I got my espressobin board, mod-ed a case for it, got it working as planned. I would like to share my setup and configurations, in the hope that it could help to save some time for people to look for a similar setup. 1. Setup
The espressobin board is mounted inside a re-purposed HP dc7900 case. It has a sata SSD drive attached, with plan to install a port multiplier and a 3.5” spindle hard drive later on. 2. Kernel and its modules
When playing with the board, I found out that the iptables is not compiled-in in the Globalscale kernel, and soon realized that quite a few other functions not turned on as well. So I re-configured the kernel options, ended up with something close to what a typical Ubuntu kernel would provide, in areas like networking support, fs types, security options, crypto API’s, etc. The “.config” file could be found here (full url: https://www.dropbox.com/s/10k4vobsby4zhtu/espressobin-kernel-config-full-20170624.tar.gz).
The build setup and process follow what’s in the wikis on this site, plus the module build. Below is a list of commands to build the kernel and the modules.
make modules_install INSTALL_MOD_PATH=pwd/kmod3720
(Note: the pwd command above is enclosed in backticks, as command substitution)
The built modules are located in kmod3720 directory (“kmod3720/lib/modules/4.4.8-armada-17.02.2-g8148be99814b/”, to be exact); and they need to be copied to the /lib/modules/4.4.8-armada-17.02.2-g8148be99814b/ directory on the espressobin target system. To make the transfer faster, they could be compressed to a tarball, with the command shown below.
tar -czf ../kmod3720.tar.gz -C kmod3720/lib/modules/ .
After the tarball is copied over to the espressobin, it could be decompressed with the commands shown below.
3. Power Consumption
The setup (espressobin with a SSD drive) runs at 4 watts most of the time, according to my Kill A Watt meter. When it is in u-boot, it’s 5 watts. When it’s doing tarball compression/extraction, it could hit 6 watts. When nothing is running, it could show 3 watts. The default ondemand scaling governor runs in one of the four frequencies: 166666, 250000, 500000, 1000000. 4. Ethernet Port and Speed
The wan port is a gigabit port, and it is capable of running saturated with netcat; and that suggests there’s not bottleneck in the path. The scp rate is around 35MB/s, likely due to the overhead of ssh encryption/decryption; this could be alleviated with the availability of the driver to the on-chip Security Engine, hopefully.