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Flash Arduino without a Bootloader from a Raspberry Pi

tl;dr: use the GPIO pins of a Raspberry Pi to flash Arduino boards without a bootloader

To keep things short: I’ve had an Anet A8 3D printer for a while now and wanted to flash an updated version of its Marlin firmware. For some reason however, the bootloader was broken. So I couldn’t flash it with avrdude by simply using a USB cable. For this case you can find lots of tutorials on how to flash Arduino boards with a second Arduino. I didn’t have a second Arduino at the time though … so why not just bit-bang it from a Raspberry Pi instead?

read on »

Managing containers with podman and systemd

tl;dr: Use simple systemd units to supervise your containers.

A while ago I stumbled upon podman, which touts itself as an alternative to Docker. Not only does podman not use any big fat daemons™ but it makes it rather easy to run containers in a user-namespace, i.e. with greatly restricted privileges on your system. The fun thing is: you are still root within the container!

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Install ESXi 6.5 on a Supermicro X10SBA

tl;dr: Work around problems with the installer by using a serial connection.

Trying to install VMware ESXi on a number of Intel Bay-Trail boards apparently fails with a hanged installation right after a message like Relocating modules and starting the kernel. There’s multiple forum posts around the internet where people suggest various workarounds, which never seemed to work for me. One suggestion which stood out to me as most promising was completely disabling the internal graphics chip and using a dicrete graphics card in the PCI Express slot. read on »

Create a CentOS mirror for Kickstarting

_This is an update over my earlier post about PXE booting. I’ve learned a few more things and refined some rough edges._ My Motivation is similar to the last post: I started building my homelab with virtual machines. Most of them are based on a minimal CentOS 7 installation, and as such I have a lot of very similar systems. Yes, I could probably use containers to great effect. But I prefer the separation/isolation that I get from virtual machines on ESXi. read on »

Local PXE Boot Server

1. motivation Today I set out to setup a local CentOS mirror for quicker PXE installations of my virtual machines. In the long run this will probably be superseded by a Spacewalk machine and until now netboot.xyz has served me well. For the time being I just wanted a faster alternative. The kpxe file for netboot.xyz is tiny and can easily be used with the builtin TFTP server of OpenWRT / LEDE project or any other TFTP server. read on »