firefly@firefly:/opt$ sudo apt-get install linux-source
Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Unable to locate package linux-source
firefly@firefly:/opt$ sudo apt install git
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Package git is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'git' has no installation candidate
firefly@firefly:/opt$ 
firefly@firefly:/opt$ 
firefly@firefly:/opt$ ffgo
Usage:
	 ffgo : 	show this usage
	 ffgo update: 	update ffgo
	 ffgo version: 	get version
	 ffgo cmdlist: 	get support cmd list
	 ffgo [cmd]: 	run cmd in cmd list
firefly@firefly:/opt$ ffgo version
OS:	 Ubuntu 20.04.3 LTS
MODEL:	 Firefly-RK3399 Board (Linux Opensource)
FIREFLY: v2.10-62-g087b2b2
DATE:	 20211228-1443
KERNEL:	 Linux version 4.4.194+ (jincheng@jincheng-PC) (local/new/internal-gitlab/rk3399/firefly: bcd190d4221dcefe664a1fe9aebe17819db54b22) (gcc version 6.3.1 20170404 (Linaro GCC 6.3-2017.05) ) #10 SMP Wed Dec 29 13:16:09 CST 2021

firefly@firefly:/opt$ sudo apt-get install build-essential lzop libncurses5-dev libssl-dev
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Package build-essential is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'build-essential' has no installation candidate
E: Unable to locate package lzop
E: Unable to locate package libncurses5-dev
E: Unable to locate package libssl-dev
firefly@firefly:/opt$ 
