Hi, On 8 December 2014 at 18:27, Kevin Hilman <khil...@kernel.org> wrote: > > Hi Simon, > > Simon Glass <s...@chromium.org> writes: > > > On 8 December 2014 at 10:58, Kevin Hilman <khil...@kernel.org> wrote: > > [...] > > >> FWIW, the XU3 firmware is broken in other ways as well which have a > >> major impact on power management. > >> > >> First, with mainline kernels using MCPM, only 6 of 8 CPUs come > >> online. However, even with that fixed[1], it turns out that the kernel > >> can't properly manage CCI due to secure firmware[2], which means that MCPM > >> (multi-cluster power management) can't work, and thus the low-power > >> cluster-idle states can't work, the big.LITTLE switcher cannot work, and > >> the ongoing work on energy-aware scheduling will not be useful on this > >> platform. > >> > >> Anyone know what are the chances of getting a non-secure version of the > >> firmware for this platform. The Samsung Chromebook2 with basically the > >> same SoC (5800 compared to the 5422 on the XU3) ships with non-secure > >> firmware so all of the above mentioned features are working just fine. > > > > I have pushed on this but apparently it is not possible - they need to > > sign every BL2. The only implementation I've seen sets up the chip in > > BL2 (U-Boot SPL) so I don't think we can work around it. > > Not quite sure I'm following... > > So is secure-mode enabled before BL2 is started? Or do you mean BL2 is > where secure-mode is enabled? If it's done in BL2, and if the > hardkernel folks are willing to sign BL2 images (which I gathered from > discussions elsewhere in this series) then it seems possible to turn off > secure-mode.
Yes it is possible - and easy - to do in BL2 / U-Boot SPL. This is what the Chromebooks do. > > > So I went to look in the u-boot-samsung repo and didn't see the code for > the SPL there. Is the BL2 source (which I understood to be u-boot SPL) > in some other repo? It's in mainline U-Boot so no particular need to go to the Samsung tree. See arch/arm/cpu/armv7/exynos/spl_boot.c and tzpc.c for the TrustZone stuff. > > > It takes us back to the 1960s where we sent off our code at night to > > run it :-) > > > > I think the best bet is the current effort to mainline the rest of the > > Chromebook code then try to build it for XU3. > > What's the status of that effort? Coming along but the big/little support is still not there. The display works and most core peripherals. Needs more SPL work. > > > >> > >> I'm working on getting these same features working on the XU3, but this > >> broken firmware as brought a halt to any real progress. > > > > Agreed, but I think this is feasible once U-Boot on XU3 is sorted out. > > Let's hope so. > > Kevin > Regards, Simon _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
