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Altera_Forum's avatar
Altera_Forum
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16 years ago

Device node

Hi,

Now after I boot uclinux I use the command mknod to create my "/dev/name(device)" to control my hardware.

Also I have done a script to do it when the system's boot, but I would like to know if there is a command that creates this virtual folder when I load my device driver, some command that I can integrate inside my modul.

At first I used the command "device_create" but It didn't go, maby I am wrong and I can't do this inside my module to create the folder in /dev associating the major number.

Thanks

6 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    You can create a nod with the help of the romfs_list in ~/nios2-linux/uClinux-dist/vendors/Altera/nios2/romfs_list

    just add it to the list
  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    Thanks for the answer but I know it. In this way "/dev/driver" is always built, I ask for a command or something thats makes "dev/driver" appear at the same time when I do an insmod of the driver.

    Lot of thanks anyway.
  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    You may check the "mdev" of busybox, which is similar to udev in creating dev nodes on the fly.

    - Hippo
  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    Hi,

    This is what I was looking for, thanks for the answer.

    I have tested the command mdev-s in the terminal, but I would like that It do it automatic when I insert a module.

    I have read the file “mdev.txt”, as I understand I have to introduce two lines of code(1- About hotplugging,2-mdev) in the init script( For me /etc/rc).

    The problem is when I recompiled to make the zImage again, lines of code that I have introduced were erased.

    I don't know if it is the correct "init script" or if I have to change something in menuconfig to preserve the code that I have introduced.

    Thanks a lot.
  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    Hi,

    There is a post in Nioswiki answering my question.

    Thanks
  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    If the Kernel is configured appropriately, you can dynamically create a device note in your module's init code using alloc_chrdev_region().

    -Michael