mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-24 13:43:28 +00:00
b5f3850727
Fix spelling issues in README.usb. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
230 lines
8.4 KiB
Text
230 lines
8.4 KiB
Text
SPDX-License-Identifier: GPL-2.0+
|
|
/*
|
|
* (C) Copyright 2001
|
|
* Denis Peter, MPL AG Switzerland
|
|
*/
|
|
|
|
USB Support
|
|
===========
|
|
|
|
The USB support is implemented on the base of the UHCI Host
|
|
controller.
|
|
|
|
Currently supported are USB Hubs, USB Keyboards, USB Floppys, USB
|
|
flash sticks and USB network adaptors.
|
|
Tested with a TEAC Floppy TEAC FD-05PUB and Chicony KU-8933 Keyboard.
|
|
|
|
How it works:
|
|
-------------
|
|
|
|
The USB (at least the USB UHCI) needs a frame list (4k), transfer
|
|
descriptor and queue headers which are all located in the main memory.
|
|
The UHCI allocates every millisecond the PCI bus and reads the current
|
|
frame pointer. This may cause to crash the OS during boot. So the USB
|
|
_MUST_ be stopped during OS boot. This is the reason, why the USB is
|
|
NOT automatically started during start-up. If someone needs the USB
|
|
he has to start it and should therefore be aware that he had to stop
|
|
it before booting the OS.
|
|
|
|
For USB keyboards this can be done by a script which is automatically
|
|
started after the U-Boot is up and running. To boot an OS with a
|
|
USB keyboard another script is necessary, which first disables the
|
|
USB and then executes the boot command. If the boot command fails,
|
|
the script can re-enable the USB keyboard.
|
|
|
|
Common USB Commands:
|
|
- usb start:
|
|
- usb reset: (re)starts the USB. All USB devices will be
|
|
initialized and a device tree is build for them.
|
|
- usb tree: shows all USB devices in a tree like display
|
|
- usb info [dev]: shows all USB infos of the device dev, or of all
|
|
the devices
|
|
- usb stop [f]: stops the USB. If f==1 the USB will also stop if
|
|
a USB keyboard is assigned as stdin. The stdin
|
|
is then switched to serial input.
|
|
Storage USB Commands:
|
|
- usb scan: scans the USB for storage devices. The USB must be
|
|
running for this command (usb start)
|
|
- usb device [dev]: show or set current USB storage device
|
|
- usb part [dev]: print partition table of one or all USB storage
|
|
devices
|
|
- usb read addr blk# cnt:
|
|
read `cnt' blocks starting at block `blk#'to
|
|
memory address `addr'
|
|
- usbboot addr dev:part:
|
|
boot from USB device
|
|
|
|
Config Switches:
|
|
----------------
|
|
CONFIG_CMD_USB enables basic USB support and the usb command
|
|
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 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 settings to your board configuration:
|
|
|
|
CONFIG_CMD_USB=y /* the 'usb' interactive command */
|
|
CONFIG_USB_HOST_ETHER=y /* Enable USB Ethernet adapters */
|
|
|
|
and one or more of the following for individual adapter hardware:
|
|
|
|
CONFIG_USB_ETHER_ASIX=y
|
|
CONFIG_USB_ETHER_ASIX88179=y
|
|
CONFIG_USB_ETHER_LAN75XX=y
|
|
CONFIG_USB_ETHER_LAN78XX=y
|
|
CONFIG_USB_ETHER_MCS7830=y
|
|
CONFIG_USB_ETHER_RTL8152=y
|
|
CONFIG_USB_ETHER_SMSC95XX=y
|
|
|
|
As with built-in networking, you will also want to enable some network
|
|
commands, for example:
|
|
|
|
CONFIG_CMD_NET=y
|
|
CONFIG_CMD_PING=y
|
|
CONFIG_CMD_DHCP=y
|
|
|
|
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.
|
|
However note that encoding these individual network settings into a
|
|
common executable is discouraged, as it leads to potential conflicts,
|
|
and all the parameters can either get stored in the board's external
|
|
environment, or get 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
|
|
distinguished from each other. MAC address conflicts are evil and
|
|
generally result in strange and erratic 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.
|