Missing dependencies break parallel fTPM builds

[jan-kiszka]

It seems we need

--- a/Samples/ARM32-FirmwareTPM/optee_ta/fTPM/lib/wolf/sub.mk
+++ b/Samples/ARM32-FirmwareTPM/optee_ta/fTPM/lib/wolf/sub.mk
@@ -56,3 +56,5 @@ srcs-y += wolf_symlink/wolfcrypt/src/tfm.c
 srcs-y += wolf_symlink/wolfcrypt/src/wolfmath.c
 srcs-y += wolf_symlink/wolfcrypt/src/des3.c
 srcs-y += wolf_symlink/wolfcrypt/src/random.c
+
+$(srcs-y): wolf_symlink

to fix sporadic build failures on larger build machines, see also https://groups.google.com/d/msgid/isar-users/424e2519-2dfa-5379-a16e-ca505e6135fe%40siemens.com.

This is more to help others as I can't open a PR before I figured out how to deal with https://opensource.microsoft.com/cla/ on the Siemens side (CLAs are complex to handle, and this process here is seems to be even more complex).

[jan-kiszka]

That change didn't help, this one does:

diff --git a/Samples/ARM32-FirmwareTPM/optee_ta/Makefile b/Samples/ARM32-FirmwareTPM/optee_ta/Makefile
index ddf6784..cef0c6f 100644
--- a/Samples/ARM32-FirmwareTPM/optee_ta/Makefile
+++ b/Samples/ARM32-FirmwareTPM/optee_ta/Makefile
@@ -3,8 +3,15 @@ export V?=0
 
 .PHONY: all
 all:
+	#
+	# Link the required external code into the libraries folder. OP-TEE
+	# build does not work well when accessing anything below the root
+	# directory. Use symlinks to trick it.
+	#
+	$(MAKE) -C fTPM CROSS_COMPILE=$(TA_CROSS_COMPILE) create_lib_symlinks
+	# Run the actual build
 	$(MAKE) -C fTPM CROSS_COMPILE=$(TA_CROSS_COMPILE)
 
 .PHONY: clean
 clean:
-	$(MAKE) -C fTPM clean
\ No newline at end of file
+	$(MAKE) -C fTPM clean
diff --git a/Samples/ARM32-FirmwareTPM/optee_ta/fTPM/sub.mk b/Samples/ARM32-FirmwareTPM/optee_ta/fTPM/sub.mk
index 2d9ba24..4eaf286 100644
--- a/Samples/ARM32-FirmwareTPM/optee_ta/fTPM/sub.mk
+++ b/Samples/ARM32-FirmwareTPM/optee_ta/fTPM/sub.mk
@@ -36,12 +36,6 @@ cflags-y += -Os
 cflags-y += -DNDEBUG
 endif
 
-#
-# Link the required external code into the libraries folder. OP-TEE build
-# does not work well when accessing anything below the root directory. Use
-# symlinks to trick it.
-#
-all: create_lib_symlinks
 clean: clean_lib_symlinks
 
 subdirs-y += lib

Maybe there is an even more elegant way to declare dependencies of all ta_dev_kit source, but I didn't find it yet.