Resolving Black Screen After "End RandomSeed" on HP EliteBook 8540w with OpenCore 1.0.2

The black screen after "End RandomSeed" typically points to misconfigured GPU settings, framebuffer issues, or missing ACPI patches in your OpenCore configuration. Let’s break this down systematically and get your HP EliteBook 8540w moving past this error while installing macOS High Sierra.

Step-by-Step Troubleshooting

1. Verify OpenCore Version

• OpenCore 1.0.2 is quite old; consider updating to at least OpenCore 0.9.x, which has better debug capabilities and more stable support for older hardware like yours.
• Updating OpenCore involves replacing the bootloader files in the EFI partition and updating your config.plist to match the newer schema.

2. Fix GPU (nVidia FX 1800M) Issues

The nVidia FX 1800M (Fermi architecture) requires Web Drivers to function on macOS High Sierra. However, during the installer phase, macOS will attempt to use a basic framebuffer, which can cause the black screen issue.

Steps to fix GPU issues:

1. Inject nVidia Framebuffer:

   • In your config.plist, under DeviceProperties, ensure:
     • boot-args includes:

       text
       Copy code
       nv_disable=1
       

       This disables the nVidia GPU during installation.

2. Disable Internal Graphics (if any):

   • Check your BIOS to ensure any onboard Intel HD graphics are disabled, as macOS High Sierra struggles with older Intel iGPUs.

3. Add nVidia Web Driver Support (Post-Installation):

   • After installation, enable nVidia Web Drivers for full GPU functionality:
     • Add the following to boot-args:

       text
       Copy code
       nvda_drv=1
       

3. Address ACPI and SSDT Issues

Misconfigured or missing ACPI patches can also cause issues after "End RandomSeed".

Steps to resolve ACPI issues:

1. Use Prebuilt SSDTs:

   • If SSDTTime patches didn’t solve your problem, use prebuilt SSDTs from the Dortania guide:
     • Download SSDT-EC-USBX and SSDT-PLUG.
     • Place them in your EFI/OC/ACPI folder.
     • Add references to these SSDTs in the config.plist.

2. Verify SMBIOS:

   • Use a compatible SMBIOS for High Sierra:
     • For your hardware, use MacBookPro6,2 or MacBookPro8,2.
     • Update this in your config.plist under PlatformInfo > Generic.

4. Fix USB Installer Boot

Improper USB configuration can cause boot issues, especially if the BaseSystem.dmg or USB is not detected correctly.

Steps to resolve USB issues:

1. Ensure Proper USB Mapping:

   • Add USBInjectAll.kext to the EFI/OC/Kexts folder.
   • Use the boot-arg:

     text
     Copy code
     -uia_exclude=HS14
     

     Replace HS14 with the USB ports you don’t use if necessary.

2. Disable "HideAuxiliary" Setting:

   • Keeping "HideAuxiliary" disabled is fine if it allows you to access BaseSystem.dmg.

5. Enable Debugging

Enable OpenCore debug logs to gather more insights into the black screen issue.

Steps to enable debugging:

1. In config.plist, under NVRAM > Add > boot-args, include:

   text
   Copy code
   -v keepsyms=1 debug=0x100 alcid=1
   

2. Under Misc > Debug, set:

   • AppleDebug: True
   • ApplePanic: True
   • SysReport: True
   • Target: 67

3. Collect logs from the EFI partition to analyze boot issues if the system still fails.

6. BIOS Configuration

Ensure your BIOS is correctly configured:

1. Disable Secure Boot.
2. Disable VT-d (unless patched in OpenCore).
3. Set SATA Mode to AHCI.
4. Disable Legacy Boot/CSM.
5. Enable UEFI Boot.

7. Validate Config.plist

Use the OpenCore Configurator or Dortania’s Validation Tools to ensure your config.plist adheres to the correct schema:

• Validate entries for:
  • DeviceProperties.
  • ACPI.
  • NVRAM.
  • Booter.
  • Kernel.

Next Steps

1. Update your OpenCore to a newer version.
2. Apply the fixes above (especially GPU boot-args and SSDTs).
3. Reboot in Verbose Mode (-v) to capture detailed logs.
4. If the issue persists, share updated debug logs for further analysis.

By methodically addressing each of these areas, you should be able to bypass the black screen issue and successfully install macOS High Sierra on your HP EliteBook 8540w. Let me know how it goes!