Thank you OP and all others who contributed to these instructions. I'm clarifying the OP's instructions. I found some points confusing and some points missing (BIOS settings causing KP).
https://osxlatitude.com/index.php?/topic/7406-e6400-yosemite-clover-guide/
PREREQUISITES:
Dell Latitude e6400 with nVidia graphics. The Intel graphics card version of the e6400 won't work.
Also, swap out any Intel Wi-Fi hardware chip with a Broadcom Wi-Fi hardware chip. I have the DW 1390 chip without any custom kext.
8 GB or more USB thumb drive.
Backup your current installation using Carbon Copy Cloner (CCC) and reinstall of the bootloader (Chameleon, Clover, etc.) that was used for the current installation onto a thumb drive. (Instructions below)
Test the full boot of your thumb drive before beginning the following.
Everything should be working from your thumb drive
YOSEMITE USING CLOVER:
Reboot your laptop and hit the F2 button to enter BIOS settings. Change the following BIOS settings (currently BIOS version A32):
Disable the following: Parallel Port, Serial Port, Internal Model, Computrace, Signed Firmware Update, Intel Fast Call for Help, VT for Direct I/O (will KP IOHIDFamily.kext), Trusted Execution.
Change System Configuration\SATA Operation to AHCI.
Apply and Exit.
Download Yosemite via the app store using a working Mac or Hackintosh. Copy it to Applications and rename to "Install OS X Yosemite Beta.app"
Download the boot pack https://mega.co.nz/#!HY8SDJjD!fJO1qXIlo3cuqJzBgOH-edH8a_WC9SsjXMoyVh95EO8 and unzip.
Insert the 8 GB USB thumb drive.
Using Disk Utility, partition it using one partition, GUID partitioning, and Mac OS Extended (Journaled) format.Run the Clover_v2k_r2898_Special Edition.pkg.
If you get a security prompt, go to System Preferences\Security and Privacy. Click the button to "Open Anyway".
While running the pkg, make sure you change the destination to the USB thumb drive instead of your computer's hard drive
Click the customize button. Choose:Installer_OS_X_Yosemite
Install Clover in the ESP
Bootloader\Install boot0af in MBR (only this option)
CloverEFI\CloverEFI 64-bits SATA (only this option)
Themes\AppleStyle
Drivers64UEFI\EmuVariableUefi-64 (only this option)
Enter your password
This will create a bootable USB drive with Yosemite and will take about 15 minutes
When done with the 15 minutes, you'll have a partition visible on your Mac's desktop named "EFI". Via Finder, navigate to EFI/Clover/. If no EFI partition on the desktop, use the included EFI Mounter V2 from the boot pack. I had no idea what the original post said about IORegistryExplorer and "OEMBoard". The following is the second method he posted.
Unzip the 0X574R.zip
Copy the 10.10 folder from 0X574R/kexts to desktop /EFI/Clover/Kexts
Copy dsdt.aml from 0X574R/ACPI/Patched to /EFI/Clover/ACPI/Patched
Replace config.plist from /0X574R to /EFI/Clover/config.plist
Copy the "Boot and Install pack.zip" file to the USB drive
Eject the USB drive and EFI drive
Plug in the USB drive into the Dell E6400 you want to install OSX.
Reboot the computer where you'll install OSX Yosemite
On BIOS boot, hit the F12 button repeatedly to get to the boot menu
Choose "USB Storage Device"
On next boot screen (it will say Merry Christmas), choose "Boot Mac OS X from USB". Do not choose any option saying "EFI" or "UEFI".
When presented with the OSX installer screen, go to the top menu, choose Disk Utility.
Partition your laptop's hard drive to one partition, GUID, Mac OS Extended (Journaled). For example, give your partition a name "YOUR_PARTIION_NAME".
Click through all the prompts and at the last prompt, choose your newly created partition and not the USB drive.
The install will take about 20 minutes and reboot automatically
On reboot, on the BIOS screen, hit the F12 button repeatedly to get to the boot menu.
Choose "USB Storage Device"
On next boot screen (it will say Merry Christmas), choose "Boot Mac OS X from YOUR_PARTIION_NAME". Do not choose any option saying "EFI" or "UEFI".
Once booted, you'll be prompted with GUI prompts for setting up your new Hackintosh. Connect to Wi-Fi.
I chose not to transfer information to this Mac or sign with Apple ID.
Create a computer account, username, password.
Open your "Boot and Install pack.zip" and unzip. Run Clover_v2k_r2953.pkg.
If you get a security prompt, go to System Preferences\Security and Privacy. Click the button to "Open Anyway".
While running the pkg, make sure you change the destination to your computer's hard drive
Click the customize button. Choose:Install Clover in the ESP
Bootloader\Install boot0af in MBR (only this option)
CloverEFI\CloverEFI 64-bits SATA (only this option)
Themes\AppleStyle
Drivers64UEFI\EmuVariableUefi-64 (only this option)
Enter your password
From the pack on your USB, copy "Kext Utility" to your desktop.
If you get a security prompt, go to System Preferences\Security and Privacy. Click the button to "Open Anyway".
Open Finder and navigate to the unzipped files of 0X574R. Select all files from 0X574R/kext/10.10 folder onto the "Kext Utility" icon on your desktop.
Enter your password. Quit when done.
Open Finder. In the left pane, you'll see "EFI". This is the destination for the steps below.
Copy dsdt.aml from 0X574R/ACPI/Patched to /EFI/Clover/ACPI/Patched
Replace config.plist from /0X574R to /EFI/Clover/config.plist
Eject USB.
Reboot the computer. You won't need to hit the F12 button again on reboot but you need to choose "Boot Mac OS X from YOUR_PARTIION_NAME".
OPTIONAL - drag and drop DellBluetoothHCI.kext to "Kext Utility" on your desktop.
Open the Launchpad dock icon -> Other -> Audio MIDI Setup.
In the left hand pane, choose "Built-in Output". Close window.Open System Preferences -> Sound.
Click the "Output" tab.
Choose "Internal Speakers"
Optional - click "Show volume in menu bar"
POST INSTALL NOTES:
Backup, backup, backup using Carbon Copy Cloner (CCC) to both file and to partition on external hard drive and thumb drive.
Create a bootable thumb drive with the base image you want to keep (everything working and base software such as Office). Activate all software.
insert thumb drive of 16 GB into your Hackintosh
Open Disk Utility
Repartition as one partition using Mac OS Extended (Journaled)
Use GUID partitioning scheme
Name the partition whatever you want but not the same name as your hard drive
Using CCC, copy your hard drive to the thumb drive
Open your "Boot and Install pack.zip" and unzip. Run Clover_v2k_r2953.pkg.
If you get a security prompt, go to System Preferences\Security and Privacy. Click the button to "Open Anyway".
While running the pkg, make sure you change the destination to your thumb drive
Click the customize button. Choose:Install Clover in the ESP
Bootloader\Install boot0af in MBR (only this option)
CloverEFI\CloverEFI 64-bits SATA (only this option)
Themes\AppleStyle
Drivers64UEFI\EmuVariableUefi-64 (only this option)
Enter your password
Test your USB backup drive by doing a fresh boot
Copy your working custom kexts to a safe folder. Copy "Kext Utility" to the same safe folder.
Never use the Apple App Store to update the Mac OS (You can run the non-OS updates like iTunes). Open a browser, search for "combo update 10.10.x" and download the DMG file and run it manually.
After update, if things don’t work such as boot, kexts, etc., redo the steps to install Clover back to your HD with the same options as above. Boot up your computer and update kexts using “Kext Utility†on your desktop with working kexts. If all else fails, boot to your USB backup thumb drive.