[U-Boot] Debugging why my kernel won't start

Wolfgang Denk wd at denx.de
Wed Aug 18 17:33:47 CEST 2010


Dear Rogan Dawes,

In message <4C6BF138.20107 at dawes.za.net> you wrote:
>
> > Try copying the raw ramdisk image (i. e. without the U-Boot header) to
> > RAM, and try that one, i. e. something like
> > 
> > 	=> cp.b ff9a0040 01600000 ...size...
> > 	...
> > 	=> bootm ff820000 1600000
> 
> Unfortunately, U-boot is expecting the second parameter to point to a
> uImage-wrapped ramdisk, not just raw bytes:

Yes, I know.  I was just trying out some things - I don't know in
which way your U-Boot version might have been modified...

> Why does it make a difference if it is in RAM vs in flash? I have 8MB of

Your kernel may not be able to pick up a ramdisk image in flash.

Mainline ARM cannot do that, for example.

[Patches to support that have been submitted, but rejected.]

> Surely that should be Ok? Besides, U-boot is supposed to copy the data
> in the image to the specified destination address, isn't it?

No, why should it copy the image? It just verifies that the checksum
is OK, and then passes the address to the kernel. The kernel will have
to copy it anyway when uncompressing it, so ther ei no use in U-Boot
adding another copy operation.

Best regards,

Wolfgang Denk

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