[U-Boot] Rockchip RK3288 u-boot with mainline kernel

[Rick Bronson]

Hi Heiko and Simon,

  Thank you both for your help, I really appreciate it.

  No, I do not have the Linux mainline running yet as I was focusing
on getting the mainline u-boot running since I saw some references
that implied I may need that to use the mainline Linux.  I did try the
mainline kernel with the vendor-fork u-boot but got nothing pas the
"Loading Linux...." line from u-boot.

  I think what I will probably do is take the easy way out and use the
vendor-fork u-boot since that boots on this hardware.

  But since I've invested some amount of time in the mainline u-boot
and it's drinving me mad that I can't seem to figure out what's wrong,
I do have one last question (hopefully).

  I've got mainline u-boot getting this far (I added debug to show
what GPIO0 and 2 are outputting).

--------------------
U-Boot SPL 2016.11-00138-g136179b-dirty (Nov 28 2016 - 13:29:59)
Trying to boot from MMC1
Card did not respond to voltage select! GPIO0=0x0 GPIO2=0x0
...
--------------------

  I've modified rk3288-firefly.dts (the closest thing to hardware I
have) to set the eMMC reset line high but as you see above, nothing is
set on any GPIO.  This leads me to believe that I do not understand
how the device tree is loaded/used in SPL.  Can anyone point me to
help on whether I should use u-boot-spl-nodtb or u-boot-spl-dtb (I've
tried both) or how to debug if I am in fact even reading my dtb.

  Thanks again,

  Rick

PS.  My Makefile is here if you are so inclined:
http://members.efn.org/~rick/pub/Makefile  See the targets u-boot-denx
and uboot_new_flash to see what I've tried.
>
> From heiko at sntech.de Tue Nov 29 08:45:02 2016
> To: u-boot at lists.denx.de
> Cc: Simon Glass <sjg at chromium.org>, Rick Bronson <rick at efn.org>,
"eddie.cai" <eddie.cai at rock-chips.com>,
linux-rockchip at lists.infradead.org
> Subject: Re: [U-Boot] Rockchip RK3288 u-boot with mainline kernel
> Date: Tue, 29 Nov 2016 11:20:52 +0100
>
> Hi Rick,
>
> Am Montag, 28. November 2016, 15:09:05 schrieb Simon Glass:
> > + A few rockchip people and linux-rockchip
> >
> > Hi Rick,
> >
> > On 25 November 2016 at 11:20, Rick Bronson <rick at efn.org> wrote:
> > > Hi All,
> > >
> > >   I've got unsupported RK3288 hardware running the latest git u-boot to
> > >
> > > SPL as explained in
> > > http://git.denx.de/?p=u-boot.git;a=blob;f=doc/README.rockchip.  My goal
> > > is to run the mainline (ie. not Android) Linux kernel on this hardware
> > >
> > > and wondered:
> > >  - Do I need to get the latest git u-boot to run before I can run the
> > >
> > > mainline kernel?  Or can I use
> > > github.com/linux-rockchip/u-boot-rockchip.git, which I have running
> > > u-boot fully.
> >
> > It's up to you - obviously mainline is where the development should
> > be, but there is no requirement that I know of.
>
> correct, the (mainline-)kernel runs just fine on both the vendor-fork of
uboot
> as well as on mainline.
>
>
> > Does mainline run on your board?
> >
> > >  - The device tree seems to be in two places, once via:
> > >         resource_tool --image=resource2.img --pack linux/logo.bmp
> > >         ${DTS}.dtb
> > >
> > >   that gets put into the resource file and then again at the end of the
> > >
> > > kernel via CONFIG_ARM_APPENDED_DTB.  Do I need both?  When I do both
> > > I get things like:
> >
> > > Unknow param: MACHINE_MODEL:rk30sdk!
> > > Unknow param: MACHINE_ID:007!
>
> ARM_APPEND_DTB is meant for boards where the bootloader cannot load the
> devicetree (to old or so) and also cannot be reasonably exchanged. So the
> append-mechanism was invented to allow bundling the devicetree with the
actual
> kernel image, so that to the bootloader it looks like just any other kernel
> image.
>
> So you essentially only need one or the other. Also at least mainline uboot
> also supports the FIT image type, where you can bundle the devicetree in a
> more generalized way.
>
> For your message I would guess the kernel didn't find a usable devicetree
> somehow and was falling back to ATAGS-based board selection?
>
>