X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=doc%2FREADME.fec_mxc;h=9ca6ac2fb59d13253af6fdd742e3b36a508d0a39;hb=a08e0a28ebe23adf6dcd7533acb196058f6c421a;hp=72a1d595f5fe520bc252f5a71e0afd00a732f606;hpb=c30eab2ddd5d2238e06ea2acde91620019ea7f85;p=oweals%2Fu-boot.git

diff --git a/doc/README.fec_mxc b/doc/README.fec_mxc
index 72a1d595f5..9ca6ac2fb5 100644
--- 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.