uavcan bootloader use new AppDes

platforms/nuttx/src/canbootloader/include/can.h

@@ -53,7 +53,8 @@ typedef enum {
 	CAN_125KBAUD  = 1,
 	CAN_250KBAUD  = 2,
 	CAN_500KBAUD  = 3,
-	CAN_1MBAUD    = 4
+	CAN_1MBAUD    = 4,
+	CAN_UNDEFINED = 999,
 } can_speed_t;
 
 typedef enum {

platforms/nuttx/src/canbootloader/uavcan/main.c

@@ -82,6 +82,8 @@
 #pragma message "******** DANGER DEBUG_APPLICATION_INPLACE is DEFINED ******"
 #endif
 
+extern bootloader_alt_app_shared_t _sapp_bl_shared;
+
 typedef volatile struct bootloader_t {
 	can_speed_t bus_speed;
 	volatile uint8_t health;
@@ -208,7 +210,7 @@ static void node_info_process(bl_timer_id id, void *context)
 			bootloader.fw_image_descriptor->minor_version;
 
 		response.software_version.vcs_commit =
-			bootloader.fw_image_descriptor->vcs_commit;
+			bootloader.fw_image_descriptor->git_hash;
 
 		response.software_version.image_crc =
 			bootloader.fw_image_descriptor->image_crc;
@@ -292,9 +294,9 @@ static void find_descriptor(void)
 	app_descriptor_t *descriptor = NULL;
 	union {
 		uint64_t ull;
-		char text[sizeof(uint64_t)];
+		uint8_t bytes[sizeof(uint64_t)];
 	} sig = {
-		.text = {APP_DESCRIPTOR_SIGNATURE}
+		.bytes = APP_DESCRIPTOR_SIGNATURE
 	};
 
 	do {
@@ -312,8 +314,8 @@ static void find_descriptor(void)
  *
  * Description:
  *   This functions validates the applications image based on the validity of
- *   the Application firmware descriptor's crc and the value of the first word
+ *   the Application firmware descriptor's 2 crcs and the value of
- *   in the FLASH image.
+ *   the first word in the FLASH image.
  *
  *
  * Input Parameters:
@@ -326,9 +328,9 @@ static void find_descriptor(void)
  ****************************************************************************/
 static bool is_app_valid(uint32_t first_word)
 {
-	uint64_t crc;
+	uint32_t block_crc1;
-	size_t i, length, crc_offset;
+	uint32_t block_crc2;
-	uint32_t word;
+	size_t length;
 
 	find_descriptor();
 
@@ -342,32 +344,21 @@ static bool is_app_valid(uint32_t first_word)
 		return false;
 	}
 
-	crc_offset = (size_t)(&bootloader.fw_image_descriptor->image_crc) -
+	block_crc1 = crc32_signature(0, sizeof(first_word), (const uint8_t *)&first_word);
-		     (size_t) bootloader.fw_image;
+	block_crc1 = crc32_signature(block_crc1, (size_t)(&bootloader.fw_image_descriptor->crc32_block1) -
-	crc_offset >>= 2u;
+				     (size_t)(bootloader.fw_image + 1), (const uint8_t *)(bootloader.fw_image + 1));
-	length >>= 2u;
 
-	crc = crc64_add_word(CRC64_INITIAL, first_word);
+	block_crc2 = crc32_signature(0,
-
+				     (size_t) bootloader.fw_image_descriptor->image_size - ((size_t)&bootloader.fw_image_descriptor->major_version
-	for (i = 1u; i < length; i++) {
+						     - (size_t)bootloader.fw_image),
-		if (i == crc_offset || i == crc_offset + 1u) {
+				     (const uint8_t *) &bootloader.fw_image_descriptor->major_version);
-			/* Zero out the CRC field while computing the CRC */
-			word = 0u;
-
-		} else {
-			word = bootloader.fw_image[i];
-		}
-
-		crc = crc64_add_word(crc, word);
-	}
-
-	crc ^= CRC64_OUTPUT_XOR;
 
 #if defined(DEBUG_APPLICATION_INPLACE)
 	return true;
 #endif
 
-	return crc == bootloader.fw_image_descriptor->image_crc;
+	return block_crc1 == bootloader.fw_image_descriptor->crc32_block1
+	       && block_crc2 == bootloader.fw_image_descriptor->crc32_block2;
 }
 
 /****************************************************************************
@@ -976,11 +967,16 @@ static void application_run(size_t fw_image_size, bootloader_app_shared_t *commo
 static int autobaud_and_get_dynamic_node_id(bl_timer_id tboot, can_speed_t *speed, uint32_t *node_id)
 {
 	board_indicate(autobaud_start);
-
+	bool autobaud_only = *speed == CAN_UNDEFINED;
 	int rv = can_autobaud(speed, tboot);
 
 	if (rv != CAN_BOOT_TIMEOUT) {
 		board_indicate(autobaud_end);
+
+		if (autobaud_only) {
+			return rv;
+		}
+
 		board_indicate(allocation_start);
 #if defined(DEBUG_APPLICATION_INPLACE)
 		*node_id = 125;
@@ -1071,9 +1067,24 @@ __EXPORT int main(int argc, char *argv[])
 
 	board_indicate(reset);
 
-	/* Was this boot a result of the Application being told it has a FW update ? */
+	/* Was this boot a result of An Alternate Application being told it has a FW update ? */
-	bootloader.app_bl_request = (OK == bootloader_app_shared_read(&common, App)) &&
+
-				    common.bus_speed && common.node_id;
+	bootloader_alt_app_shared_t *ps = (bootloader_alt_app_shared_t *) &_sapp_bl_shared;
+
+	if (ps->signature == BL_ALT_APP_SHARED_SIGNATURE) {
+
+		common.node_id = ps->node_id;
+		common.bus_speed = CAN_UNDEFINED;
+		bootloader.app_bl_request = ps->node_id != 0;
+		ps->signature = 0;
+
+	} else {
+
+		/* Was this boot a result of the Application being told it has a FW update ? */
+
+		bootloader.app_bl_request = (OK == bootloader_app_shared_read(&common, App)) &&
+					    common.bus_speed && common.node_id;
+	}
 
 	/*
 	 * Mark CRC to say this is not from
@@ -1130,6 +1141,23 @@ __EXPORT int main(int argc, char *argv[])
 	if (bootloader.app_bl_request) {
 
 		bootloader.bus_speed = common.bus_speed;
+
+		/* if the the bootloader_alt_app_shared_t was used there  is not bit rate.
+		 * So let auto baud only as signaled by bootloader.bus_speed == CAN_UNDEFINED
+		 */
+
+		if (common.bus_speed == CAN_UNDEFINED) {
+			if (CAN_OK != autobaud_and_get_dynamic_node_id(tboot, (can_speed_t *)&bootloader.bus_speed, &common.node_id)) {
+				/*
+				 * It is OK that node ID is set to the preferred Appl Node ID because
+				 *  common.crc.valid is not true yet
+				 */
+
+				goto boot;
+
+			}
+		}
+
 		can_init(can_freq2speed(common.bus_speed), CAN_Mode_Normal);
 
 	} else {

src/drivers/bootloaders/boot_app_shared.h

@@ -44,9 +44,7 @@ __BEGIN_DECLS
  * revision number of 00 used in app_descriptor_t
  */
 
-#define APP_DESCRIPTOR_SIGNATURE_ID 'A','P','D','e','s','c'
+#define APP_DESCRIPTOR_SIGNATURE { 0x40, 0xa2, 0xe4, 0xf1, 0x64, 0x68, 0x91, 0x06 }
-#define APP_DESCRIPTOR_SIGNATURE_REV '0','0'
-#define APP_DESCRIPTOR_SIGNATURE APP_DESCRIPTOR_SIGNATURE_ID, APP_DESCRIPTOR_SIGNATURE_REV
 
 /* N.B. the .ld file must emit this sections */
 # define boot_app_shared_section __attribute__((section(".app_descriptor")))
@@ -96,6 +94,15 @@ typedef begin_packed_struct struct bootloader_app_shared_t {
 	uint32_t bus_speed;
 	uint32_t node_id;
 } end_packed_struct bootloader_app_shared_t;
+
+#define BL_ALT_APP_SHARED_SIGNATURE 0xc544ad9a
+typedef begin_packed_struct struct bootloader_alt_app_shared_t {
+	uint32_t  signature;
+	uint32_t  reserved[4];
+	uint8_t   fw_server_node_id;
+	uint8_t   node_id;
+	uint8_t   path[201];
+} end_packed_struct bootloader_alt_app_shared_t;
 #pragma GCC diagnostic pop
 
 /****************************************************************************
@@ -128,12 +135,19 @@ typedef begin_packed_struct struct bootloader_app_shared_t {
 #pragma GCC diagnostic ignored "-Wpacked"
 typedef begin_packed_struct struct app_descriptor_t {
 	uint8_t signature[sizeof(uint64_t)];
-	uint64_t image_crc;
+	union {
+		uint64_t image_crc;
+		struct {
+			uint32_t crc32_block1;
+			uint32_t crc32_block2;
+		};
+	};
 	uint32_t image_size;
-	uint32_t vcs_commit;
+	uint32_t git_hash;
-	uint8_t major_version;
+	uint8_t  major_version;
-	uint8_t minor_version;
+	uint8_t  minor_version;
-	uint8_t reserved[6];
+	uint16_t board_id;
+	uint8_t reserved[ 3 + 3 + 2];
 } end_packed_struct app_descriptor_t;
 #pragma GCC diagnostic pop
 

src/drivers/bootloaders/make_can_boot_descriptor.py

@@ -7,6 +7,41 @@ import struct
 import optparse
 import binascii
 from io import BytesIO
+import array
+
+crctab = array.array('I', [
+    0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3,
+    0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91,
+    0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
+    0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5,
+    0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
+    0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
+    0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f,
+    0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,
+    0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
+    0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
+    0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457,
+    0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
+    0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb,
+    0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9,
+    0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
+    0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad,
+    0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683,
+    0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
+    0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7,
+    0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
+    0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
+    0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79,
+    0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f,
+    0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
+    0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
+    0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21,
+    0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
+    0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45,
+    0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db,
+    0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
+    0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf,
+    0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d])
 
 class GitWrapper:
     @classmethod
@@ -21,26 +56,31 @@ class GitWrapper:
 class AppDescriptor(object):
     """
     UAVCAN firmware image descriptor format:
-    uint64_t signature (bytes [7:0] set to 'APDesc00' by linker script)
+    uint64_t signature (bytes [7:0] set to '{ 0x40, 0xa2, 0xe4, 0xf1, 0x64, 0x68, 0x91, 0x06 }' by the build
-    uint64_t image_crc (set to 0 by linker script)
+    uint32_t crc32_block1   From offset 0 to . (non inclusive) (set by this tool)
-    uint32_t image_size (set to 0 by linker script)
+    uint32_t crc32_block2   From offsetof(minor_version) to end  (set by this tool)
-    uint32_t vcs_commit (set in source or by this tool)
+    uint32_t image_size    (set to 0 by linker script)
+    uint32_t vcs_commit    (set in source or by this tool)
     uint8_t version_major (set in source)
     uint8_t version_minor (set in source)
+    uint16_t board_id     (set in source)
     uint8_t reserved[6] (set to 0xFF by linker script)
     """
 
-    LENGTH = 8 + 8 + 4 + 4 + 1 + 1 + 6
+    LENGTH = 8 + 4 + 4 + 4 + 4 + 1 + 1 + 2 + 8
-    SIGNATURE = b"APDesc00"
+    DESLENGTH = 4 + 4 + 4 + 4
-    RESERVED =  b"\xFF" * 6
+    SIGNATURE = b"\x40\xa2\xe4\xf1\x64\x68\x91\x06"
+    RESERVED =  b"\xFF" * 8
 
     def __init__(self, bytes=None):
         self.signature = AppDescriptor.SIGNATURE
-        self.image_crc = 0
+        self.crc32_block1 = 0
+        self.crc32_block2 = 0
         self.image_size = 0
         self.vcs_commit = 0
         self.version_major = 0
         self.version_minor = 0
+        self.board_id = 0
         self.reserved = AppDescriptor.RESERVED
 
         if bytes:
@@ -51,15 +91,16 @@ class AppDescriptor(object):
                                  binascii.b2a_hex(bytes)))
 
     def pack(self):
-        return struct.pack("<8sQLLBB6s", self.signature, self.image_crc,
+        return struct.pack("<8sLLLLBBH8s", self.signature, self.crc32_block1,
-                           self.image_size, self.vcs_commit,
+                           self.crc32_block2, self.image_size, self.vcs_commit,
                            self.version_major, self.version_minor,
+                           self.board_id,
                            self.reserved)
 
     def unpack(self, bytes):
-        (self.signature, self.image_crc, self.image_size, self.vcs_commit,
+        (self.signature, self.crc32_block1, self.crc32_block2, self.image_size, self.vcs_commit,
-            self.version_major, self.version_minor, self.reserved) = \
+            self.version_major, self.version_minor, self.board_id, self.reserved) = \
-            struct.unpack("<8sQLLBB6s", bytes)
+            struct.unpack("<8sLLLLBBH8s", bytes)
 
         if not self.empty and not self.valid:
             raise ValueError()
@@ -67,13 +108,14 @@ class AppDescriptor(object):
     @property
     def empty(self):
         return (self.signature == AppDescriptor.SIGNATURE and
-                self.image_crc == 0 and self.image_size == 0 and
+                self.crc32_block1 == 0  and self.crc32_block2 == 0 and
-                self.reserved == AppDescriptor.RESERVED)
+                self.image_size == 0 and self.reserved == AppDescriptor.RESERVED)
 
     @property
     def valid(self):
         return (self.signature == AppDescriptor.SIGNATURE and
-                self.image_crc != 0 and self.image_size > 0 and
+                self.crc32_block1 != 0  and self.crc32_block2 != 0 and
+                self.image_size > 0 and self.board_id != 0 and
                 self.reserved == AppDescriptor.RESERVED)
 
 
@@ -136,38 +178,31 @@ class FirmwareImage(object):
         # Set the descriptor's length and CRC to the values required for
         # CRC computation
         self.app_descriptor.image_size = self.length
-        self.app_descriptor.image_crc = 0
+        self.app_descriptor.crc32_block1 = 0
+        self.app_descriptor.crc32_block2 = 0
 
         self._write_descriptor_raw()
 
+        content = bytearray(self._contents.getvalue())
+        if  self._padding:
+            content += bytearray.fromhex("ff" * self._padding)
+
         # Update the descriptor's CRC based on the computed value and write
         # it out again
-        self.app_descriptor.image_crc = self.crc
+
+        self.app_descriptor.crc32_block1 = self.crc32(content[:self.app_descriptor_offset + len(AppDescriptor.SIGNATURE)])
+        b2 = self.app_descriptor_offset + len(AppDescriptor.SIGNATURE) + AppDescriptor.DESLENGTH
+        self.app_descriptor.crc32_block2 = self.crc32(content[b2:])
 
         self._write_descriptor_raw()
 
-    @property
+    def crc32(self, bytes, crc = 0):
-    def crc(self):
-        MASK = 0xFFFFFFFFFFFFFFFF
-        POLY = 0x42F0E1EBA9EA3693
 
-        # Calculate the image CRC with the image_crc field in the app
-        # descriptor zeroed out.
-        crc_offset = self.app_descriptor_offset + len(AppDescriptor.SIGNATURE)
-        content = bytearray(self._contents.getvalue())
-        content[crc_offset:crc_offset + 8] = bytearray.fromhex("00" * 8)
-        if  self._padding:
-            content += bytearray.fromhex("ff" * self._padding)
-        val = MASK
-        for byte in content:
-            val ^= (byte << 56) & MASK
-            for bit in range(8):
-                if val & (1 << 63):
-                    val = ((val << 1) & MASK) ^ POLY
-                else:
-                    val <<= 1
 
-        return (val & MASK) ^ MASK
+        for byte in bytes:
+            index = (crc ^ byte) & 0xff
+            crc = crctab[index] ^ (crc >> 8)
+        return crc
 
     @property
     def padding(self):
@@ -234,7 +269,6 @@ class FirmwareImage(object):
     def app_descriptor(self, value):
         self._descriptor = value
 
-
 if __name__ == "__main__":
     parser = optparse.OptionParser(usage="usage: %prog [options] [IN OUT]")
     parser.add_option("--vcs-commit", dest="vcs_commit", default=None,
@@ -305,15 +339,31 @@ bootloader image to the output image.
 """.format(in_image, in_image.app_descriptor, out_image.app_descriptor,
            bootloader_size, len(bootloader_image)))
                 sys.stderr.write(
-"""------------------------------------------------------------------------------
+"""READ VALUES
+------------------------------------------------------------------------------
+Field               Type              Value
+signature           uint64            {1.signature!r}
+crc32_block1        uint32            0x{1.crc32_block1:08X}
+crc32_block2        uint32            0x{1.crc32_block2:08X}
+image_size          uint32            0x{1.image_size:X} ({1.image_size:d} B)
+vcs_commit          uint32            {1.vcs_commit:08X}
+version_major       uint8             {1.version_major:d}
+version_minor       uint8             {1.version_minor:d}
+board_id            uint32            0x{1.board_id:X}
+reserved            uint8[8]          {1.reserved!r}
+
+WRITTEN VALUES
+------------------------------------------------------------------------------
 Field               Type              Value
 signature           uint64            {2.signature!r}
-image_crc           uint64            0x{2.image_crc:016X}
+crc32_block1        uint32            0x{2.crc32_block1:08X}
+crc32_block2        uint32            0x{2.crc32_block2:08X}
 image_size          uint32            0x{2.image_size:X} ({2.image_size:d} B)
 vcs_commit          uint32            {2.vcs_commit:08X}
 version_major       uint8             {2.version_major:d}
 version_minor       uint8             {2.version_minor:d}
-reserved            uint8[6]          {2.reserved!r}
+board_id            uint32            0x{2.board_id:X}
+reserved            uint8[8]          {2.reserved!r}
 """.format(in_image, in_image.app_descriptor, out_image.app_descriptor,
            bootloader_size, len(bootloader_image)))
                 if out_image.padding:

src/drivers/uavcannode/UavcanNode.cpp

@@ -73,13 +73,14 @@ namespace uavcannode
  * image crc, size etc of this application
 */
 boot_app_shared_section app_descriptor_t AppDescriptor = {
-	.signature = {APP_DESCRIPTOR_SIGNATURE},
+	.signature = APP_DESCRIPTOR_SIGNATURE,
 	.image_crc = 0,
 	.image_size = 0,
-	.vcs_commit = 0,
+	.git_hash  = 0,
 	.major_version = APP_VERSION_MAJOR,
 	.minor_version = APP_VERSION_MINOR,
-	.reserved = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff }
+	.board_id = HW_VERSION_MAJOR << 8 | HW_VERSION_MINOR,
+	.reserved = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }
 };
 
 UavcanNode *UavcanNode::_instance;

src/lib/systemlib/crc.c

@@ -132,6 +132,44 @@ uint16_t crc16_signature(uint16_t initial, size_t length, const uint8_t *bytes)
 	return initial ^ CRC16_OUTPUT_XOR;
 }
 
+/****************************************************************************
+ * Name: crc32_signature
+ *
+ * Description:
+ *   Calculates a CRC-32 function
+ *
+ * Input Parameters:
+ *    acc     - The accumulator value to uses as the crc's starting point
+ *    length  - The number of bytes to add to the crc
+ *    bytes   - A pointer to any array of length bytes
+ *
+ * Returned Value:
+ *   The crc32 of the array of bytes
+ *
+ ****************************************************************************/
+
+uint32_t crc32_signature(uint32_t acc, size_t length, const uint8_t *bytes)
+{
+	size_t i;
+	const uint32_t poly = 0xedb88320u;
+	const uint8_t  bits = 8u;
+	uint8_t        w = bits;
+
+	for (i = 0u; i < length; i++) {
+		acc ^= bytes[i];
+		w = bits;
+
+		while (w--) {
+			const uint32_t xor = -(acc & 1);
+			acc >>= 1;
+			acc ^= (poly & xor);
+		}
+	}
+
+	return acc;
+}
+
+
 /****************************************************************************
  * Name: crc64_add_word
  *

src/lib/systemlib/crc.h

@@ -96,6 +96,27 @@ uint16_t crc16_add(uint16_t crc, uint8_t value);
 uint16_t crc16_signature(uint16_t initial, size_t length,
 			 const uint8_t *bytes);
 
+/****************************************************************************
+ * Name: crc32_signature
+ *
+ * Description:
+ *   Calculates a CRC-32
+ *   function
+ *
+ * Input Parameters:
+ *    acc     - The Initial value to uses as the crc's starting point
+ *    length  - The number of bytes to add to the crc
+ *    bytes   - A pointer to any array of length bytes
+ *
+ * Returned Value:
+ *   The crc16 of the array of bytes
+ *
+ ****************************************************************************/
+
+uint32_t crc32_signature(uint32_t acc, size_t length,
+			 const uint8_t *bytes);
+
+
 /****************************************************************************
  * Name: crc64_add_word
  *