User manual

U-Boot for MPL SBC
User Manual
 2003 by MPL AG
23
MEH-10082-002 Rev. D
High-Tech • Made in Switzerland
3.3.42 tftpboot- boot image via network using TFTP protocol
Used to load the image via the network using the TFTP protocol. For this purpose following environment variables must
be set:
•
ipaddr The IP address of the board
•
netmask The appropriate netmask
•
serverip The IP address of the TFTP Server
Abbreviation:
tftp
=> help tftp
tftpboot [loadAddress] [bootfilename]
=>
To use this command, you need to set-up a tftp server.
Example:
=> tftp 400000 u-boot-MIP405_zip.img
ENET Speed is 100 Mbps - HALF duplex connection
ARP broadcast 1
TFTP from server 192.168.3.17; our IP address is 192.168.3.37
Filename 'u-boot-MIP405_zip.img'.
Load address: 0x400000
Loading: ########################
done
Bytes transferred = 119777 (1d3e1 hex)
=>
3.3.43 usb - USB sub-system
The USB system is a little bit more complex than others sub-systems. That is mainly because the USB allows to connect
human interface devices as well as storage devices. Along this the USB controller uses buffer from the main memory
and updates these buffers all msec. This means that the USB controller arbitrate the PCI bus every msec and
reads/writes data from/to the main memory. Starting up a kernel without stooping the USB controller may cause a system
crash. So if using the USB with the U-Boot, make sure to stop the USB sub-system before starting the kernel. If you are
using an USB keyboard you must create a command in the environment which switches the USB off and then boot the
image. See 3.5.3.2 Working with an USB Keyboard for more information.
Abbreviation:
usb
=> help usb
usb reset - reset (rescan) USB controller
usb stop [f] - stop USB [f]=force stop
usb tree - show USB device tree
usb info [dev] - show available USB devices
usb scan - (re-)scan USB bus for storage devices
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'
=>
usb reset or usb start reinitializes the USB controller and searches all USB devices on the bus:
=> usb start
(Re)start USB...
USB: scanning bus for devices... 5 USB Devices found
=>