change runlevel on PetaLinux 2014.2

I would like to know how to change runlevel (set in /etc/inittab) on PetaLinux 2014.2 or other linux distro working on Microzed.

What I would like to do is to automatically login (without inputting root and password) when booted. So I try to set runlevel to 1 (Singleuser mode).

I prepared following files
- system.dtb : build from PetaLinux
- u-boot.elf : build from PetaLinux
- uImage : build from PetaLinux
- uramdisk.image.gz : made using mkimage from arm_ramdisk.image.gz
- zynq_fsbl.elf : from XSDK

Then, I made BOOT.bin from above files.

I put following files to microSD and booted from microSD.
- BOOT.bin
- image.ub

After booted, I changed /etc/inittab the "initdefaul:" line to 1(single user).
I confirmed that /etc/inittab is correctly changed.
Then I rebooted the PetaLinux and found that the runlevel is still 5 not 1.

How can I preserve the change in runlevel setting?

0 zedhed over 11 years ago

Hi y_okada,

Keep in mind when you boot your MicroZed in the manner you described above, the uramdisk.image.gz gets decompressed and mounted as the root file system in SDRAM memory. As a result, that file system is stored in volatile memory during runtime and any changes you make to the file system do not persist following a reboot.

To make the changes permanent, you would need to modify the /etc/inittab located in the file system within your uramdisk.image.gz image (or arm_ramdisk.image.gz) and then repackage that filesystem again and boot from the updated file system image. There are some instructions for modifying the RAM disk image in this thread here:

http://microzed.org/content/how-modify-ramdisk-image-comes-release-145

Regards,

-Kevin
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0 y_okada over 11 years ago in reply to zedhed

Dear Kevin

Thank you very much for your reply.

Now I understand why the change in setting is not effective.

And the information on how to change uramdisk.image.gz you show me is very helpful.
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0 y_okada over 11 years ago

I changed the ramdisk image according to the steps. But it did not change the /etc/inittab.

I found that the /etc/inittab in PetaLinux booted using microSD and those in ramdisk image were different.

On the other hand, the inittab file in PetaLinux booted using microSD is same as build/linux/rootfs/targetroot/etc/inittab in Avnet-MicroZed-z7010-v2014.2, which is used to build system.dtb, uImage, u-boot.elf.

I may make some mistakes related using the ramdisk.
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