Tiny Core Linux

Tiny Core Base => TCB Talk => Topic started by: as on November 10, 2016, 04:30:49 AM

Title: Diagnosing boot problems - any way to write boot messages to boot partition?
Post by: as on November 10, 2016, 04:30:49 AM

I am trying to boot tinycore from a hard disk.

I have no serial console access and no network access and no screen access to the machine.  Believe me I have tried every trick I can to get screen access but no go.

My goal is to get the network running so I can log in to the machine.

However it's close to impossible to diagnose what the problem is with boot because I have no way to see the boot messages.

The only possible last option I can think of is somehow to get tinycore to write its boot messages back to the boot partition that it loaded from.  Then I can examine that partition and see what the boot problem was.

Is there any possible way that tinycore can write its boot log back onto the boot partition that the kernel loaded from?

thanks!

Title: Re: Diagnosing boot problems - any way to write boot messages to boot partition?
Post by: bmarkus on November 10, 2016, 04:45:40 AM

As I understand you can't access remotely the machine due to boot issues. How do you read the log?

Title: Re: Diagnosing boot problems - any way to write boot messages to boot partition?
Post by: curaga on November 10, 2016, 05:42:41 AM

You can edit tc-config in a remastered initrd, mount your disk at the start and echo things there.

Title: Re: Diagnosing boot problems - any way to write boot messages to boot partition?
Post by: gerald_clark on November 11, 2016, 03:09:00 PM

Linux has no way to determine where it booted from.
It is the boot loader's responsibility to load thew kernel and initrd, and then jump to the kernel start address.
The kernel does not know how that was done.

Title: Re: Diagnosing boot problems - any way to write boot messages to boot partition?
Post by: wksilva on May 04, 2017, 08:04:17 AM

Very interenting problem!

Do you know that there is a "Serial Over Ethernet" solution?

May not solve your problem, but can offer options...


The first problem is this to known if the BIOS is loading something or not.

Can you boot and ping the box with a standard TC?

In the "old days" it was possible to put the kernel + initrd in the boot partition, like:

    cat  kernel  initrd  >  /dev/sdb1

The partition of course must have "the boot flag on".

Make an initrd that starts the network, and see if you can ping.

This does not solve the problem with TC, but can help you to find out if the BIOS bootloader is working or not.