Device Tree Debugging

DTB-DTS conversion (Linux kernel)

  • Convert DTS file to DTB
  • ./scripts/dtc/dtc -I dts -O dtb -o .dtb .dts
  • Convert DTB file to DTS

  • ./scripts/dtc/dtc -I dtb -O dts -o .dts .dtb

 U-boot FDT commands

  • print fdt address
  • print $fdt_addr_r (or $fdt_addr)
  • Set FDT node property
  • fdt addr $fdt_addr
    fdt set /testnode testprop testvalue
  • remove FDT node property
  • fdt addr $fdt_addr
    fdt rm /testnode testprop
  • Remove DT node
  • fdt rm /testnode
  • List FDT nodes
  • fdt list                         /* All nodes */
    fdt list /cpus                   /* All nodes under cups node */
  • Create node
  • fdt mknode / testnode

References:

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Saving file with sudo without reopening

It happens many time that you open file in vim, make major changes and when you try to save, you realize that you needed to open it as a root.

Well, you do not need to reopen that file and you can save it as sudo with below command:

:w !sudo tee %

Hit enter after typing that in, you will be prompted for a password if required and then you will then get the following message.

Press ENTER or type command to continue

Press ENTER and assuming you actually made some changes, you will then get the following message.

Press ENTER or type command to continue
W12: Warning: File "/etc/vim/vimrc" has changed and the buffer was changed in Vim as well
See ":help W12" for more info.
[O]K, (L)oad File:

Press L and quit the file.

That’s all!

Linux Useful Commands

  • List files recursively with path
    find . -name \* -print

    List txt files recursively with path

    find . -name \*.txt -print
  • Remove trailing whitespace of all files recursively
    find <dir> -type f -exec sed -i 's/ *$//' '{}' ';'