[Nexus S Android Development] steven676:
An official OTA for GSM Nexus S (GT-i9020T/i9023) is now available:

http://android.clients.google.com/packages/ota/google_crespo/9ZGgDXDi.zip (thanks bl1nkk)

Because an official release is now available, this ROM is now EOL and will receive no further support.

By popular demand, here's a new thread for my port of the Jelly Bean SDK. This is a continuation of DaxMax's thread, so if you want to see previous discussion, look there. (Thanks to DaxMax for putting up with discussion of what is essentially a distant cousin of his original ROM for so long on his thread.)

http://files.mrks.me/update-crespo-JRN83C-preview-2012063001.zip http://goo.gl/40Cxf (thanks to bl1nkk for the hosting)

MD5: 015e322b048b7e1464a90a87a5a6bcb1
SHA1: 3aca40900b40625505d4b6c0afce93c31e33770d
SHA256: 3b0b76444c307f4ffe685205cb92ad6060d957152dadef72444b3f2407510a34

Service Pack 4 for this ROM: https://docs.google.com/uc?export=download&id=0BwGWbMaI9twWRHFrRUROcDhIeVk http://goo.gl/ZVlQS (many thanks to bl1nkk for hosting) (alternately, check thread for mirrors) (see this post for changelog)

MD5: ac85b1e309ba3a3f438efe0954c11c32
SHA1: d147f777f8594c5d33dfd480143758107ff1baab
SHA256: 951d39e75e8d4891e18a1da3896567f293074262d8aef3cd0021d4239492cf00

Flash the main ROM zip (update-crespo-JRN83C-preview-2012063001.zip) first, then the service pack.

These are zips which should be flashable from ClockworkMod or other recovery. They contain /system and a boot.img and will not touch your recovery, data, or SD card. I believe you need to do a full wipe if you're flashing over ICS or below.

This ROM is quite stable and almost fully working at this point. Highlights:

Based on the Jelly Bean SDK release (JRN83C), with Google apps and other components from the Nexus 7 factory image (JRN84D). Hardware-related files and kernel from the ICS IMM76D release for Nexus S. (The source for the GPL components (mainly the kernel) is available from http://android.googlesource.com/.) The wifi hack (libhardware_legacy.wifi.so) is posted farther down this thread (including source).

Remarkably smooth. Project Butter really lives up to its name. (I've made one tweak in the init.herring.rc to make the default ICS cpufreq governor more aggressive in upping the clock frequency, in order to simulate the change in governor in the Jelly Bean kernel.)

Wifi, Bluetooth, GPS, GSM all work. NFC should work.

Sound and calls work as of July 9 (SP1).

Video recording works as of July 10 (SP2).

Tethering, including wifi tethering, works as of July 11 (SP3).

Calls via a Bluetooth headset work as of July 11 (SP3).

Google Now/voice search, offline voice text input, voice dialing, and text-to-speech all work as of July 11 (SP4).

Broken:

Voice/video chat in Google Talk Patch available to fix video/voice chat, see this post. (thanks selectormoldy for the crash log leading to fix)

Media scanning (used by Gallery and Music to find files on the SD card, among other things) is broken for some, but not for others. This appears to be triggered by something stored on the SD card/external storage. (thanks spupuz)

High-performance WifiLocks (the wifi driver drops into low-power mode when the screen turns off, even though it shouldn't when a high-perf WifiLock is held).

Sound. Note that means no phone calls of any kind, not even emergency calls, so this isn't ready for serious day-to-day use. This is likely unreasonably difficult to solve given that we have an official OTA coming in 2-3 weeks; look upthread for an account of what's been tried.

Ambient light sensor. It worked in the Galaxy Nexus-based ROM, and I'm not sure why it doesn't work in this one; in any event I'm not planning on putting more time into figuring out why. The light sensor works, but automatic brightness setting does not -- presumably something in the Android framework needs to be changed.

Video recording (as reported by users in this thread).

The Google Now/Google Search app may crash (reported by users in this thread). (This should be fixed in SP3 -- if you're still having problems, please provide a logcat.)

Tethering via wifi.

Phone calls via Bluetooth.

Voice dialing.

Voice search in Google Now. (The app fails to recognize when you stop speaking, so the search is never performed.)

Text-to-speech functionality with Google TTS (Pico TTS works).

Notes:

If the first-run setup keeps crashing on you: from the language selection (first) screen, tap on the four corners of the screen, proceeding clockwise from top left. This will bypass the first-run setup; you can then set up a Google account manually in Settings. (thanks urko95) (If you are still experiencing this with SP4, please report in this thread. A logcat would be helpful.)

Note also that there won't be much in the way of support -- I do have other things that I really should be doing ...