Topic: sarami convo 1

Enker wrote:

Somehow you got the old hashes that are missing the L1 video. I thought FreeCell supported XGD2 discs, but maybe it got broken in a newer version. hmm

If L1 video area isn't zero, I think it's a bug of ss_sector_range, not FreeCell.
http://forum.redump.org/topic/18199/xbo … s-problem/

@user7
I uploaded the latest DIC (20180614). I supported XBOX/XBOX 360 (except XGD3) in this version. If you are interested in newest version, plz test and report.

Re: sarami convo 1

sarami wrote:

If L1 video area isn't zero, I think it's a bug of ss_sector_range

Why would that be a bug? The second range is not protected, you can read it all the way through. Its not impossible that there could be some non-zero data inside, but its very unlikelly.

PX-760A (+30), PX-W4824TA (+98), GSA-H42L (+667), GDR-8164B (+102), SH-D162D (+6), SOHD-167T (+12)

Re: sarami convo 1

iR0b0t wrote:

The second range is not protected, you can read it all the way through.

Yes. I confirmed it by DIC.

Isn't ss_sector_range listed unreadable sectors (16 ranges of XBOX and 1st range of XBOX 360) ?
What purpose the second range is listed?

Re: sarami convo 1

sarami wrote:

Isn't ss_sector_range listed unreadable sectors (16 ranges of XBOX and 1st range of XBOX 360) ?

No. Xbox1 discs can also have unprotected ranges.

sarami wrote:

What purpose the second range is listed?

To have them all documented. But its very unlikelly that readable ranges will contain usable data in them.

PX-760A (+30), PX-W4824TA (+98), GSA-H42L (+667), GDR-8164B (+102), SH-D162D (+6), SOHD-167T (+12)

Re: sarami convo 1

No. Xbox1 discs can also have unprotected ranges.

I see. I checked the security sectors of Xbox1 again and found it true.

And I might find the problem of freecell. As far as seeing the source code, freecell skips reading all the ss ranges of xbox partition area and pads by zero.
But as you say, ss_sector_range outputs unprotected sectors range and these sectors are actually readable.
In a word, freecell skips their readable sectors which non zero data may exist.

its very unlikelly that readable ranges will contain usable data in them.

I confirmed some sectors in each sector range were readable and non zero byte. But I don't know if these non zero bytes are usable data or not.

I think dump tools should skip only unreadable sectors like the ring protect of CD.
Of course, If you say all sectors in sector range should be preserved by zero, I don't say anymore.

Anyway, http://forum.redump.org/topic/17899/xbo … neak-king/ of ajshell1,
it is necessary to check them in detail which bytes are different.

About Xbox 360, it needs to investigate why freecell creates a bad dump.

Re: sarami convo 1

sarami wrote:

Of course, If you say all sectors in sector range should be preserved by zero, I don't say anymore.

Back then when we first started preserving xbox stuff we talked about this topic and agreed to skip ALL possible ss ranges, because we find that most likelly xbox skippes those ranges anyways. This is similar to SafeDisc and other PC protections where we skip bad sectors even if there may be some data readable.

PX-760A (+30), PX-W4824TA (+98), GSA-H42L (+667), GDR-8164B (+102), SH-D162D (+6), SOHD-167T (+12)

Re: sarami convo 1

I see.

Final question:
According to http://xboxdevwiki.net/Xbox_Game_Disc#S … 8SS.bin.29 ,
Security sector ranges actually exist 23 (xbox) or 21 (xbox360), but ss_sector_range.exe outputs 16 (xbox) or 2 (xbox 360).
Do you know what other ranges (7 of xbox or 19 of xbox 360) mean?

This is similar to SafeDisc and other PC protections where we skip bad sectors even if there may be some data readable.

ok, DIC adopts your thoughts about RingPROTECH, ProRing, LaserLock.

Re: sarami convo 1

sarami wrote:

Do you know what other ranges (7 of xbox or 19 of xbox 360) mean?

As far as i remember those are negative values. We tried to analyse them, but did not come to any conclusion.

PX-760A (+30), PX-W4824TA (+98), GSA-H42L (+667), GDR-8164B (+102), SH-D162D (+6), SOHD-167T (+12)

Re: sarami convo 1

iR0b0t wrote:
sarami wrote:

Of course, If you say all sectors in sector range should be preserved by zero, I don't say anymore.

Back then when we first started preserving xbox stuff we talked about this topic and agreed to skip ALL possible ss ranges, because we find that most likelly xbox skippes those ranges anyways. This is similar to SafeDisc and other PC protections where we skip bad sectors even if there may be some data readable.

Aren't we skipping the SafeDisc and similar sectors due to their instability (unconstant reads between different drives)? While SS sectors are quite stable and there are only about 305-320 unreadable sectors starting after 1270-1285 readable sectors in each 4096-byte SS area (with all 4096 bytes readable in certain cases)? And aren't we replacing the unreadable sectors with 0x55 not 0x00?

Re: sarami convo 1

CD sectors are replaced by 0x55 because most common tools do that by default, there was no reason for us to switch to any other pattern. Other than that, using 0x00 for CD would probably be unreasonable in therms of detection of replaced sectors if needed.

DVDs barely have those protection mechanisms and i am not sure if any tool other that isobuster gives you an option to replace unreadable sectors by a byte pattern of your choice. 0x00 sounds okay for DVD sector replacement, at least i feel so. And so do common xbox dumping tools as well.

If i remember correctly SS areas of Xbox discs aren't stable, each ss range has different amount of readable sectors in the beginning and in the end, and if i recall it right the amount of readable sectors differs also between drives.

PX-760A (+30), PX-W4824TA (+98), GSA-H42L (+667), GDR-8164B (+102), SH-D162D (+6), SOHD-167T (+12)

Re: sarami convo 1

iR0b0t wrote:

0x00 sounds okay for DVD sector replacement, at least i feel so.

That makes bad sectors undistinguishable from empty sectors.

iR0b0t wrote:

If i remember correctly SS areas of Xbox discs aren't stable, each ss range has different amount of readable sectors in the beginning and in the end, and if i recall it right the amount of readable sectors differs also between drives.

The contents is stable, the amount of readable sectors may differ a little between the drives, but that's due to the nature of these sectors, anyway, it seems nobody has even tried to preserve them.

Re: sarami convo 1

F1ReB4LL wrote:
iR0b0t wrote:

0x00 sounds okay for DVD sector replacement, at least i feel so.

That makes bad sectors undistinguishable from empty sectors.

I agree with that, i don't see it being critical though. Besides xbox systems i have only ever seen one PC-DVD disc with this "issue", and for xbox systems we have all the range replacement logs.

F1ReB4LL wrote:
iR0b0t wrote:

If i remember correctly SS areas of Xbox discs aren't stable, each ss range has different amount of readable sectors in the beginning and in the end, and if i recall it right the amount of readable sectors differs also between drives.

The contents is stable, the amount of readable sectors may differ a little between the drives, but that's due to the nature of these sectors, anyway, it seems nobody has even tried to preserve them.

We were looking into that ages ago and didn't see any good reason to preserve those few readable sectors.

PX-760A (+30), PX-W4824TA (+98), GSA-H42L (+667), GDR-8164B (+102), SH-D162D (+6), SOHD-167T (+12)