Messages in this thread | | | From | Alexandre Courbot <> | Date | Mon, 10 Jun 2013 17:11:15 +0900 | Subject | Re: [PATCH] ARM: tegra: add basic SecureOS support |
| |
On Sat, Jun 8, 2013 at 1:33 AM, Stephen Warren <swarren@wwwdotorg.org> wrote: >>> I think we need to separate the concept of support for *a* secure >>> monitor, from support for a *particular* secure monitor. >> >> Agreed. In this case, can we assume that support for a specific secure >> monitor is not arch-specific, and that this patch should be moved >> outside of arch-tegra and down to arch/arm? In other words, the ABI of >> a particular secure monitor should be the same no matter the chip, >> shouldn't it? > > I would like to believe that the Trusted Foundations monitor had the > same ABI irrespective of which Soc it was running on. However, I have > absolutely no idea at all if that's true. Even if there's some common > subset of the ABI that is identical across all SoCs, I wouldn't be too > surprised if there were custom extensions for each different SoC, or > just perhaps even each product. > > Can you research this and find out the answer?
Will do. Information about TF is scarce unfortunately.
> What we can always do is make a compatible property that lists > everything[1], and have the driver match on the most specific value for > now, but relax the driver's matching later if it turns out that the ABI > is indeed common. > > [1] That'd need to be at least secure OS name, and secure OS version. > Perhaps the SoC and board data can be deduced from the DT's top-level > compatible properties; nvidia,tegra114-shield, nvidia,tegra114?
They can probably, but in theory nothing prevents a board from coming with different secure monitors (or none at all). In this case, just having the board name might not be enough.
Having a proper node for the firmware like David and Tomasz suggested seems to be the best way to make sure we cover all cases - I think I will try to do it this way for the next version, and hopefully come with a binding that is useful for everyone.
Thanks, Alex.
| |