Re: odroid hc1 on debian?

Sorry, I got confused by the package naming "exynos",

https://anonscm.debian.org/cgit/collab-maint/u-boot.git/tree/debian

has debian/u-boot-$package.README.Debian

thus a custom README would need to be u-boot-exynoss.README.Debian?

> Not sure if the partitioning is in sync. Debian uses 1MB
> before the first partition?

Yes, as that is the standard layout that all modern partitioning
tools use for MBR-style partition tables.

Someplace I saw a schema where u-boot got 1MB of space reserved for it, thus 2MB would be required before the first partition.

But with the 720kB space for u-boot we are fine.

I am unclear about where you took the 720k as an offset for
u-boot from. Did you derive that from the filename
"bl2.bin.hardkernel.720k_uboot"? That file isn't u-boot, but
bl2, i.e. the ATF "Trusted Boot Firmware".

My understanding is: bl2 loads u-boot, and "720k" in the name indicates

that it expects u-boot size to be that large. Smaller sizes padded with zero are fine.

The trustzone blob is expected behind u-boot, and the u-boot env after that one.

So it is one long chain of elements of fixed sizes, and having soom room in the u-boot part

makes sense, as only the vendor can update those blobs, I suppose?

One more question:

on arm, is there any code in the first sectore side by side to the partition table?

I know x86 has the mbr code in it, some tiny code to scan the partition table for the first partition with the boot flag set, and then load the first sector of that partition. Or some code that loads grub/lilo/... from non-partition space. Is arm doing the same or is arm firmware loading from sector 1+ of the boot device without code in sector 0?

Does the XU4/HC1 work with a 3.3V cable or does it require one of
the rather rare (and expensive) 2.5V or 1.8V models? If a 3.3V
cable is sufficient, send me a PM for a resonably priced source
in Germany.

The odroid usb-uart supports 1.8V-3.3V, so I guess it needs such a device. Can't find one without a huge price tag and/or international shipping costs.

But as I have several devices, my new effort is to get four wires, and cross-wire them.

Thus on one I should be able to disable the serial console (hmm, can I do that during run-time), start minicom and watch the boot log of the other device.

Regards, Andreas