doc: describe the analysis of crash dumps

[oweals/u-boot.git] / doc / README.fec_mxc

diff --git a/doc/README.fec_mxc b/doc/README.fec_mxc
index 72a1d595f5fe520bc252f5a71e0afd00a732f606..9ca6ac2fb59d13253af6fdd742e3b36a508d0a39 100644 (file)
--- a/doc/README.fec_mxc
+++ b/doc/README.fec_mxc
@@ -1,7 +1,8 @@
-U-boot config options used in fec_mxc.c
+U-Boot config options used in fec_mxc.c
 
 CONFIG_FEC_MXC
-       Selects fec_mxc.c to be compiled into u-boot.
+       Selects fec_mxc.c to be compiled into u-boot. Can read out the
+       ethaddr from the SoC eFuses (see below).
 
 CONFIG_MII
        Must be defined if CONFIG_FEC_MXC is defined.
@@ -25,3 +26,14 @@ CONFIG_FEC_MXC_NO_ANEG
 CONFIG_FEC_MXC_PHYADDR
        Optional, selects the exact phy address that should be connected
        and function fecmxc_initialize will try to initialize it.
+
+CONFIG_FEC_FIXED_SPEED
+       Optional, selects a fixed speed on the MAC interface without asking some
+       phy. This is usefull if there is a direct MAC <-> MAC connection, for
+       example if the CPU is connected directly via the RGMII interface to a
+       ethernet-switch.
+
+Reading the ethaddr from the SoC eFuses:
+if CONFIG_FEC_MXC is defined and the U-Boot environment does not contain the
+ethaddr variable, then its value gets read from the corresponding eFuses in
+the SoC. See the README files of the specific SoC for details.