identify-gdfs-backup-flashing-patching-unlocking/
How to use A2 Uploader: https://sony.yt/topic/942-a2-uploader-a2-tool-tutorial/
Howto patch A2 phones with FAR: https://sony.yt/topic/944-far-how-to-patch-permanently-a2-based-phones/
DCU-60 USB cable is used for fastport phones.
For doing anything fun, phone needs to be on BROWN certificate. Changing from RED is possible for CID⇐53. Use Omnius (now for free 
) or setool2 for CID53.
CID81/CID80/RED only has runtime patching via jjpatcher jar with bpatch - it is possible to even load elfpack now!
Modified DSS-20/25 can be used for phones with T28 Connector as serial adapter.
Use the service cable to read (boot) logs from the phone!
Firmware file structure of A2:
After flashing A2 firmware (.fbn), flash custpack and 'finalize' the phone.
Resetting the phone from menu will not remove patches but files and (even some preinstalled) content.
Firmware is split into three parts:
1) MBN: main firmware that contais all code for running, which vkp patches on.
2) FBN: image of internal filesystem (FS), contains all files that are used by the main firmware, (GUI, drivers, lang, sounds, pre-installed Java apps, etc
3) Custpack or Customization files: files stored in FS, which are modified by phone carriers to customize the operating system. Unpack to modify yourself - clean custpack from ad-links or do afterwards in FS.
Glossary
backup - if you ask yourself what it is, learn how to backup GDFS NOW!
📘 Glossary
CID (Content Identifier)
A security level marking for firmware and loader signing (e.g., CID49, CID52, CID53); higher CIDs have stricter checks and restrictions.
SUPERCID / AnyCID refers to an EROM with disabled security check, allowing patching without converting certificate colour to BROWN.
(AFAIK) CID110 phones were never released it is mainly to allow flashing firmware to phones with any CID / CID110 is a dummy /pseudo CID applied to patched A2 Sony Ericsson phones to bypass CID restrictions.
A1 / A2 Platforms
A1 = early SE platform (e.g., DB2010, DB2020); A2 = newer architecture (e.g., DB3150, DB3210, DB3310) with stricter security and different file structure. A2 is interchangeably called A200.
DB (=Digital Baseband - AFAIK)
Internal hardware code name for SE baseband platforms (e.g., DB2010, DB2020, DB3150), tied to CPU, RAM, and bootloader layout. It was Locosto before DB-plattform.
Certificate Colour
Phones have certificate “colors”: Brown (developer), Red (retail), Blue (factory)test. CID53+ restricts patching and unsigned loader access without signed tools.Browning
refers to changing certificate colour to “brown”
GDFS (Global Data File System)
A region of phone memory storing unique configuration, IMEI, and calibration data; also used to store flags enabling patch access. BACKUP! This is unique device specific!
VKP Patch
A plaintext format (.vkp) for firmware patches; used to modify ROM functions or bypass checks by patching mainly the MAIN flash (MBN).
VKP means V_Klay Patch which is taken from a patcher tool for Siemens known as V_Klay Patcher.
There are simple and advanced vkp patches: either they just replace/modify code (simple) or advanced patch uses free blocks to add functions (mostly converted by elf2vkp).
ELF / ELFpack / ELFloader / ELFlib
ELF (Executable and Linkable Format): small native apps written in c. ELFloader is the launcher; ELFpack combines it with ELFlib.
DynLib (Dynamic Library)
Shared binary used by ELF files (like a DLL); loaded at runtime by ELFloader to provide reusable functions (e.g., file I/O).
QA (QuickAccess) Patch (DB2020)
Firmware patch to disable signature checks on DB2020 phones, allowing FS/GDFS access and .vkp patching without a service box.
Heap Shift
Patch offset of Heap area to win space for advanced vkp patches
T28 11‑pin Connector
The legacy serial connector from the Ericsson T28 era; used for flashing, service mode, and accessories before the FastPort standard.
FastPort
A proprietary all-in-one connector used in most SE phones (A1 and A2) after T610; supported charging, data, audio, and accessory control.
Firmware structure
phone_acc.cxc is modem fw, AFAIU. ACC stands for the ACCess processor
/tpa/ stands for “Third Party Applications” and contains themes, menus, fonts, branding. It is writable by default
/ifs/ – stands for “Internal File System”
/system/ – Core Operating System Files (A2 only)