imx-atf: Build out of tree and from a clean directory

imx-atf built in the source tree, into ${S}/build, and do_compile never
cleaned it. The TF-A Makefile does not track build options such as SPD
or LOG_LEVEL, so after a PACKAGECONFIG change make finds every object
up to date and relinks nothing. do_unpack does not depend on
PACKAGECONFIG, so it does not rerun either, and do_deploy then ships
the bl31.bin from the previous configuration.

On imx8mq-evk this showed up after switching from the NXP BSP to the
mainline BSP, which drops the optee PACKAGECONFIG. The deployed BL31
was still the SPD=opteed build. Its imx8mq setup sets the BL32 entry to
BL32_BASE unconditionally, and the mainline boot container carries no
OP-TEE, so the board hung right after the "BL31: Built" banner. The
stale binary was reproduced byte for byte by building with SPD=opteed
and then without it in the same build directory.

Build into ${WORKDIR}/build through BUILD_BASE, clean it before every
compile, and deploy from there. The Makefile stays in ${S}, so
do_compile runs make with -C ${S}; the default do_compile would skip
make, as ${B} has no Makefile.

Tested on imx8mq-evk with the mainline BSP by building imx-atf with the
optee PACKAGECONFIG and then without it. Each build recompiles
everything, the optee bl31 carries the opteed service and the plain
one does not. With u-boot-fslc 2026.10, core-image-weston then boots on
an imx8mq-evk board through BL31, U-Boot and Linux to Weston.

Signed-off-by: Rodrigo M. Duarte <rodrigo.duarte@ossystems.com.br>

1 files changed, 13 insertions, 1 deletions

diff --git a/recipes-bsp/imx-atf/imx-atf_2.14.bb b/recipes-bsp/imx-atf/imx-atf_2.14.bb
index 407808b40..daf74d016 100644
--- a/recipes-bsp/imx-atf/imx-atf_2.14.bb
+++ b/recipes-bsp/imx-atf/imx-atf_2.14.bb
@@ -29,6 +29,12 @@ ATF_SRC ?= "git://github.com/nxp-imx/imx-atf.git;protocol=https"
 SRCBRANCH = "lf_v2.14"
 SRCREV = "af9eb2c1748ee3abc0ead7dc76e462f50c573036"
 
+# Build out of tree and from scratch: the TF-A Makefile does not track
+# build options such as SPD, so an incremental build after a
+# PACKAGECONFIG change would relink nothing and deploy a stale bl31.bin.
+B = "${WORKDIR}/build"
+do_compile[cleandirs] = "${B}"
+
 inherit deploy
 
 PACKAGECONFIG ??= "\
@@ -52,6 +58,7 @@ ATF_SYS_PWR_FULL_CTRL ?= "0"
 EXTRA_OEMAKE += "\
     CROSS_COMPILE=${TARGET_PREFIX} \
     PLAT=${ATF_PLATFORM} \
+    BUILD_BASE=${B} \
     ${PACKAGECONFIG_CONFARGS} \
     bl31 \
 "
@@ -81,6 +88,11 @@ EXTRA_OEMAKE += 'SYS_PWR_FULL_CTRL=${ATF_SYS_PWR_FULL_CTRL}'
 
 do_configure[noexec] = "1"
 
+# The Makefile is in ${S}, while the build output goes to ${B}.
+do_compile() {
+    oe_runmake -C ${S}
+}
+
 do_install[noexec] = "1"
 
 # The appends join without a leading space to build the contiguous bl31
@@ -97,7 +109,7 @@ addtask deploy after do_compile
 do_deploy() {
     OUTPUT_FOLDER="${@bb.utils.contains('PACKAGECONFIG', 'debug', 'debug', 'release', d)}"
     for deploydir in ${DEPLOYDIR} ${DEPLOYDIR}/imx-boot-tools; do
-        install -Dm 0644 ${S}/build/${ATF_PLATFORM}/${OUTPUT_FOLDER}/bl31.bin $deploydir/${ANNOTATED_NAME}
+        install -Dm 0644 ${B}/${ATF_PLATFORM}/${OUTPUT_FOLDER}/bl31.bin $deploydir/${ANNOTATED_NAME}
     done
     ln -sf ${ANNOTATED_NAME} ${DEPLOYDIR}/bl31.bin
 }