I-Appliance BBS
The Official Source for Internet Appliance Upgrades and Mods
Amazon Honor System Click Here to Pay Learn More
BBS Main List | Sign In | Sign Up | Search | Help | Linux-Hacker.netReply to Thread | Printer |

Home / Other I-Appliances / WebPal
bootstrapping probs...
bootstrapping probs...

New Messagebootstrapping probs... (modified 0 times) mrhim
Profile
Hi. I'm having some problems bootstrapping. I built the rs232c board, following bigbrd's instructions (I did hand-wire it, so that could potentially be the problem). I crank up gdb, run ``target rdp /dev/ttyS0'', and hold down SW2 and power on the webpal like bigbrd says in his instructions. Here's the weird part... sometimes gdb prints its "Trying to connect at 9600 baud" message 3 times and fails. But, sometimes I see a bunch of random ASCII on the screen right after I let go of SW2. Has anyone else seen this?

A few more details ... I'm using a "null-modem" serial cable. I don't have a straight-through one to try with, unfortunately. As for the wiring, I double (triple, quadouple, etc...) checked it and I'm pretty sure it's correct. I used the following for the webpal serial pinout:
54321
109876

based on a previous post (Xeon's, I think).

I'm not sure where to go from here so any help would be appreciated.

Thanks.

MrHim

03-29-2003 20:04:48

New MessageRE:bootstrapping probs... (modified 0 times) justdavesj
Profile | Email
Make sure that you have the baud rate set with the stty instruction. I had the same problem.

dave

03-29-2003 20:51:14

New MessageRE:bootstrapping probs... (modified 0 times) mrhim
Profile
Thanks for the quick reply, Dave :). Yup, I did set the baud rate to 9600 using stty. If you could confirm that the serial pintout is correct, I'd appreciate it.

MrHim

03-29-2003 20:56:54

New MessageRE:bootstrapping probs... (modified 0 times) justdavesj
Profile | Email
Hmmm. I have an old rs232 breakout box with lights it. That helped me to get the cable right. I remember that I did have a problem with the cable in the beginning. I will check in the morning.

dave

03-29-2003 22:44:43

New MessageRE:bootstrapping probs... (modified 0 times) m_bed
Profile
For the header connector, the square pad is pin 1, and the pin pattern is:

2_4_6_8_0
1_3_5_7_9

(.e., all odds in one row, all evens in the other).

I had a problem trying to connect to the PC with a null modem(-ish) cable: during the initialization sequence, the Webpal dropped CTS, which halted the data stream from the PC before it finished.

So I used my "fake-out" adapter, which is just a normal 3-wire hookup, with the PC's DTR being fed back to its DSR, DCD, and CTS. That got me to the point where gdb stopped kvetching about not being able to reset the board.

I guess I'll find out tonight whether disabling the hardware handshaking causes problems with downloading...

Ran

03-30-2003 10:41:24

New MessageRE:bootstrapping probs... (modified 0 times) mrhim
Profile
Ran,

interesting.... according to this
http://www.linux-hacker.net/cgi-bin/UltraBoard/UltraBoard.pl?Action=ShowPost&Board=wpalgen&Post=52&Idle=0&Sort=0&Order=Descend&Page=1&Session=
post (and Xeon), that's incorrect. Now I don't know what to think :(. You're using Bigbrd's instructions for building the rs232c, right? Did you hand-wire it or use Bigbrd's PCB design?

Now I'd really like to see what Dave's testing shows.

MrHim

03-30-2003 12:39:43

New MessageRE:bootstrapping probs... (modified 0 times) justdavesj
Profile | Email
Ran is correct on the pinout. I have posted some pictures of my interface here:

http://justdave.mine.nu/webpal/RCA_0004.JPG
http://justdave.mine.nu/webpal/RCA_0005.JPG

Also make sure that you got the right db9 cable. There are different kinds with a different pin configuration.

dave

03-30-2003 19:14:26

New MessageRE:bootstrapping probs... (modified 0 times) m_bed
Profile

Now I don't know what to think :(

Try "I should trust Ran's interpretation, because his adapter works, but mine doesn't"

It's easy to see why you might've gotten the wrong impression, since most of the connectors you've seen number sequentially down the rows. Header connectors are different because they're usually used with ribbon cables, so someone decided to use the "even-odd" scheme to make the pin numbers correspond to the conductors in the ribbon. I dunno whether there's an official industry standard for it, but I've seen dozens of designs numbered that way over the years, so my automatic assumption was that this one was done the same way.

I'm using an adapter that I bought as a kit some years back, and plug into the projet-du-jour with a cable to match the project's pinouts. It has a DB-25 soldered to the board, so I just made up a 9-to-25 pin cable with what I thought were the right crossovers and loopbacks.

Specifically, I wired up the Webpal side so it looks modem-ish, because my adapter has a female connector, and I only plan to connect to the PC (and, btw, this resulted in one of my earlier comments being misleading: when I said the webpla "dropped CTS", it was actually the signal bigbrd labels "RTS" on his schematic. It just looks like CTS on the adapter's DB-25).

I looped DTR back to DSR and DCD on the PC end, and left the handshake inputs to the webpal open, just like bigbrd did.

I crossed CTS and RTS (as labelled by bigbrd), null-modem style. This seems to have caused the problem mentioned in my last post, even though it's the right way to do it for proper hardware handshaking (shrug). If it turns out that the protocol really needs hardware handshaking, I guess I'll have to add a switch to get it past the initialization problem. But, since no one else has mentioned it, I'm guessing I can just leave it wired as in the "fake-out box". At 9600 baud, it's unlikely that hardware handshaking is really needed, anyway.

I also made sure that TD and RD wre going in the right directions: bigbrd's pinout is kind of a mix of DTE and DCE conventions, so I used the "in vs out" of the buffer chip as the definitive source.

Ran

03-30-2003 20:45:25

New MessageRE:bootstrapping probs... (modified 0 times) mrhim
Profile

Try "I should trust Ran's interpretation, because his adapter works, but mine doesn't"

;).

Thanks for the feedback, guys. Looks like I've got some re-soldering to do tomorrow.

MrHim

03-31-2003 20:30:04

New MessageRE:bootstrapping probs... (modified 0 times) mrhim
Profile
Holy macaroni! It works!

Thanks guys.

MrHim

04-06-2003 20:52:35

Reply to Thread | Printer |
All times are PSTPowered by UltraBoard v1.62



Copyright © 2000, Netmake Inc. All Rights Reserved.
See Terms and Conditions for more information.




i-opener opener laptop notebook computer help drivers dll free windows dos repair fix linux mac macintosh 2000 95 98 nt pc configure hardware software sound video netscape explorer network networking lan wan software cmos fat bios printer card mouse modem ide scsi cd rom controllers scanner tape hard drive cgi scripts source code mp3