On Tue, 30 May 2023 at 11:07, Marvin Häuser <mhaeu...@posteo.de> wrote: > > Hi Ard, > > Native PE toolchains *generally* also generate XIP images (/ALIGN = > /FILEALIGN, but with 32 Byte rather than 64 Byte alignment compared to GCC49+ > / CLANGDWARF) [1]. However, because they are underaligned by default (even > for RT images that run in an OS context and MM drivers... sigh...), platforms > manually override SectionAlignment, but not necessarily FileAlignment [2], > breaking XIP. I don't think what you are doing is perfectly safe for these, > as they will have FileAlignment < SectionAlignment (and by all chances, > BaseTools is borked too). In my opinion check for FileAlignment == > SectionAlignment. I can't vouch for how likely FileAlignment has a sane > value, the AUDK loader does not read it at all and instead checks > PointerToRawData == VirtualAddress, etc. > > BaseTools generally has poor support for non-XIP vs XIP, probably due to > notorious underalignment since the very beginning. For PEIM XIPs for example, > which must ship pre-relocated at least for Intel, GenFv just relocates the > image in-memory and then copies the changes back to the FFS file [3]. There > is no concept of changing the image file size within the procedure and as > such, a non-XIP image cannot be converted to XIP on demand. This would be > useful for a distinction between pre-memory and post-memory PEIMs, the former > of which must be XIP (thus aligned), while the latter can be loaded and > relocated in-RAM (thus can be underaligned w.r.t. FileAlignment), but alas. >
If XIP for PE images with 4k section alignment is an issue, we could always explore loading them into a separate allocation from PEI, just like we do with DXE core itself. This would actually simplify the loader code quite a lot, as we'd be able to use the PEI core image loader directly. However, it means we'd have to pass this information (array of <guid, base address> tuples describing which images were already loaded by DxeIpl) via a HOB or some other method. -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#105439): https://edk2.groups.io/g/devel/message/105439 Mute This Topic: https://groups.io/mt/99197142/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
