[U-Boot-Users] Manufacturer specific code in a bothersome place

Marc Singer elf at buici.com
Tue Jul 8 01:24:47 CEST 2003


On Tue, Jul 08, 2003 at 12:37:06AM +0200, Wolfgang Denk wrote:
> >   obj-$(CONFIG_SERIAL_16550) += serial_16550.o
> >   obj-$(CONFIG_SERIAL_LH7A400) += serial_lh7a400.o
> 
> I see, another round of config tool discussion. But this time  buttom
> up :-)

No config tool necessary.

I'll make it work for ARM920T and then you can gripe.

> > BTW, I don't think that jump-table relocation should be a problem as
> > long as the file is linked to the target (post-relocation) load
> > address.  Still, I agree that for the serial driver there is no reason
> 
> No, it doesn't work that way. U-Boot is always  linked  to  the  pre-
> relocation address in flash. The post-relocation address is not known
> at compile time, as it may depend on things like RAM size.

That's one way.  On arm, there isn't any reason to link to the flash
address since it does position independent addressing.  For the x86
implementation, I reworked the u-boot.lds to locate the pre-relocation
code to the flash address and the rest at the runtime address.  At
least on the targets (three) I've looked at, there is no reason to
pick a RAM address at runtime.  Why waste the instructions? ;-)

Cheers.




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