On Fri, 2021-02-19 at 16:02 +0100, Thomas Seeling wrote: > Hallo, > > > > is it possible to query the "breadcrumb" of a grub boot process? > > > Is there a query function that I can use to find out how my > > > system got > > > bootstrapped? > > > Use a single boot partition and install grub to use that. > > I can understand the rationale and the bigger picture for the > recommendation but I'd like to better understand the inner workings > of grub. > This is the main reason why I asked. > > I'm doing devops for lots of machines where I can't change the boot > layout (big company, policies, governance etc.). > Most of them really have 2 partitions (similar to the concept of > Android A/B emmc layout). > I want to find out the boot process breadcrumb to be sure where > things are getting installed to.
Do I understand correctly that the main question is "which grub.cfg will be used by grub at next reboot after running grub-install"? Or is there more? My (little) understanding is that grub installs statically linked files in free sectors at the beginning of the disk, that those files get loaded into memory at boot, and that they contain a way to find a grub.cfg file, which allows to prompt the user and all that. I think you might be interested in the "Embedded configuration" section of the "Writing your own configuration file" chapter of "info grub". This reference "grub-mkimage", but there does not seem to be a real documentation for grub-mkimage (there is a man page, see below). Another interesting place related to what you ask is chapter "GRUB image files". Now, It looks like there are man pages that we do not install because help2man is not available. You might find them on the net, though (or install help2man, and reinstall grub). Pierre -- http://lists.linuxfromscratch.org/listinfo/lfs-support FAQ: http://www.linuxfromscratch.org/blfs/faq.html Unsubscribe: See the above information page Do not top post on this list. A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail? http://en.wikipedia.org/wiki/Posting_style
