Re: [PATCH] [2/9] Add a kernel_address() that works for data too

[Russell King]

On Tue, Jan 05, 2010 at 09:58:53AM +0100, Sam Ravnborg wrote:
> But you can trust _etext an almost all architectures.
> It is a bug if it is missing.
> 
> So [_text, _etext] is the text section.
> 
> The data section may be placed before or after - it depends on the architecture.
> But again - only some architectures define _sdata.
> But all? define _edata.

You can not guarantee that the data segment is after the text segment,
unless you want to outlaw XIP kernels.  XIP kernels have the text
segment mapped at a completely different address to the data segment.

I'd suggest the only way to identify the data segment in a generic way
is to have everyone define _sdata, or more preferably _data (to be
consistent with _text), to be the start of the data segment.

-- 
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/