From e221174377d7e3ee848e014b96430d4c97023e93 Mon Sep 17 00:00:00 2001 From: wdenk Date: Sat, 2 Nov 2002 23:30:20 +0000 Subject: Initial revision --- doc/README.usb | 80 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 80 insertions(+) create mode 100644 doc/README.usb (limited to 'doc/README.usb') diff --git a/doc/README.usb b/doc/README.usb new file mode 100644 index 000000000..41f76f4b7 --- /dev/null +++ b/doc/README.usb @@ -0,0 +1,80 @@ +/* + * (C) Copyright 2001 + * Denis Peter, MPL AG Switzerland + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + * + */ + +USB Support for PIP405 and MIP405 (UHCI) +======================================== + +The USB support is implemented on the base of the UHCI Host +controller. + +Currently supported are USB Hubs, USB Keyboards and USB Floppys. +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 +descripor and queue headers which are all located in the main memory. +The UHCI allocates every milisecond 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 an +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 reenable the USB kbd. + +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 + an 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 staorage 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: +---------------- +CFG_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 CFG_CMD_USB +CONFIG_USB_KEYBOARD enables the USB Keyboard +CONFIG_USB_STORAGE enables the USB storage devices -- cgit v1.2.3