Hi, Would it be possible to response in plain text?
BR, Jarkko On Sat, Aug 23, 2025 at 11:38:00AM -0300, Daniel Almeida wrote: > Hi Jarkko, > > I must admit that I had a hard time understanding what you’re trying to say. > > > On 23 Aug 2025, at 09:22, Jarkko Sakkinen <jar...@kernel.org> wrote: > > > On Sat, Aug 23, 2025 at 03:12:48PM +0300, Jarkko Sakkinen wrote: > > Hi > > > > As of today can we possibly do this: > > > > 1. drivers/char/tpm (C code) > > 2. drivers/char/tpm/protocol (imported tpm2_protocol) > > > > > What do you mean? > > > ? > > > > And then build FFI from C to Rust for building commands that we need > > today etc. > > > > There's one particular challenge where this could help: early boot > code > > for D-RTM (i.e., Trenchboot) as given my crate is just a thing in > stack > > with no deps, it could be linked also to that payload. > > > > This would be much better integration step for TPM2 than having a > > separate driver on Rust side. We could start with tpm2-cmd1/cmd2, then > > move on to tpm2-space.c i.e. get all structural processing inside > Rust. > > > Can you expand on what these cmds are? > > > > > tpm2_protocol is light on definitions and should not need any kernel > > specific Rust shenanigans. > > > You mean the Rust abstractions? > > > > > Consider it as value like integer but just a bit more complex > internaal > > represention but in the end it is just a value on stack. > > > Not sure what you mean here either. > > > > > My goal with tpm2_protocol is to have ACPICA alike model of imports as > > the crate is driven by TCG spec updates and it is very likely to be > > also used by TPM-RS (also via import style process). > > > The source code since 0.10.0 version has been relocated here: > > https://git.kernel.org/pub/scm/linux/kernel/git/jarkko/tpm2-protocol.git > > The representation of commands and responses defined is pretty well > high-lighted by > > https://bsky.app/profile/jarkk0.bsky.social/post/3lx2n2uvxos2h > > I'm also working on a test that measures the estimated compile time > size and realized run-time size (suggested by Philip Tricca) so that > we know where we are at on stack usage. > > I've started to optimize it after development phase with some > low-hanging fruit cut already in 0.10.0 but this work is barely > starting [1]. > > There's also a kselftest compatible test that can be run with > "make test" in the repo using only rustc (build + run circa > 2 seconds on my laptop). > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/jarkko/ > tpm2-protocol.git/commit/?id=cd6641bf9e8c8fde8726bece9eb6cdc630d893c2 > > BR, Jarkko > > > > > My somewhat limited understanding here is that you’re trying to implement Rust > code that can be called from the rest of the kernel, but that otherwise > doesn’t > depend on it? > > > If so, I did try something similar [0]. Perhaps this is useful to you and is > somewhat applicable to your use case as well? > > [0]: https://lwn.net/Articles/970565/ > >
