On Wednesday 01 February 2023 09:17:15 Michael Walle wrote:
When DM_SERIAL is enabled, the device-tree property dm-pre-reloc is required to boot over UART with kwboot. Enable this in a Kirkwood common u-boot dtsi.
My (dev) board unfortunately, have a bootloader which can't boot over serial.
This is feature of Marvell BootROM and does not require any special from Bootloader. So you should be able to boot over UART (if you have accessible pins).
I know, but there are known versions ob the bootrom where uart boot isn't supported (correctly).
I heard about it... maybe it is a bug in client software (kwboot)? I do not have such board if you are interested in it I could try to send some details how to debug it.
I also have another board which can boot over uart. But thats in daily use ;)
Could you elaborate that a bit more? Why is this required for uart boot? kwboot will talk with the bootrom why does u-boot need anything? Or will there just be no output until the uart is initialized?
On mvebu/armada boards this dm-pre-reloc is required to ensure that DT nodes are present in SPL DTB file. Otherwise build process drop all non-pre-realoc nodes from SPL version of DTB file. And because SPL use DM serial, it is required to have uart DT nodes in DTB file. Btw, same problem is with SPI in SPL.
But... kirkwood does not use SPL, so I do not know what is reason for this here.
Yes thats what puzzled me, too.
Signed-off-by: Tony Dinh mibodhi@gmail.com
arch/arm/dts/kirkwood-u-boot.dtsi | 7 +++++++ 1 file changed, 7 insertions(+) create mode 100644 arch/arm/dts/kirkwood-u-boot.dtsi
Is this new? AFAIK only <boardname>-u-boot.dtsi is included automatically.
It is not new, Tom wrote about it quite ago: https://lore.kernel.org/u-boot/20220802121113.GG1146598@bill-the-cat/
Thats relatively new for someone not following the u-boot development that closely ;) Thanks for the pointer.
-michael