mx6: clock: take 'num' and 'denom' regs into account when calculating audio/video...

[karo-tx-uboot.git] / doc / README.enetaddr

diff --git a/doc/README.enetaddr b/doc/README.enetaddr
index 1d75aa3876efc8c47bbe9e6c76963ef0ec105bf0..50e4899787792246face19fcb4561afe0eafca1e 100644 (file)
--- a/doc/README.enetaddr
+++ b/doc/README.enetaddr
@@ -15,7 +15,7 @@ Here are the places where MAC addresses might be stored:
  - board-specific location (eeprom, dedicated flash, ...)
        Note: only used when mandatory due to hardware design etc...
 
- - environment ("ethaddr", "eth1addr", ...) (see CONFIG_ETHADDR)
+ - environment ("ethaddr", "eth1addr", ...)
        Note: this is the preferred way to permanently store MAC addresses
 
  - ethernet data (struct eth_device -> enetaddr)
@@ -28,6 +28,25 @@ Here are the places where MAC addresses might be stored:
              purpose of passing this information to an OS kernel we are about
              to boot
 
+Correct flow of setting up the MAC address (summarized):
+
+1. Read from hardware in initialize() function
+2. Read from environment in net/eth.c after initialize()
+3. The environment variable will be compared to the driver initialized
+   struct eth_device->enetaddr. If they differ, a warning is printed, and the
+   environment variable will be used unchanged.
+   If the environment variable is not set, it will be initialized from
+   eth_device->enetaddr, and a warning will be printed.
+   If both are invalid and CONFIG_NET_RANDOM_ETHADDR is defined, a random,
+   locally-assigned MAC is written to eth_device->enetaddr.
+4. Program the address into hardware if the following conditions are met:
+       a) The relevant driver has a 'write_addr' function
+       b) The user hasn't set an 'ethmacskip' environment variable
+       c) The address is valid (unicast, not all-zeros)
+
+Previous behavior had the MAC address always being programmed into hardware
+in the device's init() function.
+
 -------
  Usage
 -------
@@ -70,7 +89,7 @@ eth_parse_enetaddr(addr, enetaddr);
 Look up an environment variable and convert the stored address.  If the address
 is valid, then the function returns 1.  Otherwise, the function returns 0.  In
 all cases, the enetaddr memory is initialized.  If the env var is not found,
-then it is set to all zeros.  The common function is_valid_ether_addr() is used
+then it is set to all zeros.  The common function is_valid_ethaddr() is used
 to determine address validity.
 uchar enetaddr[6];
 if (!eth_getenv_enetaddr("ethaddr", enetaddr)) {