avionic design with actual uboot and tooling

submodule of avionic design uboot bootloader and with included tools to
get you started , read readme.md and readme-tk1-loader.md

u-boot/examples/api/Makefile

@@ -0,0 +1,64 @@
+#
+# (C) Copyright 2007 Semihalf
+#
+# SPDX-License-Identifier:	GPL-2.0+
+#
+
+ifeq ($(ARCH),powerpc)
+LOAD_ADDR = 0x40000
+endif
+ifeq ($(ARCH),arm)
+LOAD_ADDR = 0x1000000
+endif
+ifeq ($(ARCH),mips)
+ifdef CONFIG_64BIT
+LOAD_ADDR = 0xffffffff80200000
+else
+LOAD_ADDR = 0x80200000
+endif
+endif
+
+# Resulting ELF and binary exectuables will be named demo and demo.bin
+extra-y = demo
+
+# Source files located in the examples/api directory
+OBJ-y += crt0.o
+OBJ-y += demo.o
+OBJ-y += glue.o
+OBJ-y += libgenwrap.o
+
+# Source files which exist outside the examples/api directory
+EXT_COBJ-y += lib/crc32.o
+EXT_COBJ-y += lib/ctype.o
+EXT_COBJ-y += lib/div64.o
+EXT_COBJ-y += lib/string.o
+EXT_COBJ-y += lib/time.o
+EXT_COBJ-y += lib/vsprintf.o
+EXT_SOBJ-$(CONFIG_PPC) += arch/powerpc/lib/ppcstring.o
+
+# Create a list of object files to be compiled
+OBJS := $(OBJ-y) $(notdir $(EXT_COBJ-y) $(EXT_SOBJ-y))
+targets += $(OBJS)
+OBJS := $(addprefix $(obj)/,$(OBJS))
+
+#########################################################################
+
+quiet_cmd_link_demo = LD      $@
+cmd_link_demo = $(LD) --gc-sections -Ttext $(LOAD_ADDR) -o $@ $(filter-out $(PHONY), $^) $(PLATFORM_LIBS)
+
+$(obj)/demo: $(OBJS) FORCE
+	$(call if_changed,link_demo)
+
+# demo.bin is never genrated. Is this necessary?
+OBJCOPYFLAGS_demo.bin := -O binary
+$(obj)/demo.bin: $(obj)/demo FORCE
+	$(call if_changed,objcopy)
+
+# Rule to build generic library C files
+$(addprefix $(obj)/,$(notdir $(EXT_COBJ-y))): $(obj)/%.o: lib/%.c FORCE
+	$(call cmd,force_checksrc)
+	$(call if_changed_rule,cc_o_c)
+
+# Rule to build architecture-specific library assembly files
+$(addprefix $(obj)/,$(notdir $(EXT_SOBJ-y))): $(obj)/%.o: arch/powerpc/lib/%.S FORCE
+	$(call if_changed_dep,as_o_S)