Hi All,
I would like to ask how to calcuate the checksum of Zyxel NDMS V2.0 firmware. I try to unpack and pack the firmware but something wrong by use the web interface to upgrade new-firmware.bin. I have download the firmware KEENETIC-V2.00[BFW.3]B11.bin from Zyxel.ru. I guess last 4 bytes are checksum bytes and a1 b3 ea ec is actual checksum value and I try to use cksum it said that checksum value is not correct.
Anyone knows how the checksum calculation logic for this kind (Zyxel NDMS V2.0) of firmware ?
Many thanks for your help.
[root@localhost image_parts]# hexdump -C /opt/zyxel/KEENETIC-V2.00[BFW.3]B11.bin |tail
005536e0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00560000 5a 4e 42 47 15 42 00 00 5a 79 58 45 4c 20 63 75 |ZNBG.B..ZyXEL cu|
00560010 73 74 6f 6d 00 00 00 00 00 00 00 00 00 00 00 00 |stom............|
00560020 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00560030 00 00 00 00 00 00 00 00 a1 b3 ea ec |............|
0056003c
