Hi Scott, Kim, David,
On 01/17/2013 12:54 PM, Kim Phillips wrote:
On Wed, 16 Jan 2013 18:36:03 -0600
Scott Wood <scottw...@freescale.com> wrote:
On 01/16/2013 05:59:04 PM, Kim Phillips wrote:
and, if including libfdt.h which includes libfdt_env.h in
the correct order, don't include fdt.h before libfdt.h.
this is needed to get the fdt type definitions set from
the project environment before fdt.h uses them.
Signed-off-by: Kim Phillips <kim.phill...@freescale.com>
Cc: Jerry Van Baren <gvb.ub...@gmail.com>
Maybe fdt.h should include libfdt_env.h?
Or just always use libfdt.h as the public header.
Was just following along the same lines as the dtc commits 38ad79d3
"dtc/tests: don't include fdt.h prior to libfdt.h" and 20b866a7
"dtc/fdtdump: include libfdt_env.h prior to fdt.h", acked by David
G. I don't know why some only include fdt.h.
devicetree-discuss/David: is there a prescribed way to go here?
Change all fdt.h includers to just always include libfdt.h instead
of libfdt_env.h prior to fdt.h?
I started applying Kim's "sparse" patches to the u-boot source and ran
into this issue pretty hard.
In u-boot, there is an added complexity that the "tools" (host-based
u-boot support tools) support flattened device trees, but explicitly
include the u-boot version of libfdt declarations so they don't fall out
of sync if the host has a non-compatible libfdt version. Having them
out of sync would be a *horrible* situation to sort out - everything
would build OK but nothing would work right, probably with no useful
diagnostic information. This originated in 2008, so life may be better
nowadays. Or maybe not.
I would be in favor of explicitly including all the *fdt* headers in the
sources. Alternately, Scott's suggestion of just including libfdt.h as
the public header seems good, but I'm pretty sure it will mess me up
with the explicit #including in the host-based "tools" build, leaving us
with nasty work-arounds or a risk of hard to identify incompatible host
vs. u-boot fdt versions.
Who Includes Who
fdt.h - no includes
fdt_support.h - (u-boot only file)
29 #include <fdt.h>
libfdt.h
54 #include <libfdt_env.h>
55 #include <fdt.h>
libfdt_env.h
- u-boot version is minimal, uses pre-existing macros for byte swapping
- dtc version implements byte swapping, includes:
4 #include <stddef.h>
5 #include <stdint.h>
6 #include <string.h>
libfdt_env.h is where Kim typedef'ed fdt16_t, fdt32_t, fdt64_t
I suspect the original intent was to have <libfdt.h> be the file that
people #included. For whatever reason, most includes are (picking on
fdt_ro.c arbitrarily):
51 #include "libfdt_env.h"
53 #include <fdt.h>
54 #include <libfdt.h>
Since libfdt.h #includes fdt.h and libfdt_env.h, lines 51 and 53 (above)
are redundant. It sorts out OK in dtc because libfdt_env.h includes
stdint.h and defines fdt*_t, but it messes me up in u-boot where
(currently) libfdt_env.h does *not* include stdint.h... and then things
get really wonky in the u-boot "tools" directory due to the need to use
the u-boot version of the *fdt*.h headers, not random stuff installed on
the computer.
HTH,
gvb
_______________________________________________
U-Boot mailing list
U-Boot@lists.denx.de
http://lists.denx.de/mailman/listinfo/u-boot
