I thought I could share this here, because 1/it could be useful to someone (looking at you future me) 2/I might get some precious advises on how to better handle those problems.
So long story short, I've got 2 SSDs, a small one with Solus installed on (first distro ever, been learning linux with it for a few months now) and a big one with windows. Yesterday I tried to burn a new USB stick with Debian for a MOOC: strange all those partitions on that old USB... let me delete those real quick. Strange message (kernel still using blabla plz restart blabla). I restarted and voila! I'm officialy stupid, I wiped the disk with Solus installed on... (LPT tired makes you more stupid).
Anyway, all my files where elsewhere and I have a backup so I guess I'm good. Boot with a live ubuntu I had kept for whatever reason (and will keep from now on), download solus iso, burn it, boot , install, restart: nothing...
"All boot entries have been tried"...
Ok, no panic. Go to solus help: https://getsol.us/articles/troubleshooting/boot-rescue/en/, follow instruction, reboot. Nothing, same same. Can't boot any os. And the disk solus is installed on isn't available at boot, "PCI not connected"...
Ok panic a bit, but start to think: I've definitely got a linux boot entrie in my "bios" (UEFI mode on, fast boot off etc). But maybe it is an old entrie not related to anything anymore, and solus didn't update it for whatever reason (maybe it is the same name so it thought it's already good).
Painful google search: there is a tool called efibootmgr which can manipulate the system's EFI firmware (https://wiki.gentoo.org/wiki/Efibootmgr). Let me use that, delete this "old entry" and create a new one (just need the correct path to the EFI file in the ESP partition created by Solus). Reboot: 😂 it works !!
Ok now Solus is booting as expected, I think I have superpower and wonder if it means I can now hack time.
Aaaannd windows is still not booting, nor listed in Solus' boot options. Try sudo clr-boot-manager update to no avail. I still have my super efibootmgrso maybe do the same ? But it feels wrong. First, no idea where the efi file is on windows, and thinking about it it should be on the Solus ESP partition, but I wiped it and reinstalled on it... Seems I have to recreate the efi files somehow ? Is it even possible ?
Painful google search: https://superuser.com/questions/1110644/reconstructing-windows-efi-files-in-boot-partition-linuxwindows-dual-boot. They seem to imply the windows boot repair will erase the solus configuration, don't want that yet.
It also seems there is a directory structure to be rebuild, and looking at the directory structure under my Solus ESP, my guess is that Solus is expecting a Microsoft directory containing all the needed files (/EFI/Microsoft/boot/<shitload of files including the efi file>).
I still have access to my windows files through Solus, so looking at them, I find a Windows/boot/ folder which happens to have files looking like what I'm looking for. Let me try to copy them to what I think should be the correct path on the ESP partition. Reboot: kinda work... Now instead of no windows boot available, I've got one but it is explicitly broken "Incorrect configuration blabla try repair".
Seems I don't have a choice: download Windows iso (https://www.microsoft.com/en/software-download/windows10ISO), burn it (NTFS needed... had to use woeUSB application), boot, ask for repair (pray for no wipe of my Solus efi configuration...): It worked !! didn't even need to use the Windows command line as explained in the StakeExchange aforementioned, it did it alone.
Plus the Solus boot loader works perfectly fine, listing the 2 os.
So as I said, any advice on what should/shouldn't have been done is greatly appreciated, and I hpe this could be of any help (provided I wasn't just a complete idiot all along...)
