On Monday, 19 May 2025 17:47:04 CEST Torsten Wierschin wrote:
For a detailed intro see https://bootlin.com/training/yocto/ It can be used to fetch, configure, build, install and boot every part of an embedded system that contains *open source* toolchain, bootloader, kernel, filesystem, startup system, userspace etc.
I am aware of what Yocto is, but I was hoping for some more detail. However, I understand that it might be an unreasonable demand on your time to get into specific details, and I was only really making a casual enquiry.
When I previously used the OpenWrt distribution for the Ben NanoNote, which used comparable technology (as do many distribution building systems), the process involved wrapping up the different components so that the source code is obtained, verified, unpacked, patched (an important aspect), built and installed.
I can envisage the different L4Re components being similarly wrapped up and the dependency declarations (in Control files) being converted into the appropriate form for Yocto. So, the DEPENDS definition in Yocto recipes would express the Requires definition in L4Re's Control files.
One concern I might have is how the Makefile-based system used by L4Re would be used, given that it invokes all sorts of tasks that also try and organise the broader build process, satisfy dependencies, and so on. It seems to me that without simplifying the existing use of make, there might be a fair amount of duplication of work, limiting the benefits of Yocto and increasing the maintenance burden.
Unfortunately, this doesn't happen easily and the initial learning curve is steep but a lot of chip manufacturers are moving or have already moved in this direction providing customized yocto bsp layers (for Linux). The kernel is really only (but important) part of the game.
Yes, having Linux Foundation support made its adoption rather more likely amongst many of the ecosystem participants.
Thanks for referencing the Bootlin materials which are quite helpful!
Paul