kbuild: add .SECONDARY special target ...

Based on the following Linux commits:

 - 54a702f70589 ("kbuild: mark $(targets) as .SECONDARY and remove
   .PRECIOUS markers")

 - 8e9b61b293d9 ("kbuild: move .SECONDARY special target to
   Kbuild.include")

This consolidates those two commits and adjusts commit log for barebox.

GNU Make automatically deletes intermediate files that are updated
in a chain of pattern rules.

Example 1) %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
Example 2) %.o <- %.c <- %.c_shipped

arch/arm/crypto/Makefile marks such targets as .PRECIOUS to prevent Make
from deleting them, but the correct way is to use .SECONDARY.

  .SECONDARY
    Prerequisites of this special target are treated as intermediate
    files but are never automatically deleted.

  .PRECIOUS
    When make is interrupted during execution, it may delete the target
    file it is updating if the file was modified since make started.
    If you mark the file as precious, make will never delete the file
    if interrupted.

Both can avoid deletion of intermediate files, but the difference is
the behavior when Make is interrupted; .SECONDARY deletes the target,
but .PRECIOUS does not.

The use of .PRECIOUS is relatively rare since we do not want to keep
partially constructed (possibly corrupted) targets.

.SECONDARY with no prerequisites causes all targets to be treated as
secondary. This agrees the policy of Kbuild.

scripts/Kbuild.include seems a suitable place to add it because it is
included from almost all sub-makes.

I deleted 'SECONDARY' (no dot) from images/Makefile, which I guess
a typo.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild: add .DELETE_ON_ERROR special target ...

Linux commit 9c2af1c

If Make gets a fatal signal while a shell is executing, it may delete
the target file that the recipe was supposed to update.  This is needed
to make sure that it is remade from scratch when Make is next run; if
Make is interrupted after the recipe has begun to write the target file,
it results in an incomplete file whose time stamp is newer than that
of the prerequisites files.  Make automatically deletes the incomplete
file on interrupt unless the target is marked .PRECIOUS.

The situation is just the same as when the shell fails for some reasons.
Usually when a recipe line fails, if it has changed the target file at
all, the file is corrupted, or at least it is not completely updated.
Yet the file’s time stamp says that it is now up to date, so the next
time Make runs, it will not try to update that file.

However, Make does not cater to delete the incomplete target file in
this case.  We need to add .DELETE_ON_ERROR somewhere in the Makefile
to request it.

scripts/Kbuild.include seems a suitable place to add it because it is
included from almost all sub-makes.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Kbuild: Add $(quote) ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

build: fix that LZO file is always rebuilt ...

From e398a00 Mon Sep 17 00:00:00 2001
From: Sam Ravnborg <sam@ravnborg.org>
Date: Tue, 26 Dec 2017 18:09:35 +0100
Subject: [PATCH 4/4] build: fix that LZO file is always rebuilt

Port the make-cmd from linux kernel.
with the updated version $$ is porperly escaped, thus
the LZO rule works as intended.
And we avoid rebuilds when not required

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Fix linking with new ld, based on u-boot ...

U-boot commit info:
http://git.denx.de/?p=u-boot.git;a=commit;h=e391b1e

Signed-off-by: Andrey Panov <rockford@yandex.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Make: Fix if_changed when command contains backslashes ...

The call if_changed mechanism does not work when the command
contains backslashes. This basically is an issue with lzo
and bzip2 compressed kernels. The compressed binaries do not
contain the uncompressed image size, so these use size_append
to append the size. This results in backslashes in the executed
command. With this if_changed always detects a change in the
command and rebuilds the compressed image even if nothing
has changed.

Fix this by escaping backslashes in make-cmd

This was worked out together with Jan Lübbe. The same patch
has recently been accepted to the kernel.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Jan Luebbe <jlu@pengutronix.de>

scripts/Kbuild.include: update to latest kernel version ...

To get cc-disable-warning

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

svn_rev_008 ...

add missing Kconfig