Hi Tony, Hi Pali,
On 2/10/23 02:37, Tony Dinh wrote:
<snip>
Could you please check if Pogo V4 boots with CONFIG_REQUIRE_SERIAL_CONSOLE unset?
Indeed, you're right! unset CONFIG_REQUIRE_SERIAL_CONSOLE allows the Pogo V4 to boot OK, without dm-pre-reloc needed. And it booted normally with kwboot, all serial input/outputs are OK.
Also, note that just enabling DEBUG_UART would always make the board frozen when u-boot starts.
This should not be the case of course. Are you sure you've correctly configured the DEBUG UART?
I think I did that correctly (we've used that to debug the orion_timer issue previously). Here is how I've configured it:
+CONFIG_DEBUG_UART_BASE=0xf1012000 +CONFIG_DEBUG_UART_CLOCK=250000000 +CONFIG_DEBUG_UART=y
Maybe you hit same issue in mach-kirkwood as me in the past for mach-mvebu? U-Boot code was trying to initialize UART at the _new_ base register address (0xf1012000) when U-Boot was still using the _old_ base register address (0xd0012000).
I fixed it by moving code which changes base register address from arch_cpu_init() function to arch_very_early_init() function in commit: https://source.denx.de/u-boot/u-boot/-/commit/5bb2c550b11eb087437740b2a0d1fe...
Thanks Pali, this is very likely the root cause here.
Thanks for the info! Looking at that patch, I think I'm out of my depth :)
Here the line for Kirkwood, re-configuring the base address of the internal registers:
https://source.denx.de/u-boot/u-boot/-/blob/master/arch/arm/mach-kirkwood/cp...
You need to make sure, that this configuration is done before you use the DEBUG UART with base address 0xf1xx.xxxx. If you use the DEBUG UART before this, which is very likely, then you could also test if this works for you:
CONFIG_DEBUG_UART_BASE=0xd0012000
For now I will fix this Pogo V4 with the -u-boot.dtsi, so as not to mess up anybody who might try UART booting with kwboot.
Sure, please go ahead this way for now.
BTW: Many years ago my intention was to include the Kirkwood support into the "common" Marvell MVEBU support in mach-mvebu. So that mach-kirkwood and it's special handling could be dropped. It's great to see that Kirkwood is getting attention now. Perhaps this move into mach-mvebu could be addressed at some point.
Thanks, Stefan
Thanks, Tony
So this was another factor why it took me so long to figure this out :) I've just restored everything and removed the uart0 node from the Pogo V4 DTS like above and it is working.
But of course, we don't want to change the Pogo V4 DTS, so I will submit another patch just for the Pogo V4 to add -u-boot.dtsi for this box to enable the dm-pre-reloc tag for uart0.
Understood.
Thanks, Tony
Thanks, Stefan
Viele Grüße, Stefan Roese