AM5728: AM572x – serial-boot.pl

Thank you, Keerthy.

Following your instructions I moved back to the SDK provided with EVM, which is 02.00.01.07.
Still, no serial-boot.pl found over there.
But following the instructions and serial-boot.pl file i found in the internet, I wrote my own serial loader. It took me some (significant) time to make it working...:-)

I am pretty sure it works fine, as there was one pre-built u-boot-spl.bin file in 06.03.00.106 which I loaded via UART, loaded u-boot.img (via UART too) and  it turned to load Linux (no need for now).

Now, I tried both pre-built SPL's in the SDK - no success. After downloading the board is silent forever.
The same with the SPL obtained after compiling (with am57xx-evm-defconfig) u-boot .

Again, I think the download passes, as in all cases of errors I saw the CPU returning to sending ASIC ID, while after my loading it is silent (for hours).

Leon Pollak said:

But following the instructions and serial-boot.pl file i found in the internet, I wrote my own serial loader. It took me some (significant) time to make it working...:-)

Thanks! That is great.

Leon Pollak said:

I am pretty sure it works fine, as there was one pre-built u-boot-spl.bin file in 06.03.00.106 which I loaded via UART, loaded u-boot.img (via UART too) and  it turned to load Linux (no need for now).

So you could get to U-Boot prompt using your serial-boot.pl?

Leon Pollak said:

Now, I tried both pre-built SPL's in the SDK - no success. After downloading the board is silent forever.
The same with the SPL obtained after compiling (with am57xx-evm-defconfig) u-boot .

What worked in the previous step? Apologies once again as this is NOT validated. I do not have feedback on this.

- Keerthy

In the ..../board-support/prebuilt-images of the SDK 06.03.00.106 there are two files:
u-boot-am57xx-evm.img  
u-boot-spl.bin-am57xx-evm
I can download them via UART and arrive to the Linux downloading (which fails because of incorrect environment, which is OK for me now).

Now, after compilation of the am57xx_defconfig  in the "spl" directory there are 3 suspicious (for downloading) files:
u-boot-spl.bin            - works as expected
u-boot-spl-dtb.bin      - the same file as above, works as expected (binary equal)
u-boot-spl-nodtb.bin  - does not work

1. Can you be so kind to explain why there are three and what is the difference?
2. Please, give me a hint - how can I load u-boot.img via Ethernet? I mean how can i tell this to the SPL, if possible.

Many thanks!!!!

Leon Pollak said:

1. Can you be so kind to explain why there are three and what is the difference?

Sure. u-boot-spl.bin & u-boot-spl-dtb.bin are the same and the second one explicitly names that it has DTB as well.
That is the one we should be using for booting. Either of them are okay.

Leon Pollak said:

u-boot-spl-nodtb.bin  - does not work

This is legacy without DTB So please ignore that.

Leon Pollak said:

2. Please, give me a hint - how can I load u-boot.img via Ethernet? I mean how can i tell this to the SPL, if possible.

As soon as SPL is loaded successfully. You should see the SPL prints on the minicom.

- Keerthy

Thank you!!!

About the Ethernet - when the SPL is loaded it issues "C" once per 1-2 seconds and after some time switches to some non-ASCII symbol.
Does this means that it also tries to perform bootp algorithm?
Please, in order to not to disturb you - where can I read about this- I didn't find something...