Hello Simon, Lukasz,
On Tue, Dec 2, 2014 at 2:29 PM, Lukasz Majewski l.majewski@majess.pl wrote:
Hi Simon,
Hi,
On 28 November 2014 at 06:46, Lukasz Majewski l.majewski@majess.pl wrote:
Hello Javier,
Hello Lukasz,
On Fri, Nov 28, 2014 at 9:39 AM, Lukasz Majewski l.majewski@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He or she would like to replace standard (and outdated) HardKernel u-boot on their SD card and go forward with booting kernel.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:
- 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.
- All the documentation on the HardKernel wiki site refers to the
default BL2.
- We will have "new" BL2, which source code is based on 2012.07
mainline u-boot.
- 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:
- Provide updated BL2.img
- 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:
- 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)
- 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
While it is shipped with the board if you get an eMMC, the main way people will get this is by downloading it from their site. So why not download something different?
As far as I remember U3 and probably XU3 in their README only points for HardKernel's site to grab BL1 and BL2. We don't plan to include their binaries to u-boot repository.
Re the plan, I think 1 is fine so long as it is protected by a big ugly hack CONFIG and we can turn it off soon and revert the code.
Hyungwon's patches only touch u-boot and rely (temporary I hope) on BL1 and BL2/SPL from Hardkernel.
For 2, the size issue is one problem, but the clock code in U-Boot is another IMO. We should try to get both resolved. Maybe it is possible to use the peach-pit BL2 and get hardkernel to test it and sign it?
I guess that SPL from peach-pit should be tunable to work with XU3 (in a finite number of iterations including signing from HardKernel).
As it is based on recent u-boot it should be easy to produce BL2/SPL only for XU3 (if needed).
Then people will download that one instead.
is there a contact at hardkernel on the mailing list?
As fair as I know no.
I was posting questions on their forum. Maybe it is a right place to ask for contact point? As fair as I remember they were willing to sign SPL/BL2 when sent to them.
I have gotten a BL2 signed (based of their repository) which allows a bigger U-Boot for testing, and it works. I have currently requested another signed BL2 which lets one use a 1MB U-Boot image which should be adequate. This is in the works. I do not work for hardkernel but I do have a working relationship with them. From the looks of it they are more than willing to accomodate this BL2 change. I can take this action point of getting this BL2 and its related paraphernalia hosted on their website once they are OK with its testing.
Regards - Suriyan
Regards, Simon
Best regards, Lukasz Majewski
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