Re: [PATCH] of/lib: Export fdt routines to modules

[David Daney <ddaney@caviumnetworks.com>]

On 10/16/2013 04:27 PM, Michael Bohan wrote:
> Ever since the following commit, libfdt has been available for
> usage in the kernel:
>
>       commit ab25383983fb8d7786696f5371e75e79c3e9a405
>       Author: David Daney <david.daney@cavium.com>
>       Date:   Thu Jul 5 18:12:38 2012 +0200
>
>       of/lib: Allow scripts/dtc/libfdt to be used from kernel code
>
> Export these functions to modules so that they may be used
> from device drivers.
>
> Change-Id: I7f540b7cf860c4be414e32ce183be5268b2ae6af
> Signed-off-by: Michael Bohan <mbohan@codeaurora.org>
> ---
>   lib/fdt.c     |    6 ++++++
>   lib/fdt_ro.c  |   28 ++++++++++++++++++++++++++++
>   lib/fdt_rw.c  |   13 +++++++++++++
>   lib/fdt_sw.c  |    9 +++++++++
>   lib/fdt_wip.c |    6 ++++++
>   5 files changed, 62 insertions(+), 0 deletions(-)
>
> diff --git a/lib/fdt.c b/lib/fdt.c
> index 97f2006..a3fe87b 100644
> --- a/lib/fdt.c
> +++ b/lib/fdt.c
> @@ -1,2 +1,8 @@
>   #include <linux/libfdt_env.h>
> +#include <linux/module.h>
>   #include "../scripts/dtc/libfdt/fdt.c"
> +
> +EXPORT_SYMBOL_GPL(fdt_next_tag);

The code was all written by David Gibson, and is dual GPL/BSD licensed. 
  So I am not sure you should be using the GPL flavor of the export 
directive.


But more than this.  I don't understand why a driver would be parsing 
the FDT in the first place.  If there is a device tree, why hasn't it 
been unflattened, and thus used via the normal device tree functions.

David Daney