这篇文章介绍如何构建一个完整基于ARM的Ubuntu系统。
由于改文章当初写的时候是发表在国外产品论坛上面，故保留了原文内容。
使用到的硬件平台：Geekbox
补充说明：
虽然Geekbox是基于8核64Bits Cortex-A53 ARMV8架构的CPU，该方法构建的时候采用了向下兼容的32Bits的ARMV7架构。因此，该方法适用于Cortex-A7/A9/A15/A17/A12架构的ARM处理器。
In this guide, we will describe how to build an ubuntu system for Geekbox from scratch.
Different ways to achieve it:
1. Build the whole system in host PC with Chroot(emulator)
Link: TBD
2. Build in a removable media device, such as: SDCard or UDisk
Link: TBD
3. Build in the target device directly
Link: current article
Before startingCarry on the following questions before you start your work:
1. Q: armhf vs arm64
A: Google for the answer
2. Q: Ubuntu vs Lubuntu/Kubuntu
A: Google for the answer
3. Q: What is included in an ubuntu system?
A: Bootloader & ramfs(kernel + initrd) & rootfs
4. Q: how to manage your ubuntu projects
A: Continue current reading and think about your own manage mothod.
Preparations
1. Create the working directories
$ install -d ~/project/geekbox/ubuntu/{linux,initrd,rootfs,prebuilts,archives/{ubuntu-core,debs,hwpacks},images,utils,scripts}$ cd ~/project/geekbox/ubuntu
2. Download the bootloader source code
$ git clone https://github.com/geekboxzone/lollipop_u-boot u-boot
3. Download the linux kernel source code
$ git clone https://github.com/geekboxzone/lollipop_kernel -b ubuntu linux
4. Download the toolchain
$ git clone https://github.com/geekboxzone/lollipop_prebuilts_gcc_linux-x86_aarch64_aarch64-linux-android-4.9.git prebuilts/gcc/linux-x86/aarch64/aarch64-linux-android-4.9/
Note the full path of 'prebuilts/gcc/linux-x86/arm/arm-eabi-4.6', just to keep Makefile@linux happy
5. Download the initrd
$ git clone https://github.com/gouwa/initrd.git initrd
6. Download the hardware packages for Geekbox
$ git clone https://github.com/geekboxzone/ubuntu_hwpacks.git archives/hwpacks
7. Download the ubuntu-core
$ wget -P archives/ubuntu-core http://cdimage.ubuntu.com/ubuntu-core/releases/14.04.3/release/ubuntu-core-14.04.3-core-armhf.tar.gz
Visit the following link for the more versions:
[url]http://cdimage.ubuntu.com/ubuntu-core/releases[/url]
8. Download the rockchip upgrade tool, note to specify the 'ubuntu' branch:
$ git clone https://github.com/geekboxzone/utils.git -b ubuntu utils
[Optional]If you want to run the command in any path:
$ sudo cp -a utils/upgrade_tool /usr/local/bin
9. Download the rockchip mkbootimg tools
$ git clone https://github.com/neo-technologies/rockchip-mkbootimg.git mkbootimg
Build and install mkbootimg tools:
$ make -C mkbootimg/$ sudo make install -C mkbootimg/
The above steps will generate some files in /usr/local/bin/
See utils/mkbootimg/README.md file for more information
All the preparatory works above are necessary to build an ubuntu.
And we also offter some scripts to do thus work:
10. [Optional]Download the scripts:
$ git clone https://github.com/geekboxzone/ubuntu_scripts.git scripts
All the steps above just need to run one time, even if you will build the Ubuntu system many times.
Build the bootloader1. Compile:
$ make rk3368_box_defconfig -C u-boot/$ make ARCHV=aarch64 -C u-boot/
2. Copy the images to the image directory:
$ cp -a u-boot/RK3368MiniLoaderAll_V*.bin u-boot/uboot.img u-boot/trust.img images/
Build the initial ramdisk1. Compile the kernel
$ alias Make='make ARCH=arm64'$ Make -C linux ugeekbox_defconfig$ Make -C linux geekbox.img -j8
or 7.9-inch CrossDisplay
$ Make -C linux cross.img -j8
2. Copy the images to the image directory:
$ cp -a linux/resource.img images/
3. Compile the initrd
$ make -C initrd
SHA match for u-boot:
$ truncate -s '%4' images/initrd.img
View SecureNSModeBootImageShaCheck() function in following file for the information:
u-boot/board/rockchip/common/SecureBoot/SecureVerify.c
4. Generate the ramfs.img
$ mkbootimg --kernel linux/arch/arm64/boot/Image --ramdisk images/initrd.img -o images/ramfs.img
[b]Build the rootfs[/b]
Notice: Many following steps need the root privileges, do not forget to type sudo if necessary.
1. Create a blank image file using dd:
$ dd if=/dev/zero of=images/rootfs.img bs=1M count=256
Modify the count value as you want.
NOTE: if you want to build the rootfs on the host PC, recommend 2.5GB for GUI building.
2. Create linux filesystem on the newly created image:
$ mkfs.ext4 -F -L linuxroot images/rootfs.img
Notice: 'linuxroot' is the volume-label of the rootfs, it MUST BE EXACTLY MATCH the CMDLINE in parameter:
CMDLINE: console=ttyS2 root=LABEL=linuxroot
Otherwise, there will be similar mistakes as follow when mount the rootfs:
[quote]Gave up waiting for root device. Common problems:
- Boot args (cat /proc/cmdline)
- Check rootdelay= (did the system wait long enough?)
- Check root= (did the system wait for the right device?)
- Missing modules (cat /proc/modules; ls /dev)
ALERT! /dev/disk/by-label/
does not exist. Dropping to a shell!
(initramfs)[/quote]
3. Confirm that rootfs is an empty directory!!!
$ rm -rf rootfs && mkdir rootfs
4. Loop mount the the new image:
$ sudo mount -o loop images/rootfs.img rootfs
5. Remove the unnecessary files
$ sudo rm -rf rootfs/lost+found
6. Extract the ubuntu-core tarball into the mounted dir:
$ sudo tar xzf archives/ubuntu-core/ubuntu-core-14.04.3-core-armhf.tar.gz -C rootfs/
Tips: ubuntu-core is the minimal root file system.
7. Add hardware packages
$ sudo cp -a archives/hwpacks/system/ rootfs/
8. Add Wifi & Bluetooth support
$ sudo cp archives/hwpacks/wifibt/wifion rootfs/usr/local/bin/$ sudo cp archives/hwpacks/wifibt/wifioff rootfs/usr/local/bin/$ sudo cp archives/hwpacks/wifibt/wifi.conf rootfs/etc/init$ sudo cp archives/hwpacks/wifibt/bluetooth.conf rootfs/etc/init$ sudo cp archives/hwpacks/wifibt/bluetooth-ap6354.conf rootfs/etc/init
9. Setup serial console, booting as root user:
$ sudo sed -e 's/tty1/ttyS2/g' -e '/^exec/c exec /sbin -a root -L 115200 ttyS2 vt100' < rootfs/etc/init/tty1.conf=""> ttyS2.conf$ sudo mv ttyS2.conf rootfs/etc/init/ttyS2.conf
10. Setup the hostname:
$ echo Geekbox > hostname$ sudo mv hostname rootfs/etc/hostname
Congratulations!
At this point, you have completed all the minimal-ubuntu images.
And so, all you should do is to burn these images down to device.
Download the images
1. Download the U-Boot first-level loader
$ upgrade_tool ul images/RK3368MiniLoaderAll_V2.40.bin
2. Download the parameter
$ upgrade_tool di -p utils/rockdev/parameter
3. Download the U-Boot second-level loader
$ upgrade_tool di uboot images/uboot.img$ upgrade_tool di trust images/trust.img
4. Download the resource.img
$ upgrade_tool di resource images/resource.img
5. Download the ramfs.img
$ upgrade_tool di ramfs images/ramfs.img
6. Download the rootfs.img
$ upgrade_tool di linuxroot images/rootfs.img
7. Boot the device
$ upgrade_tool rd
Notice: root access is necessary if you haven't setup udev rules.
View our Wiki for more information:
[url]http://forum.geekbox.tv/viewtopic.php?f=2&t=42[/url]
Graphic desktop environment
NOTE: The following commands need run on your Geekbox target!
1. Plug-in a cable, then setup the network:
root@Geekbox:~# echo auto eth0 > /etc/network/interfaces.d/eth0root@Geekbox:~# echo iface eth0 inet dhcp >> /etc/network/interfaces.d/eth0root@Geekbox:~# ln -fs /run/resolvconf/resolv.conf /etc/resolv.confroot@Geekbox:~# ifup eth0
2. Extend the root partition:
root@Geekbox:~# resize2fs /dev/disk/by-label/linuxroot
Tips: the default volume size of root partition is specify in the first step of [Build the rootfs].
3. Install desktop packages
root@Geekbox:~# apt-get updateroot@Geekbox:~# apt-get upgraderoot@Geekbox:~# apt-get install ubuntu-desktop
4. [Optional]For bad network environment, such as: China.
Backup the ubuntu deb packages:
root@Geekbox:~# apt-get install openssh-serverroot@Geekbox:~# scp /var/cache/apt/archives/*.deb gouwa@192.168.1.168:project/geekbox/ubuntu/archives/debs
If you did this, next time when you rebuilt the ubuntu system,
you can manually pull the deb packages into the apt debs archives path of target-device:
root@Geekbox:~# scp gouwa@192.168.1.168:project/geekbox/ubuntu/archives/debs/*.deb /var/cache/apt/archives/root@Geekbox:~# apt-get update && apt-get upgrade && apt-get install ubuntu-desktop
This will save you a lot of time to download them from the website.
5. Reboot and enjoy your hard but challenging work
root@Geekbox:~# reboot
T.B.D.
1> ubuntu system depth optimization
2> Building the arm64 ubuntu system
References
1. [url]http://androtab.info/miniroot/[/url]
2. [url]http://androtab.info/radxa_rock/ubuntu/[/url]
3. [url]http://wiki.radxa.com/Rock/ubuntu[/url]
4. [url]http://wiki.t-firefly.com/index.php/Firefly-RK3288/en[/url]
5. [url]https://wiki.ubuntu.com/ARM/RootfsFromScratch[/url]
6. [url]https://github.com/neo-technologies/rockchip-mkbootimg[/url]
7. [url]https://github.com/neo-technologies/rkflashtool.git[/url]
8. [url]https://wiki.debian.org/initramfs[/url]
9. [url]http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/filesystems/ramfs-rootfs-initramfs.txt?id=HEAD[/url]
