Marcus Folkesson

Embedded Linux Artist

TIL - docker scratch image

TIL - Docker scratch image TIL, Today I Learned, is more of a "I just figured this out: here are my notes, you may find them useful too" rather than a full blog post The scratch image is the smallest possible image for docker. It does not contain any libraries nor other executables. It is simply a new, fresh and empty setup of namespaces. The FROM scratch line is even a no-op [1] in the Dockerfile, which results in that it will not create an extra layer in you image.

Posted by Marcus Folkesson on Wednesday, November 15, 2023

TIL - sort in vim

TIL - Sort in VIM TIL, Today I Learned, is more of a "I just figured this out: here are my notes, you may find them useful too" rather than a full blog post After 15+ years of daily VIM usage I just discovered the :sort function. Quite embarassing. It is also possible to sort in revese ( :sort!) and remove duplicate lines ( :sort u).

cover

Posted by Marcus Folkesson on Thursday, November 2, 2023

TIL - notmuch-lore

TIL - notmuch-lore TIL, Today I Learned, is more of a "I just figured this out: here are my notes, you may find them useful too" rather than a full blog post Notmuch [1] is an mail indexer and is a great tool to search in high-volume mailboxes (e.g. mailing lists). Being subscribed to all these mailing lists and retreiving all mails over IMAP daily could be quite annoying and harm your mail quota.

Posted by Marcus Folkesson on Saturday, October 21, 2023

TIL - git man-pages

TIL - git man-pages TIL, Today I Learned, is more of a "I just figured this out: here are my notes, you may find them useful too" rather than a full blog post I'm a big user of man-pages. Today I found a set of pages that I've not noticed before when I was reading man git: SEE ALSO gittutorial(7), gittutorial-2(7), giteveryday(7), gitcvs-migration(7), gitglossary(7), gitcore-tutorial(7), gitcli(7), The Git User’s Manual[1], gitworkflows(7) Especially

Posted by Marcus Folkesson on Monday, October 2, 2023

TIL - Git --color-moved

TIL - Git --color-moved TIL, Today I Learned, is more of a "I just figured this out: here are my notes, you may find them useful too" rather than a full blog post Did you know that Git is able to detect moved blocks and use different colors from the usual added/removed lines? Me neither until now. The paremeter is --color-moved and has been around since v0.4.0, so there is no new feature.

cover

Posted by Marcus Folkesson on Saturday, September 23, 2023

TIL - Buildroot and LIBFOO_LINUX_CONFIG_FIXUPS

TIL - Buildroot and LIBFOO_LINUX_CONFIG_FIXUPS TIL, Today I Learned, is more of a "I just figured this out: here are my notes, you may find them useful too" rather than a full blog post Some applications in a Linux system depends on certain kernel features to work properly. I'm currently working on adding support for CRIU [1] in Buildroot [2] which has such requirements. That's when I stumble upon the LIBFOO_LINUX_CONFIG_FIXUP variable.

Posted by Marcus Folkesson on Tuesday, September 12, 2023

TIL - ignore_routes_with_linkdown

TIL - ignore_routes_with_linkdown TIL, Today I Learned, is more of a "I just figured this out: here are my notes, you may find them useful too" rather than a full blog post Usually, a high level network managers such as NetworkManager or Connman, removes routes for unaccessible ("linkdown" or "unplugged") link states. If these links are not managed by a network manager but are managed in other ways or is somehow misconfigured, then you could end up with a default route that is still hanging around even if the link is down.

cover

Posted by Marcus Folkesson on Tuesday, July 4, 2023

TIL - Split streams with boost::tee_device

TIL - Split streams with boost::tee_device TIL, Today I Learned, is more of a "I just figured this out: here are my notes, you may find them useful too" rather than a full blog post Split streams could be useful if you want the same output to appear in more than one stream at once. Boost support tee_device, which works pretty much as the tee(1) [1] command line tool. Everything written to that device is splitted up and written into two streams.

cover

Posted by Marcus Folkesson on Monday, May 15, 2023

TIL - NFS UDP Support

TIL - NFS UDP Support TIL, Today I Learned, is more of a "I just figured this out: here are my notes, you may find them useful too" rather than a full blog post Today I was trying to bring up an really old board (v2.6.32 kernel) that used to mount its root filesystem via NFS. Unfortunately, I have to stick to this configuration for a few reasons. The virtual machine that came with the board did not start anymore, so I had to setup a new one.

cover

Posted by Marcus Folkesson on Saturday, May 6, 2023

TIL - Buildroot & BR_NO_CHECK_HASH_FOR

TIL - Buildroot & BR_NO_CHECK_HASH_FOR TIL, Today I Learned, is more of a "I just figured this out: here are my notes, you may find them useful too" rather than a full blog post In Buildroot [1], the integrity of (allmost) all downloaded packages is verified against a hash. Even packages that are fetched from a git repository is verified this way. This is a good thing that no one really should work around.

Posted by Marcus Folkesson on Thursday, March 30, 2023