Push to Focal (#68)

* Push to Focal

adjust example

* Push to Focal, cosmetics

Maybe the video could be renewed. I'll may take a look into that.

* Torrent info

* Link fix

* Update Developer-Guide_Build-Preparation.md

* Missing dot

docs/Developer-Guide_Build-Preparation.md

@@ -4,7 +4,7 @@
 - [VirtualBox](https://www.virtualbox.org/wiki/Downloads) or similar virtualization software **(highly recommended with a minimum of 25GB hard disk space for the virtual disk image)**,
 - Setting up VirtualBox and compile environment is easy following our [Vagrant tutorial](https://docs.armbian.com/Developer-Guide_Using-Vagrant/),
 - [Docker](Developer-Guide_Building-with-Docker.md) environment is also supported for building kernels and full OS images,
-- **The officially supported** compilation environment is [Ubuntu Bionic 18.04 x64](http://archive.ubuntu.com/ubuntu/dists/bionic/main/installer-amd64/current/images/netboot/mini.iso) **only!** (Support for Ubuntu 20.04 is implemented but experimental, no support!),
+- **The officially supported** compilation environment is [Ubuntu Focal 20.04 x64](http://archive.ubuntu.com/ubuntu/dists/focal/main/installer-amd64/current/images/netboot/mini.iso) **only!** (Support for Ubuntu 18.04 will be there until either we run into issues we do not want to waste time on or upstream support ends),
 - installed basic system, OpenSSH and Samba (optional),
 - no spaces in full path to the build script location allowed,
 - superuser rights (configured `sudo` or root shell).
@@ -70,19 +70,18 @@ This is a typical board configuration:
 	MODULES_NEXT="brcmfmac bonding"
 	#
 	KERNEL_TARGET="legacy,current,dev"
-	CLI_TARGET="buster,bionic:current"
+	CLI_TARGET="buster,bionic,focal:current"
 	DESKTOP_TARGET="stretch:legacy,current"
 	
 	CLI_BETA_TARGET=""
 	DESKTOP_BETA_TARGET=""
 	#
-	RECOMMENDED="Ubuntu_bionic_legacy_desktop:90,Debian_stretch_current:100"
-	#
 	BOARDRATING=""
 	CHIP="http://docs.armbian.com/Hardware_Allwinner-A20/"
 	HARDWARE="https://linux-sunxi.org/Banana_Pi"
 	FORUMS="https://forum.armbian.com/forum/7-allwinner-a10a20/"
 	BUY="http://amzn.to/2fToHjR"
+You can find more information about those variables [here](https://github.com/armbian/build/blob/master/config/boards/README.md).
 
 If you want that our automated system start making images for this particular board, you need to alter parameters `CLI_BETA_TARGET` and `DESKTOP_BETA_TARGET`.
 Variants are depenendend from `KERNEL_TARGET` definitions and supported userlands: `buster`, `bionic`, `stretch`.

docs/Developer-Guide_Build-Process.md

@@ -1,31 +1,31 @@
-# What is behind the build process?
+# What happens behind the build process?
 
-Build process summary:
+### Build process summary:
 
-- creates development environment on top of AMD64 Ubuntu 16.04 LTS,
-- downloads proven sources, applies patches and uses tested configurations,
-- cross-compiles universal boot loader (u-boot), kernel and other tools and drivers,
-- packs kernel, uboot, dtb and root customizations into debs,
-- debootstraps minimalistic Debian Wheezy, Jessie and Ubuntu Trusty into SD card image,
+- creates development environment on top of amd64 Ubuntu 20.04 LTS,
+- downloads proven sources, applies patches on top and uses tested configurations,
+- cross-compiles universal boot loader (***U-Boot***), kernel and other tools and drivers,
+- packs kernel, U-Boot, dtb and root customizations into Debian packages,
+- debootstraps minimalistic Debian Buster and Ubuntu Focal into SD card images,
 - installs additional packets, applies customizations and shrinks image to its actual size.
 
 Check this image [compiling example](https://youtu.be/zeShf12MNLg) with partial cache.
 
-## Creating compile environment ##
 
-At first run we are downloading all necessary dependencies. 
+### Build process details:
+
+## Creating compile environment ##
+First things first. All necessary dependencies are downloaded and installed. This happens though both http and torrent network. Btw. having too much unused traffic? [Help us to reduce ours :)](https://forum.armbian.com/topic/4198-seed-our-torrents/)
 
 ## Using board configuration ##
-
-We need to get some predefined variables about selected board. Which kernel & uboot source to use, modules to load, which is the build number, do we need to have a single partition or dual with boot on fat, which extra drivers to compile out of the kernel tree, ...
+We need to get some predefined variables about selected the board. Which kernel & uboot source to use, modules to load, which is the build number, do we need to have a single partition or dual with boot on fat, which extra drivers to compile out of the kernel tree ...
+All this stuff is predefined for each and every single supported board.
 
 ## Downloading sources ##
-
-When we know where are the sources and where they need to be the download / update process starts. This might take from several minutes to several hours.
+When we know which sources to use and where they need to be the download or updated this process starts. This might take from several minutes to several hours.
 
 ## Patching ##
-
-In patching process we are appling patches to sources. The process is defined in:
+In the patching process we are applying patches to the used sources. The process is - depending on selected board - defined in:
 
 	lib/patch/kernel/sun7i-default
 	lib/patch/kernel/sunxi-dev
@@ -34,46 +34,39 @@ In patching process we are appling patches to sources. The process is defined in
 	lib/patch/u-boot/u-boot-neo-default
 	...
 
-Patch rules for subdirectories are: **KERNEL_FAMILY-BRANCH** for kernel and **U-BOOT-SOURCE-BRANCH** for U-boot.
+Patch rules for subdirectories are: **KERNEL_FAMILY-BRANCH** for kernel and **U-BOOT-SOURCE-BRANCH** for U-Boot.
 
 ## Debootstrap ##
-
 Debootstrap creates fresh Debian / Ubuntu root filesystem templates or use cached under:
 
 	output/cache/rootfs/
 
 To recreate those files you need to remove them manually. 
+From time to time they will be recreated anyway if Armbian updates their rootfs cache.
 
 ## Kernel install ##
-
-When root filesystem is ready we need to install kernel image with modules, board definitions, firmwares. Along with this we set the CPU frequency min/max, hostname, modules, network interfaces templates. Here is also the place to install headers and fix + native compile them on the way.
+When the root filesystem is ready we need to install the kernel image with modules, board definitions and firmwares. Along with this we set the CPU frequency min/max, hostname, modules, network interfaces templates. Here is also the place to install headers and fix + native compile them on the way.
 
 ## Distribution fixes ##
-
-Each distributin has it's own way of doing things:
+Each distribution has it's own way of doing things:
 
 - serial console
 - different packets
 - configuration locations
 
 ## Board fixes ##
-
 Each board has their own tricks: **different device names, firmware loaders, configuration (de)compilers, hardware configurators**
 
 ## Desktop installation ##
-
-You can build a desktop withing the image. Consider this feature as experimental. Hardware acceleration on Allwinner boards is working within kernel 3.4.x only.
+You can build a desktop environment withing the image. Consider this feature as experimental. Do not expect to have working hardware acceleration since this is a very complicated task and needs individial care for different boards.
 
 ## External applications ##
-
-This place is reserved for custom applications. There is one example of application - USB redirector.
+This place is reserved for custom applications. There is one example of application: USB redirector.
 
 ## Closing image ##
-
 There is an option to add some extra commands just before closing an image which is also automaticaly shrink to it's actual size with some small reserve.
 
 ## Directory structure ##
-
 It will be something like this:
 
     compile.sh				compile execution script