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Using DHCP Client in U-Boot for Loading Linux Images via Network Print

 

U-Boot has a nice feature - the ability to automatically assign the networking parameters and load a boot image to the board's RAM.

Step through the following procedure in order to add DHCP client to U-Boot:

  1. Define the CONFIG_CMD_DHCP configuration parameter in the U-Boot configuration file for your board (u-boot/include/configs/<board>.h):
  2. ...
    #define CONFIG_CMD_DHCP
    ...

    Refer to the u-boot/README.u-boot file and the u-boot/doc/ directory for more DHCP-related options.

  3. Build the U-Boot image as described in the "U-Boot Build" section of the Starter Kit Guide or the Board Support Package Guide.
  4. Upgrade U-Boot on your board as described in Section 5.3.5 of the Linux Cortex-M User's Manual.
  5. Specify the boot image filename:
  6. U-Boot> setenv bootfile psl/m2s/networking.uImage
    U-Boot> saveenv

  7. Connect to the serial console, reset the board and stop auto-boot by hitting any key. At the U-Boot prompt, run the dhcp command to invoke DHCP client to obtain an IP address and boot the board:
  8. U-Boot>dhcp
    BOOTP broadcast 1
    DHCP client bound to address 172.17.11.49
    ...
    TFTP from server 172.17.0.1; our IP address is 172.17.11.49
    Filename 'psl/m2s/networking.uImage'.
    Load address: 0xa0007fc0
    Loading: #################################################################
    #################################################################
    ###########################
    done
    Bytes transferred = 2290944 (22f500 hex)
    U-boot>

  9. Now, putting it all together to make the board boot automatically:
  10. U-Boot> print netboot
    netboot=tftp ${loadaddr} ${image};run addip;bootm
    U-Boot> setenv netboot dhcp\;run addip\;bootm
    U-Boot> print netboot
    netboot=dhcp;run addip;bootm
    U-Boot> print bootcmd
    bootcmd=run flashboot
    U-Boot> setenv bootcmd run netboot
    U-Boot> saveenv
    Saving Environment to SPI Flash...
    Erasing SPI flash...Writing to SPI flash...done
    U-Boot>re

    U-Boot 2010.03-00030-ga697c91-dirty (Nov 19 2014 - 13:34:28)
    ...
    BOOTP broadcast 1
    DHCP client bound to address 172.17.11.49
    ...
    TFTP from server 172.17.0.1; our IP address is 172.17.11.49
    Filename 'psl/m2s/networking.uImage'.
    Load address: 0xa0007fc0
    Loading: #################################################################
    #################################################################
    ###########################
    done
    Bytes transferred = 2290944 (22f500 hex)
    ## Booting kernel from Legacy Image at a0007fc0 ...
    Image Name: Linux-2.6.33-arm1
    Image Type: ARM Linux Kernel Image (uncompressed)
    Data Size: 2290880 Bytes = 2.2 MB
    Load Address: a0008000
    Entry Point: a0008001
    Verifying Checksum ... OK
    Loading Kernel Image ... OK
    OK

    Starting kernel ...

    Linux version 2.6.33-arm1 (psl @ocean.emcraft.com) (gcc version 4.4.1 (Sourcery G++ Lite 2010q1-189) ) #5 Mon Dec 9 20:29:17 MSK 2013
    ...
    IP-Config: Complete:
    device=eth0, addr=172.17.11.49, mask=255.255.0.0, gw=172.17.0.137,
    host=m2s-fg484-som, domain=, nis-domain=(none),
    bootserver=172.17.0.1, rootserver=172.17.0.1, rootpath=
    Freeing init memory: 912K
    eth0: link up (100/full)
    init started: BusyBox v1.17.0 (2013-12-09 20:27:30 MSK)
    ~ #