[U-Boot-Users] Re: Problem with bootm command
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.
Software Engineering: Embedded and Realtime Systems, Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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