Raspberry Pi 2B(树莓派)具有4个Cortex-A7 CPU, 1G的内存空间,使用TF卡作为存储介质,一个百兆有线网卡,40Pin的GPIO, 4个USB接口。Brillo系统跑在上面一点问题都没有。
NOTE:
编译出来的系统只能在Raspberry Pi 2B上运行,其他的硬件版本是不支持的:CPU的指令集不同(需要armv7-a指令集)。
- 配置编译环境
相关的文档可以参考:http://source.android.com/source/initializing.html
编译用的主机要求是x64平台,运行ubuntu 14.04系统, 2G以上的内存, 60G以上的剩余空间
安装java 7(可选, 如果想编译Android项目的话,还是安装一下好):
$ sudo apt-get update $ sudo apt-get install openjdk-7-jdk
安装其他需要用到的文件:
$ sudo apt-get install git-core gnupg flex bison gperf build-essential \ zip curl zlib1g-dev gcc-multilib g++-multilib libc6-dev-i386 \ lib32ncurses5-dev x11proto-core-dev libx11-dev lib32z-dev ccache \ libgl1-mesa-dev libxml2-utils xsltproc unzip
配置USB访问权限:
$ wget -S -O - http://source.android.com/source/51-android.rules | \ sed "s/<username>/$USER/" | \ sudo tee >/dev/null /etc/udev/rules.d/51-android.rules; \ sudo udevadm control --reload-rules
- 代码下载
相关的文档可以参考:http://source.android.com/source/downloading.html
安装repo:
$ mkdir ~/bin $ PATH=~/bin:$PATH $ curl https://storage.googleapis.com/git-repo-downloads/repo > ~/bin/repo $ chmod a+x ~/bin/repo
brillo原生系统代码及Raspberry Pi 2B linux kernel 代码下载:
$ mkdir -pv /local/brillo-m8-release && cd /local/brillo-m8-release $ ~/bin/repo init -u https://android.googlesource.com/brillo/manifest -b brillo-m8-release
删除.repo/manifest.xml并将这个文件brillo-m8-release-for-rpi2b.xml.zip 解压并考贝到.repo/manifest.xml (替换),brillo原生系统使用的是brillo-m8-release这个分支,而Raspberry Pi 2B kernel使用的是rpi-4.1.y分支:
$ rm .repo/manifest.xml $ wget https://www.brobwind.com/wp-content/uploads/2015/12/brillo-m8-release-for-rpi2b.xml_.zip && unzip brillo-m8-release-for-rpi2b.xml_.zip $ cp brillo-m8-release-for-rpi2b.xml .repo/manifest.xml $ ~/bin/repo sync -j 4
下载的代码约有13G, 漫长的等待。。。
Raspbrery Pi 2B设备相关的文件请从这里下载:brillo-m8-device-hzak-rpi2b.tar.gz
$ curl https://www.brobwind.com/wp-content/uploads/2015/12/brillo-m8-device-hzak-rpi2b.tar.gz | tar -zxvf -
由于Raspberry Pi 2B默认的kernel配置,编译出来的kernel虽然能够正常开机,但是系统的一些服务会出现非正常退出的情况,所以还需要更新一下kernel的配置文件bcm2709_defconfig:
cp device/hzak/rpi/bsp/kernel-config hardware/bsp/kernel/hzak/rpi-4.1.y/arch/arm/configs/bcm2709_defconfig
- 编译
$ . build/envsetup.sh $ lunch rpi-eng $ make -j 4
又是漫长的等待。。。
- 下载
先对SD卡进行分区,并进行格式化。需要3个分区, 第一个分区存放bootcode.bin, config.txt, start.elf, fixup.dat, cmdline.txt, kernel7.img, ramdisk7.img;第二个区公为系统分区:会写入system.img;第三个分区为data分区,用于存放运行时的配置文件等。
可以参考这个(一定要知道SD卡是属于哪个设备文件, 可以用dmesg | tail 查看):
$ sudo fdisk /dev/sd? Command (m for help): o Building a new DOS disklabel with disk identifier 0x29767d95. Changes will remain in memory only, until you decide to write them. After that, of course, the previous content won't be recoverable. Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite) Command (m for help): n Partition type: p primary (0 primary, 0 extended, 4 free) e extended Select (default p): Using default response p Partition number (1-4, default 1): Using default value 1 First sector (2048-15523839, default 2048): 8192 Last sector, +sectors or +size{K,M,G} (8192-15523839, default 15523839): +400M Command (m for help): n Partition type: p primary (1 primary, 0 extended, 3 free) e extended Select (default p): Using default response p Partition number (1-4, default 2): Using default value 2 First sector (2048-15523839, default 2048): 827392 Last sector, +sectors or +size{K,M,G} (827392-15523839, default 15523839): +112M Command (m for help): n Partition type: p primary (2 primary, 0 extended, 2 free) e extended Select (default p): Using default response p Partition number (1-4, default 3): Using default value 3 First sector (2048-15523839, default 2048): 1056768 Last sector, +sectors or +size{K,M,G} (1056768-15523839, default 15523839): +512M Command (m for help): p Disk /dev/sd?: 7948 MB, 7948206080 bytes 245 heads, 62 sectors/track, 1021 cylinders, total 15523840 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x29767d95 Device Boot Start End Blocks Id System /dev/sd?1 8192 827391 409600 83 Linux /dev/sd?2 827392 1056767 114688 83 Linux /dev/sd?3 1056768 2105343 524288 83 Linux Command (m for help): w The partition table has been altered! Calling ioctl() to re-read partition table. Syncing disks.
可以看到/dev/sd?1为linux分区(id为83),一定要将其改成b (FAT32)分区,不然系统无法识别,开不了机。
下面是格式化分区:
$ sudo mkfs.vfat /dev/sd?1 $ sudo mkfs.ext4 /dev/sd?3
挂载/dev/sd?1分区,将out/target/product/rpi/boot中的文件copy过去,再将kernel, ramdisk.img也copy过去:
$ sudo mount /dev/sd?1 /mnt/ $ sudo cp out/target/product/rpi/boot/* /mnt/ $ sudo cp out/target/product/rpi/kernel /mnt/kernel7.img $ sudo cp out/target/product/rpi/ramdisk.img /mnt/ramdisk7.img $ sudo umount /mnt $ sync
接着将system.img写到/dev/sd?2分区中(一定要按照下面的方法进行操作,如果进行mount, cp, umount的操作,开机的时候会出现意想不到的问题,因为system.img中的文件是有SELinux context的,使用cp命令无法进行完整的将SELinux context copy过去; SELinux context可以通过ls -Z or ps -Z查看):
$ sudo dd if=out/target/product/rpi/system.img of=/dev/sd?2 $ sync
做完这些,你就可以将TF卡插入Raspberry Pi 2B上开机运行了。
- 运行
将Raspberry Pi 2B通过网线连入局域网,它会自动去获取IP地址。由于设备上有avahi-daemon, 所以可以PC可以通过avahi-browser来查找 它所分配的IP地址:
$ avahi-browse -a -r + eth0 IPv4 FD396216-7C5D-4D61-96E2-EFEB4B2113A9 _privet._tcp local = eth0 IPv4 FD396216-7C5D-4D61-96E2-EFEB4B2113A9 _privet._tcp local hostname = [linux.local] address = [10.0.0.13] port = [80] txt = ["note=brillo @ rpi" "flags=CA" "mmid=AAAAA" "id=764EEAA2-3183-48DF-8849-185E2EB30F0D" "services=vendor" "ty=rpi" "txtvers=3"]
我们可以看到设备的IP地址为10.0.0.13, 接着就可以查看到设备的信息:
$ curl -H "Authorization: Privet anonymous" http://10.0.0.13/privet/info $ curl -H "Authorization: Privet anonymous" -k https://10.0.0.13/privet/info
- 配置kernel的方法
$ cd hardware/bsp/kernel/hzak/rpi-4.1.y/ $ ARCH=arm CROSS_COMPILE=arm-linux-androideabi- make bcm2709_defconfig $ ARCH=arm CROSS_COMPILE=arm-linux-androideabi- make menuconfig
# 保存当前的配置
$ cp .config arch/arm/config/bcm2709_defconfig
# 最后一定要执行make mrproper, 以删除当前的配置文件和产生的中间文件,
# 不然编译的时候会报错
$ ARCH=arm CROSS_COMPILE=arm-linux-androideabi- make mrproper
官方编译Raspberry Pi 2B的方法,相关文档:
https://github.com/raspberrypi/documentation/blob/master/linux/kernel/building.md
Raspberry Pi 2 Default Build Configuration
cd linux KERNEL=kernel7 make bcm2709_defconfigBuild and install the kernel, modules and Device Tree blobs; this step takes a long time…
make zImage modules dtbs sudo make modules_install sudo cp arch/arm/boot/dts/*.dtb /boot/ sudo cp arch/arm/boot/dts/overlays/*.dtb* /boot/overlays/ sudo cp arch/arm/boot/dts/overlays/README /boot/overlays/ sudo scripts/mkknlimg arch/arm/boot/zImage /boot/$KERNEL.imgNote: On a Raspberry Pi 2, adding -j4 (make -j4 zImage modules dtbs) splits the work between all four cores, speeding up compilation significantly.