zynqmp: Add commentary about lwIP usage

This commit is contained in:
Kinsey Moore 2022-07-19 14:41:46 -05:00 committed by Joel Sherrill
parent 582141e757
commit 3348f192bd

View File

@ -244,6 +244,18 @@ Cadence GEM instances present on all ZynqMP hardware variants. All interfaces
are enabled by default, but only interfaces with operational MII busses will be
recognized and usable in RTEMS. Most ZynqMP dev boards use CGEM3.
When used with lwIP from the rtems-lwip integration repository, these BSP
variants support networking via CGEM0 and one of the other CGEM* instances
simultaneously. This is a limitation of the Xilinx driver, specifically
in code referring directly to XPAR_XEMACPS_0_BASEADDR. Attempting to use more
than two interfaces simultaneously may cause unexpected behavior. Attempting to
use a set of two interfaces that does not include CGEM0 may cause unexpected
behavior.
The interfaces will not come up by default under lwIP and must be configured
manually. There are examples of this in the start_networking() implementation
in netstart.c as used by the network tests.
Running Executables on QEMU
---------------------------