Edit: We have now a temporary git repository at gitorious:  http://gitorious.org/replicant

Before starting

• Root your phone
• Backup your current system!!!
• Install git

Setting up the build environment and getting source code

These instructions assume that you are building replicant in your home directory (~). If you are building it in another directory, modify path names accordingly.

Get the repo tool

repo is a front-end to git which is used to manage several git repositories.

 mkdir bin
 cd bin
 wget http://android.git.kernel.org/repo
 chmod a+x repo
 cd ..

Check out the Replicant repository

This step will download the Android source (minus the kernel) and the Replicant patches.

 mkdir replicant
 cd replicant
 ../bin/repo init -u git://gitorious.org/replicant/manifest.git -b replicant
 ../bin/repo sync

Optional: building the kernel and wireless LAN driver

By default, the Android build system uses a pre-compiled kernel and wireless driver rather than compiling these components from scratch. If you want to compile your own copy of either of these components, you have to compile both: the wireless driver sources included with Android are incompatible with the pre-compiled kernel.

Get the kernel source

To download the kernel sources, create a file in your replicant/.repo directory called "local_manifest.xml" containing the following:

<?xml version="1.0" encoding="UTF-8"?>
 <manifest>
  <project path="kernel" name="kernel/msm" revision="refs/heads/android-msm-2.6.27"/>
 </manifest>

Then from the ~/replicant/ directory, run:

../bin/repo sync

This will create a directory called replicant/kernel and download the kernel sources to it.

Build the kernel

To build the kernel:

cd ~/replicant/kernel
export ARCH=arm
export CROSS_COMPILE=arm-eabi-
export PATH=$PATH:~/replicant/prebuilt/linux-x86/toolchain/arm-eabi-4.2.1/bin
cp arch/arm/configs/msm_defconfig .config
make oldconfig && make

Wait several hours.

Point the build system to your kernel

Create a file called ~/replicant/buildspec.mk containing the following:

TARGET_PRODUCT:=htc_dream
TARGET_PREBUILT_KERNEL:=kernel/arch/arm/boot/zImage

This will instruct the build process to use your kernel rather than the pre-compiled kernel.

Build the wifi module

To build the wifi module:

cd ~/replicant/system/wlan/ti/sta_dk_4_0_4_32
export KERNEL_DIR=~/replicant/kernel/
make

(If make can't find your compiler, re-run same PATH export command you ran before compiling the kernel.)

Replace the pre-built wifi module with the one you just built:

cp wlan.ko ~/replicant/vendor/htc/dream-open

Build the firmware

Change the build scripts to include some important missing packages

(This section will be removed once these changes are committed to the replicant repository)

Open the file ~/replicant/vendor/htc/dream-open/htc_dream.mk and at the following text to the beginning of the file:

 PRODUCT_PACKAGES := \
 Calculator \
 Email \
 ImProvider \
 SdkSetup \
 VoiceDialer

This will include packages in the build which would otherwise be missing (including the SdkSetup? package, which will enable incoming calls).

cd ~/replicant
make

Wait and wait and wait.

Flashing the new firmware

[to be written]

Building individual pieces

Each time you want to build something

• open a new console
• Then type:

   cd ~/replicant
   source build/envsetup.sh
   export ANDROID_JAVA_HOME=$JAVA_HOME
   lunch htc_dream-eng
   make
  

• The files to flash are in ~/replicant/out/target/product/dream,flash them and then clear the cache
• boot and push the wifi firmware if you want it

If you want to build a particular project

• open a new console
• build everything if it was not done before
• Then type:

   cd ~/replicant
   source build/envsetup.sh
   export ANDROID_JAVA_HOME=$JAVA_HOME
   lunch htc_dream-eng
   #go into the directory containing an Android.mk
   mm
  

error workarrounds

hyts_Foo.c

if you have:

target Java: SettingsProvider (out/target/common/obj/APPS/SettingsProvider_intermediates/classes)
target Java: Settings (out/target/common/obj/APPS/Settings_intermediates/classes)
java.util.zip.ZipException: duplicate entry: hyts_Foo.c
	at java.util.zip.ZipOutputStream.putNextEntry(ZipOutputStream.java:192)
	at java.util.jar.JarOutputStream.putNextEntry(JarOutputStream.java:109)
	at sun.tools.jar.Main.addFile(Main.java:731)
	at sun.tools.jar.Main.update(Main.java:585)
	at sun.tools.jar.Main.run(Main.java:220)
	at sun.tools.jar.Main.main(Main.java:1167)
make: *** [out/target/common/obj/JAVA_LIBRARIES/core-tests_intermediates/javalib.jar] Error 1
make: *** Deleting file `out/target/common/obj/JAVA_LIBRARIES/core-tests_intermediates/javalib.jar'
make: *** Waiting for unfinished jobs....
Note: frameworks/base/packages/SettingsProvider/src/com/android/providers/settings/DatabaseHelper.java uses or overrides a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
Note: Some input files use or override a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
Note: Some input files use or override a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
Note: Some input files use unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
Note: Some input files use or override a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
Note: Some input files use unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.

do that:

rm -f dalvik/libcore/luni/src/test/resources/hyts_Foo.c

And it will continue to build

Note that that:

rm -rf dalvik/libcore/dom/src/test/resources/*
rm -rf dalvik/libcore/xml/src/test/resources/*

didn't work

The workarrounds came from  here and  here

No rule to make target `development/data/etc/apns-conf_sdk.xml'

if you have:

make: *** No rule to make target `development/data/etc/apns-conf_sdk.xml', needed by `out/target/product/dream-open/system/etc/apns-conf.xml'.  Stop.
make: *** Waiting for unfinished jobs....

simply re-type make and it should continue