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Unable to boot up the Raspberry pi board

e14 Contributor

Hi,

we are took new raspiberry pi 2 board. with prebuilt with HDMI screen it is booting fine. But we like to change the boot log on to serial port. we modified in cmdline.txt console to ttys0 and in /etc/inittab -- in that last line changed to ttys0-- then we got the below log.  Initially green led "ACT" is blinking rate is fast and then after some time that led blink rate is reduced and only side small blink is coming -- then no other log is coming on serial port.

"Uncompressing Linux... done, booting the kernel"   after that kernel is not booting

 

1 Either Linux kernel is booting eor

2. in the kernel do we need to configure the to serial port for the log.

 

regards,

 

Viswanath K.

  • Hello Viswanath,

     

    the first thing I suggest to check is the settings you have changed. The Raspberry PI serial used by default for terminal access will be /dev/ttyAMA0 instead of the more traditional Linux ttys0 This may be a first issue.

     

    Then as it seems that you need a headless Raspberry PI, I suggest - to be sure to do all the things correctly - to rollback the changes you have done (it is very probable that something wen wrong there) then launch

     

    sudo raspi-config

     

    from a terminal after booting with the system booting from the hdmi screen (that is, starting the X-Server). From the raspi-config menu you can enable/disable the automatic starting of the GTK (the graphic interface), enable the serial for rs232 ssh access etc.

    Then I suggest also to enable the ssh protocol to be able to reach the PI from a remote terminal, both via network connection and serial terminal.

    Try the network connection ssh login first from another computer and see if the system is working fine as expected, then if the issue continue maybe something hardware too blocking the kernel when stat connected with the serial terminal.

     

    For a detailed description of the raspi-config script options and features you can check the following link: https://www.raspberrypi.org/documentation/configuration/raspi-config.md

     

    Enrico

  • in reply to balearicdynamics

    HI,

     

    Thank you. you are right. after changing from ttys0 to ttyAMA0 we got the logs on serial port.

    I am having one doubt -- Does Raspiberry pi have any bootloader ..?? is there any support from U-boot...??

    We like to flash new kernel image not the prebuilt -- Could you please in this to us.

     

    regards,

    Viswanath K

  • in reply to e14 Contributor

    There is not a bootloader. To make a paralel, you should see the SD card from where your system boot (in a separate boot partition) just like the flash memory in the more conventional embedded linux machines. You can remake or recompile the kernel as well, and create a new image on a sd card for booting. This in the case you plan to use just the sd card to store both the boot partition and the Linux system ext4 partition (and the swap partition too).

     

    Alternatively you can boot from the sd card then move the system on an external ssd, a USBhard disk, or simply a USB (maybe more capable) stick.

     

    Enrico

     

    P.S. Better if you make these discussion setting as "questions", maybe more useful for the other users, as well as marking the answers as helpful or correct.