# match the target's total FLASH size and the bootloader size set in the\r
# device's fuses.\r
FLASH_SIZE_KB = 128\r
-BOOT_SECTION_SIZE_KB = 8\r
+BOOT_SECTION_SIZE_KB = 4\r
\r
# Bootloader address calculation formulas\r
# Do not modify these macros, but rather modify the dependent values above.\r
CALC_ADDRESS_IN_HEX = $(shell printf "0x%X" $$(( $(1) )) )\r
BOOT_START_OFFSET = $(call CALC_ADDRESS_IN_HEX, ($(FLASH_SIZE_KB) - $(BOOT_SECTION_SIZE_KB)) * 1024 )\r
-BOOT_SEC_OFFSET = $(call CALC_ADDRESS_IN_HEX, ($(FLASH_SIZE_KB) * 1024) - $(strip $(1)) )\r
+BOOT_SEC_OFFSET = $(call CALC_ADDRESS_IN_HEX, ($(FLASH_SIZE_KB) * 1024) - ($(strip $(1))) )\r
\r
# Bootloader linker section flags for relocating the API table sections to\r
# known FLASH addresses - these should not normally be user-edited.\r
-BOOT_SECTION_LD_FLAG = -Wl,--section-start=.apitable_$(strip $(1))=$(call BOOT_SEC_OFFSET, $(3)) -Wl,--undefined=BootloaderAPI_$(strip $(2))\r
-BOOT_API_LD_FLAGS = $(call BOOT_SECTION_LD_FLAG, trampolines, Trampolines, 96)\r
-BOOT_API_LD_FLAGS += $(call BOOT_SECTION_LD_FLAG, jumptable, JumpTable, 32)\r
-BOOT_API_LD_FLAGS += $(call BOOT_SECTION_LD_FLAG, signatures, Signatures, 8)\r
+BOOT_SECTION_LD_FLAG = -Wl,--section-start=$(strip $(1))=$(call BOOT_SEC_OFFSET, $(3)) -Wl,--undefined=$(strip $(2))\r
+BOOT_API_LD_FLAGS = $(call BOOT_SECTION_LD_FLAG, .apitable_trampolines, BootloaderAPI_Trampolines, 96)\r
+BOOT_API_LD_FLAGS += $(call BOOT_SECTION_LD_FLAG, .apitable_jumptable, BootloaderAPI_JumpTable, 32)\r
+BOOT_API_LD_FLAGS += $(call BOOT_SECTION_LD_FLAG, .apitable_signatures, BootloaderAPI_Signatures, 8)\r
+\r
+# Check if the bootloader needs an AUX section, located before the real bootloader section to store some of the\r
+# bootloader code. This is required for 32KB and smaller devices, where the actual bootloader is 6KB but the maximum\r
+# bootloader section size is 4KB. The actual usable application space will be reduced by 6KB for these devices.\r
+ifeq ($(BOOT_SECTION_SIZE_KB),8)\r
+ CC_FLAGS += -DAUX_BOOT_SECTION='' -DAUX_BOOT_SECTION_SIZE=0\r
+else\r
+ AUX_BOOT_SECTION_KB = (6 - $(BOOT_SECTION_SIZE_KB))\r
+\r
+ CC_FLAGS += -DAUX_BOOT_SECTION='__attribute__((section(".boot_aux")))' -DAUX_BOOT_SECTION_SIZE='($(AUX_BOOT_SECTION_KB) * 1024)'\r
+ LD_FLAGS += -Wl,--section-start=.boot_aux=$(call BOOT_SEC_OFFSET, (($(BOOT_SECTION_SIZE_KB) + $(AUX_BOOT_SECTION_KB)) * 1024 - 16))\r
+ LD_FLAGS += $(call BOOT_SECTION_LD_FLAG, .boot_aux_trampoline, Boot_AUX_Trampoline, ($(BOOT_SECTION_SIZE_KB) + $(AUX_BOOT_SECTION_KB)) * 1024)\r
+endif\r
\r
# Default target\r
all:\r