- Initialize count of System PTEs:

- Initialize count of System PTEs:
  - Use 7000 for systems with 19MB of RAM or less, 11000 for systems between 19 and 32MB of RAM, and 22000 for systems with more than that.
  - Windows will go up to 50000 on server machines, but this is likely not needed now (22000 system PTEs is roughly 100 MB).
  - This now affects the calculation of MmNonPagedSystemStart, which is now correct and reflects the nonpaged address space of the system.
  - System PTEs are not yet initialized (but their page tables are mapped by the same code which maps nonpaged pool expansion VA page tables).

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