Motorola Droid 4 - RTC driver

With Debian up & running I had a look at what needs to be done in the mainline kernel. Tony is working on the ADC parts, which are required for the battery/charger work and mentioned he will have a look at USB. He also mentioned, that somebody with spare cycles could take care of CPCAP’s rtc & watchdog. I had a look at Motorola’s vendor kernel and as far as I can see CPCAP does not come with a watchdog (unlike twl4030/twl6040). Read more →

Motorola Droid 4 - Debian

In the last post I rooted the Droid 4 and installed LineageOS with SafeStrap as bootloader. Today I took care of getting the mainline kernel running and preparing a rootfs. After some communication with Tony I got the kexec stuff running (at the end the problem was my compiler generating binaries not suitable for Android). Instead of getting a compiler toolchain for Android I decided to rewrite the binary into a shellscript, so that no compiler is required. Read more →

Motorola Droid 4 - rooting

Yesterday I received the Motorola Droid 4 from my previous article. It came in a reasonable condition with a few scratches in the case (none in the display) and some of the back cover’s clips being broken. First impression: The phone feels a bit more clumpy than the N950, but much less than the N900. The sliding mechanism feels qualitatively worse than Nokia’s and the same goes for the keyboard quality. Read more →

Motorola Droid 4

Tony Lindgren is currently working on mainline kernel support for the Motrola Droid 4 (Wikipedia, GSMArena, iFixit Teardown). He documented his work to get serial over USB on the following page: I just got myself a used one via Ebay, since it’s a decent upgrade from the Nokia N9xx phones. It’s also quite cheap (30$ in US, 50€ after import to DE (shipping + customs)). Last but not least there is no newer phone available, which has a proper hardware keyboard. Read more →