Posted by on under mac os x, generic pc, compatible hardware, slashdot, snow leopard, mdash, analys, system mac, software package, launch, new software, computerworld, software product, flagship, latest operating system, os x, homework, lt, free trial, microsoft | 
CWmike writes "While the world focused on Microsoft's launch of Windows 7, Florida-based Psystar quietly launched Rebel EFI, a software product that should worry Apple a lot more than Microsoft's latest operating system. Rebel EFI allows users to run Apple's flagship operating system, Mac OS X Snow Leopard, on non-Apple hardware. Computerworld test drove the making a Hackintosh out of a generic PC with company's new software package and found a product that has a lot of homework still to do. Reviewer Frank Ohlhorst's final analysis: 'Psystar's Rebel EFI [ a free trial is available ] is an interesting tool, but it is very limited when it comes to the selection of hardware that you can use. The company really needs to create a compatible hardware list and post that on its Web site — and it also needs to create some usable documentation. As it stands right now, you can use Rebel EFI to build a Mac clone, but unless you stick to relatively generic hardware, you will be disappointed.'"
Read more of this story at Slashdot.
Tagi: mac os x, generic pc, compatible hardware, slashdot, snow leopard, mdash, analys, system mac, software package, launch, new software, computerworld, software product, flagship, latest operating system, os x, homework, lt, free trial, microsoft
Posted by on under ceo mark, mark zuckerberg, hotseat, ebay, analys, illuminati, d8, interviewer, goats, unthinkable, liking, insignia, cult, nuts |
Earlier this week during an
interview at the D8 conference, Facebook CEO Mark Zuckerberg did the unthinkable: after finding the hotseat a little too toasty for his liking, he took off his hoodie. Interviewer Kara Swisher quickly discovered that the hoodie had a mysterious badge stitched on the inside and joked that Zuckerberg was in a cult. And then the Internet went sort of nuts. Tweets abound about Facebook's Illuminati-like status. The folks at SFWeekly managed to
recreate the diagram and did a thorough analysis on what it might mean. The Next Web thought it was
creepy. And back at Facebook HQ, three goats were sacrificed in an attempt to ward off yet another wave of bad press.
Tagi: ceo mark, mark zuckerberg, hotseat, ebay, analys, illuminati, d8, interviewer, goats, unthinkable, liking, insignia, cult, nuts
Posted by on under cutler cleveland, natural oil, bost, analys, university professor |
Gooseygoose writes with a link to this analysis by Boston University professor Cutler Cleveland "Some reports in the media attempt to downplay the significance of the release of oil from the Deepwater Horizon accident by arguing that natural oil seeps release large volumes of oil to the ocean, so why worry? Let's look at the numbers." Read on for a few more stories on the topic of the Deepwater Horizon spill.
Read more of this story at Slashdot.
Tagi: cutler cleveland, natural oil, bost, analys, university professor
Posted by planetbeing on under clock divider, audio codec, os kernel, iphe, iore, linux driver, c objects, lten, kit c, kmem, locati, class member, th c, baseband, c class, analys, datasheets, codecs, heap, peek |
Thought it might be interesting for people to take a peek at how we work.
As I stated in the previous blog post, it's necessary for us to figure out the WM8991 audio codec before we can call from the baseband (or listen to music). This is an interesting task because while there are datasheets for the WM8991 codec, and a Linux driver for it, those cannot be used immediately since it doesn't tell us where the inputs and outputs of the chip are connected to, and what protocol and clock divider settings the iPhone uses to talk to the chip (and must be configured on the chip). Those things are purely implementation specific.
In order to extract those settings, we need to be able to see those settings while the iPhone OS kernel is up and running and sound is playing. The chip does not use
MMIO, so the register settings cannot be directly peeked at through
/dev/kmem... but we're on the right track. Instead,
I2C is used to communicate with the codec for setting those registers. It turns out that since some Wolfson codecs do not allow reading from the codec registers (only writing), the operating system has to "remember" what values registers are currently set to. That is, they are cached by operating system?
Where are they cached? Well, a quick look at the disassembly shows us some code that does the following (in pseudo-C)
if register > *(this + 0xA0)
return 0
return *((uint16_t*)(*(this + 0xA8) + register * 2))
Basically, we see that the class member at offset 0xA0 contains the total number of registers accessible on the Wolfson codec, while member 0xA8 is a pointer to an array of 16-bit values that represent the current values of those registers!
Now we seem to be home free... except for the fact that IO Kit C++ objects are dynamically allocated on the heap at runtime and there is no way to tell using static analysis where they will be during a particular boot of an operating system. How will we find the location of this C++ class (AppleWM8991Audio) so that we can peek at those values?
The answer is that every object in the IOKit subsystem is anchored to the IORegistry tree. You can actually take a peek at the tree from userland with the
ioreg -l command. Every single node you see corresponds to a C++ object. However, the trouble is that there is no userland call to extract the in-kernel addresses of those objects... and that's what we need to be able to use
/dev/kmem to peek at the right places.
Fortunately, the root of the IORegistry is pointed to by a constant, and it is possible to traverse the IORegistry manually from the root (provided you know the layout of all the C++ classes!). This is exactly what I wrote a
utility called spelunk to perform: use
/dev/kmem to manually traverse the IORegistry and find the in-memory instance, instance size, and vtable location of all of the objects in the IORegistry. Armed with this information, one can use
dd and
/dev/kmem to peek at the state of any of the objects inside kernel memory.
I made a series of dumps:
registers-call-headphones,
registers-call-speakers,
registers-max-headphones,
registers-max-speakers,
registers-min-headphones,
registers-min-speakers. Here is a diff of min-speakers and max-speakers, just to show you what we're looking for:
--- hex-registers-min-speakers 2010-05-04 15:44:19.000000000 -0700
+++ hex-registers-max-speakers 2010-05-04 15:45:39.000000000 -0700
@@ -2,7 +2,7 @@
00000010 20 80 20 80 00 00 c0 00 c0 01 00 00 00 01 c0 00 | . .............|
00000020 c0 00 00 00 01 00 00 17 00 10 40 10 00 00 04 08 |..........@.....|
00000030 8b 00 8b 00 8b 00 8b 00 b0 00 b0 01 66 00 22 00 |............f.".|
-00000040 f9 00 f9 01 00 00 03 01 57 00 00 01 ec 01 00 00 |........W.......|
+00000040 f9 00 f9 01 00 00 03 01 57 00 00 01 ff 01 00 00 |........W.......|
00000050 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00000060 00 00 00 00 00 00 80 01 00 00 00 00 03 00 00 00 |................|
00000070 00 00 08 00 00 00 00 00 87 00 85 00 fc 00 00 00 |................|
So it's fairly obvious how volume control for the speakers are done. Anyway, hopefully we can plug in these values, use the current i2s drivers, and audio will work!
Tagi: clock divider, audio codec, os kernel, iphe, iore, linux driver, c objects, lten, kit c, kmem, locati, class member, th c, baseband, c class, analys, datasheets, codecs, heap, peek
Posted by on under sky news, combat troops, troops in iraq, obama, analys, xinhua, financial times, 31 august, pullout, reuters, 4th stryker brigade, half years, infantry, guardian, news articles, press release, africa |
Tagi: sky news, combat troops, troops in iraq, obama, analys, xinhua, financial times, 31 august, pullout, reuters, 4th stryker brigade, half years, infantry, guardian, news articles, press release, africa
