Intel Edison Initial Assessment
joel.sherrill at oarcorp.com
Tue Dec 9 23:34:39 UTC 2014
Some initial notes as Jeff and I investigate bringing up
RTEMS on an Intel Edison. The short answer is that the
Intel Edison is not going to work out of the box with our
PC BSP. I am really hoping others have ideas and quick
suggestions so it has a chance of working next week
at the FSW. :)
+ SoC documentation won't be out until later this month.
+ Has U-Boot and doesn't appear to have a 16-bit mode at all.
+ Looks like U-Boot will want a binary image to boot.
+ There is a comment in the Intel forums that the PCI
configuration space is memory mapped and not IO mapped
like a regular PC.
This means the PCI initialization and support code needs to
be different for Edison from other PCs.
+ All serial ports are on the PCI bus. It looks like the PCI
layout is constant so for a start, I am hacking a simple
polled driver for one UART and go from there. U-Boot
initializes it so I can ignore that part. This should be
enough to at least temporarily get around the lack of PCI
config space code.
+ There is a watchdog on it that needs to be disabled apparently.
+ Looks like it doesn't have a legacy i8254 timer and has an APIC.
Not sure what else lurks. But unless someone drops an APIC clock
driver on me, I think getting a booting hello world is a nice goal for
Joel Sherrill, Ph.D. Director of Research & Development
joel.sherrill at OARcorp.com On-Line Applications Research
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