raspberry4b install cartographer_ros

Install ubuntu18.04

flow:https://jamesachambers.com/raspberry-pi-4-ubuntu-server-desktop-18-04-3-image-unofficial/
attention:
1.raspberry pi 4 must update Bootloader Firmware First (using Raspbian)
2.use win32DiskImage flush buntu-18.04.3-preinstalled-server-arm64+raspi4.img.xz to sd card

use Updater.sh

sudo ./Updater.sh

update hosts

sudo gedit /etc/host

then restart

sudo /etc/init.d/networking restart

ubuntu update sources

use tinghua sources update sources.list：

1. back sources.list

   sudo cp /etc/apt/sources.list /etc/apt/sources.list.origin

2. copy upder code to sources.list and save

## Note, this file is written by cloud-init on first boot of an instance
## modifications made here will not survive a re-bundle.
## if you wish to make changes you can:
## a.) add 'apt_preserve_sources_list: true' to /etc/cloud/cloud.cfg
##     or do the same in user-data
## b.) add sources in /etc/apt/sources.list.d
## c.) make changes to template file /etc/cloud/templates/sources.list.tmpl

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports bionic main restricted
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports bionic main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports bionic-updates main restricted
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports bionic-updates main restricted

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports bionic universe
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports bionic universe
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports bionic-updates universe
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports bionic-updates universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu 
## team, and may not be under a free licence. Please satisfy yourself as to 
## your rights to use the software. Also, please note that software in 
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports bionic multiverse
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports bionic multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports bionic-updates multiverse
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports bionic-updates multiverse

## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports bionic-backports main restricted universe multiverse
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports bionic-backports main restricted universe multiverse

deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports bionic-security main restricted
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports bionic-security main restricted
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports bionic-security universe
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports bionic-security universe
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports bionic-security multiverse
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports bionic-security multiverse

## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
# deb http://archive.canonical.com/ubuntu bionic partner
# deb-src http://archive.canonical.com/ubuntu bionic partner

install remote desktop

sudo apt install xrdp
sudo gedit /etc/xrdp/startwm.sh

then comment out the last two lines,add new line:

gnome-session

install ros

flow:http://wiki.ros.org/melodic/Installation/Ubuntu