The IBM 39Y6070 is a NIC with a BCM5708C chip. The picture below includes two headers I soldered in.
In the top-left corner of the NIC (J334), we can access the Debug UART as shown here (again note that it doesn't come with this header):
I used a TTL to RS232 cable (here). The settings are 192008N1, the prompt is “>” (see [1] for more info). There are 3 documented commands:
Syntax | Example | Description |
---|---|---|
r<addr> | r145000 | Read a 32-bit register value from address <addr> |
d<addr> | d145000 | Dump 256 32-bit registers, starting at <addr> |
w<addr> <data> | w145000 ff | Write <data> to the 32-bit register at <addr> |
The best source for the register addresses is bnx2.h from the bnx2 linux driver, available here.