[Buildroot] Unable to boot ISO on target

[Buildroot] Unable to boot ISO on target

[Rob Kent]

Hi All,

I have created a build for an Atom N270 target (eeebox b202) and am now 
trying to create a bootable USB drive to test on the target machine. My 
configuration creates a kernel image (bzImage) and a filesystem 
(rootfs.ext2) and then creates an ISO9660 hybrid image installing 
syslinux/isolinux as a bootloader. I can run the output with qemu using 
the following command:

$ qemu-system-i386 -cpu n270 -hda output/images/rootfs.iso9660

This boots to the prompt (with a readonly filesystem).

I copy this iso image to a USB stick as follows:

$ sudo dd if=rootfs.iso9660 of=/dev/sdg bs=4M && sync

However, when I boot this on the target machine, it loads the kernel but 
then panics as its unable to find the rootfs as follows:

Kernel panic - not syncing: VFS: Unable to mount rootfs on 
unknown-block(0,0)

The output can be a bit inconsistent, but sometimes the message says its 
not able to find "sda" and to set "root=" to something else giving a 
blank list of available partitions.

It seems to me that the kernel is unable to find any suitable/readable 
partitions, but as this boots with qemu I am assuming this must be 
something to do with the ISO config/setup?

Can anyone shine any light on this? I've tried quite a lot of things 
from Google and so far had no luck.

Thanks very much,

Rob

[Buildroot] Unable to boot ISO on target

[Stefan Fröberg]

Hi

Im not quite sure what you mean by hybrid image (I always thought that
buildroot creates just plain read only iso9660 livecd images)
but can you please post your .config file and I could take a look?

-S-

Rob Kent kirjoitti 20.12.2017 klo 18:50:
> Hi All,
>
> I have created a build for an Atom N270 target (eeebox b202) and am
> now trying to create a bootable USB drive to test on the target
> machine. My configuration creates a kernel image (bzImage) and a
> filesystem (rootfs.ext2) and then creates an ISO9660 hybrid image
> installing syslinux/isolinux as a bootloader. I can run the output
> with qemu using the following command:
>
> $ qemu-system-i386 -cpu n270 -hda output/images/rootfs.iso9660
>
> This boots to the prompt (with a readonly filesystem).
>
> I copy this iso image to a USB stick as follows:
>
> $ sudo dd if=rootfs.iso9660 of=/dev/sdg bs=4M && sync
>
> However, when I boot this on the target machine, it loads the kernel
> but then panics as its unable to find the rootfs as follows:
>
> Kernel panic - not syncing: VFS: Unable to mount rootfs on
> unknown-block(0,0)
>
> The output can be a bit inconsistent, but sometimes the message says
> its not able to find "sda" and to set "root=" to something else giving
> a blank list of available partitions.
>
> It seems to me that the kernel is unable to find any suitable/readable
> partitions, but as this boots with qemu I am assuming this must be
> something to do with the ISO config/setup?
>
> Can anyone shine any light on this? I've tried quite a lot of things
> from Google and so far had no luck.
>
> Thanks very much,
>
> Rob
> _______________________________________________
> buildroot mailing list
> buildroot at busybox.net
> http://lists.busybox.net/mailman/listinfo/buildroot

[Buildroot] Unable to boot ISO on target

[Rob Kent]

Hi,

As I understand it from here:

https://buildroot.org/downloads/manual/manual.html#_boot_the_generated_images

The hybrid disk image allows it to be used as a both a USB and/or CD 
image.

Anywho, I actually just fixed my problem: I had somehow managed to 
uncheck the initrd option in menuconfig. THe system now boots on target 
as expected.

Thanks, Rob

On 2017-12-20 19:41, Stefan Fr?berg wrote:
> Hi
> 
> Im not quite sure what you mean by hybrid image (I always thought that
> buildroot creates just plain read only iso9660 livecd images)
> but can you please post your .config file and I could take a look?
> 
> -S-
> 
> Rob Kent kirjoitti 20.12.2017 klo 18:50:
>> Hi All,
>> 
>> I have created a build for an Atom N270 target (eeebox b202) and am
>> now trying to create a bootable USB drive to test on the target
>> machine. My configuration creates a kernel image (bzImage) and a
>> filesystem (rootfs.ext2) and then creates an ISO9660 hybrid image
>> installing syslinux/isolinux as a bootloader. I can run the output
>> with qemu using the following command:
>> 
>> $ qemu-system-i386 -cpu n270 -hda output/images/rootfs.iso9660
>> 
>> This boots to the prompt (with a readonly filesystem).
>> 
>> I copy this iso image to a USB stick as follows:
>> 
>> $ sudo dd if=rootfs.iso9660 of=/dev/sdg bs=4M && sync
>> 
>> However, when I boot this on the target machine, it loads the kernel
>> but then panics as its unable to find the rootfs as follows:
>> 
>> Kernel panic - not syncing: VFS: Unable to mount rootfs on
>> unknown-block(0,0)
>> 
>> The output can be a bit inconsistent, but sometimes the message says
>> its not able to find "sda" and to set "root=" to something else giving
>> a blank list of available partitions.
>> 
>> It seems to me that the kernel is unable to find any suitable/readable
>> partitions, but as this boots with qemu I am assuming this must be
>> something to do with the ISO config/setup?
>> 
>> Can anyone shine any light on this? I've tried quite a lot of things
>> from Google and so far had no luck.
>> 
>> Thanks very much,
>> 
>> Rob
>> _______________________________________________
>> buildroot mailing list
>> buildroot at busybox.net
>> http://lists.busybox.net/mailman/listinfo/buildroot
> 
> _______________________________________________
> buildroot mailing list
> buildroot at busybox.net
> http://lists.busybox.net/mailman/listinfo/buildroot

[Buildroot] Unable to boot ISO on target

[Stefan Fröberg]

Hi

Ah, Good that you got it fixed.

And thanks for the info. Been using just grub until now with livecds and
did not know that hybrid images were possible when using isolinux as
bootloader.

Merry Xmas :-)
-S-




Rob Kent kirjoitti 20.12.2017 klo 21:52:
> Hi,
>
> As I understand it from here:
>
> https://buildroot.org/downloads/manual/manual.html#_boot_the_generated_images
>
>
> The hybrid disk image allows it to be used as a both a USB and/or CD
> image.
>
> Anywho, I actually just fixed my problem: I had somehow managed to
> uncheck the initrd option in menuconfig. THe system now boots on
> target as expected.
>
> Thanks, Rob
>
> On 2017-12-20 19:41, Stefan Fr?berg wrote:
>> Hi
>>
>> Im not quite sure what you mean by hybrid image (I always thought that
>> buildroot creates just plain read only iso9660 livecd images)
>> but can you please post your .config file and I could take a look?
>>
>> -S-
>>
>> Rob Kent kirjoitti 20.12.2017 klo 18:50:
>>> Hi All,
>>>
>>> I have created a build for an Atom N270 target (eeebox b202) and am
>>> now trying to create a bootable USB drive to test on the target
>>> machine. My configuration creates a kernel image (bzImage) and a
>>> filesystem (rootfs.ext2) and then creates an ISO9660 hybrid image
>>> installing syslinux/isolinux as a bootloader. I can run the output
>>> with qemu using the following command:
>>>
>>> $ qemu-system-i386 -cpu n270 -hda output/images/rootfs.iso9660
>>>
>>> This boots to the prompt (with a readonly filesystem).
>>>
>>> I copy this iso image to a USB stick as follows:
>>>
>>> $ sudo dd if=rootfs.iso9660 of=/dev/sdg bs=4M && sync
>>>
>>> However, when I boot this on the target machine, it loads the kernel
>>> but then panics as its unable to find the rootfs as follows:
>>>
>>> Kernel panic - not syncing: VFS: Unable to mount rootfs on
>>> unknown-block(0,0)
>>>
>>> The output can be a bit inconsistent, but sometimes the message says
>>> its not able to find "sda" and to set "root=" to something else giving
>>> a blank list of available partitions.
>>>
>>> It seems to me that the kernel is unable to find any suitable/readable
>>> partitions, but as this boots with qemu I am assuming this must be
>>> something to do with the ISO config/setup?
>>>
>>> Can anyone shine any light on this? I've tried quite a lot of things
>>> from Google and so far had no luck.
>>>
>>> Thanks very much,
>>>
>>> Rob
>>> _______________________________________________
>>> buildroot mailing list
>>> buildroot at busybox.net
>>> http://lists.busybox.net/mailman/listinfo/buildroot
>>
>> _______________________________________________
>> buildroot mailing list
>> buildroot at busybox.net
>> http://lists.busybox.net/mailman/listinfo/buildroot
> _______________________________________________
> buildroot mailing list
> buildroot at busybox.net
> http://lists.busybox.net/mailman/listinfo/buildroot