[DellEMC]: EEPROM decoder for S6000, S6000-ON (#4718)

**- Why I did it**

For decoding system EEPROM of S6000 based on Dell offset format and S6000-ON’s system EEPROM in ONIE TLV format.

**- How I did it**

- Differentiate between S6000 and S6000-ON using the product name available in ‘dmi’  ( “/sys/class/dmi/id/product_name” )
- For decoding S6000 system EEPROM in Dell offset format and updating the redis DB with the EEPROM contents, added a new class ‘EepromS6000’ in eeprom.py, 
- Renamed certain methods in both Eeprom, EepromS6000 classes to accommodate the plugin-specific methods.

**- How to verify it**

- Use 'decode-syseeprom' command to list the system EEPROM details.
- Wrote a python script to load chassis class and call the appropriate methods.

UT Logs: [S6000_eeprom_logs.txt](https://github.com/Azure/sonic-buildimage/files/4735515/S6000_eeprom_logs.txt), [S6000-ON_eeprom_logs.txt](https://github.com/Azure/sonic-buildimage/files/4735461/S6000-ON_eeprom_logs.txt)
Test script: [eeprom_test_py.txt](https://github.com/Azure/sonic-buildimage/files/4735509/eeprom_test_py.txt)

device/dell/x86_64-dell_s6000_s1220-r0/plugins/eeprom.py

@@ -10,13 +10,21 @@
 #############################################################################
 
 try:
-    from sonic_eeprom import eeprom_tlvinfo
-except ImportError, e:
-    raise ImportError (str(e) + "- required module not found")
+    from sonic_eeprom.eeprom_tlvinfo import TlvInfoDecoder
+    from sonic_platform.eeprom import EepromS6000
+except ImportError as e:
+    raise ImportError(str(e) + "- required module not found")
 
 
-class board(eeprom_tlvinfo.TlvInfoDecoder):
+class board(object):
 
-    def __init__(self, name, path, cpld_root, ro):
-        self.eeprom_path = "/sys/class/i2c-adapter/i2c-10/10-0053/eeprom"
-        super(board, self).__init__(self.eeprom_path, 0, '', True)
+    def __new__(cls, name, path, cpld_root, ro):
+        eeprom_path = "/sys/class/i2c-adapter/i2c-10/10-0053/eeprom"
+
+        with open("/sys/class/dmi/id/product_name", "r") as fd:
+            board_type = fd.read()
+
+        if 'S6000-ON' in board_type:
+            return TlvInfoDecoder(eeprom_path, 0, '', True)
+        else:
+            return EepromS6000(is_plugin=True)

platform/broadcom/sonic-platform-modules-dell/s6000/sonic_platform/chassis.py

@@ -15,7 +15,7 @@ try:
     import subprocess
     from sonic_platform_base.chassis_base import ChassisBase
     from sonic_platform.sfp import Sfp
-    from sonic_platform.eeprom import Eeprom
+    from sonic_platform.eeprom import Eeprom, EepromS6000
     from sonic_platform.fan import Fan
     from sonic_platform.psu import Psu
     from sonic_platform.thermal import Thermal
@@ -68,7 +68,14 @@ class Chassis(ChassisBase):
         # Get Transceiver status
         self.modprs_register = self._get_transceiver_status()
 
-        self._eeprom = Eeprom()
+        with open("/sys/class/dmi/id/product_name", "r") as fd:
+            board_type = fd.read()
+
+        if 'S6000-ON' in board_type:
+            self._eeprom = Eeprom()
+        else:
+            self._eeprom = EepromS6000()
+
         for i in range(MAX_S6000_FAN):
             fan = Fan(i)
             self._fan_list.append(fan)
@@ -138,7 +145,7 @@ class Chassis(ChassisBase):
         Returns:
             string: The name of the chassis
         """
-        return self._eeprom.modelstr()
+        return self._eeprom.get_model()
 
     def get_presence(self):
         """
@@ -154,7 +161,7 @@ class Chassis(ChassisBase):
         Returns:
             string: Model/part number of chassis
         """
-        return self._eeprom.part_number_str()
+        return self._eeprom.get_part_number()
 
     def get_serial(self):
         """
@@ -162,7 +169,7 @@ class Chassis(ChassisBase):
         Returns:
             string: Serial number of chassis
         """
-        return self._eeprom.serial_str()
+        return self._eeprom.get_serial()
 
     def get_status(self):
         """
@@ -181,7 +188,7 @@ class Chassis(ChassisBase):
             A string containing the MAC address in the format
             'XX:XX:XX:XX:XX:XX'
         """
-        return self._eeprom.base_mac_addr()
+        return self._eeprom.get_base_mac()
 
     def get_serial_number(self):
         """
@@ -191,7 +198,7 @@ class Chassis(ChassisBase):
             A string containing the hardware serial number for this
             chassis.
         """
-        return self._eeprom.serial_number_str()
+        return self._eeprom.get_serial_number()
 
     def get_system_eeprom_info(self):
         """

platform/broadcom/sonic-platform-modules-dell/s6000/sonic_platform/eeprom.py

@@ -17,12 +17,17 @@
 
 
 try:
+    import binascii
     import os
+    import redis
+    import struct
+    from collections import OrderedDict
     from sonic_platform_base.sonic_eeprom.eeprom_base import EepromDecoder
     from sonic_platform_base.sonic_eeprom.eeprom_tlvinfo import TlvInfoDecoder
 except ImportError as e:
     raise ImportError(str(e) + "- required module not found")
 
+STATE_DB_INDEX = 6
 
 # PSU eeprom fields in format required by EepromDecoder
 psu_eeprom_format = [
@@ -200,13 +205,13 @@ class Eeprom(TlvInfoDecoder):
 
         return (False, None)
 
-    def serial_number_str(self):
+    def get_serial_number(self):
         """
         Returns the serial number.
         """
         return self.serial_number
 
-    def part_number_str(self):
+    def get_part_number(self):
         """
         Returns the part number.
         """
@@ -222,19 +227,19 @@ class Eeprom(TlvInfoDecoder):
             return int(self.fan_type.encode('hex'), 16)
 
     # System EEPROM specific methods
-    def base_mac_addr(self):
+    def get_base_mac(self):
         """
         Returns the base MAC address found in the system EEPROM.
         """
         return self.base_mac
 
-    def modelstr(self):
+    def get_model(self):
         """
         Returns the Model name.
         """
         return self.model_str
 
-    def serial_str(self):
+    def get_serial(self):
         """
         Returns the servicetag number.
         """
@@ -247,3 +252,252 @@ class Eeprom(TlvInfoDecoder):
         found in the system EEPROM.
         """
         return self.eeprom_tlv_dict
+
+
+class EepromS6000(EepromDecoder):
+
+    _EEPROM_MAX_LEN = 128
+
+    _BLK_HDR_LEN   = 6
+    _BLK_HDR_MAGIC = '\x3a\x29'
+    _BLK_HDR_REVID = 1
+
+    _BLK_CODE_MFG = 0x20
+    _BLK_CODE_SW  = 0x1F
+    _BLK_CODE_MAC = 0x21
+
+    _BLK_MFG_FORMAT = [
+        ("PPID", 20), ("DPN Rev", 3), ("Service Tag", 7), ("Part Number", 10),
+        ("Part Number Rev", 3), ("Mfg Test Results", 2)
+    ]
+
+    _BLK_SW_FORMAT = [("Card ID", 4), ("Module ID", 2)]
+    _BLK_MAC_FORMAT = [("Base MAC address", 6)]
+
+    _BLK_INFO = OrderedDict([
+        (_BLK_CODE_MFG, {"name": "MFG BLOCK", "size": 64,
+                         "offset": 0x0, "format": _BLK_MFG_FORMAT}),
+        (_BLK_CODE_SW, {"name": "SW BLOCK", "size": 48,
+                        "offset": 0x40, "format": _BLK_SW_FORMAT}),
+        (_BLK_CODE_MAC, {"name": "MAC BLOCK", "size": 16,
+                         "offset": 0x70, "format": _BLK_MAC_FORMAT})
+    ])
+
+    def __init__(self, is_plugin=False):
+        self.eeprom_path = "/sys/bus/i2c/devices/i2c-10/10-0053/eeprom"
+        super(EepromS6000, self).__init__(self.eeprom_path, None, 0, '', True)
+
+        if not is_plugin:
+            self.eeprom_data = self.read_eeprom()
+
+    def _is_valid_block_checksum(self, e):
+        crc = self.compute_dell_crc(e[:-2])
+        return crc == struct.unpack('<H', e[-2:])[0]
+
+    def _is_valid_block(self, e, blk_code):
+        return (e[:2] == self._BLK_HDR_MAGIC
+                and struct.unpack('<H', e[2:4])[0] == self._BLK_INFO[blk_code]["size"]
+                and ord(e[4]) == blk_code
+                and ord(e[5]) == self._BLK_HDR_REVID)
+
+    def _get_eeprom_field(self, e, blk_code, field_name):
+        """
+        For a field name specified in the EEPROM format, returns the
+        presence of the field and the value for the same.
+        """
+        blk_start = self._BLK_INFO[blk_code]["offset"]
+        blk_end = blk_start + self._BLK_INFO[blk_code]["size"]
+        if not self._is_valid_block(e[blk_start:blk_end], blk_code):
+            return (False, None)
+
+        field_start = blk_start + self._BLK_HDR_LEN
+        for field in self._BLK_INFO[blk_code]["format"]:
+            field_end = field_start + field[1]
+            if field[0] == field_name:
+                return (True, e[field_start:field_end])
+            field_start = field_end
+
+        return (False, None)
+
+    def decode_eeprom(self, e):
+        """
+        Decode and print out the contents of the EEPROM.
+        """
+        print "     Field Name      Len        Value"
+        print "-------------------- --- --------------------"
+        for blk_code in self._BLK_INFO.keys():
+            blk_start = self._BLK_INFO[blk_code]["offset"]
+            blk_end = blk_start + self._BLK_INFO[blk_code]["size"]
+            if not self._is_valid_block(e[blk_start:blk_end], blk_code):
+                print "Invalid Block starting at EEPROM offset %d" % (blk_start)
+                return
+
+            offset = blk_start + self._BLK_HDR_LEN
+            for f in self._BLK_INFO[blk_code]["format"]:
+                if f[0] == "Num MACs" or f[0] == "Module ID":
+                    data = str(struct.unpack('<H', e[offset:offset+f[1]])[0])
+                elif f[0] == "Card ID":
+                    data = hex(struct.unpack('<I', e[offset:offset+f[1]])[0])
+                elif f[0] == "Base MAC address":
+                    data = ":".join([binascii.b2a_hex(T) for T in e[offset:offset+f[1]]]).upper()
+                else:
+                    data = e[offset:offset+f[1]]
+                print "{:<20s} {:>3d} {:<s}".format(f[0], f[1], data)
+                offset += f[1]
+
+            if not self._is_valid_block_checksum(e[blk_start:blk_end]):
+                print "(*** block checksum invalid)"
+
+    def read_eeprom(self):
+        """
+        Read the EEPROM contents.
+        """
+        return self.read_eeprom_bytes(self._EEPROM_MAX_LEN)
+
+    def read_eeprom_db(self):
+        """
+        Print out the contents of the EEPROM from database.
+        """
+        client = redis.Redis(db=STATE_DB_INDEX)
+        db_state = client.hget('EEPROM_INFO|State', 'Initialized')
+        if db_state != '1':
+            return -1
+
+        print "     Field Name      Len        Value"
+        print "-------------------- --- --------------------"
+        for blk_code in self._BLK_INFO.keys():
+            blk_name = self._BLK_INFO[blk_code]["name"]
+            blk_start = self._BLK_INFO[blk_code]["offset"]
+            is_valid = client.hget('EEPROM_INFO|{}'.format(blk_name), 'Valid')
+            if is_valid == '0':
+                print "Invalid Block starting at EEPROM offset %d" % (blk_start)
+                break
+
+            for f in self._BLK_INFO[blk_code]["format"]:
+                data = client.hget('EEPROM_INFO|{}'.format(f[0]), 'Value')
+                print "{:<20s} {:>3d} {:<s}".format(f[0], f[1], data)
+
+            is_checksum_valid = client.hget('EEPROM_INFO|{}'.format(blk_name), 'Checksum_Valid')
+            if is_checksum_valid == '0':
+                print "(*** block checksum invalid)"
+
+        return 0
+
+    def update_eeprom_db(self, e):
+        """
+        Decode the contents of the EEPROM and update the contents to database
+        """
+        client = redis.Redis(db=STATE_DB_INDEX)
+        for blk_code in self._BLK_INFO.keys():
+            blk_name = self._BLK_INFO[blk_code]["name"]
+            blk_start = self._BLK_INFO[blk_code]["offset"]
+            blk_end = blk_start + self._BLK_INFO[blk_code]["size"]
+            if not self._is_valid_block(e[blk_start:blk_end], blk_code):
+                client.hset('EEPROM_INFO|{}'.format(blk_name), 'Valid', '0')
+                print "Invalid Block starting at EEPROM offset %d" % (blk_start)
+                break
+            else:
+                client.hset('EEPROM_INFO|{}'.format(blk_name), 'Valid', '1')
+
+            offset = blk_start + self._BLK_HDR_LEN
+            for f in self._BLK_INFO[blk_code]["format"]:
+                if f[0] == "Num MACs" or f[0] == "Module ID":
+                    data = str(struct.unpack('<H', e[offset:offset+f[1]])[0])
+                elif f[0] == "Card ID":
+                    data = hex(struct.unpack('<I', e[offset:offset+f[1]])[0])
+                elif f[0] == "Base MAC address":
+                    data = ":".join([binascii.b2a_hex(T) for T in e[offset:offset+f[1]]]).upper()
+                else:
+                    data = e[offset:offset+f[1]]
+                client.hset('EEPROM_INFO|{}'.format(f[0]), 'Value', data)
+                offset += f[1]
+
+            if not self._is_valid_block_checksum(e[blk_start:blk_end]):
+                client.hset('EEPROM_INFO|{}'.format(blk_name), 'Checksum_Valid', '0')
+            else:
+                client.hset('EEPROM_INFO|{}'.format(blk_name), 'Checksum_Valid', '1')
+
+        client.hset('EEPROM_INFO|State', 'Initialized', '1')
+        return 0
+
+    def get_base_mac(self):
+        """
+        Returns the base MAC address found in the system EEPROM.
+        """
+        (valid, data) = self._get_eeprom_field(self.eeprom_data,
+                                               self._BLK_CODE_MAC, "Base MAC address")
+        if valid:
+            return ":".join([binascii.b2a_hex(T) for T in data]).upper()
+        else:
+            return 'NA'
+
+    def get_model(self):
+        """
+        Returns the Model name.
+        """
+        return 'S6000'
+
+    def get_part_number(self):
+        """
+        Returns the part number.
+        """
+        (valid, data) = self._get_eeprom_field(self.eeprom_data,
+                                               self._BLK_CODE_MFG, "Part Number")
+        if valid:
+            return data
+        else:
+            return 'NA'
+
+    def get_serial(self):
+        """
+        Returns the Service tag.
+        """
+        (valid, data) = self._get_eeprom_field(self.eeprom_data,
+                                               self._BLK_CODE_MFG, "Service Tag")
+        if valid:
+            return data
+        else:
+            return 'NA'
+
+    def get_serial_number(self):
+        """
+        Returns the serial number.
+        """
+        (valid, data) = self._get_eeprom_field(self.eeprom_data,
+                                               self._BLK_CODE_MFG, "PPID")
+        if valid:
+            return data
+        else:
+            return 'NA'
+
+    # EEPROM Plugin specific methods
+    def is_checksum_valid(self, e):
+        # Checksum is already calculated before
+        return (True, 0)
+
+    def mgmtaddrstr(self, e):
+        """
+        Returns the base MAC address.
+        """
+        (valid, data) = self._get_eeprom_field(e, self._BLK_CODE_MAC, "Base MAC address")
+        if valid:
+            return ":".join([binascii.b2a_hex(T) for T in data]).upper()
+        else:
+            return 'NA'
+
+    def modelstr(self, e):
+        """
+        Returns the Model name.
+        """
+        return 'S6000'
+
+    def serial_number_str(self, e):
+        """
+        Returns the Service Tag.
+        """
+        (valid, data) = self._get_eeprom_field(e, self._BLK_CODE_MFG, "Service Tag")
+
+        if valid:
+            return data
+        else:
+            return 'NA'

platform/broadcom/sonic-platform-modules-dell/s6000/sonic_platform/fan.py

@@ -186,7 +186,7 @@ class Fan(FanBase):
             string: Part number of Fan
         """
         if not self.is_psu_fan:
-            return self.eeprom.part_number_str()
+            return self.eeprom.get_part_number()
         else:
             return 'NA'
 
@@ -199,7 +199,7 @@ class Fan(FanBase):
         """
         # Sample Serial number format "US-01234D-54321-25A-0123-A00"
         if not self.is_psu_fan:
-            return self.eeprom.serial_number_str()
+            return self.eeprom.get_serial_number()
         else:
             return 'NA'
 

platform/broadcom/sonic-platform-modules-dell/s6000/sonic_platform/psu.py

@@ -146,7 +146,7 @@ class Psu(PsuBase):
         Returns:
             string: Part number of PSU
         """
-        return self.eeprom.part_number_str()
+        return self.eeprom.get_part_number()
 
     def get_serial(self):
         """
@@ -156,7 +156,7 @@ class Psu(PsuBase):
             string: Serial number of PSU
         """
         # Sample Serial number format "US-01234D-54321-25A-0123-A00"
-        return self.eeprom.serial_number_str()
+        return self.eeprom.get_serial_number()
 
     def get_status(self):
         """