Revert "[noncompiling commit] Started working on a segmented memory model"

This reverts commit bfec696da052c8c9320773ca69927422efebe8c7.

14 files changed, 75 insertions, 203 deletions

diff --git a/Source/Kernel/Makefile b/Source/Kernel/Makefile
index 233b23b..6a44ecf 100644
--- a/Source/Kernel/Makefile
+++ b/Source/Kernel/Makefile
@@ -21,8 +21,6 @@ Objects = Core/loader.wtf.o \
 		MemoryManager/GDT.ns.o \
 		MemoryManager/PageDirectory.class.o \
 		MemoryManager/PageAlloc.ns.o \
-		MemoryManager/KernelSegment.class.o \
-		MemoryManager/V86Segment.class.o \
 		DeviceManager/Disp.ns.o \
 		DeviceManager/Dev.ns.o \
 		DeviceManager/Time.ns.o \
diff --git a/Source/Kernel/MemoryManager/KernelSegment.class.cpp b/Source/Kernel/MemoryManager/KernelSegment.class.cpp
deleted file mode 100644
index 154ae46..0000000
--- a/Source/Kernel/MemoryManager/KernelSegment.class.cpp
+++ /dev/null
@@ -1,51 +0,0 @@
-#include "KernelSegment.class.h"
-#include <MemoryManager/PageAlloc.ns.h>
-#include <MemoryManager/PhysMem.ns.h>
-#include <MemoryManager/PageDirectory.class.h>
-
-seg_map_t KernelSegment::map(PageDirectory* pd) {
-	for (u32int i = 0; i < 256; i++) {
-		pd->tables[i + 768] = tables[i];
-		pd->tablesPhysical[i + 768] = tablesPhysical[i];
-	}
-	m_pds.push(pd);
-	seg_map_t ret = {this, 0xC0000000, 0x40000000};
-	return ret;
-}
-
-page_t* KernelSegment::getPage(u32int addr) {
-	if (addr < 0xC0000000) return 0;
-	addr /= 0x1000;
-	u32int tableIdx = addr / 1024;
-	if (tables[tableIdx - 768] == 0) {
-		tables[tableIdx - 768] = (page_table_t*)PageAlloc::alloc(tablesPhysical + tableIdx - 768);
-		CMem::memset((u8int*)tables[tableIdx - 768], 0, 0x1000);
-		for (u32int i = 0; i < m_pds.size(); i++) {
-			m_pds[i]->tables[tableIdx] = tables[tableIdx - 768];
-			m_pds[i]->tablesPhysical[tableIdx] = tablesPhysical[tableIdx - 768];
-		}
-	}
-	return &tables[tableIdx - 768]->pages[addr % 1024];
-}
-
-bool KernelSegment::allocFrame(u32int addr) {
-	page_t *p = getPage(addr);
-	if (p == 0) return false;
-	if (p->frame != 0) return false;
-	PageDirectory::map(p, PhysMem::getFrame(), false, false);
-	return true;
-}
-
-void KernelSegment::identityMap(u32int addr) {
-	page_t *p = getPage(addr);
-	if (p == 0) return;
-	PageDirectory::map(p, (addr - 0xC0000000) / 0x1000, false, false);
-}
-
-void KernelSegment::freeFrame(u32int addr) {
-	if (addr < 0xC0000000) return;
-	addr /= 0x1000;
-	u32int tableIdx = addr / 1024;
-	if (tables[tableIdx - 768] == 0) return;
-	PageDirectory::unmap(&tables[tableIdx - 768]->pages[addr % 1024], true);
-}
diff --git a/Source/Kernel/MemoryManager/KernelSegment.class.h b/Source/Kernel/MemoryManager/KernelSegment.class.h
deleted file mode 100644
index 4d8205a..0000000
--- a/Source/Kernel/MemoryManager/KernelSegment.class.h
+++ /dev/null
@@ -1,25 +0,0 @@
-#ifndef DEF_KERNEL_SEGMENT_CLASS_H
-#define DEF_KERNEL_SEGMENT_CLASS_H
-
-#include <MemoryManager/Segment.proto.h>
-#include <MemoryManager/PageDirectory.class.h>
-
-class KernelSegment : public Segment {
-	private:
-	Vector<PageDirectory*> m_pds;
-	page_table_t *tables[256];
-	u32int tablesPhysical[256];
-
-	page_t* getPage(u32int addr);
-	
-	public:
-	seg_map_t map(PageDirectory *pd);
-	void unmap(PageDirectory *pd, seg_map_t *mapping) {}
-	bool handleFault(u32int addr, seg_map_t *mapping) { return false; }
-
-	bool allocFrame(u32int addr);	//false when page already was mapped to a frame
-	void identityMap(u32int addr);	//Used only on paging initialisation
-	void freeFrame(u32int addr);
-};
-
-#endif
diff --git a/Source/Kernel/MemoryManager/Mem.ns.cpp b/Source/Kernel/MemoryManager/Mem.ns.cpp
index 712c0f3..a0809b0 100644
--- a/Source/Kernel/MemoryManager/Mem.ns.cpp
+++ b/Source/Kernel/MemoryManager/Mem.ns.cpp
@@ -20,7 +20,7 @@ void *kallocInternal(size_t sz, bool align) {
 	u32int temp = placementAddress;
 	placementAddress += sz;
 	for (u32int i = temp; i < placementAddress; i += 0x1000) {
-		if (pagingEnabled) PhysMem::keSeg.allocFrame(i);
+		if (pagingEnabled) kernelPageDirectory->allocFrame(i, false, false);
 	}
 	return (void*)temp;
 }
@@ -34,7 +34,7 @@ void createHeap() {
 	u32int heapSize = HEAP_MIN_SIZE + heapIndexSize;							//Calculate heap size
 
 	for (u32int i = (placementAddress & 0xFFFFF000); i < heapStart; i += 0x1000) {
-		PhysMem::keSeg.allocFrame(i);
+		kernelPageDirectory->allocFrame(i, false, false);
 	}
 
 	kheap.create(heapStart, heapSize, heapIndexSize, kernelPageDirectory, false, false);
diff --git a/Source/Kernel/MemoryManager/PageAlloc.ns.cpp b/Source/Kernel/MemoryManager/PageAlloc.ns.cpp
index 1b9a322..d8ede2a 100644
--- a/Source/Kernel/MemoryManager/PageAlloc.ns.cpp
+++ b/Source/Kernel/MemoryManager/PageAlloc.ns.cpp
@@ -29,10 +29,13 @@ void* alloc(u32int* phys) {
 			next = Mem::alloc(0x1000, true);
 		} else {
 			u32int i = 0xFFFFF000;
+			page_t *p;
 			while (1) {
-				if (PhysMem::keSeg.allocFrame(i)) break;
+				p = kernelPageDirectory->getPage(i, true);
+				if (p->frame == 0) break;
 				i -= 0x1000;
 			}
+			PhysMem::allocFrame(p, true, false);
 			next = (void*)i;
 		}
 		freePage[freec] = next;
@@ -49,7 +52,7 @@ void* alloc(u32int* phys) {
 		if (p == 0) {	//THIS SHOULD NEVER HAPPEN
 			PANIC("Cached free page does not exist.");
 		} else if (p->frame == 0) {
-			PageDirectory::map(p, PhysMem::getFrame(), true, false);
+			PhysMem::allocFrame(p, true, false);
 		} else {
 			*phys = (p->frame * 0x1000);
 		}
@@ -58,7 +61,7 @@ void* alloc(u32int* phys) {
 }
 
 void free(void *ptr) {
-	PhysMem::keSeg.freeFrame((u32int)ptr);
+	kernelPageDirectory->freeFrame((u32int)ptr);
 	return;
 }
 
diff --git a/Source/Kernel/MemoryManager/PageDirectory.class.cpp b/Source/Kernel/MemoryManager/PageDirectory.class.cpp
index 575b14c..064b423 100644
--- a/Source/Kernel/MemoryManager/PageDirectory.class.cpp
+++ b/Source/Kernel/MemoryManager/PageDirectory.class.cpp
@@ -5,23 +5,6 @@
 
 extern "C" void copy_page_physical(u32int src, u32int dest);
 
-/* 			FOR MAPPING FRAMES TO PAGES     */
-void PageDirectory::map(page_t* p, u32int frame, bool is_user, bool is_writable) {
-	if (p == 0) return;
-	p->present = 1;
-	p->user = (is_user ? 1 : 0);
-	p->rw = (is_writable ? 1 : 0);
-	p->frame = (frame);
-}
-
-void PageDirectory::unmap(page_t *p, bool freePhys) {
-	if (p == 0) return;
-	if (freePhys) PhysMem::freeFrame(p->frame);
-	p->present = 0;
-	p->frame = 0;
-}
-
-/* 			FOR PAGE DIRECTORES				*/
 PageDirectory::PageDirectory() {
 	tablesPhysical = (u32int*)PageAlloc::alloc(&physicalAddr);
 	for (u32int i = 0; i < 1024; i++) {
@@ -41,7 +24,7 @@ PageDirectory::PageDirectory(PageDirectory* other) {
 				if (!(other->tables[i]->pages[j].frame))
 					continue;
 				if (i == 0 and j < 256) continue;	//Frame is below 1M, probably used by some V86 stuff. Ignore it.
-				map(&tables[i]->pages[j], PhysMem::getFrame(), true, true);
+				PhysMem::allocFrame(&tables[i]->pages[j], true, true);
 				tables[i]->pages[j].present = other->tables[i]->pages[j].present;
 				tables[i]->pages[j].rw = other->tables[i]->pages[j].rw;
 				tables[i]->pages[j].user = other->tables[i]->pages[j].user;
@@ -61,48 +44,58 @@ PageDirectory::PageDirectory(PageDirectory* other) {
 }
 
 PageDirectory::~PageDirectory() {
-	for (u32int i = 0; i < mappedSegs.size(); i++) {
-		mappedSegs[i].seg->unmap(this, &mappedSegs[i]);
-	}
 	for (int i = 0; i < 768; i++) {		//Only free addresses below 0xC0000000, upper is kernel space
 		if (tables[i] != 0) {
+			for (int j = 0; j < 1024; j++) {
+				if (i == 0 and j < 256) continue;	//Frame is below 1M, probably used by some V86 stuff. Ignore it.
+				PhysMem::freeFrame(&(tables[i]->pages[j]));
+			}
 			PageAlloc::free((void*)tables[i]);
 		}
 	}
 	PageAlloc::free((void*)tablesPhysical);
 }
 
-void PageDirectory::map(Segment* seg) {
-	mappedSegs.push(seg->map(this));
-}
-
-void PageDirectory::unmap(Segment* seg) {
-	for (u32int i = 0; i < mappedSegs.size(); i++) {
-		if (mappedSegs[i].seg == seg) {
-			seg->unmap(this, &mappedSegs[i]);
-			mappedSegs[i] = mappedSegs.back();
-			return;
-		}
-	}
-}
-
 page_t *PageDirectory::getPage(u32int address, bool make) {
 	address /= 0x1000;
 	u32int tableIdx = address / 1024;
 	if (tables[tableIdx] != 0) {
 		return &(tables[tableIdx]->pages[address % 1024]);
 	} else if (make) {
-		if (address >= 0xC0000000) return 0;
 		u32int tmp;
 		tables[tableIdx] = (page_table_t*)PageAlloc::alloc(&tmp);
 		CMem::memset((u8int*)tables[tableIdx], 0, 0x1000);
 		tablesPhysical[tableIdx] = tmp | 0x07;
+		if (tableIdx >= 768)
+			Task::allocKernelPageTable(tableIdx, tables[tableIdx], tablesPhysical[tableIdx]);
 		return &(tables[tableIdx]->pages[address % 1024]);
 	} else {
 		return 0;
 	}
 }
 
+void PageDirectory::map(page_t* p, u32int frame, bool is_user, bool is_writable) {
+		p->present = 1;
+		p->user = (is_user ? 1 : 0);
+		p->rw = (is_writable ? 1 : 0);
+		p->frame = (frame);
+}
+
+void PageDirectory::allocFrame(u32int address, bool is_user, bool is_writable) {
+	page_t *p = getPage(address, true);
+	if (address < 0x100000) {
+		map(p, address / 0x1000, is_user, is_writable);
+	} else {
+		if (p != 0) PhysMem::allocFrame(p, is_user, is_writable);
+	}
+}
+
+void PageDirectory::freeFrame(u32int address) {
+	page_t *p = getPage(address, false);
+	if (p == 0) return;
+	PhysMem::freeFrame(p);
+}
+
 void PageDirectory::switchTo() {
 	asm volatile("mov %0, %%cr3" :: "r"(physicalAddr));
 	u32int cr0;
diff --git a/Source/Kernel/MemoryManager/PageDirectory.class.h b/Source/Kernel/MemoryManager/PageDirectory.class.h
index c3403aa..e93524b 100644
--- a/Source/Kernel/MemoryManager/PageDirectory.class.h
+++ b/Source/Kernel/MemoryManager/PageDirectory.class.h
@@ -2,8 +2,6 @@
 #define DEF_PAGEDIRECTORY_CLASS_H
 
 #include <common.h>
-#include <Vector.class.h>
-#include <MemoryManager/Segment.proto.h>
 
 struct page_t {
 	u32int present		: 1;
@@ -24,21 +22,14 @@ struct PageDirectory {
 	u32int *tablesPhysical;
 	u32int physicalAddr;
 
-	Vector<seg_map_t> mappedSegs;
-
-	//For mapping a page to a frame
-	static void map(page_t *p, u32int frame, bool is_user, bool is_writable);
-	static void unmap(page_t *p, bool physFree = false);
-
 	PageDirectory();
 	PageDirectory(PageDirectory* other);	//Clones the other pagedir
 	~PageDirectory();
-	void switchTo();
 	page_t *getPage(u32int address, bool make);
-
-	//For mapping memory segments to the page directory
-	void map(Segment* seg);
-	void unmap(Segment* seg);
+	void map(page_t *p, u32int frame, bool is_user, bool is_writable);
+	void allocFrame(u32int address, bool is_user, bool is_writable);
+	void freeFrame(u32int address);
+	void switchTo();
 
 	private:
 	PageDirectory(const PageDirectory& other);
diff --git a/Source/Kernel/MemoryManager/PhysMem.ns.cpp b/Source/Kernel/MemoryManager/PhysMem.ns.cpp
index d3ce0b9..54eb4de 100644
--- a/Source/Kernel/MemoryManager/PhysMem.ns.cpp
+++ b/Source/Kernel/MemoryManager/PhysMem.ns.cpp
@@ -9,21 +9,17 @@ namespace PhysMem {
 u32int nframes;
 Bitset *frames;
 
-KernelSegment keSeg;
-
 void initPaging(u32int mem_size) {
 	nframes = mem_size / 0x1000;
 	
 	frames = new Bitset(nframes);
 
-	for (u32int i = 0; i < Mem::placementAddress / 0x1000; i++) frames->setBit(i);
-
 	kernelPageDirectory = new (Mem::alloc(sizeof(PageDirectory), true)) PageDirectory();
-	kernelPageDirectory->map(&keSeg);
 
 	u32int i = 0xC0000000;
 	while (i < Mem::placementAddress) {
-		keSeg.identityMap(i);
+		page_t *p2 = kernelPageDirectory->getPage(i, true);
+		allocFrame(p2, false, false);
 		i += 0x1000;
 	}
 	//Also map thoses pages at begning of virtual memory
@@ -46,15 +42,30 @@ void removeTemporaryPages() {
 	}
 }
 
-u32int getFrame() {
-	u32int idx = frames->firstFreeBit();
-	if (idx == (u32int) - 1) PANIC("No more free frames !");
-	frames->setBit(idx);
-	return idx;
+void allocFrame(page_t *page, bool is_user, bool is_writable) {
+	if (page->frame != 0) {
+		return;
+	} else {
+		u32int idx = frames->firstFreeBit();
+		if (idx == (u32int) - 1) PANIC("No more free frames !");
+		frames->setBit(idx);
+		page->present = 1;
+		page->user = (is_user ? 1 : 0);
+		page->rw = (is_writable ? 1 : 0);
+		page->frame = idx;
+	}
 }
 
-void freeFrame(u32int frame) {
-	frames->clearBit(frame);
+void freeFrame(page_t *page) {
+	if (page->frame == 0) {
+		return;
+	} else {
+		if (page->frame >= 0x100) {	//First 1M are reserved (system)
+			frames->clearBit(page->frame);
+		}
+		page->present = 0;
+		page->frame = 0;
+	}
 }
 
 u32int free() {
diff --git a/Source/Kernel/MemoryManager/PhysMem.ns.h b/Source/Kernel/MemoryManager/PhysMem.ns.h
index 3e6ec55..258591a 100644
--- a/Source/Kernel/MemoryManager/PhysMem.ns.h
+++ b/Source/Kernel/MemoryManager/PhysMem.ns.h
@@ -3,21 +3,17 @@
 
 #include <MemoryManager/PageDirectory.class.h>
 
-#include <MemoryManager/KernelSegment.class.h>
-
 extern PageDirectory* kernelPageDirectory;
 
 namespace PhysMem {
 	void initPaging(u32int mem_size);
 	void removeTemporaryPages();
 
-	u32int getFrame();
-	void freeFrame(u32int frame);
+	void allocFrame(page_t *page, bool is_user, bool is_writable);
+	void freeFrame(page_t *page);
 
 	u32int free();
 	u32int total();
-
-	extern KernelSegment keSeg;
 }
 
 #endif
diff --git a/Source/Kernel/MemoryManager/Segment.proto.h b/Source/Kernel/MemoryManager/Segment.proto.h
deleted file mode 100644
index 780cd10..0000000
--- a/Source/Kernel/MemoryManager/Segment.proto.h
+++ /dev/null
@@ -1,24 +0,0 @@
-#ifndef DEF_SEGMENT_PROTO_H
-#define DEF_SEGMENT_PROTO_H
-
-#include <common.h>
-
-class PageDirectory;
-class Segment;
-
-struct seg_map_t {
-	Segment* seg;
-	u32int start;
-	u32int len;
-};
-
-class Segment {
-	public:
-	virtual seg_map_t map(PageDirectory *pd) = 0;
-	virtual void unmap(PageDirectory *pd, seg_map_t *mapping) = 0;
-	virtual bool handleFault(u32int addr, seg_map_t *mapping) = 0;	//true = ok, false = app segfaulted
-
-	virtual Segment* clone() { return this; }
-};
-
-#endif
diff --git a/Source/Kernel/MemoryManager/V86Segment.class.cpp b/Source/Kernel/MemoryManager/V86Segment.class.cpp
deleted file mode 100644
index e82a94c..0000000
--- a/Source/Kernel/MemoryManager/V86Segment.class.cpp
+++ /dev/null
@@ -1,16 +0,0 @@
-#include "V86Segment.class.h"
-#include <MemoryManager/PageDirectory.class.h>
-
-seg_map_t V86Segment::map(PageDirectory *pd) {
-	for (u32int i = 0; i < 0x100000; i += 0x1000) {
-		PageDirectory::map(pd->getPage(i, true), i / 0x1000, true, true);
-	}
-	seg_map_t map = {this, 0, 0x100000};
-	return map;
-}
-
-void V86Segment::unmap(PageDirectory* pd, seg_map_t *mapping) {
-	for (u32int i = 0; i < 0x100000; i += 0x1000) {
-		PageDirectory::unmap(pd->getPage(i, false));
-	}
-}
diff --git a/Source/Kernel/MemoryManager/V86Segment.class.h b/Source/Kernel/MemoryManager/V86Segment.class.h
deleted file mode 100644
index 665506d..0000000
--- a/Source/Kernel/MemoryManager/V86Segment.class.h
+++ /dev/null
@@ -1,12 +0,0 @@
-#ifndef DEF_V86SEGMENT_CLASS_H
-#define DEF_V86SEGMENT_CLASS_H
-
-#include <MemoryManager/Segment.proto.h>
-
-class V86Segment : public Segment {
-	seg_map_t map(PageDirectory *pd);
-	void unmap(PageDirectory* pd, seg_map_t *mapping);
-	bool handleFault(u32int addr, seg_map_t *mapping) { return false; }
-};
-
-#endif
diff --git a/Source/Kernel/TaskManager/V86/V86.ns.cpp b/Source/Kernel/TaskManager/V86/V86.ns.cpp
index f6cc641..f70728c 100644
--- a/Source/Kernel/TaskManager/V86/V86.ns.cpp
+++ b/Source/Kernel/TaskManager/V86/V86.ns.cpp
@@ -19,6 +19,13 @@ void biosInt(u8int int_no, v86_regs_t &regs) {
 	while (!ret.finished) Task::currThread()->sleep(10);
 }
 
+void map(Process* p) {
+	if (p == 0) p = Task::currProcess();
+	for (u32int i = 0x00000; i < 0xFFFFF; i += 0x1000) {
+		p->getPagedir()->allocFrame(i, true, true);
+	}
+}
+
 u16int allocSeg(u16int length) {
 	if (length & 0xF) length = (length & 0xFFFF0) + 0x10;
 	u16int segments = length / 16;
diff --git a/Source/Kernel/TaskManager/V86/V86.ns.h b/Source/Kernel/TaskManager/V86/V86.ns.h
index d30c08e..ec8e928 100644
--- a/Source/Kernel/TaskManager/V86/V86.ns.h
+++ b/Source/Kernel/TaskManager/V86/V86.ns.h
@@ -26,6 +26,7 @@ namespace V86 {
 	void run(v86_function_t& entry, v86_regs_t &regs);
 	void biosInt(u8int int_no, v86_regs_t &regs);
 
+	void map(Process* p = 0);	//Maps lower 1MB of virtual memory to physical memory (lower 1MB as well)
 	u16int allocSeg(u16int size);
 	void* alloc(u16int size);
 }