Merge pull request timvideos#432 from skiphansen/allow_specified_commit

Optionally allow checkout commits and BR2_EXTERNAL to be specified.

scripts/build-linux.sh

@@ -235,6 +235,9 @@ if [ ${CPU} = vexriscv ] && [ ${BUILD_BUILDROOT:-0} = 1 ]; then
 			cd $(dirname $BD_SRC)
 			echo "Downloading Buildroot code."
 			git clone $BD_REMOTE $BD_SRC
+			if [ x$BD_COMMIT != x ]; then
+			    (cd $BD_SRC; git checkout $BD_COMMIT)
+			fi
 		)
 		fi
 
@@ -243,6 +246,9 @@ if [ ${CPU} = vexriscv ] && [ ${BUILD_BUILDROOT:-0} = 1 ]; then
 			cd $(dirname $LLV_SRC)
 			echo "Downloading Linux on LiteX-VexRiscv code."
 			git clone $LLV_REMOTE $LLV_SRC
+			if [ x$LLV_COMMIT != x ]; then
+			    (cd $LLV_SRC; git checkout $LLV_COMMIT)
+			fi
 		)
 		fi
 
@@ -258,7 +264,7 @@ if [ ${CPU} = vexriscv ] && [ ${BUILD_BUILDROOT:-0} = 1 ]; then
 		dtc -I dts -O dtb -o $TARGET_LINUX_BUILD_DIR/rv32.dtb $TARGET_LINUX_BUILD_DIR/rv32.dts
 
 		cd $BD_SRC
-		make BR2_EXTERNAL=$LLV_SRC/buildroot/ litex_vexriscv_defconfig
+		make BR2_EXTERNAL=${BR2_EXTERNAL:-$LLV_SRC/buildroot} litex_vexriscv_defconfig
 		time make
 		ls -l $BD_SRC/output/images/
 		ln -sf $BD_SRC/output/images/Image $TOP_DIR/$FIRMWARE_FILEBASE.bin