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JTAG Pinout for Alfa AP121U (preferably 16/64 version!)


spacewrench
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Has anyone seen the JTAG pinout for the Alfa AP121 Hornet router board? I bought one of the 16/64MB versions, but it came without any bootloader at all (apparently -- it powers up with LEDs half-bright, and no messages or activity on the console serial). My seller told me it's not DOA, but rather simply has not been flashed.

If I can find the pinout, I'll build a U-Boot with the correct flash memory sizes in it.

Thanks!

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Clean serial flash guide - http://cloud.wifipineapple.com/wiki/doku.php?id=guidecleanflashserial

Has a picture. That is the UART (not JTAG but similar) pin-outs. I'm not sure what the issue is.

Read this: http://cloud.wifipineapple.com/wiki/doku.php?id=guidecleanflashserial#hardware_used Might solve the problem of not seeing data.

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Uboot doesn't support that flash size on this model. Neither does OpenWRT for the hornet.

I have a 64MB Hornet working? However mine came with a working bootloader and was 8MB flash. Took a few attempts to serial flash. Somehow it worked after a few hours.

Edited by petertfm
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I have a 64MB Hornet working? However mine came with a working bootloader and was 8MB flash. Took a few attempts to serial flash. Somehow it worked after a few hours.

Did you get a response immediately on the UART? When I power up my board, the LEDs come on half-bright, and there's no output (or response to input) on the serial connection. I've left it like that for a couple of hours, and nothing ever happened. I'm pretty sure there's no bootloader at all in my Flash.

You gotta figure, though, that the factory has _some_ way of burning initial bootloaders, unless they burn them onto the chips before they solder them. But that seems somewhat unlikely on a product that is specifically designed to be flashed with new code.

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Did you get a response immediately on the UART? When I power up my board, the LEDs come on half-bright, and there's no output (or response to input) on the serial connection. I've left it like that for a couple of hours, and nothing ever happened. I'm pretty sure there's no bootloader at all in my Flash.

You gotta figure, though, that the factory has _some_ way of burning initial bootloaders, unless they burn them onto the chips before they solder them. But that seems somewhat unlikely on a product that is specifically designed to be flashed with new code.

Yes I could see the bootloader, I think your right about not having one.

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I have a 64MB Hornet working? However mine came with a working bootloader and was 8MB flash. Took a few attempts to serial flash. Somehow it worked after a few hours.

Yeah, no - What I meant was the actually 8mb flash space you get. RAM is a different matter. To me the most important reason I would get a bigger device was to get more main memory. People think that the 64MB board should do just that. It doesn't with what we have, at least not right now. We were working on a modified bootloader etc but it just isn't very viable.

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Yeah, no - What I meant was the actually 8mb flash space you get. RAM is a different matter. To me the most important reason I would get a bigger device was to get more main memory. People think that the 64MB board should do just that. It doesn't with what we have, at least not right now. We were working on a modified bootloader etc but it just isn't very viable.

Were you using one installed bootloader to load the next one? Or do you know a way to flash code directly into the chip? I found the Flash chip on the back of the board (Macronix 25L12835P, 16MB) but I don't have an interface to write to it yet. (I was thinking of wiring up a little microcontroller to twiddle the address/data lines, but if there's an easier way...)

Other question is, it should be easy to get the full 64MB of RAM if you can get a kernel booted, right? Worst case, you have to set some command-line variables or hard-code some values when you build Linux or whatever.

I was able to build uBoot for a Seagate Dockstar (Kirkwood-ARM) a year or two ago, so I wasn't really expecting a lot of trouble building the bootloader for this device, if I could just get it into the Flash!

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Excellent! The support person at Alfa just sent me the JTAG pinout. If anyone else is interested, it is:

VDD25----R7-----TRST_L-------R8-------GND (R7 & R8 not populated?)

TDI------R9------GND

TDO----R10-----GND

TMS----R11-----GND

TCK----R12-----GND

Also:

TP1=TRST_L

TP2=TDI

TP3=TDO

TP4=TMS

TP5=TCK

Test points 2-5 are near the dogleg in the thick ground trace around the CPU (where the shield would be soldered, if the device had a shield). I don't see TP1 yet.

[edit: it's slightly inboard of the 4-pin UART header]

[edit 2: remember, it's 2.5V JTAG. 2.9V or higher and you'll be sorry!]

Edited by spacewrench
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