stm32/mboot: Add mboot version string.

Adds a configurable version string to a known location at the end of mboot
flash section.  Also stores the options mboot was built with, eg usb and
which filesystems are supported.

A board can override the defaults, or disable the version string entirely
by setting MBOOT_VERSION_ALLOCATED_BYTES=0.

Signed-off-by: Victor Rajewski <victor@allumeenergy.com.au>

ports/stm32/mboot/Makefile

@@ -36,6 +36,12 @@ include $(BOARD_DIR)/mpconfigboard.mk
 # A board can set MBOOT_TEXT0_ADDR to a custom location where mboot should reside.
 MBOOT_TEXT0_ADDR ?= 0x08000000
 
+# The string in MBOOT_VERSION (default defined in version.c if not defined by a
+# board) will be stored in the final MBOOT_VERSION_ALLOCATED_BYTES bytes of mboot flash.
+# A board can change the size of this region by defining MBOOT_VERSION_ALLOCATED_BYTES.
+MBOOT_VERSION_ALLOCATED_BYTES ?= 64
+MBOOT_VERSION_INCLUDE_OPTIONS ?= 1  # if set to 1, this will append build options to version string (see version.c)
+
 USBDEV_DIR=usbdev
 DFU=$(TOP)/tools/dfu.py
 PYDFU ?= $(TOP)/tools/pydfu.py
@@ -78,9 +84,14 @@ CFLAGS += -DBUILDING_MBOOT=$(BUILDING_MBOOT)
 CFLAGS += -DMICROPY_HW_STM32WB_FLASH_SYNCRONISATION=0
 CFLAGS += -DUSBD_ENABLE_VENDOR_DEVICE_REQUESTS=1
 CFLAGS += -DBOOTLOADER_DFU_USB_VID=$(BOOTLOADER_DFU_USB_VID) -DBOOTLOADER_DFU_USB_PID=$(BOOTLOADER_DFU_USB_PID)
+ifdef MBOOT_VERSION
+CFLAGS += -DMBOOT_VERSION=\"$(MBOOT_VERSION)\"
+endif
+CFLAGS += -DMBOOT_VERSION_ALLOCATED_BYTES=$(MBOOT_VERSION_ALLOCATED_BYTES) -DMBOOT_VERSION_INCLUDE_OPTIONS=$(MBOOT_VERSION_INCLUDE_OPTIONS)
 
 MBOOT_LD_FILES ?= stm32_memory.ld stm32_sections.ld
 LDFLAGS += -nostdlib -L . $(addprefix -T,$(MBOOT_LD_FILES)) -Map=$(@:.elf=.map) --cref
+LDFLAGS += --defsym mboot_version_len=$(MBOOT_VERSION_ALLOCATED_BYTES)
 LIBS += $(shell $(CC) $(CFLAGS) -print-libgcc-file-name)
 
 # Remove uncalled code from the final image.
@@ -121,6 +132,7 @@ SRC_C += \
 	vfs_fat.c \
 	vfs_lfs.c \
 	vfs_raw.c \
+	version.c \
 	drivers/bus/softspi.c \
 	drivers/bus/softqspi.c \
 	drivers/memory/spiflash.c \
@@ -206,7 +218,7 @@ deploy-stlink: $(BUILD)/firmware.dfu
 
 $(BUILD)/firmware.dfu: $(BUILD)/firmware.elf
 	$(ECHO) "Create $@"
-	$(Q)$(OBJCOPY) -O binary -j .isr_vector -j .text -j .data $^ $(BUILD)/firmware.bin
+	$(Q)$(OBJCOPY) -O binary -j .isr_vector -j .text -j .data -j .mboot_version_text $^ $(BUILD)/firmware.bin
 	$(Q)$(PYTHON) $(DFU) -b $(MBOOT_TEXT0_ADDR):$(BUILD)/firmware.bin $@
 
 $(BUILD)/firmware.hex: $(BUILD)/firmware.elf
@@ -231,8 +243,9 @@ GEN_PINS_SRC = $(BUILD)/pins_$(BOARD).c
 GEN_PINS_HDR = $(HEADER_BUILD)/pins.h
 GEN_PINS_AF_CONST = $(HEADER_BUILD)/pins_af_const.h
 GEN_PINS_AF_DEFS = $(HEADER_BUILD)/pins_af_defs.h
+GEN_MPVERSION = $(HEADER_BUILD)/mpversion.h
 
-$(OBJ): $(GEN_QSTRDEFS_GENERATED) $(GEN_ROOT_POINTERS) $(GEN_PINS_AF_DEFS)
+$(OBJ): $(GEN_QSTRDEFS_GENERATED) $(GEN_ROOT_POINTERS) $(GEN_PINS_AF_DEFS) $(GEN_MPVERSION)
 
 $(HEADER_BUILD):
 	$(MKDIR) -p $(BUILD)/genhdr
@@ -250,6 +263,9 @@ $(GEN_PINS_AF_DEFS): $(BOARD_PINS) $(MAKE_PINS) ../$(AF_FILE) $(PREFIX_FILE) | $
 		--output-af-const $(GEN_PINS_AF_CONST) --output-af-defs $(GEN_PINS_AF_DEFS) \
 		--mboot-mode
 
+$(GEN_MPVERSION): | $(HEADER_BUILD)
+	$(PYTHON) ../../../py/makeversionhdr.py $@
+
 #########################################
 
 vpath %.S . $(TOP)

ports/stm32/mboot/README.md

@@ -89,6 +89,17 @@ How to use
    the beginning of the chunk when the end is reached.  Then use a split
    raw filesystem to inform mboot of this wrapping.
 
+   The version and config options that mboot was built with are stored in a
+   small, fixed section of bytes at the end of the flash region allocated
+   for mboot. The length of the fixed section defaults to 64 bytes, but can
+   be overridden by setting MBOOT_VERSION_ALLOCATED_BYTES. If running
+   low on flash for the mboot build, this can be reduced or even set to 0.
+   The version string stored defaults to the micropython git version as
+   generated by makeversionhdr.py. The default version string can be
+   overridden by setting MBOOT_VERSION in a board's build files. The version
+   string is appended with options mboot was built with - see version.c for
+   details. This can be prevented by setting MBOOT_VERSION_INCLUDE_OPTIONS to 0.
+
 2. Build the board's main application firmware as usual.
 
 3. Build mboot via:
@@ -209,6 +220,11 @@ and signed firmware, and can be deployed via USB DFU, or by copying it to the de
 internal filesystem (if `MBOOT_FSLOAD` is enabled). `firmware.dfu` is still unencrypted
 and can be directly flashed with jtag etc.
 
+Retrieving the mboot version in micropython
+-------------------------------------------
+The function `get_mboot_version` in `fwupdate.py` returns the version mboot was built with,
+optionally with build options.
+
 Example: Mboot on PYBv1.x
 -------------------------
 

ports/stm32/mboot/fwupdate.py

@@ -281,3 +281,25 @@ def update_mpy(*args, **kwargs):
     elems = update_app_elements(*args, **kwargs)
     if elems:
         machine.bootloader(elems)
+
+
+def get_mboot_version(
+    mboot_base=0x0800_0000,  # address of start of mboot flash section
+    mboot_len=0x8000,  # length of mboot flash section
+    mboot_ver_len=64,  # length of mboot version section (defined in mboot/Makefile or in board dir)
+    valid_prefix="mboot-",  # prefix that the version string was defined with
+    include_opts=True,  # return the options mboot was built with (set False for just the version)
+):
+    s = ""
+    for i in range(mboot_ver_len):
+        c = stm.mem8[mboot_base + mboot_len - mboot_ver_len + i]
+        if c == 0x00 or c == 0xFF:  # have hit padding or empty flash
+            break
+        s += chr(c)
+    if s.startswith(valid_prefix):
+        if include_opts:
+            return s
+        else:
+            return s.split("+")[0]  # optional mboot config info stored after "+"
+    else:  # version hasn't been set, so on the original mboot (i.e. mboot-v1.0.0)
+        return None

ports/stm32/mboot/stm32_sections.ld

@@ -47,6 +47,12 @@ SECTIONS
         _edata = .;
     } >RAM AT> FLASH_BL
 
+    /* Final section of mboot flash reserved for mboot version */
+    .mboot_version_text (ORIGIN(FLASH_BL) + LENGTH(FLASH_BL) - mboot_version_len) :
+    {
+        KEEP(*(.mboot_version));
+    } >FLASH_BL
+
     /* Zeroed-out data section */
     .bss :
     {

ports/stm32/mboot/version.c

@@ -0,0 +1,62 @@
+#include "mboot.h"
+#include "genhdr/mpversion.h"
+
+#if defined(MBOOT_VERSION_ALLOCATED_BYTES) && MBOOT_VERSION_ALLOCATED_BYTES > 0
+
+#ifndef MBOOT_VERSION
+#define MBOOT_VERSION "mboot-" MICROPY_GIT_TAG
+#endif
+
+#if MBOOT_VERSION_INCLUDE_OPTIONS  // if this is defined, append a list of build options e.g. fat.lfs2
+#define MBOOT_VERSION_USB MBOOT_VERSION "+usb"  // USB is always included
+
+#if defined(MBOOT_I2C_SCL)
+#define MBOOT_VERSION_I2C MBOOT_VERSION_USB ".i2c"
+#else
+#define MBOOT_VERSION_I2C MBOOT_VERSION_USB
+#endif
+
+#if MBOOT_ADDRESS_SPACE_64BIT
+#define MBOOT_VERSION_64BIT MBOOT_VERSION_I2C ".64"
+#else
+#define MBOOT_VERSION_64BIT MBOOT_VERSION_I2C
+#endif
+
+#if MBOOT_VFS_FAT
+#define MBOOT_VERSION_FAT MBOOT_VERSION_64BIT ".fat"
+#else
+#define MBOOT_VERSION_FAT MBOOT_VERSION_64BIT
+#endif
+
+#if MBOOT_VFS_LFS1
+#define MBOOT_VERSION_LFS1 MBOOT_VERSION_FAT ".lfs1"
+#else
+#define MBOOT_VERSION_LFS1 MBOOT_VERSION_FAT
+#endif
+
+#if MBOOT_VFS_LFS2
+#define MBOOT_VERSION_LFS2 MBOOT_VERSION_LFS1 ".lfs2"
+#else
+#define MBOOT_VERSION_LFS2 MBOOT_VERSION_LFS1
+#endif
+
+#if MBOOT_VFS_RAW
+#define MBOOT_VERSION_RAW MBOOT_VERSION_LFS2 ".raw"
+#else
+#define MBOOT_VERSION_RAW MBOOT_VERSION_LFS2
+#endif
+
+#define MBOOT_VERSION_FINAL MBOOT_VERSION_RAW
+
+#else // MBOOT_VERSION_INCLUDE_OPTIONS
+
+#define MBOOT_VERSION_FINAL MBOOT_VERSION
+
+#endif // MBOOT_VERSION_INCLUDE_OPTIONS
+
+// Ensure we don't overrun the allocated space
+_Static_assert(sizeof(MBOOT_VERSION_FINAL) <= MBOOT_VERSION_ALLOCATED_BYTES + 1, "mboot version string is too long");
+// Cuts off the null terminator
+const char mboot_version[sizeof(MBOOT_VERSION_FINAL) - 1] __attribute__((section(".mboot_version"))) __attribute__ ((__used__)) = MBOOT_VERSION_FINAL;
+
+#endif