Add scripts to make 32bit and 64 bit os image

[tk26eng]

This PR is for adding configurations for docker and scripts which can run on the docker to make rootfs of Ubuntu.

Motivation and Context

Now we want to support new os Ubuntu (bionic) as next distribution and 32bit and 64bit ARM CPU should be supported with them. I created docker configurations and some useful scripts to generate rootfs of Ubuntu.

Description

To know how to generate rootfs actually, please see docs/install/make_rootfs.md. I'll merge the contents of the file to Blueoil document after all required things like kernel or kernel modules are ready.

How has this been tested?

Test has been performed on host machine of Ubuntu 16.04. On the host, following commands were performed.

cd blueoil/
make rootfs-armhf
make rootfs-arm64

After these commands, we can see the generated files (rootfs_armhf.tgz and rootfs_arm64.tgz) under blueoil/dlk/hw/make_os/build.
About rootfs_armhf.tgz, I tested it on DE10-Nano with kernel of Blueoil's OS image.
About rootfs_arm64.tgz, I tested it on Ultra96v2 with test kernel for Ultra96v2 (This is not merged yet).
In those two environment, generated Ubuntu worked well.

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature / Optimization (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.

[iizukak]

@tk26eng
How about to use blueoil/Makefile ?

Add target to Makefile to create docker image and rootfs.

For example,

make os-docker
make rootfs-32
make rootfs-64

And we want to unity the document directory to blueoil/docs.

[hadusam]

Commented, please check them! 👍

[tk26eng]

@hadusam
I fix all, so please check it again.

[iizukak]

@hadusam How about this PR?

[hadusam]

@iizukak Oh, sorry for late. I will check this!

[iizukak]

@tk26eng
Ownership Approval.
Please get Bash readability approval from @hadusam then merge.

[hadusam]

@tk26eng
Sorry for the late response ><
Overall, please use braces in your bash scripts for readability, e.g. $ROOTFS_DIR/usr/bin/ -> ${ROOTFS_DIR}/usr/bin/.
Also, I added nit-pick comments, please check them.
LGTM except for comments! 👍 So, please fix them! 🙇

[tk26eng]

@hadusam
I removed unnecessary --privileged option for docker run in Makefile.

[hadusam]

Readability Approval, except for comments 👍

[hadusam]

LGTM
Thanks 👍

[tk26eng]

@iizukak
Could you check again ? (Please merge if no problem)

[iizukak]

@tk26eng OK will be merged after CI passed.