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+# x86_32 PAE documentation
+
+Due to missing x86_64 support it's required to use PAE enabled x86_32 code.
+The corresponding functions can be found in ``src/cpu/x86/pae/``.
+
+## Memory clearing helper functions
+
+To clear all DRAM on request of the
+[Security API](../../security/memory_clearing.md), a helper function can be used
+called `memset_pae`.
+The function has additional requirements in contrast to `memset`, and has more
+overhead as it uses virtual memory to access memory above 4GiB.
+Memory is cleared in 2MiB chunks, which might take a while.
+
+Make sure to enable caches through MTRRs, otherwise `memset_pae` will be slow!