[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
-Bari
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