Building for devices

This page complements the main page about Building with information that is specific to individual devices.

The only supported devices are Nexus S, a.k.a. "crespo", and Nexus S 4G, a.k.a. "crespo4g". Nexus S is the recommended device to use with the Android Open-Source Project. Nexus One a.k.a. "passion" is experimentatal and unsupported. Android Developer Phones (ADP1 and ADP2, a.k.a. "dream" and "sapphire") are obsolete, were experimental and unsupported in froyo, and can't be used with gingerbread.

Building fastboot and adb

If you don't already have those tools, fastboot and adb can be built with the regular build system. Follow the instructions on the page about building, and replace the main make command with

$ make fastboot adb

Booting into fastboot mode

During a cold boot, the following key combinations can be used to boot into fastboot mode, which is a mode in the bootloader that can be used to flash the devices:

Device Keys
crespo Press and hold Volume Up, then press and hold Power
crespo4g Press and hold Volume Up, then press and hold Power
passion Press and hold the trackball, then press Power
sapphire Press and hold Back, then press Power
dream Press and hold Back, then press Power

Also, on devices running froyo or later where adb is enabled, the command adb reboot bootloader can be used to reboot from Android directly into the bootloader with no key combinations.

Unlocking the bootloader

It's only possible to flash a custom system if the bootloader allows it.

This is the default setup on ADP1 and ADP2.

On Nexus One, Nexus S, and Nexus S 4G, the bootloader is locked by default. With the device in fastboot mode, the bootloader is unlocked with

$ fastboot oem unlock

The procedure must be confirmed on-screen, and deletes the user data for privacy reasons. It only needs to be run once.

On Nexus One, the operation voids the warranty and is irreversible.

On Nexus S and Nexus S 4G, the bootloader can be locked back with

$ fastboot oem lock

Obtaining proprietary binaries

While it's possible to build and run a system using exclusively source code from Android Open-Source Project, such a system can only use the devices' hardware capabilities for which Open-Source support exists.

Official binaries for Nexus S and Nexus S 4G can be downloaded from Google's Nexus driver page, which add access to additional hardware capabilities with non-Open-Source code.

There are no official binaries for Nexus One, ADP2 or ADP1.

Extracting the proprietary binaries

Each driver comes as a self-extracting script in a compressed archive. After uncompressing each archive, run the included self-extracting script from the root of the source tree, confirm that you agree to the terms of the enclosed license agreement, and the binaries and their matching makefiles will get installed in the vendor/ hierarchy of the source tree.

There's an additional step on Nexus S 4G. Build the signapk tool with

$ make signapk

Then reassemble the proprietary applicatons with

$ vendor/samsung/crespo4g/reassemble-apks.sh

Cleaning up when adding proprietary binaries

In order to make sure that the newly installed binaries are properly taken into account after being extracted, the existing output of any previous build needs to be deleted with

$ make clobber

Picking and building the configuration that matches a device

The steps to configure and build the Android Open-Source Project are described in the page about Building.

The recommended builds for the various devices are available through the lunch menu, accesed when running the lunch command with no arguments:

Device Build configuration
crespo full_crespo-userdebug
crespo4g full_crespo4g-userdebug
passion full_passion-userdebug
sapphire full_sapphire-userdebug
dream full_dream-userdebug

Flashing a device

Set the device in fastboot mode if necessary (see above).

Because user data is typically incompatible between builds of Android, it's typically better to delete it when flashing a new system.

$ fastboot erase cache
$ fastboot erase userdata

An entire Android system can be flashed in a single command: this writes teh boot, recovery and system partitions together after verifying that the system bring flashed is compatible with the installed bootloader and radio, and reboots the system.

$ fastboot flashall

On crespo, crespo4g, sapphire and dream (but not on passion), the commands above can be replaced with a single command

$ fastboot -w flashall

Nexus S and Nexus S 4G Bootloader and Cell Radio compatibility

On Nexus S and Nexus S 4G, each version of Android has only been thoroughly tested with on specific version of the underlying bootloader and cell radio software. However, no compatibility issues are expected when running newer systems with older bootloaders and radio images according to the following tables.

Nexus S:

Android Version Preferred Bootloader Preferred Radio Also possible
2.3 to 2.3.2 I9020XXJK1 I9020XXJK8
2.3.3 I9020XXKA3 I9020XXKB1 All previous versions
2.3.4 I9020XXKA3 I9020XXKD1 All previous versions

Nexus S 4G:

Android Version Preferred Bootloader Preferred Radio Also possible
2.3.4 (GRJ06D) D720SPRKC5 D720SPRKC9
2.3.4 (GRJ22) D720SPRKC5 D720SPRKD8 All previous versions

If you're building a new version of Android, if your Nexus S or Nexus S 4G has an older bootloader and radio image that is marked as being also possible in the table above but is not recognized by the build system, you can locally delete the version-bootloader and version-baseband lines in device/samsung/crespo/board-info.txt or device/samsung/crespo4g/board-info.txt.