Nekochan Net

Official Chat Channel: #nekochan // irc.nekochan.net
It is currently Mon Sep 22, 2014 2:13 am

All times are UTC - 8 hours


Forum rules


Any posts concerning pirated software or offering to buy/sell/trade commercial software are subject to removal.



Post new topic Reply to topic  [ 44 posts ]  Go to page Previous  1, 2, 3
Author Message
Unread postPosted: Fri Jul 06, 2012 4:53 pm 
Offline
User avatar

Joined: Tue Jul 21, 2009 4:07 am
Posts: 523
Location: Shenzhen, P.R.C
SAQ wrote:
- all of the proprietary SGI chips with unreleased (and probably lost) documentation.


just curious, if so, how did linux and bsd porting to sgi done? does it mean they didn't utilize these chips and all relied on main CPU? that's why its slow compared to IRIX? if not, how did they reversed engineer a specific chip? sorry for noob but is it possible to read the contents of an ASIC and copy it?

_________________
:Octane: (Sakura) :O2: (Sasuke) :1600SW: (Naruto) ... lil Jesse! (O2 laptop)
“Imagination is more important than knowledge.“ – A. Einstein


Top
 Profile  
 
Unread postPosted: Mon Jul 09, 2012 12:45 am 
Offline
User avatar

Joined: Fri Oct 09, 2009 1:44 am
Posts: 276
Location: Orgerus (France)
geo wrote:
just curious, if so, how did linux and bsd porting to sgi done? does it mean they didn't utilize these chips and all relied on main CPU?

There is no choice but to use these chips. For example, in order to be able to use the SCSI controller, you need to be able to talk to the PCI Bridge it lies beneath. But in this particular example, the SGI XBow-PCI Bridge has specific features to do some sort of dynamic bandwidth shaping for the DMA operations, as well as the ability to use virtual adresses for DMA (in other words, scatter-gather for transfers spanning multiple pages), and these are not supported by BSD or Linux because the scarce information available about this chip does not cover these well enough.

geo wrote:
if not, how did they reversed engineer a specific chip?

The main source of information are the IRIX system header files. SGI also contributed some code to Linux to support the Altix systems, which acts as an unsorted source of tidbits and quirks about these chips (many hardware defects and their workarounds are mentioned in these contributions).

Another source of information is the patents SGI filed about some of its chips. They don't dive into the details, but give a good overview of what the chips are capable of.

Several comments in the Linux Octane-specific files hint that there was some disassembly involved, at least for the Impact support. I also believe that the GR2 ``texport'' IRIX routines were disassembled by NetBSD developrs, which led to the initial XZ support in NetBSD

geo wrote:
sorry for noob but is it possible to read the contents of an ASIC and copy it?

Not really. You may be able to copy an FPGA, assuming there is a debug probe connector left on the board (assuming you recognize the FPGA flavour and have the proper tools for it), but ASIC are out of reach of mere mortals.

_________________
:Indigo:R4000 :Indigo2:R4400 :Indigo2IMP:R4400 :Indigo2:R8000 :Indigo2IMP:R10000 :Indy:R4000PC :Indy:R4000SC :Indy:R4600 :Indy:R5000SC :O2:R5000 :O2:RM7000 :Octane:2xR10000 :Octane:R12000 :O200:2xR12000 :O200: - :O200:2x2xR10000 :Fuel:R16000 :A350:
among more than 150 machines : Apollo, Data General, Digital, HP, IBM, MIPS before SGI, Motorola, NeXT, SGI, Solbourne, Sun...


Top
 Profile  
 
Unread postPosted: Mon Jul 09, 2012 6:50 am 
Offline
User avatar

Joined: Tue Jul 21, 2009 4:07 am
Posts: 523
Location: Shenzhen, P.R.C
hi miod! really thanks for this reply, really answers most of my questions that can affect some of my future project with my SGIs :)

miod wrote:
There is no choice but to use these chips. For example, in order to be able to use the SCSI controller, you need to be able to talk to the PCI Bridge it lies beneath. But in this particular example, the SGI XBow-PCI Bridge has specific features to do some sort of dynamic bandwidth shaping for the DMA operations, as well as the ability to use virtual adresses for DMA (in other words, scatter-gather for transfers spanning multiple pages), and these are not supported by BSD or Linux because the scarce information available about this chip does not cover these well enough.

yeah, also thought so, looking at the block diagrams from Ian for both O2 and Octane, there's no possible way without utilizing these chips, sorry for still asking tho, just want to confirm :) hmm so that's why porters for BSD and Linux still saying that some chips are xx% in progress, and this is why these OS are slower than the IRIX.

miod wrote:
The main source of information are the IRIX system header files. SGI also contributed some code to Linux to support the Altix systems, which acts as an unsorted source of tidbits and quirks about these chips (many hardware defects and their workarounds are mentioned in these contributions).

Another source of information is the patents SGI filed about some of its chips. They don't dive into the details, but give a good overview of what the chips are capable of.

Several comments in the Linux Octane-specific files hint that there was some disassembly involved, at least for the Impact support. I also believe that the GR2 ``texport'' IRIX routines were disassembled by NetBSD developrs, which led to the initial XZ support in NetBSD

ah i see, geeez i can imagine the porters, really need patience on gathering these infos.. but its worth especially after able to successfully boot these OS hehe i really salute to them. i just hope that maybe some old IRIX engineers still have some documents left and can share it here :)

miod wrote:
Not really. You may be able to copy an FPGA, assuming there is a debug probe connector left on the board (assuming you recognize the FPGA flavour and have the proper tools for it), but ASIC are out of reach of mere mortals.

ah i see, geez all SGI chips use ASIC right? hahaha mere mortals, like this one :)

_________________
:Octane: (Sakura) :O2: (Sasuke) :1600SW: (Naruto) ... lil Jesse! (O2 laptop)
“Imagination is more important than knowledge.“ – A. Einstein


Top
 Profile  
 
Unread postPosted: Mon Jul 09, 2012 1:26 pm 
Offline
User avatar

Joined: Tue Aug 21, 2007 9:12 pm
Posts: 2830
Location: On an Intergalactic Spaceboat of Light and Wonder
some more interesting reverse engineering techniques with a focus on smartcards: http://www.cl.cam.ac.uk/~mgk25/sc99-tamper.pdf

_________________
The people of earth never were cut out for this sedentary lifestyle. Millions of years of evolution, fine tuning these beautiful nomadic legs, and in less than two hundred years we’ve folded them up and put them away under our laptops.


Top
 Profile  
 
Unread postPosted: Mon Jul 09, 2012 6:29 pm 
Offline

Joined: Mon Sep 12, 2011 1:28 pm
Posts: 615
Location: Boston
when you see photomicrographs of chips, like these, they have usually been made by removing the package around the chip. For typical plastic or epoxy potted chips strong acids are used: see this page. I don't know what they do for metal encapsulated chips.

With detailed enough photos of the chip its internal structure can usually be discerned, since they are composed of standard pieces called "macrocells". However, tracing all the connections between the cells is very time consuming, especially with multiple layers of metal interconnect. It is possible to polish away the layers one by one until reaching the silicon. The silicon itself has features that do not photograph easily, like ion implanted regions, vertical gate structures, etc.

_________________
:PI: :O2: :Indigo2IMP: :Indigo2IMP:


Top
 Profile  
 
Unread postPosted: Mon Jul 09, 2012 8:15 pm 
Offline
User avatar

Joined: Tue Aug 21, 2007 9:12 pm
Posts: 2830
Location: On an Intergalactic Spaceboat of Light and Wonder
hey hey! once a bearcat always a bearcat! http://micro.magnet.fsu.edu/creatures/p ... rcats.html

https://www.facebook.com/photo.php?fbid ... d46ee41be3

_________________
The people of earth never were cut out for this sedentary lifestyle. Millions of years of evolution, fine tuning these beautiful nomadic legs, and in less than two hundred years we’ve folded them up and put them away under our laptops.


Top
 Profile  
 
Unread postPosted: Tue Jul 10, 2012 3:05 am 
Offline

Joined: Tue Sep 20, 2005 4:10 pm
Posts: 922
Location: IRL
guardian452 wrote:
some more interesting reverse engineering techniques with a focus on smartcards: http://www.cl.cam.ac.uk/~mgk25/sc99-tamper.pdf


Yeah, but most of those guys now work for the card and security companies, improving cards to prevent that type of thing. So hacking official smartcards nowadays is really beyond the realm of a hobbyist.

Actually what happens nowadays is that the best hackers from back then who didn't go working for the major card companies are now hired by organised crime gangs. They thus have the resources to buy code & docs on the black market for the card and card vendor they are targeting (and they are well funded - the going rate was typically 150-300k a couple of years ago). To try and protect their investment, these commercial hackers now use secure smartcards themselves when implementing their own "products". Hobbyists do have a chance of hacking these, because they typically don't follow rigorous or formal engineering principles like a proper security company would.

Alas, the technology in ageing UNIX workstations hasn't quite the same appeal to commercial hackers, so any leak would really have to be voluntary.


Top
 Profile  
 
Unread postPosted: Wed Jul 11, 2012 12:39 am 
Offline

Joined: Tue Feb 24, 2004 4:10 pm
Posts: 9647
Is it March yet ? Just for fun called them back today. Miss Wang said, "Oh sorry we don't have that now, call back in a few days later maybe we will have."

Right. If these people had a hot dog stand they'd run out of hot dogs. In fact the KFC down the street from me runs out of chicken several times a week. And last time I was stupid enough to stop by Mickey D they were out of almost everything.

And they're kickin' your butts. What's that say for American Businessmen ? hrrr hrrr hrr, what a bunch of brainless dorks. :mrgreen:


Top
 Profile  
 
Unread postPosted: Wed Jul 11, 2012 7:50 am 
Offline

Joined: Wed Jul 19, 2006 7:37 am
Posts: 5751
Location: Renton, WA
hamei wrote:
the KFC down the street from me runs out of chicken several times a week. And last time I was stupid enough to stop by Mickey D they were out of almost everything.


There is a justification for this, depending on what's important to the business owner.

Running out of things represents a potential loss. You might have made more sales and might have brought in more money.

Having extra stuff left over is an actual loss. You've already spent the money, and it's being chucked into the garbage can right in front of your face.

_________________
Damn the torpedoes, full speed ahead!

There are those who say I'm a bit of a curmudgeon. To them I reply: "GET OFF MY LAWN!"

:Indigo: :Octane: :Indigo2: :Indigo2IMP: :Indy: :PI: :O3x0: :ChallengeL: :O2000R: (single-CM)


Top
 Profile  
 
Unread postPosted: Thu Jul 12, 2012 2:48 am 
Offline

Joined: Tue Feb 24, 2004 4:10 pm
Posts: 9647
SAQ wrote:
Having extra stuff left over is an actual loss. You've already spent the money, and it's being chucked into the garbage can right in front of your face.

Are you kidding ? here is China. You think they would throw something out just because it's two weeks old ?


Top
 Profile  
 
Unread postPosted: Fri Jul 13, 2012 7:33 am 
Offline
User avatar

Joined: Tue Jul 21, 2009 4:07 am
Posts: 523
Location: Shenzhen, P.R.C
hamei wrote:
Are you kidding ? here is China. You think they would throw something out just because it's two weeks old ?

hahahaha.. indeed :)

_________________
:Octane: (Sakura) :O2: (Sasuke) :1600SW: (Naruto) ... lil Jesse! (O2 laptop)
“Imagination is more important than knowledge.“ – A. Einstein


Top
 Profile  
 
Unread postPosted: Fri Jul 13, 2012 9:26 am 
Offline
User avatar

Joined: Sun Mar 18, 2007 2:25 pm
Posts: 1841
Location: Minneapolis, Minnesota USA
Isn't it a supply chain problem rather than a poor business planning problem? I mean, KFC and MacD franchisees have to buy through the corporate food chain, and according to everything I've heard the economic slowdown in China has hit the shipping and receiving centers the hardest, so, to paraphrase Carl Spackler, they've probably got a lot of stuff on order...

_________________
Project:
No one can save us, from Kim the, waitress...
Plan:
World domination! Or something...


Top
 Profile  
 
Unread postPosted: Fri Jul 13, 2012 9:58 am 
Offline
User avatar

Joined: Wed Feb 19, 2003 1:54 pm
Posts: 976
is it big or little endian?

_________________
:Onyx2:


Top
 Profile  
 
Unread postPosted: Fri Jul 13, 2012 1:23 pm 
Offline
User avatar

Joined: Tue Aug 21, 2007 9:12 pm
Posts: 2830
Location: On an Intergalactic Spaceboat of Light and Wonder
hamei wrote:
SAQ wrote:
Having extra stuff left over is an actual loss. You've already spent the money, and it's being chucked into the garbage can right in front of your face.

Are you kidding ? here is China. You think they would throw something out just because it's two weeks old ?

it's fast food, not real chicken. you can leave it for years without any effect.

_________________
The people of earth never were cut out for this sedentary lifestyle. Millions of years of evolution, fine tuning these beautiful nomadic legs, and in less than two hundred years we’ve folded them up and put them away under our laptops.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 44 posts ]  Go to page Previous  1, 2, 3

All times are UTC - 8 hours


Who is online

Users browsing this forum: No registered users and 1 guest


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

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group