Re: [Balloon] Trying to get a loon with USB host working

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Author: David Bisset
To: Wookey
CC: Balloon
Subject: Re: [Balloon] Trying to get a loon with USB host working
I can only comment on the hardware.

Firstly the two connectors where USB Host might appear are:
J11 (on the bottom at the processor end) this is the "Comms Connector"
J13 (top next to the power connector) this is the Pinko Connector.

J11 will only be fitted on early CUED boards.
J13 should be fitted on all Balloons.

The USB Host power is an integral part of the USB Host signals as it must switch on and off appropriately.
This is available on J11, or on the white SUR connector J4 next to the processor.

The USB Host availability changes depending on board revision as a result of finding OTG doesn't work.

3v21 (early CUED and single sided CPLD Barric) USB Host - and + only available on J1,1 power on J11 and J4
3v31 USB Host - and + available on J13 p22 and p23. Power available on J11 and J4.
3v32 (single side FPGA build) same as 3v31
3v33 (Current production) USB Host + and - as 3v31 but Host power available on J13 p16 and p17.

Board revisions are in copper on the rear top left of the board, you will need a magnifier to see it...

From memory there is a "lock step" sync between bootloader rev and Kernel rev, get the wrong combination and it won't work.
YAFFS compatibility issues?
However I've not tried current builds on older hardware, however beyond USB issues caused by the above the only other hardware changes
(between 3v31 and 3v33) have been to improve audio sound quality and fix minor bugs.

Good luck


On 24 Oct 2011, at 19:22, Wookey wrote:

> Hi people
> I'm trying to wire up a loon with debian/emdebian armel rootfs and USB
> host working so I can test modern gpsd with a PPS timing signlal from
> a GPS.
> This is proving surprisingly difficult.
> I have an old CUED-vintage FPGA baloon and a single-sided
> barric-vintage CPLD loon. The CUED one work but is running arm, not
> armel (and is unhelpfully high-power). ARM doesn't have gpsd v2.95,
> only armel. We could upgrade, but does anyone know if the current 1.0
> release works OK on these boards?
> So, I try the CPLD board. That works fine and boots into installer
> kernel. It has no rootfs or kernel in flash.
> I try building current trunk and am mildly astonished to find that
> selecting 'gneric balloon' and waiting about 4 hours it all built -
> without any whinging. Well done!
> However copying the rootfs (emdebia+modules) and kernel onto root and
> boot (/dev/mtdblock1 and mtdblock0 respectively). All it does now is
> give me 'UNDEF' and die on trying to boot the kernel. Anyone recall
> what that's about?
> If I stop the bootloader and mount root and boot manually they seem OK.
> bootloader is Rev 3-3-0 for Balloon [LARGE_MEMORY_MODEL] [BIG_KERNEL]
> Last link date: Thu May 20 13:17:31 BST 2010
> installer kernel that works is:
> Linux #10 Thu May 20 02:57:47 BST 2010 armv5tel unknown
> balloon build built kernel by default.
> I also discovered that you can't use USB host on older loon with the
> breakout boards - you have to use a CUED board. Wired up wrong
> port/pins I guess.
> I have a newer loon, but without a J12 soldered on the back I don't
> think I can access USB host - right?
> This is all teriffically urgent as I am leaving on a plane tomorrow,
> and want to leave GPS-research man with a working board.
> What's the easiest way to do that?
> this is what you get if you let the balloon boot the normal kernel:
> MMU table entries
> 00000000 A3E00C0A
> 00000040 04000C02
> 00000080 08000C02
> 00000100 10000C02
> 00000140 14000C02
> 00000000 A3E00C0A
> 00000500 00000C02
> 00000A00 A0000C0A
> 00000A40 A4000C0A
> 00000E00 E0000C02
> Enabling MMU... OK
> F1DA87EC
> CB777BF1
> or, stopping at the boot prompt to enable debug:
> Enabling MMU... OK
> boot> boot
> booting yaffs...
> Rootfs is "yaffs2"
> Kernel filesize = 0x001E00A0
> Booting file "/boot/zImage"...
> kernel partition base A0008000
> kernel_magic=00000000
> kernel_region_words[9]=00000000
> copying NetBSD kernel ... done
> done!
> Jumping to 0xF0000020..
> F1DA87EC
> I've seen this before. Do I just need a newer bootloader (risk of
> total breakage if that doesn't work...
> Am I better off working with release 1.0 or current trunk in terms of
> 'known to work' especially on v3.old hardware?
> If I go to new hardware how do I get USB host wired up?
> Cheers
> Wookey
> --
> Principal hats: Linaro, Emdebian, Wookware, Balloonboard, ARM
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