[U-Boot-Users] Re: Problem with bootm command

Wolfgang Denk wd at denx.de
Tue Jul 26 13:09:13 CEST 2005

In message <4221395 at web.de> you wrote:
> I searched the do_bootm_linux() function to find out what u-boot is doing
> when booting linux using the bootm command, because the kernel patch i fou
> nd in the mailing list (which makes the kernel able to copy an initrd dire
> ctly from flash to ram) has to be used with kernel version 2.4.18, but i h
> ave 2.6.12.

It would be definitely helpful if you expolained  which  architecture
you're working on. I speculate that this is ona ARM system?

> It seems as if u-boot checks for an enviroment string called "initrd_high"
>  and if it exists, u-boot does not copy the initrd to ram -> the kernel wi

No, this is not what it does. Please read the documentation.
The behavious is documented both in the manual and in the README.

> ll fail to load the ramdisk. But there is no such string in my enviroment,
>  so shouldn't the bootm command copy initrd to it's designated sdram locat
> ion? It seems as it does not because the start address of the initrd, whic
> h u-boot delivers to the linux kernel is located in flash (one can read it
>  in the kernel booting sequence; the error is that the initrd extends phys
> ical memory, but it's quite clear why this error occures).

I cannot parse this. Isn't your flash mapped in  a  physical  address
range? Or what exacty do you mean?

All this has been discussed many  times  before.  May  I  suggest  to
search the archives?

> Is it possible to force u-boot to copy the image to ram? Of course i could

Why should it do that? It's just a waste of boot time. THe kernel can
poick it up from flash, so why bother with copying it to ram first?

>  use the cp.b command before using bootm (i tested this and it works fine)
> , but thats not what i want to do.

And it's not needed.

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
"Ada is PL/I trying to be Smalltalk.                 - Codoso diBlini

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