[U-Boot-Users] TEXT_BASE
Wolfgang Denk
wd at denx.de
Tue Feb 4 22:57:03 CET 2003
In message <722E4866-3888-11D7-8C12-00039390D626 at pepper.com> you wrote:
> I am confused about the TEXT_BASE define in the config.mk file.
>
> Should this be the address of where the loader is in flash or where it
> should go in SDRAM?
It is the physical start address of the code (not the entry point!)
in flash memory _after_ the final address mapping has been set up.
The start address in RAM usually cannot be determined at compile time
as it depends on a couple of parameters like:
- RAM size (U-Boot should always automagically adjust to different
RAM sizes and install itself always at the very end of available
memory)
- Use of "protected RAM", which will "shift down" the location where
U-Boot gets installed in RAM by an amount which may depend on
environment variable settings
- Use of a common syslog buffer within U-Boot and Linux, which also
shifts down the location where U-Boot gets installed in RAM
[I know that there are some boards that don't bother to implement
this intelligence; they will break when trying to use some of these
more advanced features.]
Best regards,
Wolfgang Denk
--
Software Engineering: Embedded and Realtime Systems, Embedded Linux
Phone: (+49)-8142-4596-87 Fax: (+49)-8142-4596-88 Email: wd at denx.de
Quote from a recent meeting: "We are going to continue having these
meetings everyday until I find out why no work is getting done."
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