mirror of
https://github.com/AsahiLinux/u-boot
synced 2025-02-17 22:49:02 +00:00
Add documentation for USB Host Networking
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> Tested-by: Eric Bénard <eric@eukrea.com>
This commit is contained in:
Simon Glass
Remy Bohmer
parent
7616e78508
commit
4fdbcf8113
1 changed files with 156 additions and 1 deletions
157
doc/README.usb
157
doc/README.usb
|
|
@ -79,4 +79,159 @@ CONFIG_USB_UHCI defines the lowlevel part.A lowlevel part must be defined
|
|||
if using CONFIG_CMD_USB
|
||||
CONFIG_USB_KEYBOARD enables the USB Keyboard
|
||||
CONFIG_USB_STORAGE enables the USB storage devices
|
||||
CONFIG_USB_HOST_ETHER enables USB ethernet dongle support
|
||||
CONFIG_USB_HOST_ETHER enables USB ethernet adapter support
|
||||
|
||||
|
||||
USB Host Networking
|
||||
===================
|
||||
|
||||
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.
|
||||
|
||||
Note: USB Host Networking is not the same as 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. In that
|
||||
case the connection is via a USB cable with the computer acting as the host.
|
||||
|
||||
With USB Host Networking, your board is the USB host. It controls the
|
||||
Ethernet adapter to which it is directly connected and the connection to
|
||||
the outside world is your adapter's Ethernet cable. Your board becomes an
|
||||
independent network device, able to connect and perform network operations
|
||||
independently of your computer.
|
||||
|
||||
|
||||
Device support
|
||||
--------------
|
||||
|
||||
Currently supported devices are listed in the drivers according to
|
||||
their vendor and product IDs. You can check your device by connecting it
|
||||
to a Linux machine and typing 'lsusb'. The drivers are in
|
||||
drivers/usb/eth.
|
||||
|
||||
For example this lsusb output line shows a device with Vendor ID 0x0x95
|
||||
and product ID 0x7720:
|
||||
|
||||
Bus 002 Device 010: ID 0b95:7720 ASIX Electronics Corp. AX88772
|
||||
|
||||
If you look at drivers/usb/eth/asix.c you will see this line within the
|
||||
supported device list, so we know this adapter is supported.
|
||||
|
||||
{ 0x0b95, 0x7720 }, /* Trendnet TU2-ET100 V3.0R */
|
||||
|
||||
If your adapter is not listed there is a still a chance that it will
|
||||
work. Try looking up the manufacturer of the chip inside your adapter.
|
||||
or take the adapter apart and look for chip markings. Then add a line
|
||||
for your vendor/product ID into the table of the appropriate driver,
|
||||
build U-Boot and see if it works. If not then there might be differences
|
||||
between the chip in your adapter and the driver. You could try to get a
|
||||
datasheet for your device and add support for it to U-Boot. This is not
|
||||
particularly difficult - you only need to provide support for four basic
|
||||
functions: init, halt, send and recv.
|
||||
|
||||
|
||||
Enabling USB Host Networking
|
||||
----------------------------
|
||||
|
||||
The normal U-Boot commands are used with USB networking, but you must
|
||||
start USB first. For example:
|
||||
|
||||
usb start
|
||||
setenv bootfile /tftpboot/uImage
|
||||
bootp
|
||||
|
||||
|
||||
To enable USB Host Ethernet in U-Boot, your platform must of course
|
||||
support USB with CONFIG_CMD_USB enabled and working. You will need to
|
||||
add some config settings to your board header file:
|
||||
|
||||
#define CONFIG_USB_HOST_ETHER /* Enable USB Ethernet adapters */
|
||||
#define CONFIG_USB_ETHER_ASIX /* Asix, or whatever driver(s) you want */
|
||||
|
||||
As with built-in networking, you will also want to enable some network
|
||||
commands, for example:
|
||||
|
||||
#define CONFIG_CMD_NET
|
||||
#define CONFIG_NET_MULTI
|
||||
#define CONFIG_CMD_PING
|
||||
#define CONFIG_CMD_DHCP
|
||||
|
||||
and some bootp options, which tell your board to obtain its subnet,
|
||||
gateway IP, host name and boot path from the bootp/dhcp server. These
|
||||
settings should start you off:
|
||||
|
||||
#define CONFIG_BOOTP_SUBNETMASK
|
||||
#define CONFIG_BOOTP_GATEWAY
|
||||
#define CONFIG_BOOTP_HOSTNAME
|
||||
#define CONFIG_BOOTP_BOOTPATH
|
||||
|
||||
You can 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.
|
||||
All of these can be obtained from the bootp server if not set.
|
||||
|
||||
#define CONFIG_IPADDR 10.0.0.2 (replace with your value)
|
||||
#define CONFIG_SERVERIP 10.0.0.1 (replace with your value)
|
||||
#define CONFIG_BOOTFILE uImage
|
||||
|
||||
|
||||
The 'usb start' command should identify the adapter something like this:
|
||||
|
||||
CrOS> usb start
|
||||
(Re)start USB...
|
||||
USB EHCI 1.00
|
||||
scanning bus for devices... 3 USB Device(s) found
|
||||
scanning bus for storage devices... 0 Storage Device(s) found
|
||||
scanning bus for ethernet devices... 1 Ethernet Device(s) found
|
||||
CrOS> print ethact
|
||||
ethact=asx0
|
||||
|
||||
You can see that it found an ethernet device and we can print out the
|
||||
device name (asx0 in this case).
|
||||
|
||||
Then 'bootp' or 'dhcp' should use it to obtain an IP address from DHCP,
|
||||
perhaps something like this:
|
||||
|
||||
CrOS> bootp
|
||||
Waiting for Ethernet connection... done.
|
||||
BOOTP broadcast 1
|
||||
BOOTP broadcast 2
|
||||
DHCP client bound to address 172.22.73.81
|
||||
Using asx0 device
|
||||
TFTP from server 172.22.72.144; our IP address is 172.22.73.81
|
||||
Filename '/tftpboot/uImage-sjg-seaboard-261347'.
|
||||
Load address: 0x40c000
|
||||
Loading: #################################################################
|
||||
#################################################################
|
||||
#################################################################
|
||||
################################################
|
||||
done
|
||||
Bytes transferred = 3557464 (364858 hex)
|
||||
CrOS>
|
||||
|
||||
|
||||
Another way of doing this is to issue a tftp command, which will cause the
|
||||
bootp to happen automatically.
|
||||
|
||||
|
||||
MAC Addresses
|
||||
-------------
|
||||
|
||||
Most Ethernet dongles have a built-in MAC address which is unique in the
|
||||
world. This is important so that devices on the network can be
|
||||
distinguised from each other. MAC address conflicts are evil and
|
||||
generally result in strange and eratic behaviour.
|
||||
|
||||
Some boards have USB Ethernet chips on-board, and these sometimes do not
|
||||
have an assigned MAC address. In this case it is up to you to assign
|
||||
one which is unique. You should obtain a valid MAC address from a range
|
||||
assigned to you before you ship the product.
|
||||
|
||||
Built-in Ethernet adapters support setting the MAC address by means of
|
||||
an ethaddr environment variable for each interface (ethaddr, eth1addr,
|
||||
eth2addr). There is similar support on the USB network side, using the
|
||||
names usbethaddr, usbeth1addr, etc. They are kept separate since we
|
||||
don't want a USB device taking the MAC address of a built-in device or
|
||||
vice versa.
|
||||
|
||||
So if your USB Ethernet chip doesn't have a MAC address available then
|
||||
you must set usbethaddr to a suitable MAC address. At the time of
|
||||
writing this functionality is only supported by the SMSC driver.
|
||||
|
|
|
|||
Loading…
Add table
Reference in a new issue