From e83408ce83fc3c49fd104c13e6e7566c9db8ed4d Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Mon, 29 Dec 2003 22:00:00 -0500
Subject: [PATCH] Import backup from 2003-12-29

---
 kernel.c |  9 ++++----
 vmm.c    | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++++++--
 vmm.h    | 27 +++++++++++++++++++++++-
 3 files changed, 90 insertions(+), 8 deletions(-)

diff --git a/kernel.c b/kernel.c
index 91960ff..e28fe35 100644
--- a/kernel.c
+++ b/kernel.c
@@ -62,16 +62,15 @@ void k_init()
 	kbd_resetLEDs();		//after enabling interrupts!!
 	if (videoMode)
 	{
-		int x, y;
-		for (x = 0; x < video_mode.XResolution; x++)
-			for (y = 0; y < video_mode.YResolution; y++)
-				video_pset(x, y, 0x00000044);
+		int p = video_mode.XResolution*video_mode.YResolution-1;
+		for (; p >= 0; p--)
+			video_psetp(p, 0x00000044);
 		video_drawConsole();
 	}
 
 	printf("HOS 0.13 - Kernel Size: %u kb\n", kernel_size()>>10);
 	printf("Memory available to OS: %u MB (Bytes: %u)\n", mm_megabytes, mm_totalmem);
-	printf("Free memory: %u bytes\t %u pages\n", mm_freemem(), mm_freemem()>>12);
+	printf("Free memory: %u bytes (%u pages)\n", mm_freemem(), mm_freemem()>>12);
 
 	dword key = 0;
 	for (;;)
diff --git a/vmm.c b/vmm.c
index bb66ba3..f748317 100644
--- a/vmm.c
+++ b/vmm.c
@@ -18,9 +18,34 @@ void	vmm_init()
 			vidPages = (vidPages >> 12);
 		vmm_mapn(0xF0000000, video_mode.PhysBasePtr, vidPages);
 	}
+	dword firstHeapEntryBlock = (dword)mm_palloc();
+	vmm_map1((dword)firstHeapEntry, firstHeapEntryBlock);
+	HeapEntryBlock *heb = (HeapEntryBlock *)firstHeapEntry;
+	vmm_heb_init(heb);
+	heb->entry[0].base = (dword)firstHeapEntry;	//start of kernel's heap memory
+	heb->entry[0].size = 4096;			//the first HeapEntryBlock is 1 page long
+	heb->entry[0].attributes = VMM_HE_HEB;		//this is a HeapEntryBlock
+	heb->entry[1].base = (dword)firstHeapEntry+4096;	//this is the start of the rest of the kernel's heap memory
+	heb->entry[1].size = 0x10000000-4096;		//the rest of the kernel's heap memory: 256mb - 4kb
+	heb->entry[1].attributes = VMM_HE_HOLE;		//this is a hold - an unmapped section of heap memory
 }
 
 
+void	vmm_heb_init(HeapEntryBlock *heb)
+{
+	int a;
+	for (a = 0; a < 256; a++)
+	{
+		heb->entry[a].base = 0;
+		heb->entry[a].size = 0;
+		heb->entry[a].attributes = VMM_HE_UNUSED;
+		heb->entry[a].link = (dword)&(heb->entry[a+1]);
+	}
+	heb->entry[255].link = 0;
+}
+
+
+
 void	vmm_map1(dword virt, dword physical)
 {
 	dword pde = virt >> 22;
@@ -40,6 +65,7 @@ void	vmm_map1(dword virt, dword physical)
 	}
 	dword *pteptr = (dword *)(0xFFC00000 | (pde << 12) | (pte << 2));
 	*pteptr = physical | 0x03;
+	invlpg(virt);
 }
 
 
@@ -54,11 +80,43 @@ void	vmm_mapn(dword virt, dword physical, dword n)
 }
 
 
+void	vmm_unmap1(dword virt)
+{
+	dword *pteptr = (dword *)(0xFFC00000 | ((virt & 0xFFC00000) >> 10) | ((virt & 0x003FF000) >> 10));
+	*pteptr = 0;
+ 	invlpg(virt);
+}
+
+
+void	vmm_unmapn(dword virt, dword n)
+{
+	for (; n > 0; n--)
+	{
+		vmm_unmap1(virt);
+		virt += 4096;
+	}
+}
+
 
 void	*malloc(dword bytes)
 {
-
-
+	HeapEntry *he = firstHeapEntry;
+	for (;;)
+	{
+		if ((he->size >= bytes) && (he->attributes = VMM_HE_FREE))
+		{
+			if (he->size == bytes)
+			{
+				he->attributes = VMM_HE_USED;
+				return (void *)(he->base);
+			}
+			else
+			{
+				//get the next HeapEntry, save in it the free mem, save in this entry the used mem...
+			}
+		}
+	}
+	return 0;
 }
 
 
diff --git a/vmm.h b/vmm.h
index ca3f890..a94b66e 100644
--- a/vmm.h
+++ b/vmm.h
@@ -1,16 +1,41 @@
-
 // vmm.h
 // Author: Josh Holtrop
 // Date: 09/30/03
 // Rewritten from scratch: 12/23/03
+// Modified: 12/29/03
 
 
+#define	VMM_HE_UNUSED	0		//available entry
+#define	VMM_HE_FREE	1		//free section of memory
+#define	VMM_HE_USED	2		//used section of memory
+#define	VMM_HE_HOLE	3		//a "hole" (unmapped) section of virtual memory
+#define	VMM_HE_HEB	4		//HeapEntryBlock
+
+
+typedef struct {
+	dword	base;			//virtual base address
+	dword	size;			//size in bytes
+	dword	attributes;		//free/used/hole
+	dword	link;			//link to next HeapEntry
+} __attribute__((packed)) HeapEntry;
+
+
+typedef struct {
+	HeapEntry	entry[256];	//256 HeapEntry objects = 4kb (1 page)
+} __attribute__((packed)) HeapEntryBlock;
+
 
 void	vmm_init();
 void   *malloc(dword bytes);
 int	free(void *ptr);
 void	vmm_map1(dword virt, dword physical);
 void	vmm_mapn(dword virt, dword physical, dword n);
+void	vmm_unmap1(dword virt);
+void	vmm_unmapn(dword virt, dword n);
+void	vmm_heb_init(HeapEntryBlock *heb);
+
+
+HeapEntry *firstHeapEntry = (HeapEntry *)0xD0000000;