On 11/14/22 13:32, Robbie Harwood wrote: > Timothée Ravier <si...@fedoraproject.org> writes: > >>> As we've talked about before, it's not possible to make updates >>> transactional. It involves, per spec and depending on processor >>> architecture, updating multiple files in different directories, >>> potentially on different filesystems entirely, one of which is fat32. >> >> I should probably have used only 'safe' here. My understanding of the >> "fallback work" was that with it, we could do updates automatically and >> retry them after failures without risking ending up in a state where we have >> no working bootloader. The update process would look like this: >> 1. Verify current bootloader hash >> 2. Fix it if not good >> 3. Copy current version to fallback >> 4. Update bootloader to new version >> >> What I've indeed forgotten to specify is that this only applies to EFI (so >> probably only x86 & aarch64) for now as that's what's implemented in bootupd. >> >> Am I missing something? > > Bootloaders are not single files. Consider UEFI: > > For grub2, there's both a .efi and some configuration that I'll handwave > for purposes of this conversation. For shim, it's more like 4 things - > the main shim*64.efi, fallback.efi, boot.efi, and boot.csv. These all > serve different purposes, and need to get loaded from specific parts of > the ESP. (Recall here that fat32 doesn't have symlinks, either.) > > While I think it will surprise no one that I don't agree with doing so, > bootupd claims the additional goal of supporting Legacy BIOS. For that, > you also need to consider updates to the MBR, which isn't a file at all.
For at least UEFI, this can be solved by using *two* boot entries. Once everything is working in the new location, switch to it. -- Sincerely, Demi Marie Obenour (she/her/hers) _______________________________________________ devel mailing list -- devel@lists.fedoraproject.org To unsubscribe send an email to devel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
