[U-Boot] [linux-sunxi] Re: Basic A33 support including dram init available in my personal repo

[Chen-Yu Tsai]

Hi,

On Mon, Mar 9, 2015 at 4:39 PM, Vishnu Patekar
<vishnupatekar0510 at gmail.com> wrote:
> Hello,
> It's sensible work by Allwinner to release the dram code under GPLv2.
>
> Now, we can have mainline u-boot support for A33 soon.
>
> Hans,
> Yes, I've very basic A33 dts created based on A23, still lot to do.

About the dts, so far the memory maps look the same. I haven't
checked the clocks or interrupts, but I bet they are the same as
well.

Could we use an overlay over A23 with just the different pieces
overriden? Though they're not the same piece of silicon, they are
damn close. Maybe even the PIO is the same.

Maxime, any thoughts?

Regards
ChenYu

> I'll send the u-boot patches soon. so that, you all can review it.
>
> On Sun, Mar 8, 2015 at 5:33 AM, Siarhei Siamashka
> <siarhei.siamashka at gmail.com> wrote:
>>
>> On Sat, 07 Mar 2015 20:06:27 +0100
>> Hans de Goede <hdegoede at redhat.com> wrote:
>>
>> > Hi,
>> >
>> > On 02-03-15 11:25, Hans de Goede wrote:
>> > > Hi,
>> > >
>> > > On 01-03-15 19:42, Vishnu Patekar wrote:
>> > >> Allwinner A33 tablets comes with the libdram binary, fortunately I've
>> > >> found the libdram code at
>> > >> https://github.com/realthunder/a33_bootloader/tree/master/basic_loader/bsp/bsp_for_a67.
>> > >
>> > > Ah, that is both good and bad...
>> > >
>> > >> I've integrated it with mainline u-boot, still lot to do to post it to upstream
>> > >
>> > > Integrated sounds as if you've copied pieces of code from the bsp code you've found
>> > > into mainline u-boot. That is a big no no (this the bad part). AFAIK the bsp code
>> > > does not come with a GPL license header, and Allwinner does not want to release
>> > > these bits under the GPL for whatever reasons, a lot can be said about this, but
>> > > in the end currently the bsp code is not GPL licensed, so we cannot use it / copy
>> > > from it. There can be no discussion on this, when you're submitting this upstream
>> > > you must not have any literal copied code in the patch you're sending upstream.
>> > >
>> > > You can use non copyrightable information from the bsp sources like register
>> > > names and the initialization algorithm (IANAL), but you must 100% write your own
>> > > code!
>> >
>> > Ok, so something (to me) quite unexpected has happened and Allwinner has just
>> > released what seems to be ALL there boot0 code under the GPL, it can found here:
>> >
>> > https://github.com/allwinner-zh/bootloader/tree/master/basic_loader/boot0
>> > https://github.com/allwinner-zh/bootloader/tree/master/basic_loader/bsp
>> >
>> > Specifically interesting for the discussion at hand is:
>> > https://github.com/allwinner-zh/bootloader/blob/master/basic_loader/bsp/bsp_for_a33/init_dram/mctl_hal.c
>> >
>> > Which caries a GPL header now. This completely changes my story above, whatever
>> > you have (or had, sorry) was fine. It should still be cleaned up a bit, but all
>> > my worries about copy and pasting non GPL code are gone now.
>>
>> It is strange that this has caught you by surprise, because you had been
>> informed about what is going on:
>>
>>     http://lists.denx.de/pipermail/u-boot/2015-March/207174.html
>>
>> Basically, we need to thank David and Vishnu for negotiating this with
>> Allwinner (and this communication has been going on for some time
>> already), which resulted in a reasonable solution in the end. You have
>> also played your role well. My intervention was only needed to ensure
>> that Vishnu does not get discouraged by your response, which originally
>> sounded like only a single less than perfect solution was possible :-)
>>
>> Yes, we are kinda lucky to have discovered this apparently leaked A33
>> dram code. I don't approve the actions of whoever is responsible for
>> this leak. But we ended up in a situation where the "bad" guys
>> (competitors?) have already got access to the code to learn all the
>> "secrets", while the "good" guys (us) could not use the code because
>> of the missing license notices. And Allwinner just made a rational
>> decision how to deal with it (in the same way as this happened with
>> the previous code leaks). Having also the A23, A83T and A80 dram
>> code open sourced under the GPL license is very much appreciated.
>> It means that U-Boot can get full support for A83T and A80 too.
>>
>> Special thanks to Vishu for not trying to hide the origin of the A33
>> dram code. I particularly like full transparency and honesty in
>> handling this case.
>>
>> I'm still not completely happy about the presence of magic numbers all
>> over the place (for example, Rockchip sources for very similar dram
>> controllers have proper named identifiers for the hardware register
>> bitfields) and other code quality problems. In a prefect world, we
>> would also get full documentation for the dram controllers and the
>> errata lists. But even the current source code is enough to move
>> from the dead point.
>>
>> --
>> Best regards,
>> Siarhei Siamashka
>
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