Posts about programming, DevOps, Linux server management, and more.
Update: I found another variant. I appended it to the end of the article. Original post: Some rudimentary ELF loaders require that p_memsz equals p_filesz for each LOAD segment in order to simplify the loading of the file. For example, the microkernels NOVA and Hedron have this restriction to bootstrap Read more…
I just want to drop a short notice that I created a small CLI utility that I think is helpful. paging-calculator helps you to calculate the indices for a given virtual address that are used for the physical address lookup at different page table levels. Paging is a mechanism that Read more…
I have a setup with a Linux Kernel and a custom initrd, hence, no full Linux distribution. The initrd is meant to be as minimal as it can be. As a consequence, even basic things such as power-off on power-button pressed must be configured manually. There is no init system Read more…
This is an educational resource I wish I had when I started digging into low-level and operating systems during my early time of my studies at the university. However, dear past me, I got your back! Do you want to see a minimal way to communicate with (virtual) hardware and Read more…
Update: Since I published this article, I gained more knowledge from own research and hints from others. I adjusted the blog post. Thanks for the help! When it comes to low-level systems engineering and producing binaries, such as firmware or kernels, dealing with linkers and especially linker scripts feels like Read more…
In this blog post, I want to show you how you can boot your custom (i.e., self developed, non-linux) kernel with GRUB 2 in a legacy x86 boot flow. The tutorial is focused on Linux as build environment. A working example can be found on my GitHub. Introduction When you Read more…