Lukasz Majewski <l.majew...@majess.pl> writes: [...]
>> On 28 November 2014 at 06:46, Lukasz Majewski <l.majew...@majess.pl> >> wrote: >> > Hello Javier, >> > >> >> Hello Lukasz, >> >> >> >> On Fri, Nov 28, 2014 at 9:39 AM, Lukasz Majewski >> >> <l.majew...@majess.pl> wrote: >> >> >> I have yet to take him up on that offer though, but it sounds >> >> >> like a good way forward. The current layout really isn't >> >> >> practical. >> >> >> >> >> > >> >> > It indeed isn't very practical, but this is what you received >> >> > from HardKernel when you buy XU3 board. >> >> > >> >> > Of course you can grab their sources, modify the layout, prepare >> >> > u-boot's SPL and send it to them to be signed. >> >> > However, it is not the way the "normal" user do things. >> >> > >> >> > He or she would like to replace standard (and outdated) >> >> > HardKernel u-boot on their SD card and go forward with booting >> >> > kernel. >> >> > >> >> >> >> I agree with Sjoed that normal users don't replace the low-level >> >> components that are provided by the board vendor. >> >> >> >> After all you can boot a mainline kernel using the vendor u-boot, >> >> just append the DTB and create a uImage. The practical reason why >> >> someone would want to replace the vendor u-boot is to have more >> >> features but is very hard to do if there is a constraint in the >> >> maximum u-boot image size (even harder if the maximum is such >> >> small like in the XU3). >> > >> > I agree that 328 KiB size for u-boot is a constraint. I don't know >> > HardKernel's justification for this. >> > >> >> >> >> > For now we _must_ focus on supporting XU3 with default BL1/BL2 >> >> > and hence we are obliged to have u-boot size smaller than 328 >> >> > KiB. >> >> > >> >> > It is challenging but for sure doable. >> >> > >> >> >> >> It is doable but I don't see why the default BL2 _must_ be used. >> > >> > For practical/pragmatic reasons: >> > >> > 1. It is difficult to have signed BL2 - each time we need to ask >> > HardKernel for signing it. It is impractical and hampers usage of >> > mainline SPL (BL2) with XU3. >> > >> > 2. All the documentation on the HardKernel wiki site refers to the >> > default BL2. >> > >> > 3. We will have "new" BL2, which source code is based on 2012.07 >> > mainline u-boot. >> > >> > 4. Two BL2 binaries - IMHO will hurt (i.e. brick) some device sooner >> > or latter. >> > >> >> >> >> A user that wants to replace the kernel or u-boot is already >> >> tech-savy and can for sure replace the BL2 as well if it's >> >> publicly available. >> > >> > Sorry, but I'm a bit sceptical about updating such low level code. >> > Bad things do happen. >> > >> >> Maybe hardkernel folks can even make the modified BL2 available on >> >> their website and the link added in the comment explaining the >> >> layout? >> > >> > We would then require HardKernel to: >> > >> > 1. Provide updated BL2.img >> > 2. Update their wiki to reflect the new BL2. >> > >> >> >> >> Also, it is an artificial constraint after all and can be easily >> >> modified. In fact I think we should push hardkernel to change that >> >> layout by default and use a BL2/SPL that has more sensible size for >> >> the u-boot binary even if they don't need it for their vendor >> >> u-boot which seems to be quite small. >> > >> > I totally agree. >> > >> > I'd like to propose a following plan: >> > >> > 1. Accept Hyungwon's patches to have XU3 u-boot < 328 KiB (with >> > link to default BL2) to have XU3 support in place (and treat it as >> > a starting point) >> > >> > 2. If u-boot's size less than 328 KiB is _really_ a problem to >> > somebody then ask hardkernel to change BL2 or: >> > - modify their sources to change the layout (I regard this >> > as a "quick hack" solution) >> > - with a lot of pain develop BL2/SPL (by whom?) which base >> > on newest mainline (then for each test hardkernel must sign the >> > binary). >> >> My 2p worth... >> >> The current Hardkernel BL1 looks broken to me - it is just too old. > > +1 > 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'm working on getting these same features working on the XU3, but this broken firmware as brought a halt to any real progress. Kevin [1] http://lists.infradead.org/pipermail/linux-arm-kernel/2014-November/305790.html [2] http://lists.infradead.org/pipermail/linux-arm-kernel/2014-November/306480.html _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
