View topic - WD ROM from SA

Main » Forums home » Conventional hard drives

All times are UTC - 5 hours [ DST ]

WD ROM from SA - checksum

Page 1 of 1

[ 14 posts ]

Previous topic | Next topic

Author

Message

andy17d

Post subject: WD ROM from SA - checksum

Posted: July 1st, 2015, 6:11

Joined: May 14th, 2015, 18:29
Posts: 75
Location: Poland

I'm trying to rebuild rom from sa modules.

I found this tutorial: http://www.hddoracle.com/viewtopic.php?f=59&t=225

Unfortunately, I do not know how to count checksum for each modules.

Checksum is located at 0x0C - 0x0F in each modules.
So how to calulate that value? Should I write 00 00 00 00 and the calculate or calculate on original sa module?

Top

pepe

Post subject: Re: WD ROM from SA - checksum

Posted: July 2nd, 2015, 9:23

Joined: October 3rd, 2005, 0:40
Posts: 4817
Location: Hungary

Just checked, it is a simle 32bit checksum.
U need to set it up so that the sum of all dwords in the module is 0.

_________________
Adatmentés - Data recovery

Top

andy17d

Post subject: Re: WD ROM from SA - checksum

Posted: July 2nd, 2015, 11:31

Joined: May 14th, 2015, 18:29
Posts: 75
Location: Poland

Not so simple for me

For example, I take mod 107

Code:

Offset(h) 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F 10 11

00000000  52 4F 59 4C 04 00 1E 00 07 01 01 00 03 C8 F8 C5 30 30  ROYL.........ÈøÅ00
00000012  30 32 30 30 30 30 00 00 00 00 00 00 06 12 01 0A 00 3E  020000
00000024  00 00 19 00 00 B2 FF 02 00 00 00 00 00 12 01 0B 00 D1
00000036  00 00 19 00 00 E1 FE 02 00 00 00 00 00 12 01 30 00 00
00000048  04 00 19 00 00 E1 FA 02 00 00 00 00 00 12 01 47 00 00
0000005A  04 00 19 00 00 20 F3 02 00 00 00 00 00 12 01 0D 00 84
0000006C  00 00 19 00 00 9C F2 02 00 00 00 00 00 12 01 4F 00 E0
0000007E  00 00 19 00 00 20 F7 02 00 00 00 00 00 46 06 FF 0F 3F
00000090  00 26 8C 02 00 00 00 00 00 26 8C 02 00 E2 6F 03 00 26
000000A2  8C 02 00 C4 DF 06 00 26 8C 02 00 A6 4F 0A 00 26 8C 02
000000B4  00 88 BF 0D 00 26 8C 02 00 6A 2F 11 00 00 00 00 00 00

First, I have to change ID (0x06 and 0x07) : 07 01 --> 0B 00

Code:

Offset(h) 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F 10 11

00000000  52 4F 59 4C 04 00 1E 00 0B 00 01 00 03 C8 F8 C5 30 30  ROYL.........ÈøÅ00

What next?

Should I calculate 32bit checksum for mod 102 with changed ID?

Top

fzabkar

Post subject: Re: WD ROM from SA - checksum

Posted: July 2nd, 2015, 14:58

Joined: September 8th, 2009, 18:21
Posts: 17232
Location: Australia

The checksum is 32-bit little endian.

Make the required changes to the module, calculate the 32-bit sum, and then subtract this sum from the checksum dword.

_________________
A backup a day keeps DR away.

Top

andy17d

Post subject: Re: WD ROM from SA - checksum

Posted: July 3rd, 2015, 4:08

Joined: May 14th, 2015, 18:29
Posts: 75
Location: Poland

fzabkar wrote:

Make the required changes to the module, calculate the 32-bit sum, and then subtract this sum from the checksum dword.

So, I calculated checksum (by chksum2) for my changed module: 0xFFFFFF08
Present checksum in module is: 53 51 C2 64.
If I understood correctly, I now subtract new checksum from the current, that is 0x64C25153 - 0xFFFFFF08 = 0x64C2524B (dword)
New checksum is 4B 52 C2 64. I checked chechsum for whole module and is 0x00000000. Success

Thank you for help!

Top

andy17d

Post subject: Re: WD ROM from SA - checksum

Posted: July 3rd, 2015, 4:43

Joined: May 14th, 2015, 18:29
Posts: 75
Location: Poland

I converted module 103 into 047 and the sum of the these modules is different

047 from 103 module

Quote:

52 4F 59 4C 01 00 1E 00 47 00 02 00 FD 20 1D 78

org 047 module

Quote:

52 4F 59 4C 01 00 1E 00 47 00 02 00 03 26 26 7F

Is it correct?

Top

pepe

Post subject: Re: WD ROM from SA - checksum

Posted: July 3rd, 2015, 5:05

Joined: October 3rd, 2005, 0:40
Posts: 4817
Location: Hungary

do the module contents look identical?

_________________
Adatmentés - Data recovery

Top

andy17d

Post subject: Re: WD ROM from SA - checksum

Posted: July 3rd, 2015, 5:13

Joined: May 14th, 2015, 18:29
Posts: 75
Location: Poland

pepe wrote:

do the module contents look identical?

Yes

047 from 103 module

Code:

52 4F 59 4C 01 00 1E 00 47 00 02 00 FD 20 1D 78 44 58 2E 30 30 33 32 20 07 07 07 00 30 00 80 01 A0 01 00 00 00 00 00 00 00 00 00 00 00 00 37 4B A0 45 20 80 71 12 0F 0E 0F 0F AE B0 8C 05 65 01 40 4F C0 02 04 0C 19 56 14 E0 EE FF FD 10 78 C0 16 2D 3E 20 00 00 00 20 00 00 80 45 20 80 71 10 0F 11 0E 11 AE B0 8C 05 65 01 40 6A C0 04 05 0E 19 56 16 DF EA FD FC 00 78 C0 16 2D 3E 20 00 00 00 20 00 00 C0 45 20 80 71 10 0F 0F 10 0F AE B0 8C 05 65 01 40 5B C0 02 05 0C 1E 56 11 DF ED FE FD 00 78 C0 16 2D 3E 3E 00 00 00 20 00 00 E0 45 24 80 71 10 0F 0E 0E 0E AE B0 8C 05 65 01 40 60 C0 02 04 0A 1E 56 13 DB EB FE FD 00 00 C0 16 2D 3E 20 00 00 00 20 00 00 E0 45 20 80 71 11 0F 0F 10 10 AE B0 8C 05 65 01 40 5F C0 01 03 09 19 56 19 DE EA FE FD 00 00 C0 16 2D 3E 3A 00 00 00 20 00 00 A0 45 20 80 71 12 0F 0F 0F 10 AE B0 8C 05 65 01 40 67 C0 03 04 0C 19 56 12 DC EA FE FC 00 00 C0 16 2D 3E 20 00 00 00 20 00 00 C0 45 20 80 71 00 0F 05 0F 05 AE B0 8C 05 65 01 40 80 C0 02 03 0B 14 56 FF DE F0 FF FB 00 00 C0 16 2D 3E 20 00 00 00 20 00 00 C0 45 20 80 71 00 0F 05 0F 05 AE B0 8C 05 65 01 40 80 C0 02 03 0B 14 56 FF DE F0 FF FB 00 00 C0 16 2D 3E 20 00 00 00 20 00 00 0F 72 0A 04 0C 60 08 04 0C 63 0A 05 0F 62 0A 06 0C 72 08 06 13 72 0B 03 00 A0 0A 05 00 A0 0A 05 20 0A 6D 0A 1D 0A 74 0A 25 0A 8E 0A 0A 0A 0A 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 81 01 11 00 12 00 11 00 12 00 11 00 12 00 00 00 00 00 01 00 1E 01 39 39 39 39 39 39 39 39 42 3D 42 00 3D 42 3F 3A 3F 00 3A 3F 42 3E 42 00 3E 42 40 3B 40 00 3B 40 43 40 43 00 40 43 44 40 44 00 40 44 3B 34 3B 00 34 3B 3B 34 3B 00 34 3B 00 00 00 00 00 00 12 FD FF FF 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 06 00 00 00 00 00 88 0B 88 0A 88 0A 88 0A 88 0A 88 0A 88 09 88 09 5B 01 03 00 5D 01 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 47 53 4C 54 4C 50 50 58 60 60 7E 7D 7E 7F 7E 78 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

org 047 module

Quote:

52 4F 59 4C 01 00 1E 00 47 00 02 00 03 26 26 7F 44 58 2E 30 30 33 32 20 07 07 07 00 30 00 80 01 A0 01 00 00 00 00 00 00 00 00 00 00 00 00 37 4B A0 45 20 80 71 12 0F 0E 0F 0F AE B0 8C 05 65 01 40 4F C0 02 04 0C 19 56 14 E0 EE FF FD 10 78 C0 16 2D 3E 20 00 00 00 20 00 00 80 45 20 80 71 10 0F 11 0E 11 AE B0 8C 05 65 01 40 6A C0 04 05 0E 19 56 16 DF EA FD FC 00 78 C0 16 2D 3E 20 00 00 00 20 00 00 C0 45 20 80 71 10 0F 0F 10 0F AE B0 8C 05 65 01 40 5B C0 02 05 0C 1E 56 11 DF ED FE FD 00 78 C0 16 2D 3E 3E 00 00 00 20 00 00 E0 45 24 80 71 10 0F 0E 0E 0E AE B0 8C 05 65 01 40 60 C0 02 04 0A 1E 56 13 DB EB FE FD 00 00 C0 16 2D 3E 20 00 00 00 20 00 00 E0 45 20 80 71 11 0F 0F 10 10 AE B0 8C 05 65 01 40 5F C0 01 03 09 19 56 19 DE EA FE FD 00 00 C0 16 2D 3E 3A 00 00 00 20 00 00 A0 45 20 80 71 12 0F 0F 0F 10 AE B0 8C 05 65 01 40 67 C0 03 04 0C 19 56 12 DC EA FE FC 00 00 C0 16 2D 3E 20 00 00 00 20 00 00 C0 45 20 80 71 00 0F 05 0F 05 AE B0 8C 05 65 01 40 80 C0 02 03 0B 14 56 FF DE F0 FF FB 00 00 C0 16 2D 3E 20 00 00 00 20 00 00 C0 45 20 80 71 00 0F 05 0F 05 AE B0 8C 05 65 01 40 80 C0 02 03 0B 14 56 FF DE F0 FF FB 00 00 C0 16 2D 3E 20 00 00 00 20 00 00 0F 72 0A 04 0C 60 08 04 0C 63 0A 05 0F 62 0A 06 0C 72 08 06 13 72 0B 03 00 A0 0A 05 00 A0 0A 05 20 0A 6D 0A 1D 0A 74 0A 25 0A 8E 0A 0A 0A 0A 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 81 01 11 00 12 00 11 00 12 00 11 00 12 00 00 00 00 00 01 00 1E 01 39 39 39 39 39 39 39 39 42 3B 42 00 3B 42 3E 39 3E 00 39 3E 42 3C 42 00 3C 42 40 3A 40 00 3A 40 42 3E 42 00 3E 42 43 3F 43 00 3F 43 3B 34 3B 00 34 3B 3B 34 3B 00 34 3B 00 00 00 00 00 00 12 FD FF FF 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 06 00 00 00 00 00 88 0B 88 0A 88 0A 88 0A 88 0A 88 0A 88 09 88 09 5B 01 03 00 5D 01 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 47 53 4C 54 4C 50 50 58 60 60 7E 7D 7E 7F 7E 78 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

Top

andy17d

Post subject: Re: WD ROM from SA - checksum

Posted: July 3rd, 2015, 8:37

Joined: May 14th, 2015, 18:29
Posts: 75
Location: Poland

pepe wrote:

do the module contents look identical?

Yes, IMHO modules look indentical.
I attached oryginal 047 module, 103 module and my work, that is 047 rebuild from 103.

Attachments:

a.zip [1.42 KiB]
Downloaded 859 times

Top

pepe

Post subject: Re: WD ROM from SA - checksum

Posted: July 3rd, 2015, 8:57

Joined: October 3rd, 2005, 0:40
Posts: 4817
Location: Hungary

BTW, why do u want to rebuild original 47 if u have it?

_________________
Adatmentés - Data recovery

Top

pepe

Post subject: Re: WD ROM from SA - checksum

Posted: July 3rd, 2015, 9:19

Joined: October 3rd, 2005, 0:40
Posts: 4817
Location: Hungary

47 and 103 is not identical, there are differences from offset 1E3, so the resulting module's checksum has to differ from your orig 47

_________________
Adatmentés - Data recovery

Top

andy17d

Post subject: Re: WD ROM from SA - checksum

Posted: July 3rd, 2015, 9:25

Joined: May 14th, 2015, 18:29
Posts: 75
Location: Poland

pepe wrote:

BTW, why do u want to rebuild original 47 if u have it?

I learn on the basis of pre-made example.

Top

andy17d

Post subject: Re: WD ROM from SA - checksum

Posted: July 16th, 2015, 7:41

Joined: May 14th, 2015, 18:29
Posts: 75
Location: Poland

I have one more question.

There is writen that "MOD 104 matches the MOD 0D template in MOD 109. However, the actual content of MOD 0D in ROM is significantly different. "
in the tutorial: http://www.hddoracle.com/viewtopic.php?f=59&t=761

Is spite of these differences rebuilt ROM will be good?

Top

fzabkar

Post subject: Re: WD ROM from SA - checksum

Posted: July 16th, 2015, 19:36

Joined: September 8th, 2009, 18:21
Posts: 17232
Location: Australia

Module 0D contains informational stuff like the firmware version, world wide name (WWN) and sometimes the model number and serial number. I believe that you can change any of these parameters without affecting the access to your data.

_________________
A backup a day keeps DR away.

Top

Page 1 of 1

[ 14 posts ]

Main » Forums home » Conventional hard drives

All times are UTC - 5 hours [ DST ]

Who is online

Users browsing this forum: Google [Bot], Majestic-12 [Bot] and 175 guests

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum