Linker file restructure, TCM and MPU additions

36 files changed, 406 insertions, 1133 deletions

diff --git a/ports/stm/Makefile b/ports/stm/Makefile
index 9b9007938..ec15e4f7f 100755
--- a/ports/stm/Makefile
+++ b/ports/stm/Makefile
@@ -93,7 +93,8 @@ endif
 # MCU Series is defined by the HAL package and doesn't need to be specified here
 C_DEFS = -D$(MCU_PACKAGE) -DUSE_HAL_DRIVER -DUSE_FULL_LL_DRIVER -D$(MCU_VARIANT)
 
-CFLAGS += $(INC) -Werror -Wall -std=gnu11 -nostdlib $(BASE_CFLAGS) $(C_DEFS) $(CFLAGS_MOD) $(COPT)
+CFLAGS += $(INC) -Werror -Wall -std=gnu11 $(BASE_CFLAGS) $(C_DEFS) $(CFLAGS_MOD) $(COPT)
+# Removed -nostdlib since it conflicts with stm32 startup files
 
 # Undo some warnings.
 # STM32 HAL uses undefined preprocessor variables, shadowed variables, casts that change alignment reqs
@@ -107,6 +108,7 @@ MCU_FLAGS_F7 = -mcpu=cortex-m7
 MCU_FLAGS_H7 = -mcpu=cortex-m7
 CFLAGS += $(MCU_FLAGS_$(MCU_SERIES))
 
+# Select HAL file for distribution via mpconfigport
 CFLAGS += -DSTM32_HAL_H='<stm32$(MCU_SERIES_LOWER)xx_hal.h>'
 
 # Floating point settings
@@ -132,7 +134,7 @@ ifndef BOOTLOADER_OFFSET
 	BOOTLOADER_OFFSET := 0x8000000
 endif
 
-LDFLAGS = $(CFLAGS) -fshort-enums -Wl,-nostdlib -Wl,-T,$(LD_FILE) -Wl,-Map=$@.map -Wl,-cref -Wl,-gc-sections -specs=nano.specs
+LDFLAGS = $(CFLAGS) -fshort-enums -Wl,-nostdlib -Wl,-T,$(LD_FILE) -Wl,-T,$(LD_COMMON) -Wl,-Map=$@.map -Wl,-cref -Wl,-gc-sections -specs=nano.specs
 LIBS := -lgcc -lc
 
 LDFLAGS += -mthumb $(MCU_FLAGS_$(MCU_SERIES))
@@ -143,7 +145,13 @@ LIBS += -lm
 endif
 
 # TinyUSB defines
-CFLAGS += -DCFG_TUSB_MCU=OPT_MCU_STM32$(MCU_SERIES) -DCFG_TUD_CDC_RX_BUFSIZE=1024 -DCFG_TUD_CDC_TX_BUFSIZE=1024 -DCFG_TUD_MSC_BUFSIZE=4096 -DCFG_TUD_MIDI_RX_BUFSIZE=128 -DCFG_TUD_MIDI_TX_BUFSIZE=128
+CFLAGS += \
+	-DCFG_TUSB_MCU=OPT_MCU_STM32$(MCU_SERIES) \
+	-DCFG_TUD_CDC_RX_BUFSIZE=1024 \
+	-DCFG_TUD_CDC_TX_BUFSIZE=1024 \
+	-DCFG_TUD_MSC_BUFSIZE=4096 \
+	-DCFG_TUD_MIDI_RX_BUFSIZE=128 \
+	-DCFG_TUD_MIDI_TX_BUFSIZE=128
 
 SRC_STM32 = $(addprefix $(HAL_DIR)/Src/stm32$(MCU_SERIES_LOWER)xx_,\
 	hal_adc.c \
@@ -218,7 +226,7 @@ endif
 
 SRC_S = \
 	supervisor/cpu.s \
-	boards/startup_$(MCU_VARIANT_LOWER).s
+	st_driver/CMSIS/Device/ST/STM32$(MCU_SERIES)xx/Source/Templates/gcc/startup_$(MCU_VARIANT_LOWER).s
 
 SRC_COMMON_HAL_EXPANDED = $(addprefix shared-bindings/, $(SRC_COMMON_HAL)) \
 						  $(addprefix shared-bindings/, $(SRC_BINDINGS_ENUMS)) \
@@ -241,6 +249,7 @@ OBJ += $(addprefix $(BUILD)/, $(SRC_SHARED_MODULE_EXPANDED:.c=.o))
 ifeq ($(INTERNAL_LIBM),1)
 OBJ += $(addprefix $(BUILD)/, $(SRC_LIBM:.c=.o))
 endif
+#OBJ += $(addprefix $(BUILD)/, $(SRC_O))
 OBJ += $(addprefix $(BUILD)/, $(SRC_S:.s=.o))
 OBJ += $(addprefix $(BUILD)/, $(SRC_MOD:.c=.o))
 
diff --git a/ports/stm/boards/STM32F401xd_fs.ld b/ports/stm/boards/STM32F401xd_fs.ld
index c42dfcca8..826e1d404 100644
--- a/ports/stm/boards/STM32F401xd_fs.ld
+++ b/ports/stm/boards/STM32F401xd_fs.ld
@@ -1,5 +1,5 @@
 /*
-    GNU linker script for STM32F401 with bootloader (such as the Meowbit)
+    GNU linker script for STM32F401 with filesystem
 */
 
 /* Specify the memory areas */
@@ -24,84 +24,3 @@ _estack = ORIGIN(RAM) + LENGTH(RAM);
 /* RAM extents for the garbage collector */
 _ram_start = ORIGIN(RAM);
 _ram_end = ORIGIN(RAM) + LENGTH(RAM);
-
-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_TEXT
-
-    /* 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_TEXT
-
-    /* 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
-
-    /* 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
-
-    /* this just checks there is enough RAM for the stack */
-    .stack :
-    {
-        . = ALIGN(4);
-        . = . + _minimum_stack_size;
-        . = ALIGN(4);
-    } >RAM
-
-    .ARM.attributes 0 : { *(.ARM.attributes) }
-}
-
-
diff --git a/ports/stm/boards/STM32F401xe_boot.ld b/ports/stm/boards/STM32F401xe_boot.ld
index 125d785fc..17dac2f1a 100644
--- a/ports/stm/boards/STM32F401xe_boot.ld
+++ b/ports/stm/boards/STM32F401xe_boot.ld
@@ -1,5 +1,5 @@
 /*
-    GNU linker script for STM32F401 with bootloader (such as the Meowbit)
+    GNU linker script for STM32F401 with bootloader (such as the Meowbit). No internal fs. 
 */
 
 /* Specify the memory areas */
@@ -24,83 +24,3 @@ _estack = ORIGIN(RAM) + LENGTH(RAM);
 _ram_start = ORIGIN(RAM);
 _ram_end = ORIGIN(RAM) + LENGTH(RAM);
 
-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_TEXT
-
-    /* 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_TEXT
-
-    /* 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
-
-    /* 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
-
-    /* this just checks there is enough RAM for the stack */
-    .stack :
-    {
-        . = ALIGN(4);
-        . = . + _minimum_stack_size;
-        . = ALIGN(4);
-    } >RAM
-
-    .ARM.attributes 0 : { *(.ARM.attributes) }
-}
-
-
diff --git a/ports/stm/boards/STM32F401xe_fs.ld b/ports/stm/boards/STM32F401xe_fs.ld
index fd30e1622..f0136943a 100644
--- a/ports/stm/boards/STM32F401xe_fs.ld
+++ b/ports/stm/boards/STM32F401xe_fs.ld
@@ -24,84 +24,3 @@ _estack = ORIGIN(RAM) + LENGTH(RAM);
 /* RAM extents for the garbage collector */
 _ram_start = ORIGIN(RAM);
 _ram_end = ORIGIN(RAM) + LENGTH(RAM);
-
-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_TEXT
-
-    /* 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_TEXT
-
-    /* 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
-
-    /* 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
-
-    /* this just checks there is enough RAM for the stack */
-    .stack :
-    {
-        . = ALIGN(4);
-        . = . + _minimum_stack_size;
-        . = ALIGN(4);
-    } >RAM
-
-    .ARM.attributes 0 : { *(.ARM.attributes) }
-}
-
-
diff --git a/ports/stm/boards/STM32F405_boot.ld b/ports/stm/boards/STM32F405_boot.ld
index 64da3b652..7e611be9d 100644
--- a/ports/stm/boards/STM32F405_boot.ld
+++ b/ports/stm/boards/STM32F405_boot.ld
@@ -1,6 +1,5 @@
 /*
     GNU linker script for STM32F405 with bootloader
-    Based on Micropython
 */
 
 /* Specify the memory areas */
@@ -26,82 +25,3 @@ _estack = ORIGIN(RAM) + LENGTH(RAM);
 _ram_start = ORIGIN(RAM);
 _ram_end = ORIGIN(RAM) + LENGTH(RAM);
 
-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_TEXT
-
-    /* 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_TEXT
-
-    /* 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
-
-    /* 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
-
-    /* this just checks there is enough RAM for the stack */
-    .stack :
-    {
-        . = ALIGN(4);
-        . = . + _minimum_stack_size;
-        . = ALIGN(4);
-    } >RAM
-
-    .ARM.attributes 0 : { *(.ARM.attributes) }
-}
-
diff --git a/ports/stm/boards/STM32F405_default.ld b/ports/stm/boards/STM32F405_default.ld
index c2b8c843e..6b497356d 100644
--- a/ports/stm/boards/STM32F405_default.ld
+++ b/ports/stm/boards/STM32F405_default.ld
@@ -1,5 +1,5 @@
 /*
-    GNU linker script for STM32F405 via Micropython
+    GNU linker script for STM32F405, no filesystem
 */
 
 /* Specify the memory areas */
@@ -25,83 +25,3 @@ _estack = ORIGIN(RAM) + LENGTH(RAM);
 _ram_start = ORIGIN(RAM);
 _ram_end = ORIGIN(RAM) + LENGTH(RAM);
 
-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_TEXT
-
-    /* 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_TEXT
-
-    /* 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
-
-    /* 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
-
-    /* this just checks there is enough RAM for the stack */
-    .stack :
-    {
-        . = ALIGN(4);
-        . = . + _minimum_stack_size;
-        . = ALIGN(4);
-    } >RAM
-
-    .ARM.attributes 0 : { *(.ARM.attributes) }
-}
-
-
diff --git a/ports/stm/boards/STM32F405_fs.ld b/ports/stm/boards/STM32F405_fs.ld
index 7f7c91784..72ee49633 100644
--- a/ports/stm/boards/STM32F405_fs.ld
+++ b/ports/stm/boards/STM32F405_fs.ld
@@ -1,5 +1,5 @@
 /*
-    GNU linker script for STM32F405 via Micropython
+    GNU linker script for STM32F405 with filesystem
 */
 
 /* Specify the memory areas */
@@ -26,83 +26,3 @@ _estack = ORIGIN(RAM) + LENGTH(RAM);
 _ram_start = ORIGIN(RAM);
 _ram_end = ORIGIN(RAM) + LENGTH(RAM);
 
-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_TEXT
-
-    /* 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_TEXT
-
-    /* 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
-
-    /* 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
-
-    /* this just checks there is enough RAM for the stack */
-    .stack :
-    {
-        . = ALIGN(4);
-        . = . + _minimum_stack_size;
-        . = ALIGN(4);
-    } >RAM
-
-    .ARM.attributes 0 : { *(.ARM.attributes) }
-}
-
-
diff --git a/ports/stm/boards/STM32F407_fs.ld b/ports/stm/boards/STM32F407_fs.ld
index 7f7c91784..d08cb8972 100644
--- a/ports/stm/boards/STM32F407_fs.ld
+++ b/ports/stm/boards/STM32F407_fs.ld
@@ -1,5 +1,5 @@
 /*
-    GNU linker script for STM32F405 via Micropython
+    GNU linker script for STM32F407 with filesystem
 */
 
 /* Specify the memory areas */
@@ -26,83 +26,3 @@ _estack = ORIGIN(RAM) + LENGTH(RAM);
 _ram_start = ORIGIN(RAM);
 _ram_end = ORIGIN(RAM) + LENGTH(RAM);
 
-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_TEXT
-
-    /* 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_TEXT
-
-    /* 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
-
-    /* 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
-
-    /* this just checks there is enough RAM for the stack */
-    .stack :
-    {
-        . = ALIGN(4);
-        . = . + _minimum_stack_size;
-        . = ALIGN(4);
-    } >RAM
-
-    .ARM.attributes 0 : { *(.ARM.attributes) }
-}
-
-
diff --git a/ports/stm/boards/STM32F411_fs.ld b/ports/stm/boards/STM32F411_fs.ld
new file mode 100644
index 000000000..28667214e
--- /dev/null
+++ b/ports/stm/boards/STM32F411_fs.ld
@@ -0,0 +1,27 @@
+/*
+    GNU linker script for STM32F411 with filesystem
+*/
+
+/* Specify the memory areas */
+MEMORY
+{
+    FLASH (rx)      : ORIGIN = 0x08000000, LENGTH = 512K /* entire flash */
+    FLASH_ISR (rx)  : ORIGIN = 0x08000000, LENGTH = 16K /* sector 0 */
+    FLASH_FS (rx)   : ORIGIN = 0x08004000, LENGTH = 48K /* sectors 1,2,3 are 16K */
+    FLASH_TEXT (rx) : ORIGIN = 0x08010000, LENGTH = 448K /* sector 4 is 64K, sectors 5,6,7 are 128K */
+    RAM (xrw)       : ORIGIN = 0x20000000, LENGTH = 128K
+}
+
+/* produce a link error if there is not this amount of RAM for these sections */
+_minimum_stack_size = 2K;
+_minimum_heap_size = 16K;
+
+/* Define tho top end of the stack.  The stack is full descending so begins just
+   above last byte of RAM.  Note that EABI requires the stack to be 8-byte
+   aligned for a call. */
+_estack = ORIGIN(RAM) + LENGTH(RAM);
+
+/* RAM extents for the garbage collector */
+_ram_start = ORIGIN(RAM);
+_ram_end = ORIGIN(RAM) + LENGTH(RAM);
+
diff --git a/ports/stm/boards/STM32F411_nvm.ld b/ports/stm/boards/STM32F411_nvm.ld
new file mode 100644
index 000000000..bb37c081b
--- /dev/null
+++ b/ports/stm/boards/STM32F411_nvm.ld
@@ -0,0 +1,27 @@
+/*
+    GNU linker script for STM32F411 with nvm
+*/
+
+/* Specify the memory areas */
+MEMORY
+{
+    FLASH (rx)      : ORIGIN = 0x08000000, LENGTH = 512K /* entire flash */
+    FLASH_ISR (rx)  : ORIGIN = 0x08000000, LENGTH = 16K /* sector 0 */
+    FLASH_FS (rx)   : ORIGIN = 0x08004000, LENGTH = 32K /* sectors 1,2 are 16K */
+    FLASH_NVM (rwx) : ORIGIN = 0x0800C000, LENGTH = 16K /* sector 3 is 16K */
+    FLASH_TEXT (rx) : ORIGIN = 0x08010000, LENGTH = 448K /* sector 4 is 64K, sectors 5,6,7 are 128K */
+    RAM (xrw)       : ORIGIN = 0x20000000, LENGTH = 128K
+}
+
+/* produce a link error if there is not this amount of RAM for these sections */
+_minimum_stack_size = 2K;
+_minimum_heap_size = 16K;
+
+/* Define the top end of the stack.  The stack is full descending so begins just
+   above last byte of RAM.  Note that EABI requires the stack to be 8-byte
+   aligned for a call. */
+_estack = ORIGIN(RAM) + LENGTH(RAM);
+
+/* RAM extents for the garbage collector */
+_ram_start = ORIGIN(RAM);
+_ram_end = ORIGIN(RAM) + LENGTH(RAM);
diff --git a/ports/stm/boards/STM32F412_fs.ld b/ports/stm/boards/STM32F412_fs.ld
new file mode 100644
index 000000000..5985b209e
--- /dev/null
+++ b/ports/stm/boards/STM32F412_fs.ld
@@ -0,0 +1,27 @@
+/*
+    GNU linker script for STM32F412 with filesystem, tcm
+*/
+
+/* Specify the memory areas */
+MEMORY
+{
+    FLASH (rx)      : ORIGIN = 0x08000000, LENGTH = 1024K /* entire flash */
+    FLASH_ISR (rx)  : ORIGIN = 0x08000000, LENGTH = 16K /* sector 0 */
+    FLASH_FS (rx)   : ORIGIN = 0x08004000, LENGTH = 48K /* sectors 1,2,3 are 16K */
+    FLASH_TEXT (rx) : ORIGIN = 0x08010000, LENGTH = 960K /* sector 4 is 64K, sectors 5,6,7 are 128K */
+    RAM (xrw)       : ORIGIN = 0x20000000, LENGTH = 256K
+}
+
+/* produce a link error if there is not this amount of RAM for these sections */
+_minimum_stack_size = 2K;
+_minimum_heap_size = 16K;
+
+/* Define tho top end of the stack.  The stack is full descending so begins just
+   above last byte of RAM.  Note that EABI requires the stack to be 8-byte
+   aligned for a call. */
+_estack = ORIGIN(RAM) + LENGTH(RAM);
+
+/* RAM extents for the garbage collector */
+_ram_start = ORIGIN(RAM);
+_ram_end = ORIGIN(RAM) + LENGTH(RAM);
+
diff --git a/ports/stm/boards/STM32F767ZITx_FLASH.ld b/ports/stm/boards/STM32F767ZITx_FLASH.ld
deleted file mode 100644
index 78a794402..000000000
--- a/ports/stm/boards/STM32F767ZITx_FLASH.ld
+++ /dev/null
@@ -1,189 +0,0 @@
-/*
-******************************************************************************
-**
-
-**  File        : LinkerScript.ld
-**
-**  Author		: Auto-generated by System Workbench for STM32
-**
-**  Abstract    : Linker script for STM32F767ZITx series
-**                2048Kbytes FLASH and 512Kbytes RAM
-**
-**                Set heap size, stack size and stack location according
-**                to application requirements.
-**
-**                Set memory bank area and size if external memory is used.
-**
-**  Target      : STMicroelectronics STM32
-**
-**  Distribution: The file is distributed “as is,” without any warranty
-**                of any kind.
-**
-*****************************************************************************
-** @attention
-**
-** <h2><center>&copy; COPYRIGHT(c) 2019 STMicroelectronics</center></h2>
-**
-** Redistribution and use in source and binary forms, with or without modification,
-** are permitted provided that the following conditions are met:
-**   1. Redistributions of source code must retain the above copyright notice,
-**      this list of conditions and the following disclaimer.
-**   2. Redistributions in binary form must reproduce the above copyright notice,
-**      this list of conditions and the following disclaimer in the documentation
-**      and/or other materials provided with the distribution.
-**   3. Neither the name of STMicroelectronics nor the names of its contributors
-**      may be used to endorse or promote products derived from this software
-**      without specific prior written permission.
-**
-** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
-** AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-** DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
-** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
-** SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
-** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
-** OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-**
-*****************************************************************************
-*/
-
-/* Entry Point */
-ENTRY(Reset_Handler)
-
-/* Highest address of the user mode stack */
-_estack = 0x20080000;    /* end of RAM */
-/* Generate a link error if heap and stack don't fit into RAM */
-_Min_Heap_Size = 0x200;      /* required amount of heap  */
-_Min_Stack_Size = 0x400; /* required amount of stack */
-
-/* Specify the memory areas */
-MEMORY
-{
-RAM (xrw)      : ORIGIN = 0x20000000, LENGTH = 512K
-FLASH (rx)      : ORIGIN = 0x8000000, LENGTH = 2048K
-}
-
-/* Define output sections */
-SECTIONS
-{
-  /* The startup code goes first into FLASH */
-  .isr_vector :
-  {
-    . = ALIGN(4);
-    KEEP(*(.isr_vector)) /* Startup code */
-    . = ALIGN(4);
-  } >FLASH
-
-  /* The program code and other data goes into FLASH */
-  .text :
-  {
-    . = ALIGN(4);
-    *(.text)           /* .text sections (code) */
-    *(.text*)          /* .text* sections (code) */
-    *(.glue_7)         /* glue arm to thumb code */
-    *(.glue_7t)        /* glue thumb to arm code */
-    *(.eh_frame)
-
-    KEEP (*(.init))
-    KEEP (*(.fini))
-
-    . = ALIGN(4);
-    _etext = .;        /* define a global symbols at end of code */
-  } >FLASH
-
-  /* Constant data goes into FLASH */
-  .rodata :
-  {
-    . = ALIGN(4);
-    *(.rodata)         /* .rodata sections (constants, strings, etc.) */
-    *(.rodata*)        /* .rodata* sections (constants, strings, etc.) */
-    . = ALIGN(4);
-  } >FLASH
-
-  .ARM.extab   : { *(.ARM.extab* .gnu.linkonce.armextab.*) } >FLASH
-  .ARM : {
-    __exidx_start = .;
-    *(.ARM.exidx*)
-    __exidx_end = .;
-  } >FLASH
-
-  .preinit_array     :
-  {
-    PROVIDE_HIDDEN (__preinit_array_start = .);
-    KEEP (*(.preinit_array*))
-    PROVIDE_HIDDEN (__preinit_array_end = .);
-  } >FLASH
-  .init_array :
-  {
-    PROVIDE_HIDDEN (__init_array_start = .);
-    KEEP (*(SORT(.init_array.*)))
-    KEEP (*(.init_array*))
-    PROVIDE_HIDDEN (__init_array_end = .);
-  } >FLASH
-  .fini_array :
-  {
-    PROVIDE_HIDDEN (__fini_array_start = .);
-    KEEP (*(SORT(.fini_array.*)))
-    KEEP (*(.fini_array*))
-    PROVIDE_HIDDEN (__fini_array_end = .);
-  } >FLASH
-
-  /* used by the startup to initialize data */
-  _sidata = LOADADDR(.data);
-
-  /* Initialized data sections goes into RAM, load LMA copy after code */
-  .data : 
-  {
-    . = ALIGN(4);
-    _sdata = .;        /* create a global symbol at data start */
-    *(.data)           /* .data sections */
-    *(.data*)          /* .data* sections */
-
-    . = ALIGN(4);
-    _edata = .;        /* define a global symbol at data end */
-  } >RAM AT> FLASH
-
-  
-  /* Uninitialized data section */
-  . = ALIGN(4);
-  .bss :
-  {
-    /* This is used by the startup in order to initialize the .bss secion */
-    _sbss = .;         /* define a global symbol at bss start */
-    __bss_start__ = _sbss;
-    *(.bss)
-    *(.bss*)
-    *(COMMON)
-
-    . = ALIGN(4);
-    _ebss = .;         /* define a global symbol at bss end */
-    __bss_end__ = _ebss;
-  } >RAM
-
-  /* User_heap_stack section, used to check that there is enough RAM left */
-  ._user_heap_stack :
-  {
-    . = ALIGN(8);
-    PROVIDE ( end = . );
-    PROVIDE ( _end = . );
-    . = . + _Min_Heap_Size;
-    . = . + _Min_Stack_Size;
-    . = ALIGN(8);
-  } >RAM
-
-  
-
-  /* Remove information from the standard libraries */
-  /DISCARD/ :
-  {
-    libc.a ( * )
-    libm.a ( * )
-    libgcc.a ( * )
-  }
-
-  .ARM.attributes 0 : { *(.ARM.attributes) }
-}
-
-
diff --git a/ports/stm/boards/STM32F767_fs.ld b/ports/stm/boards/STM32F767_fs.ld
index f0fb2d323..40f7d740a 100644
--- a/ports/stm/boards/STM32F767_fs.ld
+++ b/ports/stm/boards/STM32F767_fs.ld
@@ -1,5 +1,5 @@
 /*
-    GNU linker script for STM32F405 via Micropython
+    GNU linker script for STM32F767 with filesystem
 */
 
 /* Specify the memory areas */
@@ -25,83 +25,3 @@ _estack = ORIGIN(RAM) + LENGTH(RAM);
 _ram_start = ORIGIN(RAM);
 _ram_end = ORIGIN(RAM) + LENGTH(RAM);
 
-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_TEXT
-
-    /* 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_TEXT
-
-    /* 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
-
-    /* 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
-
-    /* this just checks there is enough RAM for the stack */
-    .stack :
-    {
-        . = ALIGN(4);
-        . = . + _minimum_stack_size;
-        . = ALIGN(4);
-    } >RAM
-
-    .ARM.attributes 0 : { *(.ARM.attributes) }
-}
-
-
diff --git a/ports/stm/boards/STM32H743_fs.ld b/ports/stm/boards/STM32H743_fs.ld
index fdeab9a3d..28cc12b4a 100644
--- a/ports/stm/boards/STM32H743_fs.ld
+++ b/ports/stm/boards/STM32H743_fs.ld
@@ -1,59 +1,11 @@
 /*
-******************************************************************************
-**
-
-**  File        : LinkerScript.ld
-**
-**  Author		: Auto-generated by System Workbench for STM32
-**
-**  Abstract    : Linker script for STM32H743ZITx series
-**                2048Kbytes FLASH and 1056Kbytes RAM
-**
-**                Set heap size, stack size and stack location according
-**                to application requirements.
-**
-**                Set memory bank area and size if external memory is used.
-**
-**  Target      : STMicroelectronics STM32
-**
-**  Distribution: The file is distributed “as is,” without any warranty
-**                of any kind.
-**
-*****************************************************************************
-** @attention
-**
-** <h2><center>&copy; COPYRIGHT(c) 2019 STMicroelectronics</center></h2>
-**
-** Redistribution and use in source and binary forms, with or without modification,
-** are permitted provided that the following conditions are met:
-**   1. Redistributions of source code must retain the above copyright notice,
-**      this list of conditions and the following disclaimer.
-**   2. Redistributions in binary form must reproduce the above copyright notice,
-**      this list of conditions and the following disclaimer in the documentation
-**      and/or other materials provided with the distribution.
-**   3. Neither the name of STMicroelectronics nor the names of its contributors
-**      may be used to endorse or promote products derived from this software
-**      without specific prior written permission.
-**
-** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
-** AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-** DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
-** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
-** SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
-** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
-** OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-**
-*****************************************************************************
+    GNU linker script for STM32H743 with filesystem, tcm
 */
 
 /* Entry Point */
 ENTRY(Reset_Handler)
 
-/* Highest address of the user mode stack */
-_estack = 0x20020000;    /* end of RAM */
+_ld_default_stack_size = 24K;
 
 /* Specify the memory areas */
 MEMORY
@@ -79,134 +31,9 @@ _minimum_heap_size = 16K;
 /* Define tho top end of the stack.  The stack is full descending so begins just
    above last byte of RAM.  Note that EABI requires the stack to be 8-byte
    aligned for a call. */
-_estack = ORIGIN(RAM) + LENGTH(RAM);
+_estack = ORIGIN(DTCM) + LENGTH(DTCM);
 
 /* RAM extents for the garbage collector */
 _ram_start = ORIGIN(RAM);
 _ram_end = ORIGIN(RAM) + LENGTH(RAM);
 
-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_TEXT
-
-    /* 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_TEXT
-
-    /* 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
-
-    /* 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
-
-    /* this just checks there is enough RAM for the stack */
-    .stack :
-    {
-        . = ALIGN(4);
-        . = . + _minimum_stack_size;
-        . = ALIGN(4);
-    } >RAM
-
-    /* itcm stuff doesn't work, results in arcane hard crashes
-    .itcm :
-    {
-        . = ALIGN(4);
-
-        *(.itcm.*)
-
-        . = ALIGN(4);
-    } > ITCM AT> FLASH_TEXT
-    _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_TEXT
-    _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) }
-}
-
-
diff --git a/ports/stm/boards/STM32F412ZGTx_FLASH.ld b/ports/stm/boards/common_default.ld
index e0586709e..41fe4dfb6 100644
--- a/ports/stm/boards/STM32F412ZGTx_FLASH.ld
+++ b/ports/stm/boards/common_default.ld
@@ -1,34 +1,20 @@
-/*
-    GNU linker script for STM32F412
-*/
-
-/* Specify the memory areas */
-MEMORY
-{
-    FLASH (rx)      : ORIGIN = 0x08000000, LENGTH = 1024K /* entire flash */
-    FLASH_ISR (rx)  : ORIGIN = 0x08000000, LENGTH = 16K /* sector 0 */
-    FLASH_FS (rx)   : ORIGIN = 0x08004000, LENGTH = 48K /* sectors 1,2,3 are 16K */
-    FLASH_TEXT (rx) : ORIGIN = 0x08010000, LENGTH = 960K /* sector 4 is 64K, sectors 5,6,7 are 128K */
-    RAM (xrw)       : ORIGIN = 0x20000000, LENGTH = 256K
-}
-
-/* produce a link error if there is not this amount of RAM for these sections */
-_minimum_stack_size = 2K;
-_minimum_heap_size = 16K;
+/* Memory layout for default case. 
 
-/* Define tho top end of the stack.  The stack is full descending so begins just
-   above last byte of RAM.  Note that EABI requires the stack to be 8-byte
-   aligned for a call. */
-_estack = ORIGIN(RAM) + LENGTH(RAM);
+    FLASH_ISR   .isr_vector
+    FLASH_TEXT  .text
+    FLASH_TEXT  .data
+    FLASH_FS    // ignored for fs use
 
-/* RAM extents for the garbage collector */
-_ram_start = ORIGIN(RAM);
-_ram_end = ORIGIN(RAM) + LENGTH(RAM);
-_heap_start = _ebss; /* heap starts just after statically allocated memory */
-_heap_end = 0x20020000; /* tunable */
+    RAM         .data
+    RAM         .bss
+    RAM         .heap
+    RAM         .stack
+*/
 
 ENTRY(Reset_Handler)
 
+_ld_default_stack_size = _minimum_stack_size;
+
 /* define output sections */
 SECTIONS
 {
@@ -51,6 +37,8 @@ SECTIONS
         . = 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 */
@@ -89,17 +77,23 @@ SECTIONS
     .heap :
     {
         . = ALIGN(4);
+        _ld_heap_start = .;
         . = . + _minimum_heap_size;
         . = ALIGN(4);
     } >RAM
+    _ld_heap_end = ORIGIN(RAM) + LENGTH(RAM);
 
     /* this just checks there is enough RAM for the stack */
     .stack :
     {
         . = ALIGN(4);
+        _ld_stack_bottom = .;
         . = . + _minimum_stack_size;
         . = ALIGN(4);
     } >RAM
+    _ld_stack_top = ORIGIN(RAM) + LENGTH(RAM);
+
 
     .ARM.attributes 0 : { *(.ARM.attributes) }
 }
+
diff --git a/ports/stm/boards/STM32F411VETx_FLASH.ld b/ports/stm/boards/common_nvm.ld
index ac1ba3240..cee71d194 100644
--- a/ports/stm/boards/STM32F411VETx_FLASH.ld
+++ b/ports/stm/boards/common_nvm.ld
@@ -1,34 +1,22 @@
-/*
-    GNU linker script for STM32F411 via Micropython
+/* Memory layout for case with dedicated nvm sector (inefficient)
+TODO: rewrite nvm module, remove this file entirely
+
+    FLASH_ISR   .isr_vector
+    FLASH_TEXT  .text
+    FLASH_TEXT  .data
+    FLASH_NVM   .nvm_data
+    FLASH_FS    // ignored for fs use
+
+    RAM         .data
+    RAM         .bss
+    RAM         .heap
+    RAM         .stack
 */
 
-/* Specify the memory areas */
-MEMORY
-{
-    FLASH (rx)      : ORIGIN = 0x08000000, LENGTH = 512K /* entire flash */
-    FLASH_ISR (rx)  : ORIGIN = 0x08000000, LENGTH = 16K /* sector 0 */
-    FLASH_FS (rx)   : ORIGIN = 0x08004000, LENGTH = 48K /* sectors 1,2,3 are 16K */
-    FLASH_TEXT (rx) : ORIGIN = 0x08010000, LENGTH = 448K /* sector 4 is 64K, sectors 5,6,7 are 128K */
-    RAM (xrw)       : ORIGIN = 0x20000000, LENGTH = 128K
-}
-
-/* produce a link error if there is not this amount of RAM for these sections */
-_minimum_stack_size = 2K;
-_minimum_heap_size = 16K;
-
-/* Define tho top end of the stack.  The stack is full descending so begins just
-   above last byte of RAM.  Note that EABI requires the stack to be 8-byte
-   aligned for a call. */
-_estack = ORIGIN(RAM) + LENGTH(RAM);
-
-/* RAM extents for the garbage collector */
-_ram_start = ORIGIN(RAM);
-_ram_end = ORIGIN(RAM) + LENGTH(RAM);
-_heap_start = _ebss; /* heap starts just after statically allocated memory */
-_heap_end = 0x2001c000; /* tunable */
-
 ENTRY(Reset_Handler)
 
+_ld_default_stack_size = _minimum_stack_size;
+
 /* define output sections */
 SECTIONS
 {
@@ -45,6 +33,14 @@ SECTIONS
         . = ALIGN(4);
     } >FLASH_ISR
 
+    /* Non-volitile memory */
+    .nvm_data :
+    {
+        . = ALIGN(4);
+        KEEP(*(.nvm_data))
+        . = ALIGN(4);
+    } >FLASH_NVM
+
     /* The program code and other data goes into FLASH */
     .text :
     {
@@ -91,19 +87,23 @@ SECTIONS
     .heap :
     {
         . = ALIGN(4);
+        _ld_heap_start = .;
         . = . + _minimum_heap_size;
         . = ALIGN(4);
     } >RAM
+    _ld_heap_end = ORIGIN(RAM) + LENGTH(RAM);
 
     /* this just checks there is enough RAM for the stack */
     .stack :
     {
         . = ALIGN(4);
+        _ld_stack_bottom = .;
         . = . + _minimum_stack_size;
         . = ALIGN(4);
     } >RAM
+    _ld_stack_top = ORIGIN(RAM) + LENGTH(RAM);
+
 
     .ARM.attributes 0 : { *(.ARM.attributes) }
 }
 
-
diff --git a/ports/stm/boards/STM32F411VETx_nvm_FLASH.ld b/ports/stm/boards/common_tcm.ld
index 8382cb781..0aab4c7f9 100644
--- a/ports/stm/boards/STM32F411VETx_nvm_FLASH.ld
+++ b/ports/stm/boards/common_tcm.ld
@@ -1,32 +1,19 @@
-/*
-    GNU linker script for STM32F411 via Micropython
-*/
-
-/* Specify the memory areas */
-MEMORY
-{
-    FLASH (rx)      : ORIGIN = 0x08000000, LENGTH = 512K /* entire flash */
-    FLASH_ISR (rx)  : ORIGIN = 0x08000000, LENGTH = 16K /* sector 0 */
-    FLASH_FS (rx)   : ORIGIN = 0x08004000, LENGTH = 32K /* sectors 1,2 are 16K */
-    FLASH_NVM (rwx) : ORIGIN = 0x0800C000, LENGTH = 16K /* sector 3 is 16K */
-    FLASH_TEXT (rx) : ORIGIN = 0x08010000, LENGTH = 448K /* sector 4 is 64K, sectors 5,6,7 are 128K */
-    RAM (xrw)       : ORIGIN = 0x20000000, LENGTH = 128K
-}
+/* Memory layout for cases with itcm and dtcm
 
-/* produce a link error if there is not this amount of RAM for these sections */
-_minimum_stack_size = 2K;
-_minimum_heap_size = 16K;
+    FLASH_ISR   .isr_vector
+    FLASH_TEXT  .text
+    FLASH_TEXT  .data
+    FLASH_FS    // ignored for fs use
 
-/* Define the top end of the stack.  The stack is full descending so begins just
-   above last byte of RAM.  Note that EABI requires the stack to be 8-byte
-   aligned for a call. */
-_estack = ORIGIN(RAM) + LENGTH(RAM);
+    RAM         .data
+    RAM         .bss
+    RAM         .heap
 
-/* RAM extents for the garbage collector */
-_ram_start = ORIGIN(RAM);
-_ram_end = ORIGIN(RAM) + LENGTH(RAM);
-_heap_start = _ebss; /* heap starts just after statically allocated memory */
-_heap_end = 0x2001c000; /* tunable */
+    ITCM        .itcm
+    DTCM        .dtcm_data
+    DTCM        .dtcm_bss
+    DTCM        .stack
+*/
 
 ENTRY(Reset_Handler)
 
@@ -46,14 +33,6 @@ SECTIONS
         . = ALIGN(4);
     } >FLASH_ISR
 
-    /* Non-volitile memory */
-    .nvm_data :
-    {
-        . = ALIGN(4);
-        KEEP(*(.nvm_data))
-        . = ALIGN(4);
-    } >FLASH_NVM
-
     /* The program code and other data goes into FLASH */
     .text :
     {
@@ -83,6 +62,9 @@ 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_TEXT
+    _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 :
@@ -95,6 +77,10 @@ SECTIONS
         . = 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 :
@@ -104,15 +90,50 @@ SECTIONS
         . = ALIGN(4);
     } >RAM
 
-    /* this just checks there is enough RAM for the stack */
-    .stack :
+    /* itcm stuff */
+    .itcm :
     {
         . = ALIGN(4);
-        . = . + _minimum_stack_size;
+
+        *(.itcm.*)
+
         . = ALIGN(4);
-    } >RAM
+    } > ITCM AT> FLASH_TEXT
+    _ld_itcm_destination = ADDR(.itcm);
+    _ld_itcm_flash_copy = LOADADDR(.itcm);
+    _ld_itcm_size = SIZEOF(.itcm);
 
-    .ARM.attributes 0 : { *(.ARM.attributes) }
-}
+    .dtcm_data :
+    {
+        . = ALIGN(4);
+
+        *(.dtcm_data.*)
+
+        . = ALIGN(4);
+    } > DTCM AT> FLASH_TEXT
+    _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) }
+}
diff --git a/ports/stm/boards/espruino_pico/mpconfigboard.mk b/ports/stm/boards/espruino_pico/mpconfigboard.mk
index 01264d512..b7937dd04 100644
--- a/ports/stm/boards/espruino_pico/mpconfigboard.mk
+++ b/ports/stm/boards/espruino_pico/mpconfigboard.mk
@@ -10,5 +10,6 @@ MCU_SERIES = F4
 MCU_VARIANT = STM32F401xE
 MCU_PACKAGE = UFQFPN48
 
+LD_COMMON = boards/common_default.ld
 LD_FILE = boards/STM32F401xd_fs.ld # use for internal flash
 
diff --git a/ports/stm/boards/espruino_wifi/mpconfigboard.mk b/ports/stm/boards/espruino_wifi/mpconfigboard.mk
index b4b394443..70d0ea2bd 100644
--- a/ports/stm/boards/espruino_wifi/mpconfigboard.mk
+++ b/ports/stm/boards/espruino_wifi/mpconfigboard.mk
@@ -10,5 +10,6 @@ MCU_SERIES = F4
 MCU_VARIANT = STM32F411xE
 MCU_PACKAGE = UFQFPN48
 
-LD_FILE = boards/STM32F411VETx_FLASH.ld
+LD_COMMON = boards/common_default.ld 
+LD_FILE = boards/STM32F411_fs.ld
 
diff --git a/ports/stm/boards/feather_stm32f405_express/mpconfigboard.mk b/ports/stm/boards/feather_stm32f405_express/mpconfigboard.mk
index 351adf1b8..85ed18f4f 100644
--- a/ports/stm/boards/feather_stm32f405_express/mpconfigboard.mk
+++ b/ports/stm/boards/feather_stm32f405_express/mpconfigboard.mk
@@ -12,6 +12,7 @@ MCU_SERIES = F4
 MCU_VARIANT = STM32F405xx
 MCU_PACKAGE = LQFP64
 
+LD_COMMON = boards/common_default.ld 
 LD_DEFAULT = boards/STM32F405_default.ld 
 LD_BOOT = boards/STM32F405_boot.ld # UF2 boot option
 UF2_OFFSET = 0x8010000
diff --git a/ports/stm/boards/meowbit_v121/mpconfigboard.mk b/ports/stm/boards/meowbit_v121/mpconfigboard.mk
index 0a725d75b..cd8d3b548 100644
--- a/ports/stm/boards/meowbit_v121/mpconfigboard.mk
+++ b/ports/stm/boards/meowbit_v121/mpconfigboard.mk
@@ -15,6 +15,7 @@ MCU_SERIES = F4
 MCU_VARIANT = STM32F401xE
 MCU_PACKAGE = LQFP64
 
+LD_COMMON = boards/common_default.ld 
 LD_FILE = boards/STM32F401xe_boot.ld 
 # LD_FILE = boards/STM32F401xe_fs.ld # use for internal flash
 
diff --git a/ports/stm/boards/nucleo_f767zi/mpconfigboard.mk b/ports/stm/boards/nucleo_f767zi/mpconfigboard.mk
index 11c221519..cac4a273e 100644
--- a/ports/stm/boards/nucleo_f767zi/mpconfigboard.mk
+++ b/ports/stm/boards/nucleo_f767zi/mpconfigboard.mk
@@ -10,5 +10,6 @@ MCU_SERIES = F7
 MCU_VARIANT = STM32F767xx
 MCU_PACKAGE = LQFP144
 
+LD_COMMON = boards/common_default.ld 
 LD_FILE = boards/STM32F767_fs.ld
 
diff --git a/ports/stm/boards/nucleo_h743zi_2/mpconfigboard.mk b/ports/stm/boards/nucleo_h743zi_2/mpconfigboard.mk
index 0f003d5fe..dd7f05f29 100644
--- a/ports/stm/boards/nucleo_h743zi_2/mpconfigboard.mk
+++ b/ports/stm/boards/nucleo_h743zi_2/mpconfigboard.mk
@@ -10,5 +10,6 @@ MCU_SERIES = H7
 MCU_VARIANT = STM32H743xx
 MCU_PACKAGE = LQFP144
 
+LD_COMMON = boards/common_tcm.ld 
 LD_FILE = boards/STM32H743_fs.ld
 
diff --git a/ports/stm/boards/pyb_nano_v2/mpconfigboard.mk b/ports/stm/boards/pyb_nano_v2/mpconfigboard.mk
index e9f1d0369..0a06852fb 100644
--- a/ports/stm/boards/pyb_nano_v2/mpconfigboard.mk
+++ b/ports/stm/boards/pyb_nano_v2/mpconfigboard.mk
@@ -12,5 +12,6 @@ MCU_SERIES = F4
 MCU_VARIANT = STM32F411xE
 MCU_PACKAGE = UFQFPN48
 
-LD_FILE = boards/STM32F411VETx_FLASH.ld
+LD_COMMON = boards/common_default.ld 
+LD_FILE = boards/STM32F411_fs.ld
 
diff --git a/ports/stm/boards/pyboard_v11/mpconfigboard.mk b/ports/stm/boards/pyboard_v11/mpconfigboard.mk
index ab2ce86a9..9d8b0f3f2 100644
--- a/ports/stm/boards/pyboard_v11/mpconfigboard.mk
+++ b/ports/stm/boards/pyboard_v11/mpconfigboard.mk
@@ -10,5 +10,6 @@ MCU_SERIES = F4
 MCU_VARIANT = STM32F405xx
 MCU_PACKAGE = LQFP64
 
+LD_COMMON = boards/common_default.ld 
 LD_FILE = boards/STM32F405_fs.ld
 
diff --git a/ports/stm/boards/stm32f411ce_blackpill/mpconfigboard.mk b/ports/stm/boards/stm32f411ce_blackpill/mpconfigboard.mk
index bf2dd5596..62887c028 100644
--- a/ports/stm/boards/stm32f411ce_blackpill/mpconfigboard.mk
+++ b/ports/stm/boards/stm32f411ce_blackpill/mpconfigboard.mk
@@ -15,5 +15,6 @@ MCU_SERIES = F4
 MCU_VARIANT = STM32F411xE
 MCU_PACKAGE = UFQFPN48
 
-LD_FILE = boards/STM32F411VETx_FLASH.ld
+LD_COMMON = boards/common_default.ld 
+LD_FILE = boards/STM32F411_fs.ld
 
diff --git a/ports/stm/boards/stm32f411ve_discovery/mpconfigboard.mk b/ports/stm/boards/stm32f411ve_discovery/mpconfigboard.mk
index da24fe3f0..761602acd 100644
--- a/ports/stm/boards/stm32f411ve_discovery/mpconfigboard.mk
+++ b/ports/stm/boards/stm32f411ve_discovery/mpconfigboard.mk
@@ -10,5 +10,6 @@ MCU_SERIES = F4
 MCU_VARIANT = STM32F411xE
 MCU_PACKAGE = LQFP100_f4
 
-LD_FILE = boards/STM32F411VETx_FLASH.ld
+LD_COMMON = boards/common_default.ld
+LD_FILE = boards/STM32F411_fs.ld
 
diff --git a/ports/stm/boards/stm32f412zg_discovery/mpconfigboard.mk b/ports/stm/boards/stm32f412zg_discovery/mpconfigboard.mk
index d227803de..09e7bda85 100644
--- a/ports/stm/boards/stm32f412zg_discovery/mpconfigboard.mk
+++ b/ports/stm/boards/stm32f412zg_discovery/mpconfigboard.mk
@@ -15,6 +15,7 @@ MCU_SERIES = F4
 MCU_VARIANT = STM32F412Zx
 MCU_PACKAGE = LQFP144
 
-LD_FILE = boards/STM32F412ZGTx_FLASH.ld
+LD_COMMON = boards/common_default.ld
+LD_FILE = boards/STM32F412_fs.ld
 
 
diff --git a/ports/stm/boards/stm32f4_discovery/mpconfigboard.mk b/ports/stm/boards/stm32f4_discovery/mpconfigboard.mk
index c8c424c0c..57a65f75a 100644
--- a/ports/stm/boards/stm32f4_discovery/mpconfigboard.mk
+++ b/ports/stm/boards/stm32f4_discovery/mpconfigboard.mk
@@ -10,5 +10,6 @@ MCU_SERIES = F4
 MCU_VARIANT = STM32F407xx
 MCU_PACKAGE = LQFP100_f4
 
+LD_COMMON = boards/common_default.ld
 LD_FILE = boards/STM32F407_fs.ld
 
diff --git a/ports/stm/boards/thunderpack/mpconfigboard.mk b/ports/stm/boards/thunderpack/mpconfigboard.mk
index 6fcaae6ab..40b0e9250 100644
--- a/ports/stm/boards/thunderpack/mpconfigboard.mk
+++ b/ports/stm/boards/thunderpack/mpconfigboard.mk
@@ -9,12 +9,9 @@ LONGINT_IMPL = NONE
 
 CIRCUITPY_NVM = 1
 
-MCU_SERIES = m4
-MCU_VARIANT = stm32f4
-MCU_SUB_VARIANT = stm32f411xe
+MCU_SERIES = F4
+MCU_VARIANT = STM32F411xE
 MCU_PACKAGE = 48
-CMSIS_MCU = STM32F411xE
-LD_FILE = boards/STM32F411VETx_nvm_FLASH.ld
-STARTUP_FILE = startup_stm32f411xe.s
-
 
+LD_FILE = boards/common_nvm.ld
+LD_FILE = boards/STM32F411_nvm.ld
diff --git a/ports/stm/mpconfigport.h b/ports/stm/mpconfigport.h
index 297c7338e..65b061124 100644
--- a/ports/stm/mpconfigport.h
+++ b/ports/stm/mpconfigport.h
@@ -28,14 +28,19 @@
 #ifndef STM32_MPCONFIGPORT_H__
 #define STM32_MPCONFIGPORT_H__
 
+#include <stdint.h>
+
 #define MICROPY_PY_COLLECTIONS_ORDEREDDICT       (1)
 #define MICROPY_PY_FUNCTION_ATTRS                (1)
 #define MICROPY_PY_IO                            (1)
 #define MICROPY_PY_REVERSE_SPECIAL_METHODS       (1)
 #define MICROPY_PY_UJSON                         (1)
 
+extern uint8_t _ld_default_stack_size;
+
 // 24kiB stack
-#define CIRCUITPY_DEFAULT_STACK_SIZE            0x6000
+// #define CIRCUITPY_DEFAULT_STACK_SIZE            0x6000
+#define CIRCUITPY_DEFAULT_STACK_SIZE            ((uint32_t) &_ld_default_stack_size)
 
 #include "py/circuitpy_mpconfig.h"
 
diff --git a/ports/stm/packages/LQFP100_f4.c b/ports/stm/packages/LQFP100_f4.c
index a2219ccc0..5bc0a5158 100644
--- a/ports/stm/packages/LQFP100_f4.c
+++ b/ports/stm/packages/LQFP100_f4.c
@@ -53,7 +53,7 @@ STATIC const mp_rom_map_elem_t mcu_pin_globals_table[] = {
   { MP_ROM_QSTR(MP_QSTR_PE14), MP_ROM_PTR(&pin_PE14) },
   { MP_ROM_QSTR(MP_QSTR_PE15), MP_ROM_PTR(&pin_PE15) },
   { MP_ROM_QSTR(MP_QSTR_PB10), MP_ROM_PTR(&pin_PB10) },
-#if MCU_LINE == FOUNDATION || MCU_LINE == ADVANCED
+#if defined(STM32F405xx) || defined(STM32F412Zx) || defined(STM32F407xx) || defined(STM32F767xx)
   { MP_ROM_QSTR(MP_QSTR_PB11), MP_ROM_PTR(&pin_PB11) },
 #endif //or VCAP1 -----------------------------------*/
   // VCAP1 or VSS -----------------------------------*/
diff --git a/ports/stm/packages/LQFP64.c b/ports/stm/packages/LQFP64.c
index 02dcfa00c..e6a492bc3 100644
--- a/ports/stm/packages/LQFP64.c
+++ b/ports/stm/packages/LQFP64.c
@@ -35,7 +35,7 @@ STATIC const mp_rom_map_elem_t mcu_pin_globals_table[] = {
   { MP_ROM_QSTR(MP_QSTR_PB01), MP_ROM_PTR(&pin_PB01) },
   { MP_ROM_QSTR(MP_QSTR_PB02), MP_ROM_PTR(&pin_PB02) },
   { MP_ROM_QSTR(MP_QSTR_PB10), MP_ROM_PTR(&pin_PB10) },
-#if MCU_LINE == FOUNDATION || MCU_LINE == ADVANCED
+#if defined(STM32F405xx) || defined(STM32F412Zx) || defined(STM32F407xx) || defined(STM32F767xx)
   { MP_ROM_QSTR(MP_QSTR_PB11), MP_ROM_PTR(&pin_PB11) },
 #endif //or VCAP1 -----------------------------------*/
   // VCAP1 or VSS -----------------------------------*/
diff --git a/ports/stm/supervisor/port.c b/ports/stm/supervisor/port.c
index fa377e74a..16796d9ce 100644
--- a/ports/stm/supervisor/port.c
+++ b/ports/stm/supervisor/port.c
@@ -44,6 +44,131 @@
 #include "clocks.h"
 #include "gpio.h"
 
+//only enable the Reset Handler overwrite for the H7 for now
+#if defined(STM32H7)
+
+// Device memories must be accessed in order.
+#define DEVICE 2
+// Normal memory can have accesses reorder and prefetched.
+#define NORMAL 0
+// Prevents instruction access.
+#define NO_EXECUTION 1
+#define EXECUTION 0
+// Shareable if the memory system manages coherency.
+#define NOT_SHAREABLE 0
+#define SHAREABLE 1
+#define NOT_CACHEABLE 0
+#define CACHEABLE 1
+#define NOT_BUFFERABLE 0
+#define BUFFERABLE 1
+#define NO_SUBREGIONS 0
+
+extern uint32_t _ld_stack_top;
+
+extern uint32_t _ld_d1_ram_bss_start;
+extern uint32_t _ld_d1_ram_bss_size;
+extern uint32_t _ld_d1_ram_data_destination;
+extern uint32_t _ld_d1_ram_data_size;
+extern uint32_t _ld_d1_ram_data_flash_copy;
+extern uint32_t _ld_dtcm_bss_start;
+extern uint32_t _ld_dtcm_bss_size;
+extern uint32_t _ld_dtcm_data_destination;
+extern uint32_t _ld_dtcm_data_size;
+extern uint32_t _ld_dtcm_data_flash_copy;
+extern uint32_t _ld_itcm_destination;
+extern uint32_t _ld_itcm_size;
+extern uint32_t _ld_itcm_flash_copy;
+
+extern void main(void);
+extern void SystemInit(void);
+
+// This replaces the Reset_Handler in startup_*.S and SystemInit in system_*.c.
+__attribute__((used, naked)) void Reset_Handler(void) {
+    __disable_irq();
+    __set_MSP((uint32_t) &_ld_stack_top);
+
+    // TODO: Is any of this commented stuff actually required? 
+
+    /* Disable I cache and D cache */ 
+    // SCB_DisableICache();
+    // SCB_DisableDCache(); // this causes an instant hardfault if used
+
+    // #if ((__FPU_PRESENT == 1) && (__FPU_USED == 1))
+    //   SCB->CPACR |= ((3UL << 10*2) | (3UL << 11*2));    /* set CP10, CP11 Full Access */
+    // #endif /* ((__FPU_PRESENT == 1) && (__FPU_USED == 1)) */
+
+    // /* Disable Systick which might be enabled by bootrom */
+    // if (SysTick->CTRL & SysTick_CTRL_ENABLE_Msk)
+    // {
+    //     SysTick->CTRL &= ~SysTick_CTRL_ENABLE_Msk;
+    // }
+
+    /* Disable MPU */
+    ARM_MPU_Disable();
+
+    // Copy all of the itcm code to run from ITCM. Do this while the MPU is disabled because we write
+    // protect it.
+    for (uint32_t i = 0; i < ((size_t) &_ld_itcm_size) / 4; i++) {
+        (&_ld_itcm_destination)[i] = (&_ld_itcm_flash_copy)[i];
+    }
+
+    // The first number in RBAR is the region number. When searching for a policy, the region with
+    // the highest number wins. If none match, then the default policy set at enable applies.
+    // TODO: what is the default policy? Where is that set? 
+
+    // TODO: do I need to subdivide this up? 
+    // Mark all the flash the same until instructed otherwise. 
+    MPU->RBAR = ARM_MPU_RBAR(11, 0x08000000U);
+    MPU->RASR = ARM_MPU_RASR(EXECUTION, ARM_MPU_AP_FULL, NORMAL, NOT_SHAREABLE, CACHEABLE, BUFFERABLE, NO_SUBREGIONS, ARM_MPU_REGION_SIZE_2MB);
+
+    // This the ITCM. Set it to read-only because we've loaded everything already and it's easy to
+    // accidentally write the wrong value to 0x00000000 (aka NULL).
+    MPU->RBAR = ARM_MPU_RBAR(12, 0x00000000U);
+    MPU->RASR = ARM_MPU_RASR(EXECUTION, ARM_MPU_AP_RO, NORMAL, NOT_SHAREABLE, CACHEABLE, BUFFERABLE, NO_SUBREGIONS, ARM_MPU_REGION_SIZE_128KB);
+
+    // This the DTCM.
+    MPU->RBAR = ARM_MPU_RBAR(14, 0x20000000U);
+    MPU->RASR = ARM_MPU_RASR(EXECUTION, ARM_MPU_AP_FULL, NORMAL, NOT_SHAREABLE, CACHEABLE, BUFFERABLE, NO_SUBREGIONS, ARM_MPU_REGION_SIZE_128KB);
+
+    // This is AXI SRAM (D1).
+    MPU->RBAR = ARM_MPU_RBAR(15, 0x24000000U);
+    MPU->RASR = ARM_MPU_RASR(EXECUTION, ARM_MPU_AP_FULL, NORMAL, NOT_SHAREABLE, CACHEABLE, BUFFERABLE, NO_SUBREGIONS, ARM_MPU_REGION_SIZE_512KB);
+
+    // TODO: what is the mask here doing? 
+    /* Enable MPU */
+    ARM_MPU_Enable(MPU_CTRL_PRIVDEFENA_Msk);
+
+    //  We're done mucking with memory so enable I cache and D cache 
+    // SCB_EnableDCache();
+    // SCB_EnableICache();
+
+    // Copy all of the data to run from DTCM.
+    for (uint32_t i = 0; i < ((size_t) &_ld_dtcm_data_size) / 4; i++) {
+        (&_ld_dtcm_data_destination)[i] = (&_ld_dtcm_data_flash_copy)[i];
+    }
+
+    // Clear DTCM bss.
+    for (uint32_t i = 0; i < ((size_t) &_ld_dtcm_bss_size) / 4; i++) {
+        (&_ld_dtcm_bss_start)[i] = 0;
+    }
+
+    // Copy all of the data to run from D1 RAM.
+    for (uint32_t i = 0; i < ((size_t) &_ld_d1_ram_data_size) / 4; i++) {
+        (&_ld_d1_ram_data_destination)[i] = (&_ld_d1_ram_data_flash_copy)[i];
+    }
+
+    // Clear D1 RAM bss.
+    for (uint32_t i = 0; i < ((size_t) &_ld_d1_ram_bss_size) / 4; i++) {
+        (&_ld_d1_ram_bss_start)[i] = 0;
+    }
+
+    SystemInit();
+    __enable_irq();
+    main();
+}
+
+#endif //end H7 specific code
+
 safe_mode_t port_init(void) {
     HAL_Init();
     __HAL_RCC_SYSCFG_CLK_ENABLE();
@@ -63,6 +188,7 @@ safe_mode_t port_init(void) {
 void reset_port(void) {
     reset_all_pins();
 
+    // TODO: it'd be nice if this was more automatic
     #if defined(STM32F4)
         i2c_reset();
         spi_reset();
@@ -81,22 +207,25 @@ void reset_cpu(void) {
     NVIC_SystemReset();
 }
 
+extern uint32_t _ld_heap_start, _ld_heap_end, _ld_stack_top, _ld_stack_bottom;
+
 uint32_t *port_heap_get_bottom(void) {
-    return port_stack_get_limit();
+    return &_ld_heap_start;
 }
 
 uint32_t *port_heap_get_top(void) {
-    return port_stack_get_top();
+    return &_ld_heap_end;
 }
 
 uint32_t *port_stack_get_limit(void) {
-    return &_ebss;
+    return &_ld_stack_bottom; 
 }
 
 uint32_t *port_stack_get_top(void) {
-    return &_estack;
+    return &_ld_stack_top;
 }
 
+// TODO: what even are these
 extern uint32_t _ebss;
 // Place the word to save just after our BSS section that gets blanked.
 void port_set_saved_word(uint32_t value) {
@@ -107,7 +236,36 @@ uint32_t port_get_saved_word(void) {
     return _ebss;
 }
 
-void HardFault_Handler(void) {
+__attribute__((used)) void MemManage_Handler(void)
+{
+    __ASM volatile ("bkpt");
+    reset_into_safe_mode(MEM_MANAGE);
+    while (true) {
+        asm("nop;");
+    }
+}
+
+__attribute__((used)) void BusFault_Handler(void)
+{
+    __ASM volatile ("bkpt");
+    reset_into_safe_mode(MEM_MANAGE);
+    while (true) {
+        asm("nop;");
+    }
+}
+
+__attribute__((used)) void UsageFault_Handler(void)
+{
+    __ASM volatile ("bkpt");
+    reset_into_safe_mode(MEM_MANAGE);
+    while (true) {
+        asm("nop;");
+    }
+}
+
+__attribute__((used)) void HardFault_Handler(void)
+{
+    __ASM volatile ("bkpt");
     reset_into_safe_mode(HARD_CRASH);
     while (true) {
         asm("nop;");
diff --git a/supervisor/linker.h b/supervisor/linker.h
index 878268c73..74b2dd5a6 100755
--- a/supervisor/linker.h
+++ b/supervisor/linker.h
@@ -29,7 +29,7 @@
 #ifndef MICROPY_INCLUDED_SUPERVISOR_LINKER_H
 #define MICROPY_INCLUDED_SUPERVISOR_LINKER_H
 
-#if defined(IMXRT10XX) || defined(FOMU) // || defined(STM32H7)
+#if defined(IMXRT10XX) || defined(FOMU) || defined(STM32H7)
 #define PLACE_IN_DTCM_DATA(name) name __attribute__((section(".dtcm_data." #name )))
 #define PLACE_IN_DTCM_BSS(name) name __attribute__((section(".dtcm_bss." #name )))
 #define PLACE_IN_ITCM(name) __attribute__((section(".itcm." #name ))) name
diff --git a/supervisor/shared/stack.c b/supervisor/shared/stack.c
index 2b7b1c03a..2a7daf465 100755
--- a/supervisor/shared/stack.c
+++ b/supervisor/shared/stack.c
@@ -46,7 +46,7 @@ void allocate_stack(void) {
 
     mp_uint_t c_size = (uint32_t) port_stack_get_top() - sp;
 
-    if (port_stack_get_top() != port_heap_get_top()) {
+    if (port_stack_get_top() != port_heap_get_top()) { //Why is this here? Doesn't apply to some chips. 
         return;
     }