Small remote debug kernels??

Small remote debug kernels??

[Liam Davies]

I would like to remote debug my kernel.
On the Cobalt box I have there is (allegedly) a bootloader bug that
stops the
kernel being any larger than 1M/2.5M, compressed/uncompressed.
I have stripped the kernel bare but can't get much lower than 6M
uncompressed.

Is there any way I can have a mini-remote debugging kernel??


Thanks
Liam

Re: Small remote debug kernels??

[Ralf Baechle]

On Fri, Feb 23, 2001 at 02:26:42PM +1000, Liam Davies wrote:

> I would like to remote debug my kernel.
> On the Cobalt box I have there is (allegedly) a bootloader bug that
> stops the
> kernel being any larger than 1M/2.5M, compressed/uncompressed.

I've never read the bootloader code during my Cobalt time but supposedly
it reserves a fixed amount of memory for loading and decompressing the
kernel.  As the firmware uses gzip routines to decompress the loaded
kernel and has an entire Linux kernel in it for reading the real kernel
from an ext2 filesystem it must be covered by the GPL and you can ask
Cobalt^WSun for the source to change this limit.

> I have stripped the kernel bare but can't get much lower than 6M
> uncompressed.
> 
> Is there any way I can have a mini-remote debugging kernel??

Either your kernel isn't really stripped or you have a huge configuration.
The 64-bit Origin kernel which I'm using here is 3037235 (unstripped) /
1874064 (striped) in size.  Did you strip symbols only and left debug
information in the object file?

  Ralf

Re: Small remote debug kernels??

[Curtis Veit]

Hi Liam,

On Fri, Feb 23, 2001 at 02:26:42PM +1000, Liam Davies wrote:
> I would like to remote debug my kernel.
> On the Cobalt box I have there is (allegedly) a bootloader bug that
> stops the
> kernel being any larger than 1M/2.5M, compressed/uncompressed.
> I have stripped the kernel bare but can't get much lower than 6M
> uncompressed.
> 
> Is there any way I can have a mini-remote debugging kernel??

It sounds like the kernel on the target system still has the
debug symbols in it. The symbols are actually only needed 
in the kernel on the host end.  (present on the same machine
as gdb.)

You can strip the kernel you put on your target with
	strip --strip-unneeded vmlinux
This should allow you to use more then a bare kernel.

It seems that you have fallen prey to a common misconception
about remote debugging.  Hope this helps.

Regards,

Curtis Veit
curtisv@lineo.com