Ok, so thanks to this post I was actually able to get OS X to boot on the 5420. Thank Bob for that. I got the /Extra folder and the corrected DSDT.aml for the 1366 x 768 resolution.
Then, I had an issue with the Installer wanting me to connect a bluetooth keyboard (prior to selecting the language), even though the built-in keyboard works (on Chameleon, anyway). Well, I disabled bluetooth in the BIOS, and it stopped doing that. However, after selecting the language, installer crashes and gives an error log. I managed to save it. It is attached. At this point, I'm lost. I dont know how to read Mac logs. I've become accustomed to Linux (minorly) but I'm primarily used Windows my whole life. I DO have OS X 10.9 on a Dell Optiplex 960, and it works good (installed using directions from http://tonycrapx86.org using his unifail installation method. Guess what, that doesn't work on these KP's out the wazoo).
I've used both AHCI and ATA hard drive modes (neither had an effect on the outcome, either way). I dont know if there's other BIOS settings I need to alter. I'm hoping to overcome obstacles here with this post
Any help is appreciated.
Installer Log 30-Jan-2014.txt
-----EDIT-----
Ok, so OS X 10.9 is a go. Still haven't run EDP because there is not an EDP profile for the 5420. I have created a thread in the EDP subforum.
Works:
Built In Sound
Sound hardware keys (Vol+, Vol-, Mute)
Bluetooth
Built in laptop monitor
Built in keyboard (Fix Command/Apple key switch: System Preferences ==> Keyboard ==> Modifier Keys ==> change Command Key to Option Key, and Option key to Command Key. Thanks to npjohnson)
Built in Mouse (as a mouse, not as a trackpad, no gestures)
Function + Up/Down Arrow to adjust brightness
Sleep/Suspend Middle mouse mini-joystick thingy that nobody ever uses
Hardware Bluetooth/WiFi switch
Internal Mic
IEEE 1394 (Untested by me, but supported OOB, reported by npjohnson post 30)
Does Not Work:
Built In Ethernet (even with BCM57XX Kext)
Built In Intel WiFi (obviously. Ordered Dell WiFi card and it worked without any further installation/configuration)
HDMI Video Out
HDMI Audio
VGA Out
Untested:
SD Card slot
Express Card (Reports of it working OOB on E6420, untested on E5420. I dont have any EC hardware )
ON A SIDE NOTE:
2 things I'd like to see fixed, but are in no way hindering operation:
On integrated keyboard, ALT key is acting as Super (Apple Logo) key. Windows key (Super) is assumedly acting as ALT key, don't know the function of ALT on Macs, don't know how to test. Known fix?
Integrated mouse trackpad does not seem to support gestures (my primary usage is for scrolling). Is there a known fix for this?