Q: 24" iMac Screen Freezes since 10.6.3 update - pls help!

Hi, for myself (running iMac 20" with AMD2400), initially trying

the "run-always-as-root, do-the-kext-install-dance-after-setting-kext-dev-mode=1"

to upgrade to 10.10.5 did not work for me, but following DjeffreyDjevrick's tip

of Aug. 14 (set kextmode as single-user) did the trick, so thanks for that!

I've not been brave enough to try El Capitan yet, but perhaps this will require

at least doing:

          sudo nvram boot-args="rootless=0"

I've learning after many upgrades from 10.6.2 that there always seems to

be something new required with each new release, so I am used to going

into safe mode until I'm certain those kext's are really loaded.

Hi Running an iMac mid 2008 with ATI 2600.

Logging in as root user and following the instructions seems to have worked again for 10.10.5

Will El Capitan run on my machine I wonder?

It cannot be long before it falls off the support list.

rootless=0 and kext-dev-mode=1 are not working under El Capitan.

you have to boot your mac into recovery mode, and disable system integrity protection there.

otherwise no unsigned kexts may be loaded.

instructions: http://totalspaces.binaryage.com/elcapitan

Cool swmaster! So after system integrity protection has been disabled the kexts work fine under El Capitan with no freezes?

They ought to. Did not verify it though. I was running into the same issue (unsigned kexts fail to load) with my MBA

running the official version of El Capitan. then i found info about rootless=0 being unsupported and thought it is

worthwhile to share with you the only possible way to put unsigned kexts to work under El Cap.

let me turn it a bit around: w/o this you have no chance to load the old ATI kexts.

on the other hand, there may be some other issues that will keep you from using them

successfully. I will give a try sometimes next week, and report back my findings.

did it. everything seems to be OK. after going into recovery mode and disabling system integrity check, one has to reboot so the changes can take place.

my iMac booted and i saw, that in addition to the new AMDSupport/AMDFramebuffer/AMD2400Controller kexts the OS also booted ATISupport.

  70    2 0xffffff7f82556000 0x125000  0x125000  com.apple.kext.AMDSupport (1.3.6) 83090AC0-12F4-3913-875B-34864770E7AD <69 68 12 11 7 5 4 3 1>

  71    0 0xffffff7f826be000 0x183000  0x183000  com.apple.kext.AMD2400Controller (1.3.6) 7ACC06ED-1DF1-3BDD-BE0F-9868CBA5802E <70 68 12 11 5 4 3 1>

  118    0 0xffffff7f81a52000 0x230000  0x230000  com.apple.ATIRadeonX2000 (10.0.0) FC15384B-F906-3FC1-9E64-2116EBA8CF2A <68 12 7 6 5 4 3 1>

  119    0 0xffffff7f82689000 0x22000    0x22000    com.apple.kext.AMDFramebuffer (1.3.6) 062D84C5-444E-374A-A4CD-D15BF1DAC978 <70 68 12 11 7 5 4 3 1>

  121    0 0xffffff7f8293e000 0x45000    0x45000    com.apple.kext.ATISupport (6.0.6) 32B62390-C30A-56D0-16D8-3FC746B9B298 <68 12 11 7 5 4 3 1>

as you can see, all the new AMDxxx kexts rely on AMDSupport (70) instead of ATISupport, so as usually I had to remove the AMDxxx ones. after deleting (of course i made copies before i did so) AMDSupport/AMDFramebuffer and AMD2400Controller, i had to wait for the kext caches to rebuild. Then i was able to reboot the iMac. it booted and right now it shows the usual kexts:

com.apple.kext.ATISupport (6.0.6)

com.apple.kext.ATI2400Controller (6.0.6)

com.apple.ATIRadeonX2000 (10.0.0)

com.apple.kext.ATIFramebuffer (6.0.6)

So besides of ATIRadeonX2000 everything comes from 10.6.2.

there is a small difference i noticed during the procedure. as El Capitan was booting with it's original kexts, the login screen was black. as i replaced them with the old ones, the login screen shows my desktop blurred. maybe it's just a coincidence, i'll report if i notice some more systematic behaviour on that.

i had to say that i did not have freezes with the original El Capitan GM, but i was using it like for 10-15 minutes.

Hello to all you guys.

First of all sorry for my bad English.

I installed El Capitan 10.11 (15A284) on my iMac mid 2007 with the ATI Radeon HD 2400 XT 128 MB,

and found the same old problems of screen freeze, usual symptoms. So I decided to try with the dear old kext ATI.
This is the procedure that worked for me, using EasyKext Utility and SIPUtility.app by CVAD.

1) restarted in safe mode (cmd + r)
2) open the terminal by entering the command csrutil disable
3) Restart
4) in the folder system / library / extensions eliminated

AMD2400Controller.kext
AMDFramebuffer.kext
AMDSupport.kext
by backing up first
5) used EasyKext Utility to install

ATI2400Controller.kext

ATIFramebuffer.kext

ATISupport.kext
6) used to validate kext SipUtility kext using the first flag "CSR_ALLOW_UNTRUSTED_KEXT"
7) restart in safe mode
8) open the terminal by entering the command csrutil enable
9) restart

Now ATI extensions are loaded even if unknown and everything seems to work well (3 days without rebooting).
In recent years these pages I have been very useful, I thank all those who helped, hoping to have given my small contribution

Hi, Davide.  Thank you for the clear and detailed posting.  So if I understand correctly, you are turning off System Integrity Protection in El Capitan, then installing the old ATI kext files, then validating them through Terminal, then re-enabling System Integrity Protection.  If this is true and the System Information panel is showing these ATI extensions as actually enabled after your restart (Step 9), then this means you have found a way to install the old kexts without having to keep System Integrity Protection turned off.  If this is the case, then great news and thanks very much! - Tony

Hi aieronimo,

yes it's exactly what i did.

Below what I got doing "csrutil status" on Terminal:

Last login: Mon Oct  5 12:09:40 on console

def:~ def1$ csrutil status

System Integrity Protection status: enabled.

def:~ def1$

A screenshot of current extension

Description

ATIFramebuffer:

  Versione: 1.6.6

  Ultima modifica: 03/10/15, 10:15

  ID bundle: com.apple.kext.ATIFramebuffer

  Caricato: Sì

  Informazioni: ATIFramebuffer 1.6.6.25 (7429)

  Ottenuto da: Sconosciuta/o

  Tipo: Intel

  Architetture: i386, x86_64

  64-bit (Intel): Sì

  Posizione: /System/Library/Extensions/ATIFramebuffer.kext

  Versione kext: 6.0.6

  Indirizzo di caricamento: 18446743521840400000

  Caricabile: No

  Errori di convalida firma: Kext signature validation error code -67061

  Dipendenze: Soddisfatte

  Firmato da: Sconosciuta/o

ATI2400Controller:

  Versione: 1.6.6

  Ultima modifica: 03/10/15, 10:15

  ID bundle: com.apple.kext.ATI2400Controller

  Caricato: Sì

  Informazioni: ATI2400Controller 1.6.6.25 (7429)

  Ottenuto da: Sconosciuta/o

  Tipo: Intel

  Architetture: i386, x86_64

  64-bit (Intel): Sì

  Posizione: /System/Library/Extensions/ATI2400Controller.kext

  Versione kext: 6.0.6

  Indirizzo di caricamento: 18446743521840500000

  Caricabile: No

  Errori di convalida firma: Kext signature validation error code -67061

  Dipendenze: Soddisfatte

  Firmato da: Sconosciuta/o

ATISupport:

  Versione: 1.6.6

  Ultima modifica: 03/10/15, 10:15

  ID bundle: com.apple.kext.ATISupport

  Caricato: Sì

  Informazioni: ATISupport 1.6.6.25 (7429)

  Ottenuto da: Sconosciuta/o

  Tipo: Intel

  Architetture: i386, x86_64

  64-bit (Intel): Sì

  Posizione: /System/Library/Extensions/ATISupport.kext

  Versione kext: 6.0.6

  Indirizzo di caricamento: 18446743521837200000

  Caricabile: No

  Errori di convalida firma: Kext signature validation error code -67061

  Dipendenze: Soddisfatte

  Firmato da: Sconosciuta/o

I hope this helps , let me know if everything works for you

Thanks again.  I happen to speak Italian, so see that each ATI kext is loaded ("caricato").  I see, though, that each kext is not listed as loadable ("caricabile").  I assume that does not matter so long as "caricato" shows si' ("yes").

When you go to System Information panel, then to Software, and then to Kexts - where it shows the master list of loaded kexts - do these three ATI kexts show as loaded?

(I am not in front of my iMac at the moment, so the path above may not be exactly correct.)

Thanks again. - Tony

Hi Tony,

in the System Information panel/software/extension it show caricato=si (loaded=yes) as you can see in my previous screenshot.

It's strange  it's show "not loadable" but is loaded. Everything is ok at the moment, no more freezes since 03/10/15.

Thanks again for this tip.  I will not be able to try it out on my system for some time, as I am checking other programs for El Capitan compatibility before installing the new OS.  (It could take several weeks....)  But I really appreciate this tip. - Tony

Finally did another update on my iMac 2007.  I gave up at 10.9.4  and missed out Yosemite completely.  I did the El Capitan update last night and followed the instructions posted by davidefrombruino - Oct 4, 2015 11:30 PM

Everything went ok,  although my system was freezing for fun immediately after the El Cap upgrade and right through to patching the kext,  including just after I deleted the AMD Kext files but before I could install the ATI ones    so after about 6 hard shutdowns,  I finally got my system running stable with El Capitan.

I had already used the SipUtility to validate the kext but on re-enabled the System Integrity Protection using "csrutil enable" and then rebooting by second monitor failed to be enabled.

The ATI Kext were flagged as "Kext signature validation error code -67061"

System running fine though on both monitors with SIP disabled.

I did the El Capitan update today and followed the instructions posted by davidefrombruino, but with the ATI2600controller.kext, because I have the 24" iMac from 2008.

So far no freezes and everything works fine. 

Thanks for the guide davidefrombruino !

davidefrombruino  for president!!

iMac Early 2008 and Ati 2600Pro now works fine