README.usb 3.1 KB

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  1. /*
  2. * (C) Copyright 2001
  3. * Denis Peter, MPL AG Switzerland
  4. *
  5. * See file CREDITS for list of people who contributed to this
  6. * project.
  7. *
  8. * This program is free software; you can redistribute it and/or
  9. * modify it under the terms of the GNU General Public License as
  10. * published by the Free Software Foundation; either version 2 of
  11. * the License, or (at your option) any later version.
  12. *
  13. * This program is distributed in the hope that it will be useful,
  14. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16. * GNU General Public License for more details.
  17. *
  18. * You should have received a copy of the GNU General Public License
  19. * along with this program; if not, write to the Free Software
  20. * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  21. * MA 02111-1307 USA
  22. *
  23. */
  24. USB Support for PIP405 and MIP405 (UHCI)
  25. ========================================
  26. The USB support is implemented on the base of the UHCI Host
  27. controller.
  28. Currently supported are USB Hubs, USB Keyboards and USB Floppys.
  29. Tested with a TEAC Floppy TEAC FD-05PUB and Chicony KU-8933 Keyboard.
  30. How it works:
  31. -------------
  32. The USB (at least the USB UHCI) needs a frame list (4k), transfer
  33. descripor and queue headers which are all located in the main memory.
  34. The UHCI allocates every milisecond the PCI bus and reads the current
  35. frame pointer. This may cause to crash the OS during boot. So the USB
  36. _MUST_ be stopped during OS boot. This is the reason, why the USB is
  37. NOT automatically started during start-up. If someone needs the USB
  38. he has to start it and should therefore be aware that he had to stop
  39. it before booting the OS.
  40. For USB keyboards this can be done by a script which is automatically
  41. started after the U-Boot is up and running. To boot an OS with a an
  42. USB keyboard another script is necessary, which first disables the
  43. USB and then executes the boot command. If the boot command fails,
  44. the script can reenable the USB kbd.
  45. Common USB Commands:
  46. - usb start:
  47. - usb reset: (re)starts the USB. All USB devices will be
  48. initialized and a device tree is build for them.
  49. - usb tree: shows all USB devices in a tree like display
  50. - usb info [dev]: shows all USB infos of the device dev, or of all
  51. the devices
  52. - usb stop [f]: stops the USB. If f==1 the USB will also stop if
  53. an USB keyboard is assigned as stdin. The stdin
  54. is then switched to serial input.
  55. Storage USB Commands:
  56. - usb scan: scans the USB for storage devices.The USB must be
  57. running for this command (usb start)
  58. - usb device [dev]: show or set current USB staorage device
  59. - usb part [dev]: print partition table of one or all USB storage
  60. devices
  61. - usb read addr blk# cnt:
  62. read `cnt' blocks starting at block `blk#'to
  63. memory address `addr'
  64. - usbboot addr dev:part:
  65. boot from USB device
  66. Config Switches:
  67. ----------------
  68. CONFIG_CMD_USB enables basic USB support and the usb command
  69. CONFIG_USB_UHCI defines the lowlevel part.A lowlevel part must be defined
  70. if using CONFIG_CMD_USB
  71. CONFIG_USB_KEYBOARD enables the USB Keyboard
  72. CONFIG_USB_STORAGE enables the USB storage devices