[Sony Ericsson XPERIA X10 Mini] aPaullyG:
The u20a is the 850MHz/1900MHz/2100MHz version of the Mini Pro, I figured I'd start a thread to help consolidate information specific to this version of the handset.

If you live in the US, Canada, Central and South America (Check with your carrier), New Zealand (Using NZ Telecom) or Bangladesh, this is the version you want for 3G support.

For Australian's this is the version to buy for use on Telstra and 3 Hutchinson. For Vodafone Au they use both 850 and 900 as well as 2100MHz, if you never go regional you may benefit from the u20a as Vodafone are now deploying 850MHz for infil of some of their their 2100MHz urban networks, their regional and fringe services are 900MHz mostly and require a u20i. Optus is 2100/900 only so you'd want a u20i.

Officially language support for all u20a models seems to be English, Spanish, Portuguese and French with American specific customisations to those languages in most builds.

The u20a currently available in the Australian Market via carriers 3 and Telstra.

As far as I know it is (or will be) available in Canada via Rogers, Through SE and various carriers in Argentina, Brazil, Chile, El Salvador, Peru, Columbia, Mexico and also other parts of Central and South America.

There appears to be a Sony US Generic firmware out now, so it looks like the Mini Pro has been released there or is due to be soon, hopefully it wont take too long to track down the CDF number for this model.

Firmwares and variants list. (needs updating)

U20a VIVO-1-2-5 CDF1238-9793 1239-7565 Vivo BR/Black
U20a WORLD-1-2-5 CDF1237-6083 1239-7456 Movistar PE/Black
U20a WORLD-1-2-5 CDF1237-6745 1238-2489 Claro PE/Black
U20a WORLD-1-2-5 CDF1238-0148 1238-2495 Comcel 3GSM CO/Black
U20a WORLD-1-2-5 CDF1238-2298 1239-2226 3 AU/Black
U20a WORLD-1-2-5 CDF1238-8213 1239-7684 Customized BR/Black, 1239-7686 Customized BR/Red
U20a WORLD-1-2-5 CDF1238-9769 1239-7432 Telemovil SV/Black
U20a WORLD-1-2-5 CDF1238-9785 1239-7563 Claro BR/Black, 1240-1219 Claro BR/RED
U20a WORLD-1-2-5 CDF1238-9789 1239-7712 Movistar CL/Black
U20a WORLD-1-2-5 CDF1239-0004 1239-7718 Entel PCS CL/Black
U20a WORLD-1-2-5 CDF1239-0006 1239-7701 Claro CL/Black
U20a WORLD-1-2-5 CDF1239-0083 1239-7453 Movistar MX/Black, 1241-2786 Movistar MX/Red
U20a WORLD-1-2-5 CDF1239-2457 1239-2229 Telecom NZ/Black
U20a WORLD-1-2-5 CDF1239-2460 1238-4468 Customized GEL/Black, 1239-6209 Customized GEL/Black, 1240-1185 Customized GEL/Black, 1240-1188 Customized GEL/Red
U20a WORLD-1-2-5 CDF1239-5023 1238-9150 Telstra AU/Black, 1243-2969 Telstra AU/Pink
U20a WORLD-1-2-5 CDF1239-7520 1239-7437 TELCEL GSM MX/Black, 1240-1215 TELCEL GSM MX/Pearl White, 1241-8383 TELCEL GSM MX/Red, 1243-1507 TELCEL GSM MX/Pearl White, 1243-1509 TELCEL GSM MX/Black, 1243-1510 TELCEL GSM MX/Red
U20a WORLD-1-2-5 CDF1240-8130 1240-8004 Movistar GT/Black
U20a WORLD-1-2-5 CDF1242-5721 1242-5537 Customized BD/Pearl White, 1242-5539 Customized BD/Red, 1242-5540 Customized BD/Black

http://www.ptcrb.com/ctiastaff/complete/view_complete_request.cfm?modelid=17493

Root/Debrand info:

The usual tricks work as for the u20i from my experience so check the debrand and root threads etc. The 2.1 update appears to carry a payload for for the 3G radio hardware, as there are multiple reports of u20i software disabling 3G on u20a's, crossflashing is therefore not advised.

Any additional/updated information welcome especially if you have a u20a with a CDF not listed above or can correct or expand existing CDF's

(I decided to remove the CDF's for proto firmware for the time being, as they were carrier branded, I couldn't confirm their authenticity and the brick risk on a regular u20a was high even if they were correct).

Brazil (CDF1238-8213) seems to be the most frequently updated firmware of the generics, running about 4-6 weeks behind UK for the translation additions into Brazilian Portuguese. There is some inherent safety with this as you're unlikely to get bombed with an unrootable update without warning from the UK people getting it a few weeks before.

SE BR seems to be the division with its act together the most and all u20a American versions should support the same language set. (English, Canadian French, Brazil Portuguese, Latin Spanish).

Brazil Generic however uses a qwerty Portuguese/Spanish latin keyboard, to switch to a qwerty English layout, the following needs to be done. So root the phone using your method of choice and make sure usb debugging is turned on. (USB debugging is your safety line if you screw up, it should always be turned on immediately after you flash a new firmware and left on.)

Here you will edit one file and replace another file, I recommend you make copies of the originals before you mess with them.

Firstly edit /system/usr/keyboard-config/keyprint.xml.

Where it says "QWERTY Portuguese" change to "QWERTY"

and the line <script name="latin" keyboard="qwerty-br"> you'll replace the "qwerty=br" to qwerty-en so it reads <script name="latin" keyboard="qwerty-en"> (This changes the keymap for "Default Input" if that is checked in the locale settings and you're in English you'll have qwerty English layout)

For 1.6 Copy /system/usr/keychars/mimmi/keyprints/qwerty-en.kcm.bin to /system/usr/keychars/qwerty.kcm.bin

You need to replace the qwerty.kcm file, you can copy over it or you can rename the original then copy in qwerty-en.kcm.bin and rename it to qwerty.kcm.bin)

(This makes the layout qwerty English, across the board even with "Default Input" off)

On 2.1, SE Brazil didn't include the English qwerty layout, so you'll need to get the .kcm file here.

In this case it's just a drop in replacement for mimmi_keypad.kcm.bin found in /system/usr/keychars/

I personally just did everything above in root explorer because I'm lazy and careful, you may wish to use adb for file operations and do the editing of keyprint.xml on your pc.

After you're done, switch to another language in the phones locale settings and switch back to English, you should then have a English qwerty keyboard.

WARNING: If you need the qwerty english layout on Brazil firmware, keep the following in mind. Every time you update the phone, you will need to root and change the keymap. In the event of an unrootable update you will be stuck with the Portuguese/Spanish layout, so apply updates with some degree of caution.

If you're not comfortable with this, the best firmware option for the qwerty English layout is the CDF1239-2460 GEL firmware, which sadly thus far hasn't seen a single update. The other option is to crossflash to UK Generic for the u20i, I'm unsure if changing to firmware for the u20i model could potentially impact operation of the gsm radio hardware at some stage, at the moment there appears to be no difference in operation of the unit on either firmware.

If you do get stuck on an unworkable firmware, Davinci Team or Omnius can get you back, if you're careful though it shouldn't come to this.

Brazil Generic 1.6 files (not decrypted) from the \blob_fs directory on SEUS/PC Companion for those who wish to update via that method.

http://www.megaupload.com/?d=CSLYZY5Q

Decrypted Brazil u20a 2.1 http://www.megaupload.com/?d=OXMYJ1X0