+ * \brief Clone a page from an entry
+ * \param Ent Pointer to the entry in the PML4/PDP/PD/PT
+ * \param NextLevel Pointer to contents of the entry
+ * \param Addr Dest address
+ * \note Used in COW
+ */
+void MM_int_ClonePageEnt( Uint64 *Ent, void *NextLevel, tVAddr Addr, int bTable )
+{
+ tPAddr curpage = *Ent & PADDR_MASK;
+ int bCopied = 0;
+
+ if( MM_GetRefCount( curpage ) <= 0 ) {
+ Log_KernelPanic("MMVirt", "Page %P still marked COW, but unreferenced", curpage);
+ }
+ if( MM_GetRefCount( curpage ) == 1 )
+ {
+ *Ent &= ~PF_COW;
+ *Ent |= PF_PRESENT|PF_WRITE;
+ Log_Debug("MMVirt", "COW ent at %p (%p) only %P", Ent, NextLevel, curpage);
+ }
+ else
+ {
+ void *tmp;
+ tPAddr paddr;
+
+ if( !(paddr = MM_AllocPhys()) ) {
+ Threads_SegFault(Addr);
+ return ;
+ }
+
+ ASSERT(paddr != curpage);
+
+ tmp = (void*)MM_MapTemp(paddr);
+ memcpy( tmp, NextLevel, 0x1000 );
+ MM_FreeTemp( (tVAddr)tmp );
+
+ Log_Debug("MMVirt", "COW ent at %p (%p) from %P to %P", Ent, NextLevel, curpage, paddr);
+
+ MM_DerefPhys( curpage );
+ *Ent &= PF_USER;
+ *Ent |= paddr|PF_PRESENT|PF_WRITE;
+
+ bCopied = 1;
+ }
+ INVLPG( (tVAddr)NextLevel );
+
+ // Mark COW on contents if it's a PDPT, Dir or Table
+ if(bTable)
+ {
+ Uint64 *dp = NextLevel;
+ int i;
+ for( i = 0; i < 512; i ++ )
+ {
+ if( !(dp[i] & PF_PRESENT) )
+ continue;
+
+ if( bCopied )
+ MM_RefPhys( dp[i] & PADDR_MASK );
+ if( dp[i] & PF_WRITE ) {
+ dp[i] &= ~PF_WRITE;
+ dp[i] |= PF_COW;
+ }
+ }
+ }
+}
+
+/*