Slashdot Mirror
Domain: kernelthread.com
Stories and comments across the archive that link to kernelthread.com.
Stories · 40
-
A Technical History of Apple's Operating Systems
An anonymous reader writes "As part of his 1680-page book Mac OS X Internals: A Systems Approach, Amit Singh of kernelthread.com wrote a very detailed technical history of Apple's operating systems. Since he had to cut down on the history chapter because of the book's already too-large size, most of this chapter didn't make it to the printed book. Singh has made available the history chapter as a free PDF. The file is 140 pages long, and is generously filled with figures and screenshots. It starts with the internals of the original Apple I and goes through a tour of all operating systems Apple dabbled with, including internals of A/UX, Lisa OS, and such. It even covers details of outside influences like the Xerox Alto, STAR System, Smalltalk, and Sketchpad, and closer to home things like Mach, NeXTStep, and OpenStep." -
Understanding OS X Kernel Internals
jglidell writes "The OS X kernel has been in the news alot this past year, whether it's why its slow, Mach/micro-kernel makes it bad, it's going closed source and what not. Amit Singh has put up a new presentation on the innards of OS X. It does a pretty good job of summing up the OS X kernel architecture, and has some pretty detailed diagrams... for instance they show that there are so many process/threads layers in OS X. So if you are in the mood for doing some OS studying then head over." -
10 Things Apple Did To Make Mac OS X Faster
bariswheel writes "This kernelthread article seeks to investigate further to the inner core of OS X and the improvements therein. The subtopics are the following: BootCache, Kernel Extensions Cache, Hot File Clustering, Working Set Detection, On-the-fly Defragmentation, Prebinding, Helping Developers Create Code Faster, Helping Developers Create Faster Code, Journaling in HFS Plus, and Instant-on." -
Understanding Mac OS X Kernel
An anonymous reader writes "Kernelthread.com has published a flash presentation overview of the Mac OS X kernel. Its title is 'A Tour of the Mac OS X Kernel' and it also covers Tiger features. Maybe interesting to note is that the slides are from a talk given to the NSA. Well, there is a nice security architecture diagram towards the end of the presentation." -
Understanding Mac OS X Kernel
An anonymous reader writes "Kernelthread.com has published a flash presentation overview of the Mac OS X kernel. Its title is 'A Tour of the Mac OS X Kernel' and it also covers Tiger features. Maybe interesting to note is that the slides are from a talk given to the NSA. Well, there is a nice security architecture diagram towards the end of the presentation." -
Watching Under The Hood Of Tiger's Spotlight
jaketheitguy writes "Over at KernelThread.com, Amit Singh has released a commandline app called FSLogger for looking under the hood of Tiger's Spotlight. You can watch all kinds of filesystem changes going on in realtime. The utility apparently intercepts and displays filesystem change data as it goes out to Spotlight from the kernel. It even tells you which app is making the changes. Looks like Apple has included some pretty powerful API's in Tiger and there may be some othre really interesting uses of this API as mentioned on the app's page. I for one would really like to be able to tell if somebody changed ANY files on my system without my knowledge. I think you can do that with Singh's program, but how do you make sure somebody cannot disable the program?" -
Watching Under The Hood Of Tiger's Spotlight
jaketheitguy writes "Over at KernelThread.com, Amit Singh has released a commandline app called FSLogger for looking under the hood of Tiger's Spotlight. You can watch all kinds of filesystem changes going on in realtime. The utility apparently intercepts and displays filesystem change data as it goes out to Spotlight from the kernel. It even tells you which app is making the changes. Looks like Apple has included some pretty powerful API's in Tiger and there may be some othre really interesting uses of this API as mentioned on the app's page. I for one would really like to be able to tell if somebody changed ANY files on my system without my knowledge. I think you can do that with Singh's program, but how do you make sure somebody cannot disable the program?" -
Amit Singh's Challenge: Find a Decade-Old Bug
dreicodan writes "Well this has too many juicy Mac OS X nuggets in one bag! All details are on this page, but I'll summarise. Apparently Amit Singh discovered a 10+ year old serious bug in OS X. The bug started in Nextstep and is still in Panther (and apparently Tiger, too). Then Amit wrote a program to demo the bug, but also made the program capable of hiding what it does using some complicated Mach kernel voodo! He then threw a challenge open to OS X experts to figure out the bug. It turns out that a week and some 1000 downloads later, three brilliant hackers (Alexy Proskuryakov, Andrew Wellington, Graham Dennis) were able to solve the puzzle. Also looks like other than these guys, nobody got anywhere with the problem. Be ready for extremely gory details of how the program was written and how it was decoded. Its a thrilling read, and OS X hacking doesn't get any more hardcore than this! Hopefully Apple fixes this bug now at last." -
Amit Singh's Challenge: Find a Decade-Old Bug
dreicodan writes "Well this has too many juicy Mac OS X nuggets in one bag! All details are on this page, but I'll summarise. Apparently Amit Singh discovered a 10+ year old serious bug in OS X. The bug started in Nextstep and is still in Panther (and apparently Tiger, too). Then Amit wrote a program to demo the bug, but also made the program capable of hiding what it does using some complicated Mach kernel voodo! He then threw a challenge open to OS X experts to figure out the bug. It turns out that a week and some 1000 downloads later, three brilliant hackers (Alexy Proskuryakov, Andrew Wellington, Graham Dennis) were able to solve the puzzle. Also looks like other than these guys, nobody got anywhere with the problem. Be ready for extremely gory details of how the program was written and how it was decoded. Its a thrilling read, and OS X hacking doesn't get any more hardcore than this! Hopefully Apple fixes this bug now at last." -
Amit Singh's Challenge: Find a Decade-Old Bug
dreicodan writes "Well this has too many juicy Mac OS X nuggets in one bag! All details are on this page, but I'll summarise. Apparently Amit Singh discovered a 10+ year old serious bug in OS X. The bug started in Nextstep and is still in Panther (and apparently Tiger, too). Then Amit wrote a program to demo the bug, but also made the program capable of hiding what it does using some complicated Mach kernel voodo! He then threw a challenge open to OS X experts to figure out the bug. It turns out that a week and some 1000 downloads later, three brilliant hackers (Alexy Proskuryakov, Andrew Wellington, Graham Dennis) were able to solve the puzzle. Also looks like other than these guys, nobody got anywhere with the problem. Be ready for extremely gory details of how the program was written and how it was decoded. Its a thrilling read, and OS X hacking doesn't get any more hardcore than this! Hopefully Apple fixes this bug now at last." -
PowerBook As A New Kind Of Human Interface Device
An anonymous reader writes "As covered earlier on Slashdot, Amit Singh had shown how to access and use the motion sensor feature in the late model PowerBooks for innovative things, which created quite a buzz in the Mac community. In an ingenius new article, Singh has taken the idea all the way and released software which lets you use a PowerBook with a motion sensor as a general purpose input device which works with existing apps. IMHO the coolest use of this is for playing games: be sure to check out the video footage in the article. For instance, in a car racing game, you steer by tilting the PowerBook left and right, go faster by tilting it forward, brake by tilting it backwards! You can also scroll in apps. Google Map scrolling with my PowerBook feels like flying in an aiprlane over the terrain. I must say you have to try this in real life to appreciate the experience ... go to the Apple store or something if you don't have the hardware ;-) Before this my girlfriend (who uses a Dell notebook) has never called anything computer related "jawdropping"! Wouldn't it be nice to have a gaming motion sensor be standard issue in all future laptops?" -
IBM Using iPod to boot Linux on PCs
Applejack writes "Looks like iPod fever has caught on to Big Blue. IBM has a yet unreleased iPod-based software for rescue, restore, and recovery of failed Windows PCs. I read this description of the software on Amit Singh's blog, whose group at IBM apparently created this stuff. If I understand this correctly (and I think I do), the iPod contains IBM's rescue software along with Linux. A crashed PC boots into Linux from the iPod, after which you get all kinds of rescue & restore functionality ... web browsing and all, even if the PC's drive is totally hosed. All this while the iPod keeps working normally as a music player as it would. The blog has pointers to further information, including a Windows Media demo of the thing. " Should be noted this is not iPod specific; USB devices will do. -
Having Fun With PowerBook Motion Sensors
mjk325 writes "Amit Singh has published a discussion on the 'Sudden Motion Sensor' feature in the latest revision PowerBooks. One utility he has released displays a 3-D view of the PowerBook that follows the actual movement of the physical machine. Another utility creates windows that rotate in opposite directions to the physical machine to appear always straight. My brand new PB has the motion sensor, but apparently the utilities work on any system using software faking." -
Having Fun With PowerBook Motion Sensors
mjk325 writes "Amit Singh has published a discussion on the 'Sudden Motion Sensor' feature in the latest revision PowerBooks. One utility he has released displays a 3-D view of the PowerBook that follows the actual movement of the physical machine. Another utility creates windows that rotate in opposite directions to the physical machine to appear always straight. My brand new PB has the motion sensor, but apparently the utilities work on any system using software faking." -
Running Ancient UNIX On Nintendo Gameboy
An anonymous reader writes "Amit Singh has a piece on his site about running the 5th edition UNIX distribution on a Nintendo Gameboy, of all things. Tons of screenshots and source included but what really makes this entertaining and informational in an ubergeekly sort of way is his side stories on UNIX history ... ARM CPU ... compiling and running random programs on the Gameboy, etc. There are even notes on recompiling the original Unix kernel to make it smaller for the GBA!" -
Running Ancient UNIX On Nintendo Gameboy
An anonymous reader writes "Amit Singh has a piece on his site about running the 5th edition UNIX distribution on a Nintendo Gameboy, of all things. Tons of screenshots and source included but what really makes this entertaining and informational in an ubergeekly sort of way is his side stories on UNIX history ... ARM CPU ... compiling and running random programs on the Gameboy, etc. There are even notes on recompiling the original Unix kernel to make it smaller for the GBA!" -
A Taste Of Computer Security
andrew_ps writes "Amit Singh has published on his KernelThread.com a paper (mini book really) on computer security. A Taste of Computer Security is a VERY comprehensive paper in what it covers, but is remarkably easy to read. This is not some list of "sploits" though! Topics covered include popular notions about security, types of mal-ware, viruses & worms, memory attacks/defences, intrusion, sandboxing, review of Solaris 10 security and plenty of others. Most notably it includes probably one of the most fair and intelligent analysis of the Unix-Vs-Windows security issue that I have ever seen." -
A Taste Of Computer Security
andrew_ps writes "Amit Singh has published on his KernelThread.com a paper (mini book really) on computer security. A Taste of Computer Security is a VERY comprehensive paper in what it covers, but is remarkably easy to read. This is not some list of "sploits" though! Topics covered include popular notions about security, types of mal-ware, viruses & worms, memory attacks/defences, intrusion, sandboxing, review of Solaris 10 security and plenty of others. Most notably it includes probably one of the most fair and intelligent analysis of the Unix-Vs-Windows security issue that I have ever seen." -
A Taste Of Computer Security
andrew_ps writes "Amit Singh has published on his KernelThread.com a paper (mini book really) on computer security. A Taste of Computer Security is a VERY comprehensive paper in what it covers, but is remarkably easy to read. This is not some list of "sploits" though! Topics covered include popular notions about security, types of mal-ware, viruses & worms, memory attacks/defences, intrusion, sandboxing, review of Solaris 10 security and plenty of others. Most notably it includes probably one of the most fair and intelligent analysis of the Unix-Vs-Windows security issue that I have ever seen." -
A Taste Of Computer Security
andrew_ps writes "Amit Singh has published on his KernelThread.com a paper (mini book really) on computer security. A Taste of Computer Security is a VERY comprehensive paper in what it covers, but is remarkably easy to read. This is not some list of "sploits" though! Topics covered include popular notions about security, types of mal-ware, viruses & worms, memory attacks/defences, intrusion, sandboxing, review of Solaris 10 security and plenty of others. Most notably it includes probably one of the most fair and intelligent analysis of the Unix-Vs-Windows security issue that I have ever seen." -
More Power To The Firmware
An anonymous reader writes "In More Power To The Firmware Amit Singh talks about technical details of EFI, the next-gen BIOS replacement standard Intel, Microsoft and others are pushing. This is a very informative piece where he talks of issues with legacy BIOS, how it affects those who develop in the firmware environment and how EFI plans to solve these problems. EFI usage examples are included, including a programming example. He contrasts EFI with Open Firmware as well. IMO the second half of the article is even more interesting, where sample FORTH code is provided for displaying a window/mouse pointer GUI inside the Apple/Mac firmware! And of course, there's code for a new 'Towers of Hanoi' animation using the Mac firmware (remember Hanoimania?). Aspiring Mac Firmware Hackers could also check out the suggested projects ;-)" -
More Power To The Firmware
An anonymous reader writes "In More Power To The Firmware Amit Singh talks about technical details of EFI, the next-gen BIOS replacement standard Intel, Microsoft and others are pushing. This is a very informative piece where he talks of issues with legacy BIOS, how it affects those who develop in the firmware environment and how EFI plans to solve these problems. EFI usage examples are included, including a programming example. He contrasts EFI with Open Firmware as well. IMO the second half of the article is even more interesting, where sample FORTH code is provided for displaying a window/mouse pointer GUI inside the Apple/Mac firmware! And of course, there's code for a new 'Towers of Hanoi' animation using the Mac firmware (remember Hanoimania?). Aspiring Mac Firmware Hackers could also check out the suggested projects ;-)" -
Making Operating Systems Faster
mbrowling writes "In an article over at kernelthread.com Amit Singh discusses 'Ten Things Apple Did To Make Mac OS X Faster'. The theme seems to be that since you won't run into 'earth-shattering algorithmic breakthroughs' in every OS releases, what're you gonna do to bump your performance numbers higher? Although the example used is OS X, the article points out that Windows uses the same approach." -
Making Operating Systems Faster
mbrowling writes "In an article over at kernelthread.com Amit Singh discusses 'Ten Things Apple Did To Make Mac OS X Faster'. The theme seems to be that since you won't run into 'earth-shattering algorithmic breakthroughs' in every OS releases, what're you gonna do to bump your performance numbers higher? Although the example used is OS X, the article points out that Windows uses the same approach." -
Making Operating Systems Faster
mbrowling writes "In an article over at kernelthread.com Amit Singh discusses 'Ten Things Apple Did To Make Mac OS X Faster'. The theme seems to be that since you won't run into 'earth-shattering algorithmic breakthroughs' in every OS releases, what're you gonna do to bump your performance numbers higher? Although the example used is OS X, the article points out that Windows uses the same approach." -
Measuring Fragmentation in HFS+
keyblob8K writes "Amit Singh takes a look at fragmentation in HFS+. The author provides numbers from his experiments on several HFS+ disks, and more interestingly he also provides the program he developed for this purpose. From his own limited testing, Apple's filesystem seems pretty solid in the fragmentation avoidance department. I gave hfsdebug a whirl on my 8-month-old iMac and the disk seems to be in good shape. I don't have much idea about ext2/3 or reiser, but I know that my NTFS disks are way more fragmented than this after similar amount of use." -
Measuring Fragmentation in HFS+
keyblob8K writes "Amit Singh takes a look at fragmentation in HFS+. The author provides numbers from his experiments on several HFS+ disks, and more interestingly he also provides the program he developed for this purpose. From his own limited testing, Apple's filesystem seems pretty solid in the fragmentation avoidance department. I gave hfsdebug a whirl on my 8-month-old iMac and the disk seems to be in good shape. I don't have much idea about ext2/3 or reiser, but I know that my NTFS disks are way more fragmented than this after similar amount of use." -
Measuring Fragmentation in HFS+
keyblob8K writes "Amit Singh takes a look at fragmentation in HFS+. The author provides numbers from his experiments on several HFS+ disks, and more interestingly he also provides the program he developed for this purpose. From his own limited testing, Apple's filesystem seems pretty solid in the fragmentation avoidance department. I gave hfsdebug a whirl on my 8-month-old iMac and the disk seems to be in good shape. I don't have much idea about ext2/3 or reiser, but I know that my NTFS disks are way more fragmented than this after similar amount of use." -
A History of Apple's Operating Systems
jpkunst writes "Amit Singh of kernelthread.com has written A History of Apple's Operating Systems. From the introduction: 'This document discusses operating systems that Apple has created in the past, and many that it tried to create. Through this discussion, we will come across several technologies the confluence of which eventually led to Mac OS X'." -
A History of Apple's Operating Systems
jpkunst writes "Amit Singh of kernelthread.com has written A History of Apple's Operating Systems. From the introduction: 'This document discusses operating systems that Apple has created in the past, and many that it tried to create. Through this discussion, we will come across several technologies the confluence of which eventually led to Mac OS X'." -
An Introduction to Virtualization
JamieX writes "kernelthread.com brings you a very cool and instructional article in An Introduction to Virtualization... The piece talks about the history of VM's, why they are becoming important again, implementation issues and most of all a look at a large number of virtualization solutions for all kinds of operating systems... many of them barely known... essentially more than you want to know about virtualization on a single page! Great read and reference." -
An Introduction to Virtualization
JamieX writes "kernelthread.com brings you a very cool and instructional article in An Introduction to Virtualization... The piece talks about the history of VM's, why they are becoming important again, implementation issues and most of all a look at a large number of virtualization solutions for all kinds of operating systems... many of them barely known... essentially more than you want to know about virtualization on a single page! Great read and reference." -
An Answer To "What is Mac OS X?"
XCube writes: "'What is Mac OS X?' is a fascinating article over at KernelThread.com. According to Amit Singh it's a hacker-over-friendly answer to that question and a low-level taste of Apple's OS. The extensive article covers many details on Mac OS X: history, Mac firmware & boot loader, system architecture, kernel, startup, file systems, app environments, programming facilities, available software, and more. A great read if you are interested in Mac OS X, though some stuff is too technical methinks. On second thought, this may be a better read if you're *not* interested in Mac OS X! The author says he wrote it to introduce Mac OS X to the Linux User's Group at his work." -
An Answer To "What is Mac OS X?"
XCube writes: "'What is Mac OS X?' is a fascinating article over at KernelThread.com. According to Amit Singh it's a hacker-over-friendly answer to that question and a low-level taste of Apple's OS. The extensive article covers many details on Mac OS X: history, Mac firmware & boot loader, system architecture, kernel, startup, file systems, app environments, programming facilities, available software, and more. A great read if you are interested in Mac OS X, though some stuff is too technical methinks. On second thought, this may be a better read if you're *not* interested in Mac OS X! The author says he wrote it to introduce Mac OS X to the Linux User's Group at his work." -
55 Operating Systems On A PowerBook
OttoMagick writes "I found an article called 'Many Systems on One Machine' over at Kernelthread.com that shows over 55 operating systems running on a 17inch Powerbook. The article includes screenshots and descriptions of each system, and also hacks and tips on getting the nasty ones installed. The author Amit Singh (the Hanoimania guy, covered earlier on Slashdot) explains his reasons for all this in a related FAAQ (frequently asked + anticipated questions) ... In all a very interesting read, specially the FAAQ, where he calls the setup "the iPod of operating systems". Now thats an Apple Power User! I wonder what Steve Jobs would say if he sees people doing such things to his machines!!" -
55 Operating Systems On A PowerBook
OttoMagick writes "I found an article called 'Many Systems on One Machine' over at Kernelthread.com that shows over 55 operating systems running on a 17inch Powerbook. The article includes screenshots and descriptions of each system, and also hacks and tips on getting the nasty ones installed. The author Amit Singh (the Hanoimania guy, covered earlier on Slashdot) explains his reasons for all this in a related FAAQ (frequently asked + anticipated questions) ... In all a very interesting read, specially the FAAQ, where he calls the setup "the iPod of operating systems". Now thats an Apple Power User! I wonder what Steve Jobs would say if he sees people doing such things to his machines!!" -
55 Operating Systems On A PowerBook
OttoMagick writes "I found an article called 'Many Systems on One Machine' over at Kernelthread.com that shows over 55 operating systems running on a 17inch Powerbook. The article includes screenshots and descriptions of each system, and also hacks and tips on getting the nasty ones installed. The author Amit Singh (the Hanoimania guy, covered earlier on Slashdot) explains his reasons for all this in a related FAAQ (frequently asked + anticipated questions) ... In all a very interesting read, specially the FAAQ, where he calls the setup "the iPod of operating systems". Now thats an Apple Power User! I wonder what Steve Jobs would say if he sees people doing such things to his machines!!" -
55 Operating Systems On A PowerBook
OttoMagick writes "I found an article called 'Many Systems on One Machine' over at Kernelthread.com that shows over 55 operating systems running on a 17inch Powerbook. The article includes screenshots and descriptions of each system, and also hacks and tips on getting the nasty ones installed. The author Amit Singh (the Hanoimania guy, covered earlier on Slashdot) explains his reasons for all this in a related FAAQ (frequently asked + anticipated questions) ... In all a very interesting read, specially the FAAQ, where he calls the setup "the iPod of operating systems". Now thats an Apple Power User! I wonder what Steve Jobs would say if he sees people doing such things to his machines!!" -
108 Ways To Do The Towers of Hanoi
hlarwood74 writes "While it is common to program in a few different languages, somebody has written "towers of hanoi" in 108 different ways, most of them in different programming languages. It's not just the number of languages though ... there are many neat implementations and in some cases he's come up with some strange ways of solving hanoi such as this: "you ping the hanoi machine with the number of disks encoded in the type of service field, and you get response packets whose sequence numbers represent the disk moves need to solve the puzzle". I wanted to ask "why" but the title of the page (hanoimania) explains a few things :)" -
108 Ways To Do The Towers of Hanoi
hlarwood74 writes "While it is common to program in a few different languages, somebody has written "towers of hanoi" in 108 different ways, most of them in different programming languages. It's not just the number of languages though ... there are many neat implementations and in some cases he's come up with some strange ways of solving hanoi such as this: "you ping the hanoi machine with the number of disks encoded in the type of service field, and you get response packets whose sequence numbers represent the disk moves need to solve the puzzle". I wanted to ask "why" but the title of the page (hanoimania) explains a few things :)"