Commands

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 Commands:

extract dtb file.

1.go to the linux path 

cd linux/scripts/dtc

  decompile dtb to dts

2.dtc -I dtb -O dts -o <deviceTree_source_file_name.dts> <devicetree.dtb> 

  compile dts to dtb 

3.dtc -I dts -O dtb -f <deviceTree_source_file_name.dts> -o <devicetree.dtb> 

dmesg

  • dmesg -x => print log level type
  • dmesg -T => human readable formate.
  • dmesg -t => Will not print timestamps
  • dmesg -l err,warn will print only error and warn messages
  • dmesg -w & -

Dynamic logs

    • echo 'file driver/usb/core/* =p'  > /sys/kernel/debug/dynamic_debug/control 

kernel config

  •  cat /boot/config-<kernle_version> | grep CONFIG_DYMANIC_DEDBUG.    

Ko:

  • strings <file_name.ko>
  • objdump --section-headers <file_name.ko>
  • objdump --section-headers --section=.modinfo --full-contents <file_name.ko>

Device Tree: 

  • cat /sys/firmware/devicetree/base/
  • cat /proc/device-tree


ldd

  • ldd <binary_flie> or ldd <excutable_file >  --> give list of dependent libraries


EXTRACTION

  • tar -czvf tar-archieve-name.tar.gz source-folder-name  --> create tar.gz
  • tar -xzvf tar-archieve-name.tar.gz --> extract tar.gz

  • zip -r tecmint_files.zip tecmint_files 
  • unrar x <file_name.rar> --> 
  • unzip   <file_name.zip>
  • zip -r tecmint_files.zip tecmint_files 
  • unzip tecmint_files.zip -d /tmp/unziped

  • unsquashfs <squashfs_file.squashfs>
  • mksquashfs squashfs-root/ rootfs.squashfs

Yum has a very handy 'whatprovides' function to find things like this out:

Code:
 yum whatprovides */lib64/libGL.so.1
that will tell you that it is provided in the 'mesa-libGL' package.

  • rpm -i your_name.rpm --> install 
  • rpm -u your-rpm-package_name.rpm  -> update


yum -y install packagename --> The '-y' implies 'yes'.

enable the kernel prints:

  • echo 1 > /proc/sys/kernel/printk
Patch:
    create patch:
diff -u OriginalFile UpdatedFile > PatchFile
diff -ru Original_directory Updated_directory  > File
apply patch:
patch foo.c < patch.diff
create patch:
diff -u OriginalFileOriginalFile UpdatedFile > PatchFile
diff -ru Original_directory Updated_directory  > File
apply patch:
patch foo.c < patch.diff

NFS mount:

  • mount -t nfs -o nolock <IP_address>:<Directtory_to_share> <Mouting_Ponit_direcory> 
  • showmount -e 

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