Import backup from 2004-07-29

Makefile

@@ -12,9 +12,8 @@ all:
 #	make -C rmmod
 
 clean:
-	make -C kernel clean
-	make -C include clean
-#	make -C rmmod clean
+	- make -C kernel clean
+	- make -C rmmod clean
 	- rm *~ hos.flp
 
 

kernel/kernel.c

@@ -96,6 +96,7 @@ void k_init()
 
 void isr(u32_t num)
 {
+	criticalCounter++;
 	for (;;)
 	{
 		(*(char*)(CONSOLE_MEMORY+158))++;
@@ -104,8 +105,10 @@ void isr(u32_t num)
 	{
 
 	}
+	criticalCounter--;
 }
 
+
 void k_enter_critical()		// functions for implementing "atomic actions"
 {
 	disable_ints();

kernel/mm/mm.c

@@ -61,12 +61,9 @@ void	mm_init()
 //  specified in base for a length of pages pages
 void	mm_pfreen(u32_t base, u32_t pages)
 {
-	u32_t a;
-	u32_t max = base + (pages << 12);
-	for (a = base; a < max; a += 4096)
-	{
-		mm_pfree(a);
-	}
+	pages = base + (pages << 12);		//convert #pages to #bytes
+	for (; base < pages; base += 4096)
+		mm_pfree(base);
 }
 
 
@@ -78,7 +75,7 @@ void	mm_pfree(u32_t base)
 	u32_t bitNumber = (base >> 12) & 0x07; //pageNumber % 8;
 	page_bitmap[byteNumber] = page_bitmap[byteNumber] & ((0x01 << bitNumber) ^ 0xFF);
 	mm_freepages++;
-	if (mm_first_free_byte > byteNumber)
+	if (byteNumber < mm_first_free_byte)
 		mm_first_free_byte = byteNumber;
 }
 
@@ -87,12 +84,9 @@ void	mm_pfree(u32_t base)
 //  specified in base for a length of pages pages
 void	mm_preserven(u32_t base, u32_t pages)
 {
-	u32_t a;
-	u32_t max = base + (pages << 12);
-	for (a = base; a < max; a += 4096)
-	{
-		mm_preserve(a);
-	}
+	pages = base + (pages << 12);		//convert #pages to #bytes
+	for (; base < pages; base += 4096)
+		mm_preserve(base);
 }
 
 

kernel/mm/vmm.c

@@ -2,7 +2,7 @@
 // Author: Josh Holtrop
 // Date: 09/30/03
 // Rewritten from scratch: 12/23/03
-// Modified: 07/13/04
+// Modified: 07/29/04
 
 #include "hos_defines.h"
 #include "kernel.h"
@@ -10,14 +10,14 @@
 #include "asmfuncs.h"
 #include "mm/mm.h"
 
-u32_t	vmm_map(void *virt);
+int	vmm_map(void *virt);
 int	vmm_map1(unsigned int virt, unsigned int physical);
 int	vmm_mapn(unsigned int virt, unsigned int physical, unsigned int n);
 void	vmm_unmap1(unsigned int virt);
 void	vmm_unmapn(unsigned int virt, unsigned int n);
 int	vmm_map_range(void *virt_start, void *virt_end, u32_t phys_start);
 void	vmm_heb_init(HeapEntryBlock_t *heb);
-void	vmm_addToQueue(u32_t queue, HeapEntry_t *he);
+void	vmm_addToQueue(u32_t queue, HeapEntry_t *preceeding, HeapEntry_t *he);
 int	vmm_countHeapEntries(HeapEntry_t *he);
 HeapEntry_t *vmm_followChain(HeapEntry_t *he);
 HeapEntry_t *vmm_getUnusedEntry();
@@ -29,8 +29,9 @@ extern	mb_info_t mb_info_block;
 extern	mb_module_t mb_modules[MAX_MODULES];
 extern	u32_t mm_freepages;
 
-HeapEntryQueue_t heapEntryQueues[VMM_HE_TYPES];		// sorted, linked queue of HeapEntry objects
+HeapEntryQueue_t heapEntryQueues[VMM_HE_TYPES];		// linked queue of HeapEntry objects
 HeapEntry_t heapEntryHeadNodes[VMM_HE_TYPES];		// head nodes for linked queues
+HeapEntry_t heapEntryTailNodes[VMM_HE_TYPES];		// tail nodes for linked queues
 HeapEntryBlock_t initialHEB;				// block for initial 256 HeapEntry objects
 
 
@@ -40,33 +41,38 @@ void	vmm_init()
 {
 	int i;
 	for (i = 0; i < mb_info_block.mods_count; i++)	//page in the kernel modules
-		vmm_map_range((void*)mb_modules[i].mod_start, (void*)mb_modules[i].mod_end- 1, mb_modules[i].mod_start - VIRT_OFFSET);
+		vmm_map_range((void*)mb_modules[i].mod_start, (void*)mb_modules[i].mod_end - 1, mb_modules[i].mod_start - VIRT_OFFSET);
+	for (i = 0; i < VMM_HE_TYPES; i++)
+	{
+		heapEntryQueues[i].head = &heapEntryHeadNodes[i];
+		heapEntryHeadNodes[i].next = &heapEntryTailNodes[i];
+		heapEntryTailNodes[i].prev = &heapEntryHeadNodes[i];
+	}
 	vmm_heb_init(&initialHEB);
-	vmm_addToQueue(VMM_HE_UNUSED, &initialHEB.entry[0]);
+	vmm_addToQueue(VMM_HE_UNUSED, &heapEntryHeadNodes[VMM_HE_UNUSED], &initialHEB.entry[0]);
 	HeapEntry_t *wilderness = vmm_stripUnusedEntry();
 	wilderness->base = (void *) HEAP_START;
 	wilderness->length = HEAP_LENGTH;
-	vmm_addToQueue(VMM_HE_HOLE, wilderness);
+	vmm_addToQueue(VMM_HE_HOLE, &heapEntryHeadNodes[VMM_HE_HOLE], wilderness);
 }
 
 
 /* Allocate a physical page and map the virtual address to it, return physical address allocated or NULL */
-u32_t	vmm_map(void *virt)
+int	vmm_map(void *virt)
 {
-	u32_t phys = mm_palloc();
-	if (!phys);
-		return NULL;
-	vmm_map1((u32_t)virt, phys);
-	return phys;
+	if (mm_freepages < 10);
+		return -1;
+	vmm_map1((u32_t)virt, mm_palloc());
+	return 0;
 }
 
 
 // This function maps a virtual address to a physical address using the page directory / page table
-int	vmm_map1(unsigned int virt, unsigned int physical)
+int	vmm_map1(u32_t virt, u32_t physical)
 {
-	unsigned int pde = virt >> 22;
-	unsigned int pte = (virt & 0x003FF000) >> 12;
-	unsigned int *pageTables = (unsigned int *)0xFFFFF000;	//this is the location of the page directory
+	u32_t pde = virt >> 22;
+	u32_t pte = (virt & 0x003FF000) >> 12;
+	u32_t *pageTables = (u32_t *)0xFFFFF000;	//this is the location of the page directory
 	if (!(pageTables[pde] & 0x01))		//the page directory entry is not present, we must allocate a page table
 	{
 		u32_t newpagetable;
@@ -76,14 +82,14 @@ int	vmm_map1(unsigned int virt, unsigned int physical)
 		invlpg_(virt);		//in case it was cached, so we can fill page table safely
 		memsetd((void*)(0xFFC00000 | (pde << 12)), 0, 1024);	//zero out new page table
 	}
-	*(unsigned int *)(0xFFC00000 | (pde << 12) | (pte << 2)) = (physical & 0xFFFFF000) | 0x03;
+	*(u32_t *)(0xFFC00000 | (pde << 12) | (pte << 2)) = (physical & 0xFFFFF000) | 0x03;
 	invlpg_(virt);
 	return 0;
 }
 
 
 // This function maps a variable number of pages in a row
-int	vmm_mapn(unsigned int virt, unsigned int physical, unsigned int n)
+int	vmm_mapn(u32_t virt, u32_t physical, u32_t n)
 {
 	while (n > 0)
 	{
@@ -98,15 +104,15 @@ int	vmm_mapn(unsigned int virt, unsigned int physical, unsigned int n)
 
 
 // This function removes the virtual address's entry in the page directory / page table
-void	vmm_unmap1(unsigned int virt)
+void	vmm_unmap1(u32_t virt)
 {
-	*(unsigned int *)(0xFFC00000 | ((virt & 0xFFC00000) >> 10) | ((virt & 0x003FF000) >> 10)) = 0;
+	*(u32_t *)(0xFFC00000 | ((virt & 0xFFC00000) >> 10) | ((virt & 0x003FF000) >> 10)) = 0;
  	invlpg_(virt);
 }
 
 
 // This function removes multiple pages' entries
-void	vmm_unmapn(unsigned int virt, unsigned int n)
+void	vmm_unmapn(u32_t virt, u32_t n)
 {
 	while (n > 0)
 	{
@@ -117,14 +123,15 @@ void	vmm_unmapn(unsigned int virt, unsigned int n)
 }
 
 
+// This function maps an entire address range into memory
 int	vmm_map_range(void *virt_start, void *virt_end, u32_t phys_start)
 {
 	if (virt_end < virt_start)
-		return 1;	// invalid region
+		return -1;	// invalid region
 	while (virt_start < virt_end)
 	{
 		if (vmm_map1((u32_t)virt_start, phys_start))
-			return 2;	// out of memory
+			return -2;	// out of memory
 		virt_start += 4096;
 		phys_start += 4096;
 	}
@@ -132,6 +139,8 @@ int	vmm_map_range(void *virt_start, void *virt_end, u32_t phys_start)
 }
 
 
+
+// kernel virtual memory allocator
 void *kmalloc(u32_t size)
 {
 	k_enter_critical();
@@ -141,28 +150,86 @@ void *kmalloc(u32_t size)
 }
 
 
+// kernel virtual memory de-allocator
+int kfree(void *addr)
+{
+	k_enter_critical();
+	
+	k_leave_critical();
+	return 0;
+}
+
+
+// This function allocates a virtual page and maps it to a physical page
 void *vmm_palloc()
 {
 	k_enter_critical();
-	HeapEntry_t *he = heapEntryQueues[VMM_HE_HOLE].start;
-	if (he->length == 4096)
+	HeapEntry_t *he = heapEntryQueues[VMM_HE_HOLE].head->next;
+	HeapEntry_t *wilderness = he;
+	while (he)
 	{
-		heapEntryQueues[VMM_HE_HOLE].start = he->next;
-		heapEntryQueues[VMM_HE_HOLE].count--;
-		he->next = 0;
-		vmm_addToQueue(VMM_HE_USED, he);
-		return he->base;
+		if (he->length == 4096)
+		{
+			((HeapEntry_t *)he->prev)->next = he->next;
+			((HeapEntry_t *)he->next)->prev = he->prev;
+			heapEntryQueues[VMM_HE_HOLE].count--;
+			he->next = NULL;
+			he->prev = NULL;
+			vmm_addToQueue(VMM_HE_USED, &heapEntryHeadNodes[VMM_HE_USED], he);
+			vmm_map(he->base);
+			k_leave_critical();
+			return he->base;
+		}
+		if (he->length > wilderness->length)
+			wilderness = he;
+		he = (HeapEntry_t *)he->next;
 	}
-	
+	if (wilderness->length < 0x00010000)		//leave 16 pages free
+	{
+		k_leave_critical();
+		return NULL;
+	}
+	wilderness->length -= 4096;			//strip 4k from the top
+	he = vmm_getUnusedEntry();
+	he->base = wilderness->base + wilderness->length;
+	he->length = 4096;
+	vmm_addToQueue(VMM_HE_USED, &heapEntryHeadNodes[VMM_HE_USED], he);
+	vmm_map(he->base);
 	k_leave_critical();
-	return NULL;
+	return he->base;
+}
+
+
+// This function frees a previously-allocated virtual page
+int vmm_pfree(void *addr)
+{
+	k_enter_critical();
+	HeapEntry_t *he = heapEntryQueues[VMM_HE_USED].head->next;
+	while (he)
+	{
+		if (he->base == addr)		//found the page to free
+		{
+			((HeapEntry_t *)he->prev)->next = he->next;
+			((HeapEntry_t *)he->next)->prev = he->prev;
+			heapEntryQueues[VMM_HE_USED].count--;
+			he->next = NULL;
+			he->prev = NULL;
+			vmm_unmap1((u32_t)he->base);
+			vmm_addToQueue(VMM_HE_HOLE, &heapEntryHeadNodes[VMM_HE_HOLE], he);
+			k_leave_critical();
+			return 0;
+		}
+		he = he->next;
+	}
+	k_leave_critical();
+	return -1;	// page not found
 }
 
 
 // This function allocates and zeros memory for the given number of objects,
 //  given the size of each object
 /*
-void	*calloc(unsigned int number, unsigned int size)
+void	*calloc(u32_t number, u32_t size)
 {
 	void *mem = malloc(number * size);
 	if (!mem)
@@ -172,64 +239,34 @@ void	*calloc(unsigned int number, unsigned int size)
 }*/
 
 
+
 // This function initialzes a Heap Entry Block to entries linked together
 void	vmm_heb_init(HeapEntryBlock_t *heb)
 {
 	int a;
 	for (a = 0; a < 255; a++)
+	{
 		heb->entry[a].next = &heb->entry[a+1];
+		heb->entry[a+1].prev = &heb->entry[a];
+	}
+	heb->entry[0].prev = NULL;
 	heb->entry[255].next = NULL;
 }
 
 
-// This function adds a HeapEntry structure list to the appropriate place in the queue
-void vmm_addToQueue(u32_t queue, HeapEntry_t *he)
+// This function adds a HeapEntry structure to the queue following 'preceeding' the queue
+void vmm_addToQueue(u32_t queue, HeapEntry_t *preceeding, HeapEntry_t *he)
 {
-	if (heapEntryQueues[queue].start == NULL)	//queue is empty
-	{
-		heapEntryQueues[queue].start = he;
-		heapEntryQueues[queue].count = vmm_countHeapEntries(he);
-		return;
-	}
-
-	switch (queue)
-	{
-		HeapEntry_t *prevhe;
-		case VMM_HE_UNUSED:	// don't sort at all, add to end
-			prevhe = vmm_followChain(heapEntryQueues[queue].start);
-			prevhe->next = he;
-			heapEntryQueues[queue].count += vmm_countHeapEntries(he);
-			break;
-		case VMM_HE_USED:	// sort by base address
-			prevhe = heapEntryQueues[queue].start;
-			while (prevhe->next)
-			{
-				if (((HeapEntry_t *)prevhe->next)->base > he->base)
-					break;
-				prevhe = prevhe->next;
-			}
-			he->next = prevhe->next;
-			prevhe->next = he;
-			heapEntryQueues[queue].count++;
-			break;
-		case VMM_HE_HOLE:	// sort by length
-		case VMM_HE_FREE:
-			prevhe = heapEntryQueues[queue].start;
-			while (prevhe->next)
-			{
-				if (((HeapEntry_t *)prevhe->next)->length > he->length)
-					break;
-				prevhe = prevhe->next;
-			}
-			he->next = prevhe->next;
-			prevhe->next = he;
-			heapEntryQueues[queue].count++;
-			break;
-	}
+	heapEntryQueues[queue].count += vmm_countHeapEntries(he);
+	HeapEntry_t *last = vmm_followChain(he);
+	last->next = preceeding->next;
+	he->prev = preceeding;
+	((HeapEntry_t *)last->next)->prev = last;
+	preceeding->next = he;
 }
 
 
-// This function returns how many HeapEntry objects are in a queue starting from the object given
+// This function returns how many HeapEntry objects are in a queue starting/including from the object given
 int vmm_countHeapEntries(HeapEntry_t *he)
 {
 	int count = 0;
@@ -256,15 +293,22 @@ HeapEntry_t *vmm_getUnusedEntry()
 {
 	if (heapEntryQueues[VMM_HE_UNUSED].count < 5)
 	{
-		HeapEntry_t *wilderness = vmm_followChain(heapEntryQueues[VMM_HE_HOLE].start);
-		wilderness->length -= 4096;
+		HeapEntry_t *he = heapEntryQueues[VMM_HE_HOLE].head->next;
+		HeapEntry_t *wilderness = he;
+		while (he)
+		{
+			if ((he->length) > (wilderness->length))
+				wilderness = he;
+			he = (HeapEntry_t *)he->next;
+		}
+		wilderness->length -= 4096;			//strip 4k from the top
 		HeapEntryBlock_t *newHEB = wilderness->base + wilderness->length;
 		vmm_map(newHEB);
 		vmm_heb_init(newHEB);
-		HeapEntry_t *newDesc = vmm_stripUnusedEntry();
+		HeapEntry_t *newDesc = vmm_stripUnusedEntry();	//descriptor for the new HEB
 		newDesc->base = newHEB;
 		newDesc->length = 4096;
-		vmm_addToQueue(VMM_HE_USED, newDesc);
+		vmm_addToQueue(VMM_HE_USED, heapEntryTailNodes[VMM_HE_USED].prev, newDesc);
 	}
 	return vmm_stripUnusedEntry();
 }
@@ -273,10 +317,12 @@ HeapEntry_t *vmm_getUnusedEntry()
 // Return pointer to an unused HeapEntry object, ASSUMES THERE IS ONE PRESENT IN QUEUE
 HeapEntry_t *vmm_stripUnusedEntry()
 {
-	HeapEntry_t *he = heapEntryQueues[VMM_HE_UNUSED].start;
-	heapEntryQueues[VMM_HE_UNUSED].start = he->next;
+	HeapEntry_t *he = heapEntryQueues[VMM_HE_UNUSED].head->next;
+	heapEntryQueues[VMM_HE_UNUSED].head->next = he->next;
+	((HeapEntry_t *)he->next)->prev = he->prev;
 	heapEntryQueues[VMM_HE_UNUSED].count--;
 	he->next = 0;
+	he->prev = 0;
 	return he;
 }
 

kernel/mm/vmm.h

@@ -33,13 +33,15 @@ typedef struct {
 
 typedef struct {
 	int	count;
-	HeapEntry_t *start;
+	HeapEntry_t *head;
 } HeapEntryQueue_t;
 
 
 void	vmm_init();
 void *kmalloc(u32_t size);
+int kfree(void *addr);
 void *vmm_palloc();
+int vmm_pfree(void *addr);
 
 #endif