Dear Simon Glass,
In message 1302642840-6958-3-git-send-email-sjg@chromium.org you wrote:
This describes what it is for, devices supported, how to enable for your board in U-Boot, setting up the server, and notes about MAC addresses.
Signed-off-by: Simon Glass sjg@chromium.org
...
+If you have a supported USB Ethernet adapter you can use it in U-Boot +to obtain an IP address and load a kernel from a network server.
I have a few questions.
Is this the only possible use? What about netconsole? What about getting the time using SNTP? What about loading other files than a kernel?
+USB Host Networking is different from making your board act as a USB +client. In that case your board is pretending to be an Ethernet adapter +and will appear as a network interface to an attached computer. The +connection is via a USB cable with the computer acting as the host.
...the computer is the host.
+With USB Host Networking, your board is the USB host. It controls the
...the board is the host.
I am confused.
+Ethernet adapter to which it is directly connected and the connection to +the outside world is your adapter's Ethernet cable. Your board becomes a +first class network device, able to connect and perform network +operations independently of your computer.
What is the definition of a "first class network device", what's a "second class network device", and what's the difference?
+usb start +setenv bootfile /tftpboot/uImage +setenv autoload y +bootp
+(The autoload option makes bootp automatically load the boot file.)
Is it necessary to explain unrelated details here?
+You will also want to enable the network commands:
+#define CONFIG_CMD_NET +#define CONFIG_NET_MULTI +#define CONFIG_CMD_PING +#define CONFIG_CMD_DHCP
Why these? What about others like NFS or SNTP or NETCONSOLE ?
+gateway IP, host name and boot path from the bootp/dhcp server:
+#define CONFIG_BOOTP_SUBNETMASK +#define CONFIG_BOOTP_GATEWAY +#define CONFIG_BOOTP_HOSTNAME +#define CONFIG_BOOTP_BOOTPATH
WHich of this is actually related to USB Host Networking (versus genral network configuration).
+You should also set the default IP address of your board and the server +as well as the default file to load when a 'bootp' command is issued.
+#define CONFIG_IPADDR 10.0.0.2 +#define CONFIG_SERVERIP 10.0.0.1
NAK!!! This is a reliable way to get a plain NAK when submitting your code to mainline.
+Then 'bootp' should use it to obtain an IP address from DHCP, perhaps +something like this:
I don't understand why you insist on using bootp here. I guess dhcp would work as well, as would a plain tftp ?
+Server Setup
Unrelated, please delete.
Best regards,
Wolfgang Denk