samd: Rearrange the mcu specific loader files.

robert-hh · robert-hh · commit 8e77db80d119 · 2023-03-26T18:47:24.000+02:00
Such that they are easier to adapt. The maximum code size is set by:

MICROPY_HW_CODESIZE=xxx

The value xxx must be set as plain integer bytes size, to allow
size comparison in header files. It ca be set in mpconfigmcu.mk for
the MCU family as default or in mpconfigboard.mk for a specific board.

Actual default values:
- SAMD21: 0x2e000 == 184k
- SAMD51: 0x5c000 == 368k

Setting the maximum code size allows the loader to raise and error
if the code gets larger than the space dedicated for it.
diff --git a/ports/samd/Makefile b/ports/samd/Makefile
@@ -65,7 +65,10 @@ CFLAGS += $(INC) -Wall -Werror -std=c99 -nostdlib -mthumb $(CFLAGS_MCU) -fsingle
 CFLAGS += -DMCU_$(MCU_SERIES) -D__$(CMSIS_MCU)__
 CFLAGS += $(CFLAGS_EXTRA)
 
-LDFLAGS += -nostdlib $(addprefix -T,$(LD_FILES)) -Map=$@.map --cref
+LDDEFINES = \
+	-DMICROPY_HW_CODESIZE=$(MICROPY_HW_CODESIZE)
+
+LDFLAGS += -nostdlib -Map=$@.map --cref
 
 LIBS += $(shell $(CC) $(CFLAGS) -print-libgcc-file-name)
 
@@ -178,8 +181,10 @@ endif
 all: $(BUILD)/firmware.uf2
 
 $(BUILD)/firmware.elf: $(OBJ)
+	$(ECHO) "PREPROCESS LINK $@"
+	$(Q)$(CC) -E -x c $(LDDEFINES) $(LD_FILES)| grep -v '^#' > $(BUILD)/link.ld
 	$(ECHO) "LINK $@"
-	$(Q)$(LD) $(LDFLAGS) -o $@ $^ $(LIBS)
+	$(Q)$(LD) -T$(BUILD)/link.ld $(LDFLAGS) -o $@ $^ $(LIBS)
 	$(Q)$(SIZE) $@
 
 $(BUILD)/firmware.bin: $(BUILD)/firmware.elf
diff --git a/ports/samd/boards/samd21x18a.ld b/ports/samd/boards/samd21x18a.ld
@@ -2,19 +2,25 @@
     GNU linker script for SAMD21
 */
 
+/* MICROPY_HW_CODESIZE is defined in mpconfigmcu.mk or mpconfigboard.mk */
+
+_flashsize = 256K;  /* The physical flash size */
+_bootloader = 8K;   /* Must match the ORIGIN value of FLASH */
+_codesize = MICROPY_HW_CODESIZE;  /* the space dedicated to code */
+
 /* Specify the memory areas */
 MEMORY
 {
-    FLASH (rx)  : ORIGIN = 0x00002000, LENGTH = 256K - 8K
+    FLASH (rx)  : ORIGIN = 0x00002000, LENGTH = _codesize
     RAM (xrw)   : ORIGIN = 0x20000000, LENGTH = 32K
 }
 
 /* Top end of the stack, with room for double-tap variable */
 _estack = ORIGIN(RAM) + LENGTH(RAM) - 8;
 _sstack = _estack - 8K;
 
-_oflash_fs = ORIGIN(FLASH) + 192K - 8K;
-_sflash_fs = LENGTH(FLASH) - 192K + 8K - 1;
+_oflash_fs = ORIGIN(FLASH) + _codesize;
+_sflash_fs = _flashsize - _codesize - _bootloader;
 
 _sheap = _ebss;
 _eheap = _sstack;
diff --git a/ports/samd/boards/samd51x19a.ld b/ports/samd/boards/samd51x19a.ld
@@ -2,19 +2,25 @@
     GNU linker script for SAMD51
 */
 
+/* MICROPY_HW_CODESIZE is defined in mpconfigmcu.mk or mpconfigboard.mk */
+
+_flashsize = 512K;  /* The physical flash size */
+_bootloader = 16K;  /* Must match the ORIGIN value of FLASH */
+_codesize = MICROPY_HW_CODESIZE;  /* the space dedicated to code */
+
 /* Specify the memory areas */
 MEMORY
 {
-    FLASH (rx)  : ORIGIN = 0x00004000, LENGTH = 512K - 16K
+    FLASH (rx)  : ORIGIN = 0x00004000, LENGTH = _codesize
     RAM (xrw)   : ORIGIN = 0x20000000, LENGTH = 192K
 }
 
 /* Top end of the stack, with room for double-tap variable */
 _estack = ORIGIN(RAM) + LENGTH(RAM) - 8;
 _sstack = _estack - 16K;
 
-_oflash_fs = ORIGIN(FLASH) + 384K - 16K;
-_sflash_fs = LENGTH(FLASH) - 384K + 16K - 1;
+_oflash_fs = ORIGIN(FLASH) + _codesize;
+_sflash_fs = _flashsize - _codesize - _bootloader;
 
 _sheap = _ebss;
 _eheap = _sstack;
diff --git a/ports/samd/boards/samd51x20a.ld b/ports/samd/boards/samd51x20a.ld
@@ -2,19 +2,25 @@
     GNU linker script for SAMD51x20
 */
 
+/* MICROPY_HW_CODESIZE is defined in mpconfigmcu.mk or mpconfigboard.mk */
+
+_flashsize = 1024K; /* The physical flash size */
+_bootloader = 16K;  /* Must match the ORIGIN value of FLASH */
+_codesize = MICROPY_HW_CODESIZE;  /* the space dedicated to code */
+
 /* Specify the memory areas */
 MEMORY
 {
-    FLASH (rx)  : ORIGIN = 0x00004000, LENGTH = 1024K - 16K
+    FLASH (rx)  : ORIGIN = 0x00004000, LENGTH = _codesize
     RAM (xrw)   : ORIGIN = 0x20000000, LENGTH = 256K
 }
 
 /* Top end of the stack, with room for double-tap variable */
 _estack = ORIGIN(RAM) + LENGTH(RAM) - 8;
 _sstack = _estack - 16K;
 
-_oflash_fs = ORIGIN(FLASH) + 384K - 16K;
-_sflash_fs = LENGTH(FLASH) - 384K + 16K - 1;
+_oflash_fs = ORIGIN(FLASH) + _codesize;
+_sflash_fs = _flashsize - _codesize - _bootloader;
 
 _sheap = _ebss;
 _eheap = _sstack;
diff --git a/ports/samd/mcu/samd21/mpconfigmcu.mk b/ports/samd/mcu/samd21/mpconfigmcu.mk
@@ -2,6 +2,11 @@ CFLAGS_MCU += -mtune=cortex-m0plus -mcpu=cortex-m0plus -msoft-float
 
 MPY_CROSS_MCU_ARCH = armv6m
 
+# MICROPY_HW_CODESIZE must be give as plain integer. 0x2e000 == 184k
+MICROPY_HW_CODESIZE ?= 0x2e000
+
+CFLAGS += -DMICROPY_HW_CODESIZE=$(MICROPY_HW_CODESIZE)
+
 SRC_S += shared/runtime/gchelper_thumb1.s
 
 LIBM_SRC_C +=  $(addprefix lib/libm/,\
diff --git a/ports/samd/mcu/samd51/mpconfigmcu.mk b/ports/samd/mcu/samd51/mpconfigmcu.mk
@@ -2,6 +2,11 @@ CFLAGS_MCU += -mtune=cortex-m4 -mcpu=cortex-m4 -mfpu=fpv4-sp-d16 -mfloat-abi=har
 
 MPY_CROSS_MCU_ARCH = armv7m
 
+# MICROPY_HW_CODESIZE must be give as plain integer: 0x5c000 == 368k
+MICROPY_HW_CODESIZE ?= 0x5c000
+
+CFLAGS += -DMICROPY_HW_CODESIZE=$(MICROPY_HW_CODESIZE)
+
 MICROPY_VFS_LFS2 ?= 1
 MICROPY_VFS_FAT ?= 1
 FROZEN_MANIFEST ?= mcu/$(MCU_SERIES_LOWER)/manifest.py
