Update: There is a newer thread for 10.6 over here This older tutorial will likely not be updated at all now that most users have moved on to 10.6. New users should proceed to 10.6 directly; there is no good reason to do a new install with an old version of OSX.

Here's what I've figured out so far on getting OSX working on the dell studio xps 1340, aka dell studio xps 13.

Working "out of the box":

• gig-ethernet, usb, firewire, sata
• system suspend
• touchpad as mouse
• webcam (video only), video capture verified with photo booth application
• Bluetooth in HID mode (think dumb mouse)

Working with mods below:

• GeForce 9400M G graphics with quartz extreme, external HDMI/VGA/display port
• Built-in speaker, hotkey volume/mute controls
• Intel speedstep
• Touchpad gestures, and working touchpad after resume with modified version of voodoo team's Voodoops2controller
• Battery status & suspend on lid closed
• Bluetooth in HCI mode (full functionality)
• touchpad usability after resume

Not working:

• Built-in digital mic, mic-in jack, mute of speakers when headphones attached
• Dell 1515 802.11 wireless (atheros ar9280 aka ar5009). However some systems ship with the older Dell 1510 802.11 which is broadcom based and works. Update: Apple's OSX driver for this newer Atheros hardware has materialized in the 10.6.0 (Snow Leopard) beta distribution. I've tested it & confirmed that it is working "out of the box" on this laptop as of that beta release.
• SLI with 9500m video
• SD flash card. Perhaps someone could try the new VoodooSDHCI solution and report back.

Not tested yet (let us know):

• Infrared
• expresscard

For installation I recommend the XxX 10.5.6 distribution, or a boo132+retail disk solution, as other pre-packaged distros don't seem to handle booting off of nvidia sata devices.
(Before XxX I tried the iPC livedvd, and that would hang during boot, apparently due to lack of nvidia sata support. Older distributions such as kalyway, boot & install but the OS randomly hangs, apparently due to problems with the sata drivers.)

With XxX, during the install, you need not select any of the optional kexts. Note that more is not necessarily better - you can screw up features such as system suspend by installing kexts that were meant for other chipsets such as older nvidia chipsets.

For working quartz Extreme & core image (QE/CI), install my modified IOPCIFamily kext 10.5.6 version, 10.5.7 version and my EFI plist here. My EFI plist includes EFI strings for the 9400m video and for the IDT audio. To apply the plist to your com.apple.boot.plist using OSX86 Tools:

1. Save attached plist file as something.plist
2. Run OSX86 Tools
3. Select Add EFI Strings/Boot Flag
4. Select Import Hex/Plist
5. Select Import File
6. Select the plist file you just saved, click choose
7. Select import string to boot editor
8. select apply changes to com.apple.boot.plist

Replace the existing IOPCIFamily kext with my modified kext (manually or using something like kexthelper).

Update:
The IOPCIFamily change I made isn't necessary if you instead use natit (or EFI injection via dsdt). I'd recommend the natit approach at this point for 10.5.8 users as it avoids having to modify apple's stock kexts. With my modified Natit.kext  Natit.bcc9.v3.zip ( 25.05K ) Number of downloads: 168
, the same EFI graphics strings are injected as with the IOPCIFamily+com.apple.Boot.plist approach.

To fix the touchpad gestures, touchpad resume-ability, keyboard issues, you can install the VoodooPS2Controller. First you should uninstall any distro-provided AppleACPIPS2Nub,ApplePS2Controller kexts before installing the voodoops2controller pkg else you'll get panics and problems with keyboard input. Apparently it's still not legal to link to the voodoops2 package, so go look for VoodooPS2Controller-0.98-installer.pkg. After installing the stock 0.98 version to set up the trackpad control panel entry, I recommend replacing voodoops2controller.kext with my updated version. My updated version here, allows the touchpad to work after resume, and doesn't swap the mac command/option keys. It is based upon some enhancements posted over here http://forum.voodooprojects.org/index.php/topic,304.0.html

For working IDT audio you'll also need the attached AppleHDA.kext. Thanks to the Dell 1535/1735 folks (ridgeline, boombeng) for coming up with IDT audio pathmaps that begin to work on this laptop. Unfortunately this kext is from 10.5.3 and at also seems to be flaky for some users, as it was for the 1535/1735. This old kext will also make the system fail to shutdown cleanly, though there is a workaround for that.
You should *not* need to install HDAEnabler.kext as advised elsewhere as my EFI plist includes the audio EFI string already.
Update: Verify working audio by ensuring that "Internal Speakers" is available and selected under System Preferences->sound->output, then go to the sound effects tab and try something.

For working CPU throttling (intel speedstep) use my modified version of superhai's VoodooPower.kext. Attached. (I've attached my source code changes as well, which is only of interest if you're a developer, here.) Superhai has some support applications: GenericCPUPMControl, vpower over here, and there's also cpu-x to monitor the CPU multiplier state.

For battery status and system sleep upon lid close, you need

1. the ACPI Embedded Controller to load properly. Turns out a bug in AppleACPIPlatform was causing the embedded controller (AppleACPIEC) to fail to load, I've made a patch to AppleACPIPlatform to fix that. Replace the stock version in /System/Library/Extensions/AppleACPIPlatform.kext/Contents/MacOS with my patched version. Again, use something like kexthelper if you need help preserving permissions and ownership when making this change. 10.5.6 version, 10.5.7 version, 10.5.8 version
2. a cleaned up DSDT. Here is mine, based upon A06 BIOS. (A06, A07 and A08 BIOS have identical DSDT, by the way). Install DSDT.aml to a location where your Chameleon bootloader will pick it up at boot time. I recommend creating the /Extra directory and copying dsdt.aml from my .zip into /Extra/DSDT.aml (note that filename case matters to Chameleon here).
3. An updated version of the Chameleon bootloader if you're using an older bootloader that cannot patch the DSDT. The bootloader that comes with the XxX distro is chameleon 1.0.11 based and won't patch the DSDT. I recommend you update your bootloader to the Chameleon-2.0-r431 revision
4. VoodooBattery, for the battery icon

For bluetooth with HCI, I've written a driver that enables that, posted over here

There are a few drivers that don't behave well across a suspend/resume, the best fix I've come up with so far is to install sleepwatcher&its enclosed startup package, from here: http://www.bernhard-baehr.de/, then install my custom /etc/rc.sleep, /etc/rc.wakeup scripts from here. These scripts address

1. Firewire GUID being stuck at 0000000000000000, logging errors and keeping the system from re-suspending
2. Automatic configuring of bluetooth HCI modeWith my new driver referenced above, you don't need sleepwatcher for this

I could really use some help on the non-working components! Such as:

• For SLI video, need someone who has the 9500m to try and work on a 2nd graphics EFI string for the 9200m part. I think the right devicepath for the 9200m is:
  PciRoot(0x1)/Pci(0x0c,0x0)/Pci(0x0,0x0), but I don't have a 9500m to play with this.
• For audio, it'd be great if someone could figure out how to get the 10.5.6 version of the IDT-modified AppleHDA.kext to work. I get no audio devices with this version. Also both analog&digital mics work under linux with alsa 1.0.19, but not under OSX, even with what looks like the right pathmap. Clues?
• USB devices such as disk drives get "device removal" events upon wakeup from suspend.
• Something seems wrong with the IOAHCISerialATAPI driver. Upon wakeup from suspend the disk activity light flashes every 2 seconds or so apparently with the driver trying to stat the dvd-rom drive. Putting a disk in the drive fixes this.

Contributions welcome