I will document what I can find about the RV86 screen, here:
https://linux-sunxi.org/Lichee_RV_86_Panel
On Thu, May 26, 2022 at 9:02 AM Bram Stolk <b.st...@gmail.com> wrote:
> Awesome!
> I now have the mainline kernel running.
> Thanks for all your help.
> I added this info to the wiki.
> (I did have to add some kernel parameters to get the serial console.)
> I also copied my Debian rootfs, and it works fine.
>
> And indeed, the display stays black.
> I do see the backlight come on, for the display.
> But copying data to /dev/fb0 does nothing.
> I'll try to poke around a bit, to see if I can get more info.
> Maybe the driver has a verbose flag that I can turn on.
>
> $ sudo fbset -v -i -s
> Linux Frame Buffer Device Configuration Version 2.1 (23/06/1999)
> (C) Copyright 1995-1999 by Geert Uytterhoeven
>
> Opening frame buffer device `/dev/fb0'
> Using current video mode from `/dev/fb0'
>
> mode "480x480"
> geometry 480 480 480 480 32
> timings 0 0 0 0 0 0 0
> accel true
> rgba 8/16,8/8,8/0,0/0
> endmode
>
> Getting further frame buffer information
> Frame buffer device information:
> Name : sun4i-drmdrmfb
> Address : 0
> Size : 921600
> Type : PACKED PIXELS
> Visual : TRUECOLOR
> XPanStep : 1
> YPanStep : 1
> YWrapStep : 0
> LineLength : 1920
> Accelerator : No
>
> On Wed, May 25, 2022 at 6:33 PM Samuel Holland <sam...@sholland.org>
> wrote:
>
>> On 5/25/22 7:08 PM, Bram Stolk wrote:
>> > Thanks again, Samuel, for all your help.
>> >
>> > Still not getting there:
>> >
>> > => booti ${kernel_addr_r} ${ramdisk_addr_r}:0 ${fdt_addr_r}
>> > Moving Image from 0x40040000 to 0x40200000, end=415e10d8
>> > ERROR: Did not find a cmdline Flattened Device Tree
>> > Could not find a valid device tree
>> >
>> > I will read up on "device trees" but I am not sure if I am responsible
>> for
>> > setting that up before booting?
>>
>> It is recommended to reuse the devicetree from U-Boot, which is already
>> loaded
>> into RAM. Its address is stored in the predefined environment variable[1]
>> $fdtcontroladdr. Since it appears you don't have a ramdisk, you can try:
>>
>> booti ${kernel_addr_r} - ${fdtcontroladdr}
>>
>> where the hyphen is a shortcut for "no ramdisk".
>>
>> The devicetree at $fdtcontroladdr contains extra information detected by
>> firmware during boot, such as the size of RAM, which varies between
>> boards. That
>> information would be missing, and Linux would fail to boot, if you loaded
>> a DTB
>> file with "ext4load" or similar.
>>
>> A generally simpler option may be to use an extlinux.conf file, since
>> that hides
>> most of these details. The following example may be all you need:
>>
>> # cat /boot/extlinux/extlinux.conf
>> label default
>> linux ../Image
>> append root=/dev/mmcblk0p2 rootwait
>> #
>>
>> This will be loaded automatically if you mark your boot partition as
>> bootable in
>> the partition table. Then you don't have to deal with environment
>> variables,
>> booti vs. bootm, scripts, or devicetrees, etc.
>>
>> Regards,
>> Samuel
>>
>> [1]:
>>
>> https://u-boot.readthedocs.io/en/latest/develop/devicetree/control.html?highlight=fdtcontroladdr#configuration
>>
>
>
> --
> Owner/Director of Game Studio Abraham Stolk Inc.
> Vancouver BC, Canada
> b.st...@gmail.com
>
>
--
Owner/Director of Game Studio Abraham Stolk Inc.
Vancouver BC, Canada
b.st...@gmail.com
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