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

Reply via email to