From cb944fc8a944abe6921f7477cf73fc4b23e713a5 Mon Sep 17 00:00:00 2001
From: John Hodge <tpg@mutabah.net>
Date: Fri, 28 May 2010 23:32:38 +0800
Subject: [PATCH] Untested work on physical mm setup

---
 Kernel/arch/x86_64/include/mm_virt.h |  2 +
 Kernel/arch/x86_64/mm_phys.c         | 59 +++++++++++++++++++++++++++-
 2 files changed, 60 insertions(+), 1 deletion(-)

diff --git a/Kernel/arch/x86_64/include/mm_virt.h b/Kernel/arch/x86_64/include/mm_virt.h
index 206dcd93..26753362 100644
--- a/Kernel/arch/x86_64/include/mm_virt.h
+++ b/Kernel/arch/x86_64/include/mm_virt.h
@@ -29,6 +29,7 @@
  *       D000 00000000 -       D080 00000000	39	512	GiB	Per-Process Data
  *       D080 00000000 -       D100 00000000	39	512	GiB	Kernel Supplied User Code
  *       E000 00000000 -       E400 00000000	42	4	TiB	Physical Page Reference Counts (2**40 = 2**52 bytes)
+ *       E400 00000000 -       E400 80000000	31	2	GiB	Physical Page Super Bitmap (64 pages per bit)
  *       FD00 00000000 -       FD80 00000000	39	512 GiB	Local APIC
  *       FE00 00000000 -       FE80 00000000	39	512 GiB	Fractal Mapping (PML4 510)
  *       FE80 00000000 -       FF00 00000000	39	512 GiB	Temp Fractal Mapping
@@ -55,6 +56,7 @@
 #define MM_PPD_VFS  	(KERNEL_BASE|(0xD008##00000000))
 #define MM_USER_CODE	(KERNEL_BASE|(0xD080##00000000))
 #define MM_PAGE_COUNTS	(KERNEL_BASE|(0xE000##00000000))
+#define MM_PAGE_SUPBMP	(KERNEL_BASE|(0xE400##00000000))
 
 #define MM_LOCALAPIC	(KERNEL_BASE|(0xFD00##00000000))
 #define MM_FRACTAL_BASE	(KERNEL_BASE|(0xFE00##00000000))
diff --git a/Kernel/arch/x86_64/mm_phys.c b/Kernel/arch/x86_64/mm_phys.c
index 5a5f5eab..92a38f2a 100644
--- a/Kernel/arch/x86_64/mm_phys.c
+++ b/Kernel/arch/x86_64/mm_phys.c
@@ -37,6 +37,7 @@ void MM_InitPhys_Multiboot(tMBoot_Info *MBoot)
 	tMBoot_MMapEnt	*ent;
 	Uint64	maxAddr = 0;
 	 int	numPages;
+	 int	superPages;
 	
 	Log("MM_InitPhys_Multiboot: (MBoot=%p)", MBoot);
 	
@@ -74,6 +75,7 @@ void MM_InitPhys_Multiboot(tMBoot_Info *MBoot)
 	// Find a contigous section of memory to hold it in
 	// - Starting from the end of the kernel
 	// - We also need a region for the super bitmap
+	superPages = ((giMaxPhysPage+64*8-1)/(64*8) + 0xFFF) >> 12;
 	numPages = (giMaxPhysPage + 7) * sizeof(*gaiPageReferences);
 	numPages = (numPages + 0xFFF) >> 12;
 	Log(" MM_InitPhys_Multiboot: numPages = %i", numPages);
@@ -97,7 +99,58 @@ void MM_InitPhys_Multiboot(tMBoot_Info *MBoot)
 	// Scan for a nice range
 	else
 	{
-		
+		 int	todo = numPages + superPages;
+		tPAddr	paddr = 0;
+		tVAddr	vaddr = MM_PAGE_COUNTS;
+		// Scan!
+		for(
+			ent = mmapStart;
+			(Uint)ent < (Uint)mmapStart + MBoot->MMapLength;
+			ent = (tMBoot_MMapEnt *)( (Uint)ent + ent->Size )
+			)
+		{
+			 int	avail;
+			
+			// RAM only please
+			if( ent->Type != 1 )
+				continue;
+			
+			// Let's not put it below the kernel, shall we?
+			if( ent->Base + ent->Size < (tPAddr)&gKernelEnd )
+				continue;
+			
+			// Check if the kernel is in this range
+			if( ent->Base < (tPAddr)&gKernelEnd - KERNEL_BASE && ent->Base + ent->Size > (tPAddr)&gKernelEnd )
+			{
+				avail = (ent->Size-((tPAddr)&gKernelEnd-KERNEL_BASE-ent->Base)) >> 12;
+				paddr = (tPAddr)&gKernelEnd - KERNEL_BASE;
+			}
+			// No? then we can use all of the block
+			else
+			{
+				avail = ent->Size >> 12;
+				paddr = ent->Base;
+			}
+			
+			// Map
+			// - Counts
+			if( todo ) {
+				 int	i, max;
+				max = todo < avail ? todo : avail;
+				for( i = 0; i < max; i ++ )
+				{
+					MM_Map(vaddr, paddr);
+					todo --;
+					vaddr += 0x1000;
+					paddr += 0x1000;
+				}
+				// Alter the destination address when needed
+				if(todo == superPages)
+					vaddr = MM_PAGE_SUPBMP;
+			}
+			else
+				break;
+		}
 	}
 	
 	// Fill the bitmaps
@@ -120,6 +173,10 @@ void MM_InitPhys_Multiboot(tMBoot_Info *MBoot)
 			(ent->Size>>12)*sizeof(*gaiPageReferences)
 			);
 	}
+	
+	// Reference the used pages
+	// - Kernel
+	// - Reference Counts and Bitmap
 }
 
 /**
-- 
2.20.1