Arm-Linux 移植 Ubuntu

前言：

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)

2. Build in a removable media device, such as: SDCard or UDisk

3. Build in the target device directly 【current article】

Before starting

Carry on the following questions before you start your work:

Q: What is included in an ubuntu system?

A: Bootloader & ramfs(kernel + initrd) & rootfs

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

1. Download the bootloader source code

$ git clone https://github.com/geekboxzone/lollipop_u-boot u-boot

1. Download the linux kernel source code

$ git clone https://github.com/geekboxzone/lollipop_kernel -b ubuntu linux

1. 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*

1. Download the initrd

$ git clone https://github.com/gouwa/initrd.git initrd

1. Download the hardware packages for Geekbox

$ git clone https://github.com/geekboxzone/ubuntu_hwpacks.git archives/hwpacks

1. 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]

1. 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

1. 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:
```bash
$ 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 bootloader

1. Compile:

$ make rk3368_box_defconfig -C u-boot/$ make ARCHV=aarch64 -C u-boot/

1. 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 ramdisk

1. 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

1. Copy the images to the image directory:

$ cp -a linux/resource.img images/

1. 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

1. Generate the ramfs.img

$ mkbootimg --kernel linux/arch/arm64/boot/Image --ramdisk images/initrd.img -o images/ramfs.img

Build the rootfs

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.

1. 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]

1. Confirm that rootfs is an empty directory!!!

$ rm -rf rootfs && mkdir rootfs

1. Loop mount the the new image:

$ sudo mount -o loop images/rootfs.img rootfs

1. Remove the unnecessary files

$ sudo rm -rf rootfs/lost+found

1. 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.

1. Add hardware packages

$ sudo cp -a archives/hwpacks/system/ rootfs/

1. 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:
```bash
$ 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

1. 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

1. Download the parameter

$ upgrade_tool di -p utils/rockdev/parameter

1. Download the U-Boot second-level loader

$ upgrade_tool di uboot images/uboot.img$ upgrade_tool di trust images/trust.img

1. Download the resource.img

$ upgrade_tool di resource images/resource.img

1. Download the ramfs.img

$ upgrade_tool di ramfs images/ramfs.img

1. Download the rootfs.img

$ upgrade_tool di linuxroot images/rootfs.img

1. 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/eth0
root@Geekbox:~# echo iface eth0 inet dhcp >> /etc/network/interfaces.d/eth0
root@Geekbox:~# ln -fs /run/resolvconf/resolv.conf /etc/resolv.conf
root@Geekbox:~# ifup eth0

1. 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].

1. Install desktop packages

root@Geekbox:~# apt-get update
root@Geekbox:~# apt-get upgrade
root@Geekbox:~# apt-get install ubuntu-desktop

1. [Optional]For bad network environment, such as: China.

Backup the ubuntu deb packages:

root@Geekbox:~# apt-get install openssh-server
root@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.

1. 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]