# bytes, and so will need to be doubled to obtain the byte address needed by AVR-GCC.
FLASH_SIZE_KB = 128
BOOT_SECTION_SIZE_KB = 4
+
+
+# Formulas used to calculate the starting address of the Bootloader section, and the User Application
+# API jump table (for more information on the latter, see the bootloader documentation). These formulas
+# should not need to be altered - modify the FLASH_SIZE_KB and BOOT_SECTION_KB values above instead.
BOOT_START = 0x$(shell echo "obase=16; ($(FLASH_SIZE_KB) - $(BOOT_SECTION_SIZE_KB)) * 1024" | bc)
BOOT_API_TABLESTART = 0x$(shell echo "obase=16; (($(FLASH_SIZE_KB) * 1024) - 32)" | bc)
# -Map: create map file
# --cref: add cross reference to map file
LDFLAGS = -Wl,-Map=$(TARGET).map,--cref
-LDFLAGS += -Wl,--section-start=.text=$(BOOT_START) -Wl,--section-start=.apitable=$(BOOT_API_TABLESTART)
+LDFLAGS += -Wl,--section-start=.text=$(BOOT_START) -Wl,--section-start=.apitable=$(BOOT_API_TABLESTART) -Wl,--undefined=BootloaderAPI_JumpTable
LDFLAGS += -Wl,--relax
LDFLAGS += -Wl,--gc-sections
LDFLAGS += $(EXTMEMOPTS)