(2024-11-11) CAT S22 Flip: a keypad Android flip phone done almost right ------------------------------------------------------------------------ Since KaiOS flopped (and I'm sure it's already pretty safe to declare that), the question of finding a decent keypad phone with modern application support is relevant again. And things like Xiaomi Qin1s or AGM M7 are not exactly the kind of support I'd have expected in 2024. Luckily, Bullitt Mobile to the rescue once again, and the model that still can be found new (although sometimes unofficially), CAT S22 Flip, seems to deliver the very experience I was looking for. It has a Qualcomm Snapdragon 215 (although its Fastboot menu was compiled for 430), 2 gigs of RAM and 16 gigs of built-in flash storage with, of course, ability to expand it with a microSD card which I surely did. It runs Android 11 Go Edition with some (unwanted but removable with root) T-Mobile/Sprint customization, and it looks like the firmware comes in two versions: 29.04 and 30.03, the latter being what my device has, and TBH I doubt this model will get any more updates in the future. And here's where things get interesting: it has both a physical keypad and a touchscreen, although you'd never guess it had one from the pictures. Hence, both Gboard and KikaInput are preinstalled in the firmware, and, thankfully, I managed to replace both of them with Unexpected Keyboard and Traditional T9 respectively. Hardware-wise, this phone is, as Action Retro would say, "not too shabby", despite only supporting a single SIM in the nano-SIM form factor. The lack of a 3.5mm audio port was compensated with an adapter in the box (which, by the way, you will need if you want to listen to the FM radio), and the lack of wireless charging was compensated with a two-pin dock connector on the back. Good luck finding that dock though, but you still have an option nevertheless. And let's not forget a really useful flashlight, which has recently almost replaced my regular flashlight for the kind of tasks where I have to wander around the house at night. My only real complaint about all this is the size: CAT S22 Flip is almost twice as thick as CAT B40 while being just as wide and only a couple of centimiters shorter than it... in the closed state. You won't really understand how humongous it looks until you see it in person. Granted that it's heavier than B40 as well... I think you get the idea. I understand that this chungus houses a removable 2000 mAh battery but still, they should have consulted whoever manufactures Sigma X-Style 31 how it should be done. So let's hope that all this extra size and weight is for some impact and ingress protection the brand claims for this model. To be honest, rooting and debloating are the first things one should do with such a phone, although it's not without its quirks. The XDA forum has a guide ([1]) on how to root the S22 Flip, but my mileage varied a bit. First, the guide doesn't tell you what to do if the "OEM Unlocking" option is greyed out. My device already came here carrier-unlocked (although the T-mobile branding is all over in the firmware) but I still had no option to toggle the OEM unlocking until I entered my Google account. Afterwards, beware that the firmware has encryption setting turned on, so running "fastboot flashing unlock" will erase your userdata partition. Then you can follow the guide, although I didn't have to patch the vbmeta partition either. Maybe I'll post the patched v30 boot.img somewhere alongside the simplified guide, we'll see. The post-rooting steps though are the very thing where one can screw up very easily. Of course, I installed F-Droid (and FFUpdater and Obtainium via F-Droid) and a number of essential things, the De-Bloater application being among them. This is a Magisk module to move system applications out of the visibility while not physically deleting them. Nevertheless, it still can render the system unbootable, so be careful. By the way, you can find TWRP for this device, but I tested it and found out that it will do more harm than good, so I don't recommend it. Here's the list of packages (as they're called in De-Bloater) I debloated this way and the system still boots and every basic function works: * 12-Key Keyboard * Android Setup * Calculator * Calendar * Camera * Carrier Device Manager * Carrier Hub * Cat phones * Chrome * Clock * com.android.providers.partnerbookmarks * Data Restore Tool * Digital Wellbeing * Drive * Duo * Files by Google * Gallery Go * Gboard * Gmail * Google Assistant Go * Google Contacts Sync * Google Go * Google Location History * Google Partner Setup * Google Play services * Google Play Store * Google Services Framework * Google SetupWizard Customization * Google Speech Services * Google TV * Keep Notes * Maps * Market Feedback Agent * MCM Client * Messages * Mobile Installer * Speech Services by Google * T-Mobile (AdaptClient.apk and TMobile.apk) * T-Mobile Diagnostics * TDC * TMO-RSU-Common * TMO-RSU-Sys-Service * Unlock * Visual Voicemail * YouTube * YouTube Music Quite a lot to remove for such a device, if you ask me. I even considered moving to a LineageOS setup (yes, there is one for S22) but it's not quite ready yet, as it has no support for the programmable side button and, which is more important to me, for the external display. Also, do not remove Quickstep even if you install an alternative launcher: you'll lose the ability to switch and close windows. Maybe this stock Android distribution just was built this way, who knows. Other than that, it's a pretty "normal" Android 11, so you can install whatever you want, of course, remembering about the amount of RAM and storage here. I, for instance, switched to my favorite Android launcher for small screens, KISS Launcher, and likewise replaced a lot of the aforementioned debloated stuff with its FOSS counterparts: Files by Google => Amaze, Gmail => Thunderbird (former K-9 Mail), YouTube => Clipious, YouTube Music => InnerTune, Maps => OsmAnd~, Gallery Go => Fossify Gallery and so on. I think F-Droid is an excellent starting point to look for such replacements. Of course, all that is fun and games, but how about the *real* stuff some of you come to this phlog for? Well, for starters, let's list some secret codes (where applicable, only the mnemonic is provided): - *#*#INFO#*#*: standard Android info - *#*#LOG#*#*: Qualcomm LogKit launcher/stopper - *#*#ENGMODE#*#*: a comprehensive engineering menu with netmonitor and other stats - *#*#0202#*#*: some TFT stats or version - *#*#02#*#*: device info - *#*#2846#*#*: version info and test toolkit Okay, let's see where the IMEI is stored in there. And it MIGHT seem like it's stored in the plain ASCII in the partition called "factory" at the offset 104 (0x68), but that's an illusion, it gets overwritten there from somewhere else. Nor is it stored in the fsc, fsg, modemst1 or modemst2 partitions. So where is it? Well, the answer seems to be not so pleasant: it's stored in the "persist" partition, in the encrypted form. Namely, the mounted path of the directory is /mnt/vendor/persist/data/keymaster64, and inside this directory there is a "keymaster64" file that contains the index of all encrypted factory information files, including the IMEI number, in the same directory. It's the Qualcomm KeyMaster, baby! Well, it looks like I've got myself another rather long-term research target in addition to the Pixels. So, what's my overall first impression about CAT S22 Flip? Well, about 7/10. It definitely is usable (especially once rooted and debloated), it definitely is rugged, it definitely is "smart", but it also is a little too bulky in size and too non-free to my taste, considering not only IMEI encryption but also the amount of work required to debloat the stock OS and lackluster support for third-party builds like LineageOS and TWRP. As I said, it makes a nice research target for the future efforts and a nice Android workhorse for the present time, but I'd also like to find something that would even more adequately respond to my needs. Something Android-based, maybe with a keypad/touchscreen combo as well, but slicker outside and friendlier to folks like me inside. --- Luxferre --- [1]: https://xdaforums.com/t/tut-root-how-to-root-cat-s22-flip-on-version-30.46269 1/