[PATHv11 01/43] submodule: add lwIP as git submodule

[Maxim Uvarov]

add external lwIP library as a git submodule.
Use STABLE-2_2_0_RELEASE tag.

Signed-off-by: Maxim Uvarov <maxim.uvarov at linaro.org>
---
 .gitmodules            | 4 ++++
 Makefile               | 8 +++++++-
 net/lwip/lwip-external | 1 +
 3 files changed, 12 insertions(+), 1 deletion(-)
 create mode 100644 .gitmodules
 create mode 160000 net/lwip/lwip-external

diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000000..7930a8b563
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,4 @@
+[submodule "lwip"]
+	path = net/lwip/lwip-external
+	url = https://git.savannah.nongnu.org/git/lwip.git
+	branch = master
diff --git a/Makefile b/Makefile
index 08604ed3c7..132a60575a 100644
--- a/Makefile
+++ b/Makefile
@@ -1872,6 +1872,12 @@ endef
 include/config/uboot.release: include/config/auto.conf FORCE
 	$(call filechk,uboot.release)
 
+initsubmodules:
+	(cd $(srctree) && \
+	if [ ! -f $(srctree)/net/lwip/lwip-external/README ]; then \
+	flock `git rev-parse --git-dir`/config git submodule init && \
+	flock `git rev-parse --git-dir`/config git submodule update; \
+	fi; )
 
 # Things we need to do before we recursively start building the kernel
 # or the modules are listed in "prepare".
@@ -1896,7 +1902,7 @@ ifneq ($(KBUILD_SRC),)
 endif
 
 # prepare2 creates a makefile if using a separate output directory
-prepare2: prepare3 outputmakefile cfg
+prepare2: prepare3 outputmakefile cfg initsubmodules
 
 prepare1: prepare2 $(version_h) $(timestamp_h) $(dt_h) $(env_h) \
                    include/config/auto.conf
diff --git a/net/lwip/lwip-external b/net/lwip/lwip-external
new file mode 160000
index 0000000000..0a0452b2c3
--- /dev/null
+++ b/net/lwip/lwip-external
@@ -0,0 +1 @@
+Subproject commit 0a0452b2c39bdd91e252aef045c115f88f6ca773
-- 
2.30.2