Merge branch 'uboot'

[karo-tx-uboot.git] / doc / README.drivers.eth

diff --git a/doc/README.drivers.eth b/doc/README.drivers.eth
index e06d3ad44ba1cfd2128a778de7daa800b325fbea..eb83038b5dbd1880edc1e9f0cfa34f3ed6eb6a24 100644 (file)
--- a/doc/README.drivers.eth
+++ b/doc/README.drivers.eth
@@ -70,6 +70,7 @@ int ape_register(bd_t *bis, int iobase)
        dev->halt = ape_halt;
        dev->send = ape_send;
        dev->recv = ape_recv;
        dev->halt = ape_halt;
        dev->send = ape_send;
        dev->recv = ape_recv;

+       dev->write_hwaddr = ape_write_hwaddr;

 
        eth_register(dev);
 
 
        eth_register(dev);
 


@@ -88,7 +89,7 @@ The return value for this function should be as follows:
 < 0 - failure (hardware failure, not probe failure)
 >=0 - number of interfaces detected
 
 < 0 - failure (hardware failure, not probe failure)
 >=0 - number of interfaces detected
 

-You might notice that many drivers seem to use xxx_initialize() rather than 
+You might notice that many drivers seem to use xxx_initialize() rather than

 xxx_register().  This is the old naming convention and should be avoided as it
 causes confusion with the driver-specific init function.
 
 xxx_register().  This is the old naming convention and should be avoided as it
 causes confusion with the driver-specific init function.
 


@@ -102,11 +103,12 @@ not checking its state or doing random probing.
  -----------
 
 Now that we've registered with the ethernet layer, we can start getting some
  -----------
 
 Now that we've registered with the ethernet layer, we can start getting some

-real work done.  You will need four functions:
+real work done.  You will need five functions:

        int ape_init(struct eth_device *dev, bd_t *bis);
        int ape_send(struct eth_device *dev, volatile void *packet, int length);
        int ape_recv(struct eth_device *dev);
        int ape_halt(struct eth_device *dev);
        int ape_init(struct eth_device *dev, bd_t *bis);
        int ape_send(struct eth_device *dev, volatile void *packet, int length);
        int ape_recv(struct eth_device *dev);
        int ape_halt(struct eth_device *dev);

+       int ape_write_hwaddr(struct eth_device *dev);

 
 The init function checks the hardware (probing/identifying) and gets it ready
 for send/recv operations.  You often do things here such as resetting the MAC
 
 The init function checks the hardware (probing/identifying) and gets it ready
 for send/recv operations.  You often do things here such as resetting the MAC


@@ -122,10 +124,12 @@ function can be called multiple times in a row.
 
 The recv function should process packets as long as the hardware has them
 readily available before returning.  i.e. you should drain the hardware fifo.
 
 The recv function should process packets as long as the hardware has them
 readily available before returning.  i.e. you should drain the hardware fifo.

-The common code sets up packet buffers for you already (NetRxPackets), so there
-is no need to allocate your own.  For each packet you receive, you should call
-the NetReceive() function on it with the packet length.  So the pseudo code
-here would look something like:
+For each packet you receive, you should call the NetReceive() function on it
+along with the packet length.  The common code sets up packet buffers for you
+already in the .bss (NetRxPackets), so there should be no need to allocate your
+own.  This doesn't mean you must use the NetRxPackets array however; you're
+free to call the NetReceive() function with any buffer you wish.  So the pseudo
+code here would look something like:

 int ape_recv(struct eth_device *dev)
 {
        int length, i = 0;
 int ape_recv(struct eth_device *dev)
 {
        int length, i = 0;


@@ -145,7 +149,11 @@ int ape_recv(struct eth_device *dev)
 }
 
 The halt function should turn off / disable the hardware and place it back in
 }
 
 The halt function should turn off / disable the hardware and place it back in

-its reset state.
+its reset state.  It can be called at any time (before any call to the related
+init function), so make sure it can handle this sort of thing.
+
+The write_hwaddr function should program the MAC address stored in dev->enetaddr
+into the Ethernet controller.

 
 So the call graph at this stage would look something like:
 some net operation (ping / tftp / whatever...)
 
 So the call graph at this stage would look something like:
 some net operation (ping / tftp / whatever...)