[syslinux] I/O error

[Anton Gerasimov]

>> Thanks. I've looked through all the links, and it seems everything is
>> fine wrt. to what was mentioned there (I've disabled 64 bits in mke2fs,
>> but it didn't help). I'd be glad to provide more details, but the error
>> message is the only info I've got by now. It seems nothing else can be
>> got from syslinux shell without modifiying the code.
>>
>> I've tried to make it load the kernel image that was build for my host
>> (originally I was using kernel image built in Yocto) and it did boot, so
>> maybe this is where the problem is. Looks like adding debug prints can't
>> be avoided.
>>
>> Thanks,
>> Anton
>>
>  
>  
> A: Because it fouls the order in which people normally read text.
> Q: Why is top-posting such a bad thing?
> A: Top-posting.
> Q: What is the most annoying thing in e-mail?
>
>
> 0_ Please avoid top-posting.
>
> 1_ Beware: YOCTO/OE uses a customized Syslinux.
>
> 2_ It is still not clear (to me) when exactly the failure occurs. Does 
> it fail before the bootloader? Is the bootloader itself failing? Is the 
> _kernel_ not loading, after the bootloader step got already to the boot 
> prompt?
>
> 3_ Perhaps it would help if you would post your entire syslinux.cfg.
>
> 4_ Someone might be interested in knowing the exact complete command 
> line that you are using in qemu (so the situation could be replicated 
> by others, maybe).
>
> 5_ You could also test with a publicly-available kernel that is known 
> to boot correctly.
>
> Regards,
> Ady.
>

0_ Sorry, didn't quite get what you mean at first.

1_ Yes, but I'm using normal one, because Yocto doesn't support
extlinux. Looks like they also modify kernel image in a way that is
supported by their custom patches to syslinux, digging into it right now.

2_ The bootloader fails at the stage of loading the kernel, i.e. before
transferring control to the kernel. I get:
  Loading /boot/vmlinuz... failed: I/O error
  boot:

dropping me to syslinux CLI. Just found out that the actual error
happens in floadfile after fread (com32/lib/syslinux/floadfile.c:96 in
current master)

3_ It can be reproduced with syslinux.cfg as simple as

  DEFAULT Syslinux Yocto Test
  LABEL Syslinux Yocto Test
      KERNEL /boot/vmlinuz
4_ The simplest qemu command line for reproducing that error is:
qemu-system-x86_64 -m 256 -hda /path/to/disk.img

You need a kernel compiled in Yocto in /boot/vmlinuz and syslinux
installed with 'extlinux --install /mnt/boot' with disk image mounted
(-s option doesn't help, you just need to wait longer before the error
appears with it enabled).

5_ Kernels not built inside Yocto will probably work like those I've
already tried.

Thanks,
Anton

-- 
Anton Gerasimov, ATS Advanced Telematic Systems GmbH
Kantstrasse 162, 10623 Berlin
Managing Directors: Dirk Pöschl, Armin G. Schmidt
Register Court: HRB 151501 B, Amtsgericht Charlottenburg