Merge pull request #7209 from kYc0o/mcuboot_nrf52dk

Add MCUBoot linking options for RIOT images

Makefile.include

@@ -1,7 +1,7 @@
 # include Makefile.local if it exists
 -include Makefile.local
 
-all:
+all: link
 
 # set undefined variables
 RIOTBASE       ?= $(dir $(lastword $(MAKEFILE_LIST)))
@@ -279,7 +279,7 @@ endif
 BASELIBS += $(BINDIR)/${APPLICATION}.a
 BASELIBS += $(APPDEPS)
 
-.PHONY: all clean flash term doc debug debug-server reset objdump help info-modules
+.PHONY: all link clean flash term doc debug debug-server reset objdump help info-modules
 .PHONY: ..in-docker-container
 
 ELFFILE ?= $(BINDIR)/$(APPLICATION).elf
@@ -293,17 +293,19 @@ LINKFLAGPREFIX ?= -Wl,
 
 DIRS += $(EXTERNAL_MODULE_DIRS)
 
+_LINK = $(if $(CPPMIX),$(CXX),$(LINK)) $(UNDEF) $(LINKFLAGPREFIX)--start-group $(BASELIBS) -lm $(LINKFLAGPREFIX)--end-group  $(LINKFLAGPREFIX)-Map=$(BINDIR)/$(APPLICATION).map $(LINKFLAGPREFIX)--cref $(LINKFLAGS)
+
 ifeq ($(BUILD_IN_DOCKER),1)
-all: ..in-docker-container
+link: ..in-docker-container
 else
 ## make script for your application. Build RIOT-base here!
-all: ..compiler-check ..build-message $(RIOTBUILD_CONFIG_HEADER_C) $(USEPKG:%=${BINDIR}/%.a) $(APPDEPS)
+link: ..compiler-check ..build-message $(RIOTBUILD_CONFIG_HEADER_C) $(USEPKG:%=${BINDIR}/%.a) $(APPDEPS)
 	$(Q)DIRS="$(DIRS)" "$(MAKE)" -C $(APPDIR) -f $(RIOTMAKE)/application.inc.mk
 ifeq (,$(RIOTNOLINK))
 ifeq ($(BUILDOSXNATIVE),1)
 	$(Q)$(if $(CPPMIX),$(CXX),$(LINK)) $(UNDEF) -o $(ELFFILE) $$(find $(BASELIBS) -size +8c) $(LINKFLAGS) $(LINKFLAGPREFIX)-no_pie
 else
-	$(Q)$(if $(CPPMIX),$(CXX),$(LINK)) $(UNDEF) -o $(ELFFILE) $(LINKFLAGPREFIX)--start-group $(BASELIBS) -lm $(LINKFLAGPREFIX)--end-group  $(LINKFLAGPREFIX)-Map=$(BINDIR)/$(APPLICATION).map $(LINKFLAGPREFIX)--cref $(LINKFLAGS)
+	$(Q)$(_LINK) -o $(ELFFILE)
 endif
 	$(Q)$(SIZE) $(ELFFILE)
 	$(Q)$(OBJCOPY) $(OFLAGS) $(ELFFILE) $(HEXFILE)
@@ -567,3 +569,6 @@ endif
 CFLAGS := $(patsubst -D%,,$(CFLAGS))
 CFLAGS := $(patsubst -U%,,$(CFLAGS))
 CFLAGS += -include '$(RIOTBUILD_CONFIG_HEADER_C)'
+
+# include multislot support
+include $(RIOTMAKE)/multislot.mk

boards/nrf52840dk/Makefile.include

@@ -12,7 +12,7 @@ export JLINK_DEVICE := nrf52
 # special options when using SoftDevice
 ifneq (,$(filter nordic_softdevice_ble,$(USEPKG)))
 export JLINK_PRE_FLASH := erase\nloadfile $(BINDIR)/softdevice.hex
-export JLINK_FLASH_ADDR := 0x1f000
+export FLASH_ADDR := 0x1f000
 export LINKER_SCRIPT ?= $(RIOTCPU)/$(CPU)/ldscripts/$(CPU_MODEL)_sd.ld
 endif
 include $(RIOTMAKE)/tools/jlink.inc.mk

boards/nrf52dk/Makefile.include

@@ -12,7 +12,7 @@ export JLINK_DEVICE := nrf52
 # special options when using SoftDevice
 ifneq (,$(filter nordic_softdevice_ble,$(USEPKG)))
 export JLINK_PRE_FLASH := erase\nloadfile $(BINDIR)/softdevice.hex
-export JLINK_FLASH_ADDR := 0x1f000
+export FLASH_ADDR := 0x1f000
 export LINKER_SCRIPT ?= $(RIOTCPU)/$(CPU)/ldscripts/$(CPU_MODEL)_sd.ld
 endif
 include $(RIOTMAKE)/tools/jlink.inc.mk

cpu/cortexm_common/Makefile.include

@@ -3,3 +3,5 @@ INCLUDES += -I$(RIOTCPU)/cortexm_common/include
 INCLUDES += -I$(RIOTCPU)/cortexm_common/include/vendor
 
 USEMODULE += cortexm_common_periph
+
+export IMAGE_HDR_SIZE ?= 512

cpu/cortexm_common/ldscripts/multislot.ld

@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2017 Kaspar Schleiser
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @addtogroup      cpu_cortex_common
+ * @{
+ *
+ * @file
+ * @brief           Offset definitions for cortex MCUs
+ *
+ * @author          Kaspar Schleiser <kaspar@schleiser.de>
+ *
+ * @}
+ */
+
+boot_offset = DEFINED( offset ) ? offset : 0x0 ;
+rom_length = DEFINED( length ) ? length : rom_length ;

cpu/nrf52/Makefile.include

@@ -1,5 +1,11 @@
 export CPU_ARCH = cortex-m4f
 export CPU_FAM  = nrf52
 
+# Export internal ROM alignment and slot sizes for bootloader support
+export IMAGE_ALIGN = 8
+export SLOT0_SIZE = 0x8000
+export SLOT1_SIZE = 0x3C000
+export SLOT2_SIZE = 0x3C000
+
 include $(RIOTCPU)/nrf5x_common/Makefile.include
 include $(RIOTMAKE)/arch/cortexm.inc.mk

cpu/nrf52/ldscripts/nrf52832xxaa.ld

@@ -18,10 +18,14 @@
  * @}
  */
 
+rom_length = 512K;
+
+INCLUDE multislot.ld
+
 MEMORY
 {
-    rom (rx)    : ORIGIN = 0x00000000, LENGTH = 512K
-    ram (rwx)   : ORIGIN = 0x20000000, LENGTH = 64K
+    rom (rx)    : ORIGIN = 0x00000000 + boot_offset, LENGTH = rom_length
+    ram (rwx)   : ORIGIN = 0x20000000,               LENGTH = 64K
 }
 
 INCLUDE cortexm_base.ld

dist/tools/jlink/jlink.sh

@@ -12,7 +12,7 @@
 # JLINK_SERIAL:     Device serial used by JLink
 # JLINK_IF:         Interface used by JLink, default: "SWD"
 # JLINK_SPEED:      Interface clock speed to use (in kHz), default "2000"
-# JLINK_FLASH_ADDR: Starting address of the target's flash memory, default: "0"
+# FLASH_ADDR:       Starting address of the target's flash memory, default: "0"
 # JLINK_PRE_FLASH:  Additional JLink commands to execute before flashing
 # JLINK_POST_FLASH: Additional JLink commands to execute after flashing
 #
@@ -57,8 +57,6 @@ _JLINK=JLinkExe
 _JLINK_SERVER=JLinkGDBServer
 _JLINK_IF=SWD
 _JLINK_SPEED=2000
-# default starting address of the devices flash memory
-_FLASH_ADDR=0
 
 #
 # a couple of tests for certain configuration options
@@ -86,8 +84,9 @@ test_config() {
         echo "Error: No target device defined in JLINK_DEVICE env var"
         exit 1
     fi
-    if [ -z "${JLINK_FLASH_ADDR}" ]; then
-        JLINK_FLASH_ADDR=${_FLASH_ADDR}
+    if [ -z "${FLASH_ADDR}" ]; then
+        echo "Error: No flash address defined in FLASH_ADDR env var"
+        exit 1
     fi
 }
 
@@ -142,7 +141,7 @@ do_flash() {
     if [ ! -z "${JLINK_PRE_FLASH}" ]; then
         printf "${JLINK_PRE_FLASH}\n" >> ${BINDIR}/burn.seg
     fi
-    echo "loadbin ${HEXFILE} ${JLINK_FLASH_ADDR}" >> ${BINDIR}/burn.seg
+    echo "loadbin ${HEXFILE} ${FLASH_ADDR}" >> ${BINDIR}/burn.seg
     if [ ! -z "${JLINK_POST_FLASH}" ]; then
         printf "${JLINK_POST_FLASH}\n" >> ${BINDIR}/burn.seg
     fi
@@ -211,6 +210,7 @@ shift # pop $1 from $@
 case "${ACTION}" in
   flash)
     echo "### Flashing Target ###"
+    echo "### Flashing at address ${FLASH_ADDR} ###"
     do_flash "$@"
     ;;
   debug)

dist/tools/mcuboot/imgtool.md

@@ -0,0 +1,89 @@
+## Image tool
+
+The Python program `imgtool.py` can be used to perform the
+operations that are necessary to manage keys and sign images.
+
+This program is written for Python3, and has several dependencies on
+Python libraries.  These can be installed using 'pip3' manually:
+
+    pip3 install --user pycrypto
+    pip3 install --user pyasn1
+    pip3 install --user ecdsa
+
+or, on Ubuntu, using the package manager:
+
+    sudo apt-get install python3-crypto python3-pyasn1 python3-ecdsa
+
+## Managing keys
+
+This tool currently supports rsa-2048 and ecdsa-p256 keys.  You can
+generate a keypair for one of these types using the 'keygen' command:
+
+    ./imgtool.py keygen -k filename.pem -t rsa-2048
+
+or use ecdsa-p256 for the type.  The key type used should match what
+mcuboot is configured to verify.
+
+This key file is what is used to sign images, this file should be
+protected, and not widely distributed.
+
+## Incorporating the public key into the code
+
+There is a development key distributed with mcuboot that can be used
+for testing.  Since this private key is widely distributed, it should
+never be used for production.  Once you have generated a production
+key, as described above, you should replace the public key in the
+bootloader with the generated one.
+
+For Zephyr, the keys live in the file `boot/zephyr/keys.c`.  For
+mynewt, follow the instructions in `doc/signed_images.md` to generate
+the key file.
+
+    ./imgtool.py getpub -k filename.pem
+
+will extract the public key from the given private key file, and
+output it as a C data structure.  You can replace or insert this code
+into the key file.
+
+## Signing images
+
+Image signing takes a binary image intended for Slot 0 and adds a
+header and trailer that the bootloader is expecting:
+
+    usage: imgtool.py sign [-h] -k filename --align ALIGN -v VERSION -H
+                           HEADER_SIZE [--pad PAD] [--rsa-pkcs1-15]
+                           infile outfile
+
+    positional arguments:
+      infile
+      outfile
+
+    optional arguments:
+      -h, --help            show this help message and exit
+      -k filename, --key filename
+      --align ALIGN
+      -v VERSION, --version VERSION
+      -H HEADER_SIZE, --header-size HEADER_SIZE
+      --included-header     Image has gap for header
+      --pad PAD             Pad image to this many bytes, adding trailer magic
+      --rsa-pkcs1-15        Use old PKCS#1 v1.5 signature algorithm
+
+The main arguments given are the key file generated above, a version
+field to place in the header (1.2.3 for example), the alignment of the
+flash device in question, and the header size.
+
+The header size depends on the operating system and the particular
+flash device.  For Zephyr, it will be configured as part of the build,
+and will be a small power of two.  By default, the header will be
+prepended to the image.  If `--included-header` is given, the image
+must start with header-size bytes of zeros, and the header will be
+overwritten over these bytes.
+
+The optional --pad argument will place a trailer on the image that
+indicates that the image should be considered an upgrade.  Writing
+this image in slot 1 will then cause the bootloader to upgrade to it.
+
+Lastly, the --rsa-pkcs1-15 will cause the tool to use the older,
+deprecated pkcs#1 v1.5 signing algorithm when using RSA.  This can be
+enabled in the bootloader as well, and may be needed if you are using
+an older version of the bootloader.

dist/tools/mcuboot/imgtool.py

@@ -0,0 +1,100 @@
+#! /usr/bin/env python3
+
+import argparse
+from imgtool import keys
+from imgtool import image
+from imgtool import version
+import sys
+
+def gen_rsa2048(args):
+    keys.RSA2048.generate().export_private(args.key)
+def gen_ecdsa_p256(args):
+    keys.ecdsa256p1.generate().export_private(args.key)
+def gen_ecdsa_p224(args):
+    print("TODO: p-224 not yet implemented")
+
+keygens = {
+        'rsa-2048': gen_rsa2048,
+        'ecdsa-p256': gen_ecdsa_p256,
+        'ecdsa-p224': gen_ecdsa_p224, }
+
+def do_keygen(args):
+    if args.type not in keygens:
+        msg = "Unexpected key type: {}".format(args.type)
+        raise argparse.ArgumentTypeError(msg)
+    keygens[args.type](args)
+
+def do_getpub(args):
+    key = keys.load(args.key)
+    key.emit_c()
+
+def do_sign(args):
+    align = args.align
+    if args.rsa_pkcs1_15:
+        keys.sign_rsa_pss = False
+    img = image.Image.load(args.infile, version=args.version,
+            header_size=args.header_size,
+            included_header=args.included_header,
+            pad=args.pad)
+    key = keys.load(args.key) if args.key else None
+    img.sign(key)
+
+    if args.pad:
+        img.pad_to(args.pad, args.align)
+
+    img.save(args.outfile)
+
+subcmds = {
+        'keygen': do_keygen,
+        'getpub': do_getpub,
+        'sign': do_sign, }
+
+def alignment_value(text):
+    value = int(text)
+    if value not in [1, 2, 4, 8]:
+        msg = "{} must be one of 1, 2, 4 or 8".format(value)
+        raise argparse.ArgumentTypeError(msg)
+    return value
+
+def intparse(text):
+    """Parse a command line argument as an integer.
+
+    Accepts 0x and other prefixes to allow other bases to be used."""
+    return int(text, 0)
+
+def args():
+    parser = argparse.ArgumentParser()
+    subs = parser.add_subparsers(help='subcommand help', dest='subcmd')
+
+    keygenp = subs.add_parser('keygen', help='Generate pub/private keypair')
+    keygenp.add_argument('-k', '--key', metavar='filename', required=True)
+    keygenp.add_argument('-t', '--type', metavar='type',
+            choices=['rsa-2048', 'ecdsa-p224', 'ecdsa-p256'],
+            required=True)
+
+    getpub = subs.add_parser('getpub', help='Get public key from keypair')
+    getpub.add_argument('-k', '--key', metavar='filename', required=True)
+
+    sign = subs.add_parser('sign', help='Sign an image with a private key')
+    sign.add_argument('-k', '--key', metavar='filename')
+    sign.add_argument("--align", type=alignment_value, required=True)
+    sign.add_argument("-v", "--version", type=version.decode_version, required=True)
+    sign.add_argument("-H", "--header-size", type=intparse, required=True)
+    sign.add_argument("--included-header", default=False, action='store_true',
+            help='Image has gap for header')
+    sign.add_argument("--pad", type=intparse,
+            help='Pad image to this many bytes, adding trailer magic')
+    sign.add_argument("--rsa-pkcs1-15", help='Use old PKCS#1 v1.5 signature algorithm',
+            default=False, action='store_true')
+    sign.add_argument("infile")
+    sign.add_argument("outfile")
+
+    args = parser.parse_args()
+    if args.subcmd is None:
+        print('Must specify a subcommand', file=sys.stderr)
+        sys.exit(1)
+
+    subcmds[args.subcmd](args)
+
+if __name__ == '__main__':
+    args()

dist/tools/mcuboot/imgtool/image.py

@@ -0,0 +1,172 @@
+"""
+Image signing and management.
+"""
+
+from . import version as versmod
+import hashlib
+import struct
+
+IMAGE_MAGIC = 0x96f3b83c
+IMAGE_HEADER_SIZE = 32
+
+# Image header flags.
+IMAGE_F = {
+        'PIC':                   0x0000001,
+        'SHA256':                0x0000002,
+        'PKCS15_RSA2048_SHA256': 0x0000004,
+        'ECDSA224_SHA256':       0x0000008,
+        'NON_BOOTABLE':          0x0000010,
+        'ECDSA256_SHA256':       0x0000020,
+        'PKCS1_PSS_RSA2048_SHA256': 0x0000040, }
+
+TLV_VALUES = {
+        'SHA256': 1,
+        'RSA2048': 2,
+        'ECDSA224': 3,
+        'ECDSA256': 4, }
+
+TLV_HEADER_SIZE = 4
+
+# Sizes of the image trailer, depending on image alignment.
+trailer_sizes = {
+        1: 402,
+        2: 788,
+        4: 1560,
+        8: 3104, }
+
+boot_magic = bytes([
+    0x77, 0xc2, 0x95, 0xf3,
+    0x60, 0xd2, 0xef, 0x7f,
+    0x35, 0x52, 0x50, 0x0f,
+    0x2c, 0xb6, 0x79, 0x80, ])
+
+class TLV():
+    def __init__(self):
+        self.buf = bytearray()
+
+    def add(self, kind, payload):
+        """Add a TLV record.  Kind should be a string found in TLV_VALUES above."""
+        buf = struct.pack('<BBH', TLV_VALUES[kind], 0, len(payload))
+        self.buf += buf
+        self.buf += payload
+
+    def get(self):
+        return bytes(self.buf)
+
+class Image():
+    @classmethod
+    def load(cls, path, included_header=False, **kwargs):
+        """Load an image from a given file"""
+        with open(path, 'rb') as f:
+            payload = f.read()
+        obj = cls(**kwargs)
+        obj.payload = payload
+
+        # Add the image header if needed.
+        if not included_header and obj.header_size > 0:
+            obj.payload = (b'\000' * obj.header_size) + obj.payload
+
+        obj.check()
+        return obj
+
+    def __init__(self, version=None, header_size=IMAGE_HEADER_SIZE, pad=0):
+        self.version = version or versmod.decode_version("0")
+        self.header_size = header_size or IMAGE_HEADER_SIZE
+        self.pad = pad
+
+    def __repr__(self):
+        return "<Image version={}, header_size={}, pad={}, payloadlen=0x{:x}>".format(
+                self.version,
+                self.header_size,
+                self.pad,
+                len(self.payload))
+
+    def save(self, path):
+        with open(path, 'wb') as f:
+            f.write(self.payload)
+
+    def check(self):
+        """Perform some sanity checking of the image."""
+        # If there is a header requested, make sure that the image
+        # starts with all zeros.
+        if self.header_size > 0:
+            if any(v != 0 for v in self.payload[0:self.header_size]):
+                raise Exception("Padding requested, but image does not start with zeros")
+
+    def sign(self, key):
+        self.add_header(key)
+
+        tlv = TLV()
+
+        # Note that ecdsa wants to do the hashing itself, which means
+        # we get to hash it twice.
+        sha = hashlib.sha256()
+        sha.update(self.payload)
+        digest = sha.digest()
+
+        tlv.add('SHA256', digest)
+
+        if key is not None:
+            sig = key.sign(self.payload)
+            tlv.add(key.sig_tlv(), sig)
+
+        self.payload += tlv.get()
+
+    def add_header(self, key):
+        """Install the image header.
+
+        The key is needed to know the type of signature, and
+        approximate the size of the signature."""
+
+        flags = 0
+        tlvsz = 0
+        if key is not None:
+            flags |= IMAGE_F[key.sig_type()]
+            tlvsz += TLV_HEADER_SIZE + key.sig_len()
+
+        flags |= IMAGE_F['SHA256']
+        tlvsz += 4 + hashlib.sha256().digest_size
+
+        fmt = ('<' +
+            # type ImageHdr struct {
+            'I' +   # Magic uint32
+            'H' +   # TlvSz uint16
+            'B' +   # KeyId uint8
+            'B' +   # Pad1  uint8
+            'H' +   # HdrSz uint16
+            'H' +   # Pad2  uint16
+            'I' +   # ImgSz uint32
+            'I' +   # Flags uint32
+            'BBHI' + # Vers  ImageVersion
+            'I'     # Pad3  uint32
+            ) # }
+        assert struct.calcsize(fmt) == IMAGE_HEADER_SIZE
+        header = struct.pack(fmt,
+                IMAGE_MAGIC,
+                tlvsz, # TlvSz
+                0, # KeyId (TODO: allow other ids)
+                0,  # Pad1
+                self.header_size,
+                0, # Pad2
+                len(self.payload) - self.header_size, # ImageSz
+                flags, # Flags
+                self.version.major,
+                self.version.minor or 0,
+                self.version.revision or 0,
+                self.version.build or 0,
+                0) # Pad3
+        self.payload = bytearray(self.payload)
+        self.payload[:len(header)] = header
+
+    def pad_to(self, size, align):
+        """Pad the image to the given size, with the given flash alignment."""
+        tsize = trailer_sizes[align]
+        padding = size - (len(self.payload) + tsize)
+        if padding < 0:
+            msg = "Image size (0x{:x}) + trailer (0x{:x}) exceeds requested size 0x{:x}".format(
+                    len(self.payload), tsize, size)
+            raise Exception(msg)
+        pbytes = b'\xff' * padding
+        pbytes += boot_magic
+        pbytes += b'\xff' * (tsize - len(boot_magic))
+        self.payload += pbytes

dist/tools/mcuboot/imgtool/keys.py

@@ -0,0 +1,137 @@
+"""
+Cryptographic key management for imgtool.
+"""
+
+from Crypto.Hash import SHA256
+from Crypto.PublicKey import RSA
+from Crypto.Signature import PKCS1_v1_5, PKCS1_PSS
+from ecdsa import SigningKey, NIST256p, util
+import hashlib
+from pyasn1.type import namedtype, univ
+from pyasn1.codec.der.encoder import encode
+
+# By default, we use RSA-PSS (PKCS 2.1).  That can be overridden on
+# the command line to support the older (less secure) PKCS1.5
+sign_rsa_pss = True
+
+AUTOGEN_MESSAGE = "/* Autogenerated by imgtool.py, do not edit. */"
+
+class RSAPublicKey(univ.Sequence):
+    componentType = namedtype.NamedTypes(
+            namedtype.NamedType('modulus', univ.Integer()),
+            namedtype.NamedType('publicExponent', univ.Integer()))
+
+class RSA2048():
+    def __init__(self, key):
+        """Construct an RSA2048 key with the given key data"""
+        self.key = key
+
+    @staticmethod
+    def generate():
+        return RSA2048(RSA.generate(2048))
+
+    def export_private(self, path):
+        with open(path, 'wb') as f:
+            f.write(self.key.exportKey('PEM'))
+
+    def emit_c(self):
+        node = RSAPublicKey()
+        node['modulus'] = self.key.n
+        node['publicExponent'] = self.key.e
+        print(AUTOGEN_MESSAGE)
+        print("const unsigned char rsa_pub_key[] = {", end='')
+        encoded = bytearray(encode(node))
+        for count, b in enumerate(encoded):
+            if count % 8 == 0:
+                print("\n\t", end='')
+            else:
+                print(" ", end='')
+            print("0x{:02x},".format(b), end='')
+        print("\n};")
+        print("const unsigned int rsa_pub_key_len = {};".format(len(encoded)))
+
+    def sig_type(self):
+        """Return the type of this signature (as a string)"""
+        if sign_rsa_pss:
+            return "PKCS1_PSS_RSA2048_SHA256"
+        else:
+            return "PKCS15_RSA2048_SHA256"
+
+    def sig_len(self):
+        return 256
+
+    def sig_tlv(self):
+        return "RSA2048"
+
+    def sign(self, payload):
+        sha = SHA256.new(payload)
+        if sign_rsa_pss:
+            signer = PKCS1_PSS.new(self.key)
+        else:
+            signer = PKCS1_v1_5.new(self.key)
+        signature = signer.sign(sha)
+        assert len(signature) == self.sig_len()
+        return signature
+
+class ECDSA256P1():
+    def __init__(self, key):
+        """Construct an ECDSA P-256 private key"""
+        self.key = key
+
+    @staticmethod
+    def generate():
+        return ECDSA256P1(SigningKey.generate(curve=NIST256p))
+
+    def export_private(self, path):
+        with open(path, 'wb') as f:
+            f.write(key.to_pem())
+
+    def emit_c(self):
+        vk = self.key.get_verifying_key()
+        print(AUTOGEN_MESSAGE)
+        print("const unsigned char ecdsa_pub_key[] = {", end='')
+        encoded = bytes(vk.to_der())
+        for count, b in enumerate(encoded):
+            if count % 8 == 0:
+                print("\n\t", end='')
+            else:
+                print(" ", end='')
+            print("0x{:02x},".format(b), end='')
+        print("\n};")
+        print("const unsigned int ecdsa_pub_key_len = {};".format(len(encoded)))
+
+    def sign(self, payload):
+        # To make this fixed length, possibly pad with zeros.
+        sig = self.key.sign(payload, hashfunc=hashlib.sha256, sigencode=util.sigencode_der)
+        sig += b'\000' * (self.sig_len() - len(sig))
+        return sig
+
+    def sig_len(self):
+        # The DER encoding depends on the high bit, and can be
+        # anywhere from 70 to 72 bytes.  Because we have to fill in
+        # the length field before computing the signature, however,
+        # we'll give the largest, and the sig checking code will allow
+        # for it to be up to two bytes larger than the actual
+        # signature.
+        return 72
+
+    def sig_type(self):
+        """Return the type of this signature (as a string)"""
+        return "ECDSA256_SHA256"
+
+    def sig_tlv(self):
+        return "ECDSA256"
+
+def load(path):
+    with open(path, 'rb') as f:
+        pem = f.read()
+    try:
+        key = RSA.importKey(pem)
+        if key.n.bit_length() != 2048:
+            raise Exception("Unsupported RSA bit length, only 2048 supported")
+        return RSA2048(key)
+    except ValueError:
+        key = SigningKey.from_pem(pem)
+        if key.curve.name != 'NIST256p':
+            raise Exception("Unsupported ECDSA curve")
+        return ECDSA256P1(key)

dist/tools/mcuboot/imgtool/version.py

@@ -0,0 +1,33 @@
+"""
+Semi Semantic Versioning
+
+Implements a subset of semantic versioning that is supportable by the image header.
+"""
+
+import argparse
+from collections import namedtuple
+import re
+
+SemiSemVersion = namedtuple('SemiSemVersion', ['major', 'minor', 'revision', 'build'])
+
+version_re = re.compile(r"""^([1-9]\d*|0)(\.([1-9]\d*|0)(\.([1-9]\d*|0)(\+([1-9]\d*|0))?)?)?$""")
+def decode_version(text):
+    """Decode the version string, which should be of the form maj.min.rev+build"""
+    m = version_re.match(text)
+    # print("decode:", text, m.groups())
+    if m:
+        result = SemiSemVersion(
+                int(m.group(1)) if m.group(1) else 0,
+                int(m.group(3)) if m.group(3) else 0,
+                int(m.group(5)) if m.group(5) else 0,
+                int(m.group(7)) if m.group(7) else 0)
+        return result
+    else:
+        msg = "Invalid version number, should be maj.min.rev+build with later parts optional"
+        raise argparse.ArgumentTypeError(msg)
+
+if __name__ == '__main__':
+    print(decode_version("1.2"))
+    print(decode_version("1.0"))
+    print(decode_version("0.0.2+75"))
+    print(decode_version("0.0.0+00"))

makefiles/multislot.mk

@@ -0,0 +1,54 @@
+ifdef SLOT0_SIZE
+
+IMGTOOL ?= $(RIOTBASE)/dist/tools/mcuboot/imgtool.py
+override IMGTOOL := $(abspath $(IMGTOOL))
+
+BINFILE ?= $(BINDIR)/$(APPLICATION).bin
+SIGN_BINFILE = $(BINDIR)/signed-$(APPLICATION).bin
+MCUBOOT_KEYFILE ?= $(BINDIR)/key.pem
+OFLAGS = -O binary
+MCUBOOT_BIN ?= $(BINDIR)/mcuboot.bin
+MCUBOOT_BIN_URL ?= http://download.riot-os.org/mynewt.mcuboot.bin
+MCUBOOT_BIN_MD5 ?= 0c71a0589bd3709fc2d90f07a0035ce7
+
+create-key: $(MCUBOOT_KEYFILE)
+
+ifeq ($(BINDIR)/key.pem,$(MCUBOOT_KEYFILE))
+$(MCUBOOT_KEYFILE):
+	$(Q)mkdir -p $(BINDIR)
+	$(Q)$(IMGTOOL) keygen -k $@ -t rsa-2048
+endif
+
+mcuboot: create-key link
+	@$(COLOR_ECHO)
+	@$(COLOR_ECHO) '${COLOR_PURPLE}Re-linking for MCUBoot at $(SLOT0_SIZE)...${COLOR_RESET}'
+	@$(COLOR_ECHO)
+	$(Q)$(_LINK) $(LINKFLAGPREFIX)--defsym=offset="$$(($(SLOT0_SIZE) + $(IMAGE_HDR_SIZE)))" \
+	$(LINKFLAGPREFIX)--defsym=length="$$(($(SLOT1_SIZE) - $(IMAGE_HDR_SIZE)))" \
+	$(LINKFLAGPREFIX)--defsym=image_header="$(IMAGE_HDR_SIZE)" -o $(ELFFILE) && \
+	$(OBJCOPY) $(OFLAGS) $(ELFFILE) $(BINFILE) && \
+	$(IMGTOOL) sign --key $(MCUBOOT_KEYFILE) --version $(IMAGE_VERSION) --align \
+	$(IMAGE_ALIGN) -H $(IMAGE_HDR_SIZE) $(BINFILE) $(SIGN_BINFILE)
+	@$(COLOR_ECHO)
+	@$(COLOR_ECHO) '${COLOR_PURPLE}Signed with $(MCUBOOT_KEYFILE) for version $(IMAGE_VERSION)\
+	${COLOR_RESET}'
+	@$(COLOR_ECHO)
+
+$(MCUBOOT_BIN):
+	$(Q)$(DLCACHE) $(MCUBOOT_BIN_URL) $(MCUBOOT_BIN_MD5) $@
+
+.PHONY: flash-bootloader flash-mcuboot
+
+flash-bootloader: HEXFILE = $(MCUBOOT_BIN)
+flash-bootloader: $(MCUBOOT_BIN) $(FLASHDEPS)
+	FLASH_ADDR=0x0 $(FLASHER) $(FFLAGS)
+
+flash-mcuboot: HEXFILE = $(SIGN_BINFILE)
+flash-mcuboot: mcuboot $(FLASHDEPS) flash-bootloader
+	FLASH_ADDR=$(SLOT0_SIZE) $(FLASHER) $(FFLAGS)
+
+else
+mcuboot:
+	$(Q)echo "error: mcuboot not supported on board $(BOARD)!"
+	$(Q)false
+endif # SLOT0_SIZE

makefiles/vars.inc.mk

@@ -1,3 +1,6 @@
+# set default values for selected global variables
+FLASH_ADDR ?= 0x0
+
 export Q                     # Used in front of Makefile lines to suppress the printing of the command if user did not opt-in to see them.
 export QQ                    # as Q, but be more quiet
 export QUIET                 # The parameter to use whether to show verbose makefile commands or not.
@@ -53,6 +56,7 @@ export WERROR                # Treat all compiler warnings as errors if set to 1
 export GITCACHE              # path to git-cache executable
 export FLASHER               # The command to call on "make flash".
 export FFLAGS                # The parameters to supply to FLASHER.
+export FLASH_ADDR          # Define an offset to flash code into ROM memory.
 export TERMPROG              # The command to call on "make term".
 export TERMFLAGS             # Additional parameters to supply to TERMPROG.
 export PORT                  # The port to connect the TERMPROG to.

tests/mcuboot/Makefile

@@ -0,0 +1,14 @@
+APPLICATION = hello_mcuboot
+
+BOARD ?= nrf52dk
+
+include ../Makefile.tests_common
+
+BOARD_WHITELIST := nrf52dk
+
+export IMAGE_VERSION = 1.1.1+1
+
+# this test is supposed to always build the mcuboot image
+all: mcuboot
+
+include $(RIOTBASE)/Makefile.include

tests/mcuboot/README.md

@@ -0,0 +1,20 @@
+# MCUBoot test application
+This test is intended to compile a hello-world program taking into account
+the existence of the MCUBoot bootloader at the first 32K in the ROM.
+
+For this first support, a pre-compiled mynewt MCUBoot binary is downloaded at
+compile time.
+
+The goal is to produce an ELF file which is linked to be flashed at a
+`BOOTLOADER_OFFSET` offset rather than the beginning of ROM. MCUBoot also
+expects an image padded with some specific headers containing the version
+information, and TLVs with hash and signing information. This is done through
+the imgtool.py application, which is executed automatically by the build
+system.
+
+This test can be called using `make mcuboot` to produce such ELF file,
+which can also be flashed using `make flash-mcuboot`.This command also flashes
+the pre-compiled bootloader.
+
+It's also possible to build and flash MCUBoot by following the instructions on
+the MCUBoot repository either using mynewt or zephyr operating systems.

tests/mcuboot/main.c

@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2017 Inria
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @ingroup     tests
+ * @{
+ *
+ * @file
+ * @brief       MCUBoot compile test application
+ *
+ * @author      Francisco Acosta <francisco.acosta@inria.fr>
+ *
+ * @}
+ */
+
+#include <stdio.h>
+#include "cpu.h"
+
+int main(void)
+{
+    puts("Hello MCUBoot!");
+
+    printf("You are running RIOT on a(n) %s board.\n", RIOT_BOARD);
+    printf("This board features a(n) %s MCU.\n", RIOT_MCU);
+    printf("The startup address is: %p\n", (void*)SCB->VTOR);
+
+    return 0;
+}