/* Memory layout for cases with itcm and dtcm FLASH_ISR .isr_vector FLASH_FIRMWARE .text FLASH_FIRMWARE .data FLASH_FS // ignored for fs use RAM .data RAM .bss RAM .heap ITCM .itcm DTCM .dtcm_data DTCM .dtcm_bss DTCM .stack */ ENTRY(Reset_Handler) /* define output sections */ SECTIONS { /* The startup code goes first into FLASH */ .isr_vector : { . = ALIGN(4); KEEP(*(.isr_vector)) /* Startup code */ /* This first flash block is 16K annd the isr vectors only take up about 400 bytes. Micropython pads this with files, but this didn't work with the size of Circuitpython's ff object. */ . = ALIGN(4); } >FLASH_ISR /* The program code and other data goes into FLASH */ .text : { . = ALIGN(4); *(.text*) /* .text* sections (code) */ *(.rodata*) /* .rodata* sections (constants, strings, etc.) */ /* *(.glue_7) */ /* glue arm to thumb code */ /* *(.glue_7t) */ /* glue thumb to arm code */ . = ALIGN(4); _etext = .; /* define a global symbol at end of code */ } >FLASH_FIRMWARE /* used by the startup to initialize data */ _sidata = LOADADDR(.data); /* This is the initialized data section The program executes knowing that the data is in the RAM but the loader puts the initial values in the FLASH (inidata). It is one task of the startup to copy the initial values from FLASH to RAM. */ .data : { . = ALIGN(4); _sdata = .; /* create a global symbol at data start; used by startup code in order to initialise the .data section in RAM */ *(.data*) /* .data* sections */ . = ALIGN(4); _edata = .; /* define a global symbol at data end; used by startup code in order to initialise the .data section in RAM */ } >RAM AT> FLASH_FIRMWARE _ld_d1_ram_data_destination = ADDR(.data); _ld_d1_ram_data_flash_copy = LOADADDR(.data); _ld_d1_ram_data_size = SIZEOF(.data); /* Uninitialized data section */ .bss : { . = ALIGN(4); _sbss = .; /* define a global symbol at bss start; used by startup code */ *(.bss*) *(COMMON) . = ALIGN(4); _ebss = .; /* define a global symbol at bss end; used by startup code and GC */ } >RAM _ld_d1_ram_bss_start = ADDR(.bss); _ld_d1_ram_bss_size = SIZEOF(.bss); _ld_heap_start = _ld_d1_ram_bss_start + _ld_d1_ram_bss_size; _ld_heap_end = ORIGIN(RAM) + LENGTH(RAM); /* this is to define the start of the heap, and make sure we have a minimum size */ .heap : { . = ALIGN(4); . = . + _minimum_heap_size; . = ALIGN(4); } >RAM /* itcm stuff */ .itcm : { . = ALIGN(4); *(.itcm.*) . = ALIGN(4); } > ITCM AT> FLASH_FIRMWARE _ld_itcm_destination = ADDR(.itcm); _ld_itcm_flash_copy = LOADADDR(.itcm); _ld_itcm_size = SIZEOF(.itcm); .dtcm_data : { . = ALIGN(4); *(.dtcm_data.*) . = ALIGN(4); } > DTCM AT> FLASH_FIRMWARE _ld_dtcm_data_destination = ADDR(.dtcm_data); _ld_dtcm_data_flash_copy = LOADADDR(.dtcm_data); _ld_dtcm_data_size = SIZEOF(.dtcm_data); .dtcm_bss : { . = ALIGN(4); *(.dtcm_bss.*) . = ALIGN(4); } > DTCM AT> DTCM _ld_dtcm_bss_start = ADDR(.dtcm_bss); _ld_dtcm_bss_size = SIZEOF(.dtcm_bss); .stack : { . = ALIGN(8); _ld_stack_bottom = .; . += _ld_default_stack_size; } > DTCM _ld_stack_top = ORIGIN(DTCM) + LENGTH(DTCM); .ARM.attributes 0 : { *(.ARM.attributes) } }