[U-Boot-Users] Using tools/mkimage
wd at denx.de
Tue Aug 5 09:47:30 CEST 2003
In message <20030805073513.GA32163 at buici.com> you wrote:
> Nice to see some organized documentation. I'm not finding mkimage in
Yes :-) Sorry for antedating the official announcement. Detlev?
> the table of contents. Where is it described?
Sorry, it ain't (yet). It's implicitely hitten in the kernel
Makefiles. But you made your point, now I know what to add next :-)
> > It makes no sense to use a zImage file. It was one of the intentions
> > of U-Bot (well, it was PPCBoot then) to get rid of this bootstrap
> > loader.
> Perhaps it is strong to say "no sense". In fact, there is a good
It makes no sense. U-Boot provides an interface which (1) includes
all of the functionality of the bottstrap loader [plus much more] and
(2) which assumes the kernel call interface, which is not used by the
> reason to use zImage when u-boot is one of several methods of booting
> a kernel. It helps us to know that the same exact code is running in
> every situation.
I think it is the kernel you care about right? So run the same
kernel, once by wrapping it with a bootstrap loader into a zImage
file, and once by wrapping it with mkimape into an uImage file.
> > I don't see any use of the "-e" option in this command. And zImage is
> > not what you want. If you want to use an uncompressed kernel image
> > this should be something like
> > mkimage -A arm -O linux -T kernel -C none -a 0x0C008000 \
> > -e 0x0C008000 -n 'ARM Linux' \
> > -d arch/arm/boot/compressed/piggy uImage
> I'm not sure what you mean. Setting -a sets -e automatically.
Maybe. But load address and entry point address are not necessarily
> Where do you get a uImage file?
As file "uImage" - the last argument in above call.
> I'm not sure why, but it appears to be working now. It is probable
> that one of the components was out-of-sync.
What you are doing is bogus. "bootm" is meant to start images which
have the expected kernel interface. If you load a zImage file (let's
ignore for a moment that this makes no sense :-) you should use the
"go" command toi start it as this provides the interfqce for the
zImage bootstrap loader (i. e. none).
> I'm on to a new problem. For some reason, a kernel booted from blob
> returns a bogo-mips value of 79 while the same kernel booted from
> u-boot returns a bogo-mips value of 39. It's an intriguing mystery.
Different initialization of the hardware? Different passing of
parameters? When booting a image with a non-matching call interface
many things can go wrong.
Software Engineering: Embedded and Realtime Systems, Embedded Linux
Phone: (+49)-8142-4596-87 Fax: (+49)-8142-4596-88 Email: wd at denx.de
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