Marcus Folkesson

Embedded Linux Artist

Board bring-up part 2: NAND flash

Board bring-up part 2: NAND flash I'm currently working with a board bring up for a custom hardware based on a OMAPL138 from Texas Instruments. It is fun to work with "real" bring-ups. Most of my customers use System On Modules (SoM:s) these days. You get a lot for free with those modules but a lot of the fun is stripped away. This post is not intended to be guide, it is more of a follow-me-through-my-work-post divided into three parts.

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Posted by Marcus Folkesson on Thursday, August 15, 2024

Board bring-up part 1: Memory hassle

Board bring-up part 1: Memory hassle I'm currently working with a board bring up for a custom hardware based on a OMAPL138 from Texas Instruments. It is fun to work with "real" bring-ups. Most of my customers use System On Modules (SoM:s) these days. You get a lot for free with those modules but a lot of the fun is stripped away. This post is not intended to be guide, it is more of a follow-me-through-my-work-post divided into three parts.

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Posted by Marcus Folkesson on Wednesday, August 14, 2024

Forge a kitchen knife

Forge a kitchen knife Another attempt to forge a knife. The metal I use for this project is part of a feather harrow that I collected from my father farm. I cut out a ~8x4cm long piece from the springs of the feather harrow: Bosse (the dog) never leaves me, so I got him a sack to snuggle down on at the outside of the garage. I used the gas forge for the entire project.

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Posted by Marcus Folkesson on Thursday, August 1, 2024

--build, --host and --target explained

--build, --host and --target explained Too often I see abuse of the --host, --build and --target options during (cross-)compilation of code using autotools. The feeling is more that people try different values until it seems to produce what they want without knowing what they are actually doing. But who can blame them. What these parameters do it not obvious and very few people compile their own crosscompiler nowadays - or ever did.

Posted by Marcus Folkesson on Wednesday, July 17, 2024

Forge a knife blade from a car spring

Forge a knife blade from a car spring I helped my friend to change springs on his car, so I kept the broken spring as forging material. The carbon content of spring steel is aroundd 0.6 to 0.8% which works well for hardening - so lets forge a knife! I cut out a ~10cm long piece from the car spring. I use the induction heater to straight it out and flatten it a little.

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Posted by Marcus Folkesson on Sunday, July 14, 2024

OMAPL138 AIS generator

OMAPL138 AIS Generator I'm currently working on an old platform based on OMAPL138 from Texas Instruments. The OMAPL138 SoC is cool in itself, it is a ARM9 core with a C674x DSP coprocessor. My project scope is to modernize the platform to a more recent kernel/bootloader and add support for a few more interfaces due to a new HW revision. The OMAPL138 is from 2009 but still active. The latest revision for the chip (Rev.

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Posted by Marcus Folkesson on Saturday, July 13, 2024

TIL - Git bundle

TIL - Git bundle 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 git bundle [1] subcommand has been around for many years but is something I came across quite recently. The command allows you to create, unpack, and manipulate bundles files, which are used to share git repositories without an active server.

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Posted by Marcus Folkesson on Saturday, July 13, 2024

What time is it? RTCs explained in embedded Linux

What time is it? RTCs explained in embedded Linux Most smart devices keep track of time and it's usually something that everyone expects to be "right", accurate and just work. I mean, you can keep time pretty well with just a pendulum or a spring [1], so why would this be a complicated thing in an embedded system? Your smart alarm clock, smart phone or even your new cool IoT refrigerator make all use of the time for sure, but they probably do it for different purposes and have different requirements of the accuracy of time.

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Posted by Marcus Folkesson on Tuesday, July 2, 2024

Knife making

Knife Making It's been a long time since I made knives. Knife making was actually the reason I bought my gas forge a few years ago and it's still something I intend to do. I forged a few knife blades back then, but it was way too much manual grinding to be fun and I didn't have the right tools back then, and I'm still missing a belt grinder in my toolbox.

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Posted by Marcus Folkesson on Monday, July 1, 2024

NOAA Weather satellites

NOAA Weather satellites Me and a friend started to talk about SDR (Software Defined Radio) and GNURadio [1], which reminds me of a old project I did for many years ago - reading out images from NOAA weather satellites using SDR, a QFH antenna and GNU Radio! I found some old pictures, but unfortunately, I do not remember the details as it was almost ten years ago. But I do know that we were using a HackRF [3] to catch the radio signals.

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Posted by Marcus Folkesson on Thursday, May 30, 2024