be more careful when dumping sysrepo configuration

I've seen one lab device with a zero-size JSON file, which obviously
cannot be restored. That's fishy and this should not happen, so let's
try to be a bit more robust when creating that file:

- do not overwrite in place (which might hit a FS race and cause an
  empty file)
- check that sysrepocfg produced "some data" (if it crashed early
  enough, it would previously still have been an empty file due to the
  output redirection)

The actual writeout is a bit more involved than I would prefer, and
because I want locking (thanks, Tomas), I think it's easier to use two
scripts for this one.

Change-Id: I43fccd3a49cae77f88b282ccac07471453910c25
4 files changed
tree: 2ee2ed437121af75525c3b93a731b99e0b1c710a
  1. .gitmodules
  2. .zuul.yaml
  3. Config.in
  4. README.md
  5. board/
  6. ci/
  7. configs/
  8. crypto/
  9. dev-setup-git.sh
  10. doc/
  11. external.desc
  12. external.mk
  13. package/
  14. submodules/
  15. tests/
README.md

How to use this

This repository contains CzechLight-specific bits for Buildroot. Buildroot is a tool which produces system images for flashing to embedded devices. They have a nice documentation which explains everything that one might need.

The system architecture is described in another document. This is a quick build HOWTO.

Quick Start

Everything is in Gerrit. One should not need to clone anything from anywhere else. The build will download source tarballs of various open source components, though.

By default, each change of this repo uploaded to Gerrit causes the CI system to produce a firmware update. On Gerrit, the change will get a comment from Zuul with a link to the CI log server. Next to the logs, a file named artifacts/update.raucb can be used for updating devices.

Behind the scenes, the system uses Zuul with a configuration tracked in git.

Developer Workflow

Here's how to reproduce the build on a developer's workstation:

git clone ssh://$YOUR_LOGIN@cesnet.cz@gerrit.cesnet.cz:29418/CzechLight/br2-external czechlight
pushd czechlight
git submodule update --init --recursive
popd
mkdir build-clearfog
cd build-clearfog
../czechlight/dev-setup-git.sh
make czechlight_clearfog_defconfig
make

A full rebuild takes between 30 and 45 minutes on a T460s laptop.

WARNING: Buildroot is fragile. It is not safe to perform incremental builds after changing an "important" setting. Please check their manual for details.

Installing

Updates via RAUC

Apart from the traditional way of re-flashing the SD card or the eMMC from scratch, it's also possible to use RAUC to update. This method preserves the U-Boot version and the U-Boot's environment. Apart from that, everything starting with the kernel and the DTB file and including the root FS is updated. Configuration stored in /cfg is brought along and preserved as well.

To install an update:

# build node
make
rsync -avP images/update.raucb somewhere.example.org:path/to/web/root

# target, perhaps via an USB console or over SSH
rauc install http://somewhere.example.org/update.raucb
reboot

Because /cfg is preserved, it can happen that there are data, which are incompatible with the version you are uploading. The reason could be that a YANG model got downgraded to an older one (example: cla-sysrepo downgrade). This is signalled by the failure of the cfg-restore-sysrepo.service service. In this case, one needs to edit the /cfg/sysrepo/startup.json file and remove the offending content. The exact errors will be shown in the systemd journal and also in the console.

Initial installation

Clearfog

On a regular Clearfog Base with an eMMC, one has to bootstrap the device first. If recovering a totally bricked board, one can use the kwboot command to upload the initial U-Boot via the console. Ensure that the jumpers are set to 0 1 0 0 1 (default for eMMC boot is 0 0 1 1 1), and then use U-Boot's kwboot tool:

./host/bin/kwboot -b ./u-boot-spl.kwb -t -p /dev/ttyUSB0

Once in U-Boot (a stock factory image is OK as well), plug a USB flash disk which contains images/usb-flash.img and execute:

usb start; fatload usb 0:1 00800000 boot.scr; source 00800000

The system will boot and flash the eMMC from the USB drive. Once the status LED starts blinking in yellow, data are being transferred to the eMMC. The light changes to solid yellow in later phases of the flashing process. Once everything is done, the status LED shows a solid white light and the system reboots automatically.

Turn off power, remove the USB flash, re-jumper the board (0 0 1 1 1), power-cycle, and configure MAC addresses at the U-Boot prompt. The MAC addresses are found on the label at the front panel.

=> setenv eth1addr 00:11:17:01:XX:XX
=> setenv eth2addr 00:11:17:01:XX:YY
=> setenv eth3addr 00:11:17:01:XX:ZZ

Also set up the system type:

Modelczechlight variable value
ROADM Line Degreesdn-roadm-line-g2
WSS Add/Dropsdn-roadm-add-drop-g2
Hi-resolution Add/Dropsdn-roadm-hires-add-drop-g2
Coherent Add/Dropsdn-roadm-coherent-a-d-g2
Inline EDFA Amplifiersdn-inline-g2

Some prototypes have deprecated PCBs (blue). On these, skip the -g2 suffix. All red PCBs are -g2.

=> setenv czechlight sdn-roadm-line-g2
=> saveenv
Saving Environment to MMC... Writing to redundant MMC(0)... OK
=> boot

Once the system boots (which currently requires a reboot for some unknown reason -- fsck, perhaps?), configure hostname, plug in the network cable, and update SW:

# hostnamectl set-hostname line-XYZSERIALNO
# cp /etc/hostname /cfg/etc/
# rauc install http://somewhere.example.org/update.raucb
# reboot

Beaglebone Black

Obtain a reasonable Linux distro image for BBB and flash it to a µSD card. Unlock eMMC boot partitions (echo 0 > /sys/class/block/mmcblk1boot0/force_ro; echo 0 > /sys/class/block/mmcblk1boot1/force_ro). Clean the eMMC data (blkdiscard /dev/mmcblk1). Flash the content of images/emmc.img to device's /dev/mmcblk1. Flash what fits into /dev/mmcblk1boot0 and /dev/mmcblk1boot1. Fetching the image over web (python3 -m http.server and wget http://...:8000/emmc.img -O - | dd of=/dev/mmcblk1 conv=sparse) works well.