NetModule

JS Helper application for HW-584 v2

• The Tool itself open https://pexmor.github.io/NetModule/ - in-browser "local" tool
• https://github.com/nielsonm236/NetMod-ServerApp - The alternative firmware for the HW-584v2

Tools used

• SRecord - a CLI for manipulating the files
• stm8flash - a tool used to flash the STM8 MCUs (SWIM protocol) can use ST-Link v2
• hexdump to check the binary
• stlink - a suite of tools for STM32 make use of ST-Link v2 (Note: not used for HW-584v2)

Hints

To get canonical hexdump (hex + printable ascii) of a file eeprom.bin:

hexdump -C eeprom.bin

To show srecord file contents:

srec_info NetworkModule-MQTT-Home.srec

gives you this output:

Format: Motorola S-Record
Header: "NetworkModule.sm8"
srec_info: NetworkModule-MQTT-Home.srec: 1010:
    warning: data records not in strictly ascending order (expected >= 0xFDD2,
    got 0x4000)
Execution Start Address: FFFFFFFF
Data:   000A - 000F
        4000 - 406D
        8000 - FDD1

This original file as the warning and output says is not sorted and contains extra content.

In order to fix it it has to be tweaked as:

• remove the extra segements 000A - 000F and 4000 - 406D
• fix the record counter

This can be done manually by:

• removing the records starting with: S32500004000 up to S31300004060
• as well as line starting with S30B0000000A
• do not forget to remove control line with number of records S7

analysis (based on Motorola S-Rec wiki page):

Command cut -c-2 NetworkModule-MQTT-Home.sx | sort | uniq -c reveals that it has:

• 1 S0 (Header) record
• 1013 S3 (data 32-bit address) records
• 1 S7 (Start address 32-bit) record.

Where the S3 data records consists of numerous fields.

For example (the first code record):

S3250000800082009E0D820000008200000082000000820000008200000082000000820000009F

splits into:

• S3 type string
• 25 length in bytes
• 00008000 address field (not included in length)
• 82009E0D82000000820000008200000082000000820000008200000082000000 data field
• 9F - checksum field

let's try to parse it with Python see p01_parse.py

Example file from: https://github.com/nielsonm236/NetMod-ServerApp/releases/download/20240612.0226/NetworkModule-MQTT-Home.sx

srec_cat NetworkModule-MQTT-Home.sx | cut -c-2 | sort | uniq -c

yields (note added S5 data count record):

srec_cat: NetworkModule-MQTT-Home.sx: 1010: warning: data records not in
    strictly ascending order (expected >= 0xFDD2, got 0x4000)
      1 S0
   1012 S1
      1 S5
      1 S7

based on:

srec_info NetworkModule-MQTT-Home.sx

Format: Motorola S-Record
Header: "NetworkModule.sm8"
srec_info: NetworkModule-MQTT-Home.sx: 1010: warning: data records not in
    strictly ascending order (expected >= 0xFDD2, got 0x4000)
Execution Start Address: FFFFFFFF
Data:   000A - 000F
        4000 - 406D
        8000 - FDD1

we can cut the desired adress range 8000 - FDD1 the code (note: 0xfdd2 which is last address +1):

srec_cat NetworkModule-MQTT-Home.sx -crop 0x8000 0xfdd2 | srec_info

which can be simplified as:

srec_cat NetworkModule-MQTT-Home.sx -crop 0x8000 | sort | uniq -c

Without the data_count

srec_cat NetworkModule-MQTT-Home.sx -crop 0x8000 -disable=data-count -address‐length=4 | cut -c-2 | sort | uniq -c

which gives:

srec_cat: NetworkModule-MQTT-Home.sx: 1010: warning: data records not in
    strictly ascending order (expected >= 0xFDD2, got 0x4000)
      1 S0
   1007 S1
      1 S7

# we can omit also the start address but it is not needed
# srec_cat NetworkModule-MQTT-Home.sx -motorola -crop 0x8000 -address-length=4 -disable=exec-start-address -disable=data-count | tee ~/tmp/final.srec
srec_cat NetworkModule-MQTT-Home.sx -motorola -crop 0x8000 -address-length=4 -disable=data-count | tee ~/tmp/final.srec

Final result gives:

srec_info ~/tmp/final.srec

then the output turn into:

Format: Motorola S-Record
Header: "NetworkModule.sm8"
Execution Start Address: FFFFFFFF
Data: 8000 - FDD1

ready to be flashed, compare that to the original file, which also has the code block split into two parts the first one contains constants (a html, etc.) and the seconds is the actual code.

Advance srec_cat

Example taken from https://mcuoneclipse.com/2015/04/26/crc-checksum-generation-with-srecord-tools-for-gnu-and-eclipse/ to show how the srec_cat can be used.

# srec_cat command file to add the CRC and produce application file to be flashed
# Usage: srec_cat @filename

# first: create CRC checksum
FRDM-KL25Z_CRC.srec                # input file
-fill 0xFF 0x0410 0x20000          # fill code area with 0xff
-crop 0x0410 0x1FFFE               # just keep code area for CRC calculation below (CRC will be at 0x1FFFE..0x1FFFF)
-CRC16_Big_Endian 0x1FFFE -CCITT   # calculate big endian CCITT CRC16 at given address.
-crop 0x1FFFE 0x20000              # keep the CRC itself

# second: add application file
FRDM-KL25Z_CRC.srec                # input file
-fill 0xFF 0x0410 0x1FFFE          # fill code area with 0xff

# finally, produce the output file
-Output                            # produce output
FRDM-KL25Z_CRC_Added.srec