在tiny210的板子上编译android源文件的时候，按照你们手册的步骤，在./build-android 时遇到如下的错误警告，请问怎么修改环境变量？我自己安装jdk后然后再执行./build-android可不可以？
另外，是不是你们开发手册上只是介绍了编译android源文件，并没有介绍编译android前系统编译环境的搭建？我们需要自己搭建好编译环境，再执行./build-android么？
初次接触android请多多指教！
[root@localhost Android-2.3.1]# ./build-android
including device/htc/passion/vendorsetup.sh
including device/samsung/smdkc110/vendorsetup.sh
including device/samsung/smdkv210/vendorsetup.sh
============================================
PLATFORM_VERSION_CODENAME=REL
PLATFORM_VERSION=2.3.1
TARGET_PRODUCT=full_mini210
TARGET_BUILD_VARIANT=eng
TARGET_SIMULATOR=false
TARGET_BUILD_TYPE=release
TARGET_BUILD_APPS=
TARGET_ARCH=arm
HOST_ARCH=x86
HOST_OS=linux
HOST_BUILD_TYPE=release
BUILD_ID=GINGERBREAD
============================================
which: no javac in (/opt/FriendlyARM/tiny210/android/Android-2.3.1/jdk1.6.0_23/bin:/usr/lib/qt-3.3/bin:/usr/lib/ccache:/usr/local/sbin:/usr/sbin:/sbin:/usr/local/bin:/usr/bin:/bin:/opt/FriendlyARM/toolschain/4.5.1/bin:/root/bin:/opt/FriendlyARM/toolschain/4.5.1/bin)
Checking build tools versions...
build/core/main.mk:76: ************************************************************
build/core/main.mk:77: You are attempting to build on a 32-bit system.
build/core/main.mk:78: Only 64-bit build environments are supported beyond froyo/2.2.
build/core/main.mk:79: ************************************************************
************************************************************
You are attempting to build with the incorrect version
of javac.
Your version is: /bin/bash: javac: command not found.
The correct version is: 1.6.
Please follow the machine setup instructions at
http://source.android.com/download************************************************************
build/core/main.mk:145: *** stop. Stop
