[LinuxBIOS] USB Host to Host Debug Dongle/Cable

Denis Dowling dpd at alphalink.com.au
Sat Jul 22 01:28:10 CEST 2006

There are a couple of other "ports" on a PC that could be used for 
initial debugging. I have used a spare IDE channel as a general 8 bit IO 
port. In fact you can address up to 8 different ports per channel. A 
simple outb(b, 0x170) gets reflected on the port. This is dead easy to 
interface with. Connect a logic analyser or a small circuit and then 
just write to the port. Does not help if the IDE sits out on the PCI bus 

Another thought would be to tap the SMBus signals. These are routed to 
all memory DIMMS. With some careful soldering you can tap the signals 
off the DIMM to a logic analyser. The code can then just write to an 
unised i2c address.


Ronald G Minnich wrote:
> Bari Ari wrote:
>> SemiconductorStore.com has several of the the USB debug cables currently 
>> in stock for $80:
>> http://shop.semiconductorstore.com/iwwida.pvx?;item?item_no=NET20DC%20%20%20%20%20%20%20%201?comp=SYM 
>> They say that PLX is still processing orders for them as well.
> yes, but ... depending on obsolete hardware for future debug strategy is 
> not a good plan.
> ron

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