On Mon, 4 Mar 2013, Marek Vasut wrote:
Date: Mon, 4 Mar 2013 13:15:33 +0100
From: Marek Vasut <marek.va...@gmail.com>
To: r...@controlq.com
Cc: arm@openbsd.org
Subject: Re: Any platform useful as a graphical desktop?
Dear Rob Sciuk,
On Sun, 3 Mar 2013, Marek Vasut wrote:
Bootp is weird junk, just use tftp to transfer your files (using the
'tftp' command in U-Boot) and then 'bootm' that stuff. Note that the FDT
location is passed to the kernel in one of the CPU registers, R2 IIRC.
Best regards,
Marek Vasut
True, but dhcpd/bootp only knows about the kernel file ... when using the
dhcp protocol to download the file system, fdt and kernel, you have to
explicitly arrange for the files other than the kernel image to be loaded
into memory first. Hence the extension ... and yes, R2 contains a pointer
to the fdt (on PPC, not sure about ARM), but it has to get to RAM somehow
... unless you have it in flash and are point to it directly ...
Uh, so why not switch to tftp or nfs since it's much easier to work with ?
This was a work related project on a PPC/FPGA(7) ATCA platform. A number
of constraints were in place, and the mechanism described allows MAC
address setup in U-Boot (as determined by querying the Shelf controller
via a serial port), and a great deal of flexibility in that by changing
ONLY the dhcpd configuration, we can load different OS/FPGA loads onto the
blade. It has worked very well for us, as the ATCA platform is a
controlled environment (and WE have control). I don't defend the design
decision, only mention it as it works well. Also, this application is a
high powered telecom simulator aimed at CO's of major telecom carriers,
not a mass market product such as PDA.
Your comments regarding the aged Bootp protocol were well taken, but a
close code inspection gave us the all the necessary info to extend the
protocol, and the end result has provided good flexibility for future
enhancements with a minimum of coding.
Given another project, particularly one aimed at end users, I would be
loathe to use Bootp (extended) given the ability to use tftp and/or NFS
directly, and I would love to see the OF support become a widespread
standard mechanism within the ARM world ... so basically, yes, I agree
with you 8-).
Cheers,
Rob.
ps: Any thoughts about supporting a (net?) BSD on the Palm platforms??
You did some very nice work in this area prior to your graduation!!!!!
