Re: Fwd: evbarm ldscript vs. KERNEL_BASE_PHYS != KERNEL_BASE_VIRT

[Rafal Boni <rafal%pobox.com@localhost>]

Nick Hudson wrote:
> On Monday 10 March 2008 20:11:27 Rafal Boni wrote:
> > Oops, I guess there isn't a separate evbarm list; forwarding here.
> >
> > --rafal
> >
> > Encapsulated message
> >   evbarm ldscript vs. KERNEL_BASE_PHYS != KERNEL_BASE_VIRT
> >  From: Rafal Boni <rafal%pobox.com@localhost>
> >  To: port-evbarm%netbsd.org@localhost
> >  CC: port-hpcarm%netbsd.org@localhost
> >
> > If I build a kernel where KERNEL_BASE_PHYS != KERNEL_BASE_VIRT, the BSS
> > ends up having it's (ELF) physaddr set to one based at KERNEL_BASE_VIRT
> > instead of KERNEL_BASE_PHYS.  This seems like a bug to me and it makes
> > it hard for me to correctly load such a kernel, since my loader tries
> > to zero memory that's likely unmapped at the time.
> >
> > Diff that fixes it for me is below; I thought I'd pass this by the list
> > for feedback since I'm far from an ARM gooroo.
>
> I think this is standard linker behaviour
>
>
> "   The linker will normally set the LMA equal to the VMA.  You can
> change that by using the `AT' keyword.  The expression LMA that follows
> the `AT' keyword specifies the load address of the section."

Sorry, I guess I should have added a bit of context.  The LMA is set to 
an address based at KERNEL_BASE_PHYS for the text & data sections in the 
evbarm linker script already; it just isn't done so for the BSS (& sbss, 
etc.).

My question is whether it was only done for text & data (not bss, sbss, 
etc.) due to an oversight, or was this intentional?  It certainly seems 
wrong to me, but I don't own any of the evbarm-supported eval boards, so 
can't say it has no side effects there.

--rafal