From 3def834c65c57d689f65f58821404ead785a358c Mon Sep 17 00:00:00 2001
From: Amelia Blachuciak <amelia.blachuciak@intel.com>
Date: Tue, 9 Jul 2019 14:40:41 +0200
Subject: [PATCH] make: add cross-compilation support

There might be a need for user to cross-compile SPDK for other platforms
than native. Since DPDK supports cross-compilation already, only enablement of
cross-compilation for SPDK is missing. This patch aims to provide the user
with additional option to configure script that works similar to what DPDK already provides.

To enable cross-compilation run ./configure.sh with additional --cross-prefix parameter.
The parameter should work in similar manner to DPDK CROSS parameter
and specifies prefix of cross-compiler defined in PATH variable.

Note: To cross-compile, toolchain must have SPDK dependencies such as e.g. Libaio.

Signed-off-by: Amelia Blachuciak <amelia.blachuciak@intel.com>
Change-Id: Ia7cb879d39d624552cad1af98a563070ea7676b2
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/460977
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
Reviewed-by: Paul Luse <paul.e.luse@intel.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
---
 CONFIG             | 3 +++
 configure          | 8 +++++++-
 dpdkbuild/Makefile | 4 ++++
 3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/CONFIG b/CONFIG
index e2bb8a358..1a1515e73 100644
--- a/CONFIG
+++ b/CONFIG
@@ -37,6 +37,9 @@ CONFIG_PREFIX="/usr/local"
 # Target architecture
 CONFIG_ARCH=native
 
+# Prefix for cross compilation
+CONFIG_CROSS_PREFIX=
+
 # Build with debug logging. Turn off for performance testing and normal usage
 CONFIG_DEBUG=n
 
diff --git a/configure b/configure
index 2669cbbef..7c7d7f583 100755
--- a/configure
+++ b/configure
@@ -18,6 +18,9 @@ function usage()
 	echo " --prefix=path             Configure installation prefix (default: /usr/local)"
 	echo " --target-arch=arch        Target build architecture. Must be a valid GNU arch. Default: native"
 	echo ""
+	echo " --cross-prefix=prefix     Prefix for cross compilation (default: none)"
+	echo "                           example: aarch64-linux-gnu"
+	echo ""
 	echo " --enable-debug            Configure for debug builds"
 	echo " --enable-log-bt           Enable support of backtrace printing in SPDK logs (requires libunwind)."
 	echo " --enable-werror           Treat compiler warnings as errors"
@@ -124,6 +127,9 @@ for i in "$@"; do
 		--target-arch=*)
 			CONFIG[ARCH]="${i#*=}"
 			;;
+		--cross-prefix=*)
+			CONFIG[CROSS_PREFIX]="${i#*=}"
+			;;
 		--enable-debug)
 			CONFIG[DEBUG]=y
 			;;
@@ -342,7 +348,7 @@ for i in "$@"; do
 done
 
 # Detect the compiler toolchain
-scripts/detect_cc.sh --cc="$CC" --cxx="$CXX" --lto="${CONFIG[LTO]}" --ld="$LD" > mk/cc.mk
+scripts/detect_cc.sh --cc="$CC" --cxx="$CXX" --lto="${CONFIG[LTO]}" --ld="$LD" --cross-prefix="${CONFIG[CROSS_PREFIX]}"  > mk/cc.mk
 
 CC=$(cat mk/cc.mk | grep "CC=" | cut -d "=" -f 2)
 CC_TYPE=$(cat mk/cc.mk | grep "CC_TYPE=" | cut -d "=" -f 2)
diff --git a/dpdkbuild/Makefile b/dpdkbuild/Makefile
index e086998ed..e458af28a 100644
--- a/dpdkbuild/Makefile
+++ b/dpdkbuild/Makefile
@@ -93,6 +93,10 @@ else
 DPDK_CONFIG := $(TARGET_MACHINE)-native
 endif
 
+ifneq ($(CONFIG_CROSS_PREFIX),)
+DPDK_OPTS += CROSS=$(CONFIG_CROSS_PREFIX)-
+endif
+
 ifeq ($(OS),Linux)
 DPDK_CONFIG := $(DPDK_CONFIG)-linuxapp
 NPROC := $(shell nproc)