Hi,
On 08-01-15 18:11, Lars Doelle wrote:
Hi,
I tried the microSD procedure and the results are
such, that all works well for u-boot-sunxi, but all
fails for mainline u-boot.
In the later case, i get some endless binary stuff out
of the microSD tty line, mostly 'U's and some
unprintable chars, while in the first case, i get a
proper u-boot(-sunxi) console on microSD tty.
There has been a recent fix to get CONFIG_UART0_PORT_F
working with upstream u-boot, which is not yet
upstream (it is queued for merging once v2015.01 is
released).
If you want to play with upstream u-boot on a tablet the
best thing todo is to use my sunxi-wip branch:
https://github.com/jwrdegoede/u-boot-sunxi/tree/sunxi-wip
That also has the ability to use your tablets lcd screen
for u-boot boot messages output (and I'm working on
adding support for the OTG connector to use it with
a usb keyboard). See one of the existing tablet configs
as example how to create a config for your tablet with
lcd output support, see: http://linux-sunxi.org/LCD
for details on the LCD timings stuff. Note you can start
with a config without LCD support and the PORT_F uart
for testing.
The unprintable chars you are seeing are the result of
u-boot trying to use the sdcard slot as an actual sdcard
slot :)
Note that since u-boot gets build twice when using the
SPL (such as we do for sunxi), we have 2 .config files,
to use fel-boot + port-f uart with sdcard breakout, you
need to specify CONFIG_SPL_FEL=y and CONFIG_UART0_PORT_F=y
in both config files, so in both of:
.config and spl/.config
E.g. to use this setup on my Ippo_Q8H tablet I do:
make -j4 CROSS_COMPILE=arm-linux-gnu- Ippo_q8h_v1_2_felconfig
Note the felconfig instead of defconfig, this will automatically
set CONFIG_SPL_FEL=y, then edit .config *and* spl/.config and
change CONFIG_UART0_PORT_F=n into CONFIG_UART0_PORT_F=y in BOTH
files, then do:
make -j4 CROSS_COMPILE=arm-linux-gnu-
And then fel boot as usual and you will get a working uart on
the sd breakout (assuming that you are using my sunxi-wip
branch or the official u-boot-sunxi/next, but that one does
not yet have LCD support).
Thus for now, I'm stuck there with the device,
[[Tristan-Auron-Planet-1]], an A20 tablet, with
respect to upgrading to mainline u-boot.
I hope the above helps, I would certainly welcome a _defconfig
file for upstream u-boot for that tablet, preferably one with
LCD support :)
If you need any further help do not hesitate to ask.
I really wonder what this could be. I had no problems
booting the tablet with u-boot-sunxi and could use
the u-boot-sunxi binary both for this device and for
a Lime2 board. I can perfectly boot the Lime2 board
using mainline u-boot.
Thus, my finding is such, that u-boot issues some difference
between the tablet and the board which are not noticeable
on u-boot-sunxi. As good as I understand both hardware,
it should really behave identical as only the core SoC
material is invoked at that time.
I tried setting the dram parameters for the tablet as
reported by meminfo and removed some extra Lime2
specific stuff from the config but results are still identical.
I can still boot the Lime2 board using it, but not the tablet.
Also, I tried deactivating vga, usbkbd. No change.
I regret for not being able to provide any more specific
diagnosis, but hope the effect is somehow familiar. Perhaps
there more stuff i should try to deactivate in mainline u-boot?
There should be some chance do find the issue by a
differential diagnosis. Any suggestions, hints, guesses?
As said I think the missing fix for the uart on port f config
is the cause of your problems.
Regards,
Hans
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