U-Boot

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U-Boot

• CS-423
• Dick Steflik

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U-Boot

• Actual Name Das U-Boot
• Universal Bootstrap Loader
• Used on PPC, ARM, AVR32, MIPS, x86, 68K, Nios and
  MicroBlaze architectures
• GNU General Public License

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Source Code

• http//git.denx.de

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NGW100

• Connect NGW100 to Host PC with serial cable
• In Hyperterminal create a profile called ngw100
  (115000,8,1,1,0), start connection
• Plug-in power to ngw100 to start boot-up
• To access U-Boot interrupt the boot-up process by
  hitting any key within the first 2 sec of the
  boot-up process
• Commandline interface w/help

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U-Boot Commands

• Information Commands
• bdinfo list board information on console
• coninfo list console information
• flinfo list flash memory information
• iminfor list application image information
• help lists commands , for help on specific
  command type help command

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U-Boot Commands

• Memory Commands
• base print or set base address
• crc32 calculate the crc32 checksum over an
  address range
• cmp compare two memory ranges (cmp staddr1
  staddr2 size (hex))
• cp copy memory ( cp source targer size (hex))
• md display memory ( md (.b,.w,.l) addr size
  (hex))
• .b-byte , .w-word, .l-long
• mm modify memory (mm (.b,.w,.l) addr (hex))
  will prompt for new value
• mtest simple memory test (mtest start end
  pattern (hex))
• mw memory write (mw .b, .w, .l address value
  count (hex))
• nm memory modify (nm .b, .w, .l address
  (hex))
• loop infinite loop on address range (loop .b,
  .w, .l address number_of_objects (hex))

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U-Boot Commands

• Flash Memory Commands
• cp copy memory (cp .b, .w, .l source target
  count (hex))
• flinfo print Flash memory information
• erase erase flash memory (see help for options)
• protect enable or disable flash protection
• mtdparts define a Linux compatible Memory
  Technology Device (MTD) partition scheme (see
  manual for more info on this command)

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U-Boot Commands

• Execution Control Commands
• autoscr - run script from memory
• bootm - boot application image from memory
• go - start application at address 'addr
• Download Commands
• bootp - boot image via network using BOOTP/TFTP
  protocol
• dhcp - invoke DHCP client to obtain IP/boot
  params
• loadb - load binary file over serial line (kermit
  mode)
• loads - load S-Record file over serial line
• rarpboot- boot image via network using RARP/TFTP
  protocol
• tftpboot- boot image via network using TFTP
  protocol

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U-Boot Commands

• Environment Variables Commands these are
  environment variables that are used during boot
  up of the application image, uBoot loads the
  environment variables form persistent storage
  (flash) as part of the boot strap. To remove a
  variable set its value to null. To create a new
  one set the name to a value (this will go away
  when the system is rebooted, to make it permanent
  do a saveenv before the boot or power down)
• printenv- print environment variables
• saveenv - save environment variables to
  persistent storage
• setenv - set environment variables (set name
  value )
• run - run commands in an environment variable
• bootd - boot default, i.e., run 'bootcmd'