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post #21 of (permalink) Old 07-04-2013, 08:41 PM
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@TELVM: Many thanks to you for pointing into the right direction with the link! Much appreciated!!!

I tested it on XP SP3 with the hal.dll from XP SP1 and it worked. Be careful I have not done a lot of tests, but connecting a USB stick worked.
Be advised that the link patches another location very near my patching location. But in my opinion the patch from the link only enables up to 16 GB RAM instead of mine which should enable 64 GB RAM.

For XP SP3 we patch the following offset in ntkrpamp.exe which enables all available RAM up to 64 GB:
- WinDbg "bp nt!MiPagesInLoaderBlock+0x5d" from
e0d73851 751b jne nt!MiPagesInLoaderBlock+0x7a (e0d7386e)
e0d73851 90 nop
e0d73852 90 nop
- IDA from
INIT:005D0851 jnz short loc_5D086E
INIT:005D0851 nop
INIT:005D0852 nop
- hex editor offset 0x1B2A51 from
75 1B
90 90

After ntkrpamp.exe is changed we have to do the following to replace the original kernel file:
- correct the checksum of ntkrpamp.exe with LordPE
- add /PAE switch to boot.ini
Do not omit this step otherwise we can not address the full RAM! This is necessary, because
we will use hal.dll from XP SP1.
- replace the original kernel file by the patched one:
- rename the file "C:\Windows\Driver Cache\i386\driver.cab" to "driver.cab_"
- rename the file "C:\Windows\Driver Cache\i386\sp3.cab" to "sp3.cab_"
- rename the file "C:\Windows\system32\ntkrnlpa.exe" to "ntkrnlpa.exe_"
- cancel the "Windows File Protection" message box and choose "Yes"
- copy the patched file ntkrpamp.exe to "C:\Windows\system32\ntkrnlpa.exe"
- cancel the "Windows File Protection" message box and choose "Yes"
- rename the file "C:\Windows\system32\hal.dll" to "hal.dll_"
- copy hal.dll from XP SP1 (internal file name halmacpi.dll) to "C:\Windows\system32\hal.dll"
- do not forget to add the boot.ini switch /PAE, otherwise we can not address the full RAM,
because we use hal.dll from XP SP1
- reboot

Again many thanks to TELVM for clearing things up!
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