Makefile: Add mechanism for platforms to have multiple builtin DTBs

Currently, we can only include one DTB as builtin for a platform
using FDT_PAYLOAD_DTB make variable in platform config.mk.

This patch adds new mechanism using which we can convert any DTS
file to C source and futher compile-n-link it with libplatsbi.a.

The generated C source will have the DTB contents as an array
"const char <varprefix>_start[]" where <varprefix> is specified
in platform objects.mk makefile.

Example1
--------
If we have built-in k210.dts and desired <varprefix> is
"dt_k210" then specify following in platform objects.mk:
platform-objs-y += k210.o
platform-varprefix-k210.o = dt_k210

Example2
--------
If we have built-in abc/k210.dts and desired <varprefix> is
"dt_abc_k210" then specify following in platform objects.mk:
platform-objs-y += abc/k210.o
platform-varprefix-abc-k210.o = dt_abc_k210

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/Makefile b/Makefile
index 5c08414..bf9c983 100644
--- a/Makefile
+++ b/Makefile
@@ -290,6 +290,12 @@ compile_objcopy = $(CMD_PREFIX)mkdir -p `dirname $(1)`; \
 compile_dts = $(CMD_PREFIX)mkdir -p `dirname $(1)`; \
 	     echo " DTC       $(subst $(build_dir)/,,$(1))"; \
 	     $(CPP) $(DTSCPPFLAGS) $(2) | $(DTC) -O dtb -i `dirname $(2)` -o $(1)
+compile_d2c = $(CMD_PREFIX)mkdir -p `dirname $(1)`; \
+	     echo " D2C       $(subst $(build_dir)/,,$(1))"; \
+	     $(src_dir)/scripts/d2c.sh -i $(4) -a $(3) -p $(2) > $(1)
+compile_gen_dep = $(CMD_PREFIX)mkdir -p `dirname $(1)`; \
+	     echo " GEN-DEP   $(subst $(build_dir)/,,$(1))"; \
+	     echo "$(1:.dep=$(2)): $(3)" >> $(1)
 
 targets-y  = $(build_dir)/lib/libsbi.a
 targets-y  += $(build_dir)/lib/libsbiutils.a
@@ -342,12 +348,23 @@ $(platform_build_dir)/%.dep: $(platform_src_dir)/%.c
 $(platform_build_dir)/%.o: $(platform_src_dir)/%.c
 	$(call compile_cc,$@,$<)
 
+$(platform_build_dir)/%.o: $(platform_build_dir)/%.c
+	$(call compile_cc,$@,$<)
+
 $(platform_build_dir)/%.dep: $(platform_src_dir)/%.S
 	$(call compile_as_dep,$@,$<)
 
 $(platform_build_dir)/%.o: $(platform_src_dir)/%.S
 	$(call compile_as,$@,$<)
 
+$(platform_build_dir)/%.dep: $(platform_src_dir)/%.dts
+	$(call compile_gen_dep,$@,.dtb,$<)
+	$(call compile_gen_dep,$@,.c,$(@:.dep=.dtb))
+	$(call compile_gen_dep,$@,.o,$(@:.dep=.c))
+
+$(platform_build_dir)/%.c: $(platform_build_dir)/%.dtb
+	$(call compile_d2c,$@,$(platform-varprefix-$(subst .dtb,.o,$(subst /,-,$(subst $(platform_build_dir)/,,$<)))),16,$<)
+
 $(platform_build_dir)/%.dtb: $(platform_src_dir)/%.dts
 	$(call compile_dts,$@,$<)