Have GordonsGate Driver set up.
SEUS (Sony Ericsson Update Service) is the official tool. Instead use:
Far manager with SEFP2 and CXC plugins + tutorials
→ ALT+F7 for search in FAR-Manager →sefp2w.145 / 144 can not delete files on red phones! → sefp2w.139 definitely works! http://forum.farmanager.com/viewtopic.php?t=5163

https://sony.yt/topic/944-far-how-to-patch-permanently-a2-based-phones/
https://www.topsony.com/forum/showthread.php/10301-Flashing-with-jdflasher
jdflasher (no A2)
A2-Uploader
XS++
Setool2 Lite
SEMCtool v2.2
SeTool2 (change server address to use)
WotanServer / other smartcard locked services?
hardware dongles: z3x box, Sonicsbox (Sonics SE Tools 1.120), cruiser cable,
jjpatcher+bpatch for CID80+ jar patcher
patch joiner or just add +1000; between patches

Original v1:

;Phone model and firmware version
;Description
;Recommendations (optional)
;(c) Author
;(p) Porter (if patch is ported from any other phone/firmware)
;(!) Important information, for example: (!) HeapShift. (optional)
;(i) Not important information (optional)
;(r) Respects (or nickname of man who provided any information for patch) (optional)
;(e) Nickname of man, who edited patch's code changing patch's functionality (optional) (optional)

The v2. if I may call this like that, is described in SEDEV Recovery Patch Help:

1. "Created" - C, c, Copyright Symbol, also can be used TradeMark Symbol, but this symbol currently is not recommended - tag for creators of the patch.
2. "Edited" - E, e - this covers modding, enhancing or other changes from base patch.
3. "Updated" - U, u - this covers updating and big fixing only. Updating means that the developer changes date / time / credits / some very small enhancing can be addressed as update too.
4. "Ported" - P, p - Only for crediting people who ported patch.
5. "Idea by" - I, i - Registered Symbol can also be used - this covers all who assisted in development ONLY.
6. The Information Symbol ( circle with "i" in the middle ) - Can be used to add (!) type information, if needed - for informative part ( non-tagged comment lines ), compatibility, requirement or other important data.

Open a dissassembler as IDA, apply the patch with the IDC script, disassemble it.
If you want to change it, write your .asm file and compile it with FASMARM. 

1.- Open firmware in IDA (You know this step already?)
2.- Apply patch wih IDC script.
3.- Disassemble
4.- Make .asm file
5.- Port
6.- Reassemble 

http://web.archive.org/web/20101128170128/http://se-developers.net/viewtopic.php?f=38&t=771
http://www.se-developers.net/viewtopic.php?f=38&t=771

Cxc2raw
by mc_kibel on 03 Feb 2010 12:53


Hello,
it's a simple app by me (thanks to ndt and den_po).
I was too lazy to run winhex everytime after using read3150 :D
Just drag'n'drop phone_app.cxc file on .exe, that's all.
It autmatically detect if cxc header is 0x1000 (phone) or 0x2000 (read3150), then app removes header.
By the way app will show some info about current .cxc, for example:


    cxc2raw
    (c) mc_kibel
    Thanks: ndt, den_po
    File from: Read3150.exe
    Cxc file size:
    ->30881440b
    ->30157kb
    ->29mb
    Cxc header size:
    ->0x2000
    ->8192b
    Platform: DB3210
    Firmware base address: 0x14000000
    Succes!
    Press any key to continue...


Edit: Little update, sorry for that :D Support phone_app.cxc from DB3150 / DB3210 / and added DB3350.

To me, C901 is the perfect latest bar type SE phone. W995/C905 are awesome CID53 A2 phones too, but I cannot arrange with a slider. Sony camera module is IMO pretty good for photos, even better with driver mod. Recording video only useable for quick snapshot. Fell in love with the video-led as torch, unfortunately A2 phones cannot dim LED. Created elfs for tracking free call minutes, hireminder for alarm triggered by accelerometer and modified SEns9x input bcfg controls because I liked playing it so much. And the not-so-KISS-anymore TorchC901 elf.
I've actively used it as daily driver till mid 2023 and do sometimes w/o SIM. I felt forced to have a 1+6 lineageOS-microG phone in the world of google apps :'(

K800 was my second SE phone type. It was a good phone and upgrade to K750. I loved the two top buttons in emulator games. The red camera focus LED could be used as flashlight. Decent photo camera with XENON flash. Had troubles with joystick, patch as workaround. M2 memory cards. Velour paint can get sticky after years (see lifehacks:liquid).
I had it crossflashed K800 → K810 with fixed drivers.

K750 was my first Sony Ericsson phone, which was crossflashed to W800, as soon as I got to know what magic was out there.
It is a good phone and a huge upgrade to my first&old Nokia 3510i. Patching and modding was awesome, the world of J2ME apps discovered. Had trouble with joystick, patch as workaround. Dimmable LED flash was awesome torch, triggered by camera shutter and flashing on incoming call. Useable camera for its times. The start of personal good ringtones and iMY.