[U-Boot-Users] Booting From hard disk.

Wolfgang Denk wd at denx.de
Mon Dec 13 22:22:55 CET 2004

In message <eae046ff041213082036dfdb35 at mail.gmail.com> you wrote:
> > Are you sure that your image is working at all? Does it boot when you
> > download it over TFTP and boot then?
> Since there is no net option in our board, we cant check this.

Then load the kernel image using the BDi2000, or  over  serial  line.

> in our board, the ram starts from 0xa0000000, and is of 32 MB.
> while creating the uImage, the load address and entry point as 0xa0008000,
> and we are loading the image from IDE device to the RAM as,
> $diskboot 0xa0001000 0:1

Start thinking.

How big is your kernel image?  Let's  assume  a  small  configuration
which fits into 500 kB (= 0x7d000).

You load it at address 0xa0001000, so it will take up the  area  from
0xa0001000 ... 0xa007e000.

Your load address is 0xa0008000 which is right in the middle  of  the
area where you stored the kernel image.

What do you think will happen when U-Boot  starts  uncompressing  the
kernel image and write it to the area starting at 0xa0008000?

Do you really expect anything elase  but  a  crash  because  you  are
overwriting the not-yet-uncompressed tail part of the image?

> We are able to get the uImage header information properly,
> but after the "Starting kernel", it is restarting, with "data abort"

Sounds as good a crash as any other to me...

> We have checked the contents of RAM, using md, it is properly copied
> at 0xa0001000.

Of course. U-Boot is working perfectly fine. It does exactly what you
tell it.

> then, after restarting, we cheked the contents at 0xa0008000, at the
> both the locations,
> the kernel is proper.

Don't try to outweird me.  I don't believe you.

Best regards,

Wolfgang Denk

Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
An age is called Dark not because  the  light  fails  to  shine,  but
because people refuse to see it.           -- James Michener, "Space"

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