[U-Boot] [PATCH v2 4/4] efi_loader: allow multiple source files for EFI apps

[Heinrich Schuchardt]

With this patch an EFI application can be built
out of multiple source files.

All object files that are to be included into the EFI
application %.efi must be added to variable %-objs. E.g.

	helloworld-objs = helloworld.o

script/Makefile.lib automatically generates file %_efi.d
containing the dependency definition.

This file is included in the next run of make. From now on
all objects in %-objs are built.

The %_efi.d file should be included in the source
distribution.

After adding a new file to %-objs the first make run will
fail due to the outdated %_efi.d file.

Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
---
v2
	new patch
---
 lib/efi_loader/Makefile         |  3 +++
 lib/efi_loader/helloworld_efi.d |  1 +
 scripts/Makefile.lib            | 12 ++++++++++--
 3 files changed, 14 insertions(+), 2 deletions(-)
 create mode 100644 lib/efi_loader/helloworld_efi.d

diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile
index 5200497230..d6a9635cc8 100644
--- a/lib/efi_loader/Makefile
+++ b/lib/efi_loader/Makefile
@@ -10,6 +10,9 @@
 CFLAGS_helloworld.o := $(CFLAGS_EFI)
 CFLAGS_REMOVE_helloworld.o := $(CFLAGS_NON_EFI)
 
+helloworld-objs = \
+helloworld.o
+
 ifneq ($(CONFIG_CMD_BOOTEFI_HELLO_COMPILE),)
 always += helloworld.efi
 endif
diff --git a/lib/efi_loader/helloworld_efi.d b/lib/efi_loader/helloworld_efi.d
new file mode 100644
index 0000000000..892db64c8b
--- /dev/null
+++ b/lib/efi_loader/helloworld_efi.d
@@ -0,0 +1 @@
+lib/efi_loader/helloworld_efi.d: lib/efi_loader/helloworld.o
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index ebc74f8987..1a9f32902d 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -373,14 +373,22 @@ $(obj)/%.efi: $(obj)/%_efi.so
 
 quiet_cmd_efi_ld = LD      $@
 cmd_efi_ld = $(LD) -nostdlib -znocombreloc -T $(EFI_LDS_PATH) -shared \
-		-Bsymbolic $^ -o $@
+		-Bsymbolic $(foreach _s, $($*-objs), $(obj)/$(_s)) -o $@
 
 EFI_LDS_PATH = $(srctree)/arch/$(ARCH)/lib/$(EFI_LDS)
 
-$(obj)/%_efi.so: $(obj)/%.o arch/$(ARCH)/lib/$(EFI_CRT0) \
+.PRECIOUS: $(obj)/%_efi.d
+
+$(obj)/%_efi.so: $(obj)/%.o $(obj)/%.d arch/$(ARCH)/lib/$(EFI_CRT0) \
 		arch/$(ARCH)/lib/$(EFI_RELOC)
+	@echo $(obj)/$*_efi.d: $(foreach _s, $($*-objs), $(obj)/$(_s)) \
+		> $(obj)/$*_efi.d
 	$(call cmd,efi_ld)
 
+$(obj)/%.d:;
+
+include $(wildcard $(foreach _s, $(filter %_efi.o, $(obj-y)), $(_s:.o=.d)))
+
 # ACPI
 # ---------------------------------------------------------------------------
 quiet_cmd_acpi_c_asl= ASL     $<
-- 
2.11.0