Yocto Project - dev manual log

Customizing images
- local.conf
  IMAGE_INSTALL_append
  add strace, rebuild, test - seemed to result in a significant rebuild
  real time to do 'nothing' rebuild = 28 seconds
  real time to add 'pciutils, usbutils' rebuild = 7 minutes
  real time to add 'kbd, kbd-keymaps' rebuild = 5:30 minutes

- IMAGE_FEATURES and EXTRA_IMAGE_FEATURES

  in conf/local.conf "read-only-rootfs empty-root-password allow-empty-password"
- Custom .bb
  Move above changes into meta/recipes-core/images/core-image-steve.bb
  rebuild, test - quick.
  Add image feature ssh-server-dropbear
Writing a new recipe
- Creating the Base Recipe Using devtool add
  Follow the autotools amhello example, to create an application, store in git repo locally
  Run 'devtool add amhello /mnt/ee/repo/amhello' -> recipe in workspace
  Run 'devtool build-image core-image-steve' to build image including recipes from workspace
  deployed in /usr/bin/hello
- Creating a layer in which to put the recipe

  bitbake-layers create-layer ../meta-steve

  bitbake-layers add-layer ../meta-steve

- Move recipe to layer

  devtool finish amhello meta-steve

- Re-build image

  Add amhello to core-image-steve.bb

  gotcha - the recipe is missing the 'S = "${WORKDIR}/git"' line. This results in no build

  see Build an example package based on a git repository

Headless ubuntu server install (EFI)

Installing ubuntu server on a UEFI machine, via serial console only

Create USB stick (real or for qemu)

$ qemu-img create -f raw ubuntu_efi_inst.img 2G
Formatting 'ubuntu_efi_inst.img', fmt=raw size=2147483648

Create an EFI System Partition (ESP) on it

[steve@steve-GA-880GMA-UD2H archlinux]$ gdisk ubuntu_efi_inst.img 

GPT fdisk (gdisk) version 1.0.1

Partition table scan:

  MBR: not present

  BSD: not present

  APM: not present

  GPT: not present

Creating new GPT entries.

Command (? for help): n

Partition number (1-128, default 1): 

First sector (34-4194270, default = 2048) or {+-}size{KMGTP}: 

Last sector (2048-4194270, default = 4194270) or {+-}size{KMGTP}: 

Current type is 'Linux filesystem'

Hex code or GUID (L to show codes, Enter = 8300): ef00

Changed type of partition to 'EFI System'

Command (? for help): w

Final checks complete. About to write GPT data. THIS WILL OVERWRITE EXISTING

PARTITIONS!!

Do you want to proceed? (Y/N): y

OK; writing new GUID partition table (GPT) to ubuntu_efi_inst.img.

Warning: The kernel is still using the old partition table.

The new table will be used at the next reboot or after you

run partprobe(8) or kpartx(8)

The operation has completed successfully.

Format it

$ sudo losetup --partscan --show --find ubuntu_efi_inst.img 

/dev/loop3

$ sudo mkfs -t vfat /dev/loop3p1

mkfs.fat 3.0.28 (2015-05-16)

unable to get drive geometry, using default 255/63

Mount it

$ sudo mkdir /mnt/target

$ sudo mount /dev/loop3p1 /mnt/target

Loop mount the installation iso

$ sudo mount -o loop Downloads/ubuntu-16.04.2-server-amd64.iso /mnt/loop/

mount: /dev/loop4 is write-protected, mounting read-only

Copy files needed for EFI boot

$ sudo cp -vr /mnt/loop/EFI /mnt/target/

$ sudo cp -vr /mnt/loop/boot /mnt/target/

$ sudo cp -vr /mnt/loop/install /mnt/target/

Copy the ISO on to it (work-around for installer issues)

Copy the iso file onto the partition, needed during ubuntu install to mount CD

$ sudo cp Downloads/ubuntu-16.04.2-server-amd64.iso /mnt/target/

Patch grub and linux cmd line, to use serial console

$ sudo vi /mnt/target/boot/grub/grub.cfg

#add the lines below, at the top of the file

serial --speed=115200 --unit=0 --word=8 --parity=no --stop=1

terminal_input --append serial

terminal_output --append serial

#subsequent terminal entries need to also use --append eg.

terminal_output --append gfxterm

#edit any wanted linux entries to use console as below

#see also https://www.kernel.org/doc/Documentation/ia64/serial.txt

linux /install/vmlinuz  file=/cdrom/preseed/ubuntu-server.seed earlycon=uart,io,0x3f8 earlycon=uart,io,0x3f8 console=uart,io,0x3f8 ---

Boot from the prepared drive

#now boot using qemu or real system (with mnt/target written to usb storage device)

#for qemu we need to make a destination for the ubuntu install

$ qemu-img create -f qcow2 ubuntu2.qcow2 16G

Formatting 'ubuntu2.qcow2', fmt=qcow2 size=17179869184 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16

#optionally run with -nographic,or switch to serial view (ctrl-alt-3)

sudo qemu-system-x86_64 -smp 2 -enable-kvm -m 1G -hda ubuntu2.qcow2 -drive file="ubuntu_efi_inst.img",index=1,media=disk,format=raw -bios /usr/share/edk2/ovmf/OVMF_CODE.fd -nographic

Ubuntu installation process begins

Complete localization options

# on seeing error "Your installation CD-ROM couldn't be mounted."

# https://askubuntu.com/questions/671159/bootable-usb-needs-cd-rom

# skip retry, exit to shell

# mount disk

~ # mount -t vfat /dev/sdb1 /media

~ # mount -o loop /media/ubuntu-16.04.2-server-amd64.iso /cdrom

~ # exit

# now detect CD-ROM

# don't unmount partitions that are in use (the CD is mounted from here)

# do guided install on other disk (sda in this example)

# after the step 'Install grub bootloader' you should get the 'Installation complete' message

# this is a good point to drop back into the shell, and review what has been done

Review grub setup on target drive

~ # cat /target/boot/efi/EFI/ubuntu/grub.cfg 

search.fs_uuid 6b25fe16-1db7-49c2-91a8-15bd590dade8 root hd0,gpt2 

set prefix=($root)'/boot/grub'

configfile $prefix/grub.cfg

~ # grep terminal /target/boot/grub/grub.cfg 

terminal_input --append serial

terminal_output --append serial

terminal_output --append gfxterm

~ # grep serial /target/boot/grub/grub.cfg 

serial --speed=115200 --unit=0 --word=8 --parity=no --stop=1

terminal_input --append serial

terminal_output --append serial

~ # grep console /target/boot/grub/grub.cfg 

linux /boot/vmlinuz-4.4.0-62-generic.efi.signed root=/dev/sda2 ro earlycon=uart,io,0x3f8 console=uart,io,0x3f8  

#now exit, and reboot

#good luck!

HC-06 Bluetooth Module

Based on http://www.martyncurrey.com/arduino-with-hc-05-bluetooth-module-at-mode/

Default mode

Note, use 'software serial' mode on Arduino, as regular uart (pins 0, 1) are also used for USB communication (needed by the IDE).

In the example use pins 2, 3 for RX/TX.
Use voltage divider to get 5v output from Arduino to 3.3v safe for RX on HC-05.

On power up, 2 blinks per second = disconnected
Connect using android device, with 'Serial Bluetooth Terminal' app
Pair device, then connect.
Now should have a steady led
Use code from - https://github.com/bugwhine/arduino/blob/master/bluetooth/bluetooth.ino
Default baud rate for bluetooth side is 9600
From arduino IDE, run program, and open serial monitor
Should be possible to communicate between arduino serial monitor and bluetooth serial app on phone


[steve Arduino]$ hcitool scan
Scanning ...
98:D3:32:20:87:15 HC-06

[steve Arduino]$ sudo rfcomm bind 0 98:D3:32:20:87:15 1

[steve Arduino]$ sudo minicom -s

Serial Port Setup

A -    Serial Device      : /dev/rfcomm0

E  -    Bps/Par/Bits       

C:   9600

Serial comms should now work between minicom, and the arduino serial monitor.

nodejs

sudo dnf install bluez-libs-devel

sudo npm -g install bluetooth-serial-port

Use example code from https://github.com/eelcocramer/node-bluetooth-serial-port,

or - https://github.com/bugwhine/arduino/blob/master/bluetooth/btserial.js

node btserial.js

connected

Received: Size of data buf = 1

h

Received: Size of data buf = 6

ello

Docker, Jenkins, Github

Ensure that user belongs to docker group

[steve ~]$ id steve
uid=1000(steve) gid=1000(steve) groups=1000(steve),10(wheel),975(vboxusers),1002(docker)

User a persistent volume (to keep data), and the :z option to deal with selinux

[steve ~]$ docker run -p 8080:8080 -p 50000:50000 -v /home/steve/jenkins:/var/jenkins_home:z jenkins

Create repo on github, push code and makefile

https://github.com/bugwhine/hellojenkins

Install gcc and related tools into jenkins container

[steve ~]$ docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                                              NAMES
04105a89f166        jenkins             "/bin/tini -- /usr/lo"   5 minutes ago       Up 5 minutes        0.0.0.0:8080->8080/tcp, 0.0.0.0:50000->50000/tcp   ecstatic_williams

[steve ~]$ docker exec -u root  04105a89f166 apt-get -y install gcc make

Create job in jenkins

- Source Code Management

  - git

  - Repository URL: git@github.com:bugwhine/hellojenkins.git

  - Credentials: bugwhine (add using dropdown)

- Build

  - execute shell

    - make

Build now