[LinuxBIOS] USB Host to Host Debug Dongle/Cable

Bari Ari bari at onelabs.com
Sat Jul 22 06:57:23 CEST 2006

Denis Dowling wrote:
> 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 
> though.
The problem here is that IDE is going the way of the serial port as 
well. Maybe a SATA debug module is a way to go. I could spin a simple 
FPGA based card for output.
> 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
A debug card could also be designed the same form factor as a memory 
dimm. It could be placed into an unused memory slot to debug via the 
SMbus. This is easier than the SATA method to build.

copyright c 2006, patent pending


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