[U-Boot] IXP425 TEXT_BASE

[Wolfgang Denk]

Dear Darius Augulis,

In message <4A784702.40806 at gmail.com> you wrote:
>
> > No. TEXT_BASE is an absolute address.
> 
> yes, but depends on the physical RAM base and size.

Only on ARM (and other architectures that copied it's broken
implementation). TEXT_BASE is an absolute address (in the boot flash)
on PowerPC.

> could you please explain more? why to the end of RAM?

YOu want to have a maximum of contiguous RAM available to load Linux
kernel, ramdisk images etc.

> for example I have 16MB RAM, base is 0x10000000. TEXT_BASE = 0x10400000.
> Why is better to set this to 0x10F00000 ? To have more stack and malloc 
> memory? But U-boot will never exceed such limit? Please explain where I 
> am wrong. Thanks!

With RAM from 0x10000000...0x10ffffff you should probably put
TEXT_BASE at 0x10f80000 which then would leave you some 15 MB of
contiguous RAM for your use.

With your setup you jusy have some 3+ MB below U-Boot and some 11+ MB
above it. It makes not much sense to have U-Boot sitting right in the
middle of precious RAM like this.

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
The idea of male and female are universal constants.
	-- Kirk, "Metamorphosis", stardate 3219.8