Linux Capabilities in a nutshell

Capabilities are being used more and more, mainly thanks to SystemD, Docker and orchestrators like Kubernetes. But I think the documentation is a bit hard to grasp and I found some parts of capabilities implementation confusing so I decided to condense my current knowledge into a shorter article.

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Running x86_64/amd64 executables on PPC64le IBM Power 9 Gentoo

Running android-studio on a Talos II ppc64 machine requires the aapt2 binary. That is currently only a part of the x86_64 build-tools, so I had to learn a way to run x86_64 executables on ppc64 cpu. The first option is full emulation (emulating x86_64 kernel and apps), the other is QEMU’s user mode translation (emulating only user-mode, translating syscalls to a running ppc64 kernel). Let’s have a quick look at the QEMU user-mode translation.

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Missing Android manual

We all got Android devices without a proper manual so here are some basics I have learned over time…

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How to boot Windows partition virtually under KVM with UEFI firmware

It is actually quite easy to boot Windows virtualized using KVM. But to properly use the UEFI bootloader, suitable QEMU arguments are required. Here is a lightly commented QEMU command I use to boot virtual Windows 10 I have on a separate partition.

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Posted in Linux, Server stuff | 11 Comments

RC5 device addressees and commands are partly “standardized”

During my attempt to program an Atmel micro-controller to act as a remote controller sending RC5 commands, the original remote suddenly stopped sending the correct Standby code to the device and I noticed device ID part of the RC5 frame has changed from 0x10 into 0x11. I accidentally switched the original remote to a mode for a different type of appliance! I realized that after I found a nice PDF from Freescale semiconductor showing a table with common device IDs and command IDs.

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Telegram emoji list with codes and descriptions

After almost 2 years of using Telegram, I finally discovered that it is possible to enter emoji using its name after “:” character. Unfortunately I couldn’t find any complete list of available emojis anywhere, so I had to dig deep into the Telegram desktop source code to generate it.

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Samsung printer problem on GNU/Linux (printing black pages)

I’ve been using Samsung ML-2160 printer on Gentoo Linux for some time without problems but then I connected it to a box running Arch Linux and I some problems came up. It was printing almost completely black pages (with a few narrow white strips).

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[cz] Proč je Facebook a Messenger špatný

Facebook prý spojuje lidi a umožňuje být neustále s přáteli, aniž bych vystrčil nohu z baráku či postele. Facebook se tváří jako nejlepší kamarád a pomocník, že dělá pro nás to nejlepší. Ale je tomu opravdu tak? Continue reading

Posted in Uncategorized, Web | Tagged , , , , , | 2 Comments

Referer sending options in Firefox

Sending Referer header to the target site after every click on a link is basically revealing URL of the referring site. Several sites mention it as a potential privacy concern but as far as I know there is no UI option in common browsers. Firefox since 28 added “hidden” options for this.
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Tips for making a new password and how passwords work

From what I have seen, many people use weak passwords. But it’s actually easy to make them strong. Let’s see. Continue reading

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