Date: Wed, 30 Apr 2014 01:18:17 +0200 From: Bernd Walter <ticso@cicely7.cicely.de> To: Thomas Skibo <ThomasSkibo@sbcglobal.net> Cc: freebsd-arm <freebsd-arm@freebsd.org>, ticso@cicely.de Subject: Re: SMP support for ZEDBOARD Message-ID: <20140429231817.GK39364@cicely7.cicely.de> In-Reply-To: <536029BE.5090108@sbcglobal.net> References: <20140429030345.GB28551@cicely7.cicely.de> <35977CB2-45FD-4703-BAAC-87E47688FB3F@netsense.nl> <535FD615.6020500@sbcglobal.net> <20140429183404.GU28551@cicely7.cicely.de> <536009B1.6040503@sbcglobal.net> <20140429205740.GE39364@cicely7.cicely.de> <20140429210334.GF39364@cicely7.cicely.de> <20140429212013.GG39364@cicely7.cicely.de> <20140429212929.GH39364@cicely7.cicely.de> <536029BE.5090108@sbcglobal.net>
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On Tue, Apr 29, 2014 at 03:37:50PM -0700, Thomas Skibo wrote: > > > On 4/29/14, 2:29 PM, Bernd Walter wrote: > >>>> > >>>>Oh - interesting. > >>>>I thought it is just booting from SD and assumed we can use what you > >>>>did for the Zedboard to begin with. > >>>>Wonder why they added a flash chip, when they could have gone without. > >>>>Is this a pin strapping configuration, or something, which can be > >>>>changed? > > It looks like it can't boot (directly) from the SD card because it is > attached to SDIO1 and not SDIO0. I guess it can only boot from SDIO0 > and SDIO0 isn't available if you have two USB interfaces and Ethernet. > Take a look at the MIO-at-a-Glance Table in the Zynq manual (page 52 in > my copy). Hence, the need to boot from the QSPI flash. I remember someone on the forum mentioning second SDIO0 when droping the other USB, which isn't really usefull at all it seems. Maybe next board generation, but even then likely still not the primary SDIO. > >>Did I get it right, that the ROMcode loades the FSBL from either JTAG > >>or flash. > >>The FSBL then could load u-boot from whatever it supports, but on > >>the parallella they load u-boot from QSPI, so it has to be updated? > >>I do have a JTAG available, according to the parallella schematics > >>however it is setup via solder pull-up vs pull-down resistor. > >>I also have a hot air soldering station, but still not nice. > >>I also would have to lock up where the JTAG is - probably on one of the > >>Samtec connectors :-( > > > >Ok - JTAG is on the SAMTEC. > >Bootmode as well - the resistor mode pin was cascaded JTAG vs dedicated. > >No soldering, but needs some kind of breakout board. > >I remember having seen 0.1" breakout somewhere already, not sure if > >it's possible to get one of them. > >A JTAG defintively should be reachable in case it's bricked. > > > > It should be possible to create a u-boot that will work with either > FreeBSD or Linux, program it once, and be done. Xilinx's latest u-boot > release can do this because it has CONFIG_API set and allows a uEnv.txt > file to customize the boot environment. This is how I can boot FreeBSD > with an unmodified u-boot. I think I may already have a config built > that might work. > > Then, it's a matter of reprogramming the QSPI flash. This describes how > to program the QSPI flash presumably even if it's blank: > > https://github.com/parallella/parallella-hw/tree/master/boards/parallella-I/firmware > > But if the flash is already programmed, I think it might be possible to > stop it at a u-boot prompt, skip to step 9 and program the new image. > Just hope there's no power failure while rewriting! Looks like they use JTAG to load a u-boot, from which they flash the SPI. Anyway, until things are well tested you could brick the board. I definitively want a breakout board to have JTAG access. Will ask on the forum for options, worst case I will do a layout on myself, but prefer getting something ready. In this description loading u-boot via JTAG is done using Xilinx tools. so you need a Xilinx supported JTAG - which I have. Unclear if it is possible via OpenOCD, which would open more JTAG adapters. -- B.Walter <bernd@bwct.de> http://www.bwct.de Modbus/TCP Ethernet I/O Baugruppen, ARM basierte FreeBSD Rechner uvm.
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