[noncompiling commit] Started working on a segmented memory model

14 files changed, 203 insertions, 75 deletions

diff --git a/Source/Kernel/Makefile b/Source/Kernel/Makefile
index 6a44ecf..233b23b 100644
--- a/Source/Kernel/Makefile
+++ b/Source/Kernel/Makefile
@@ -21,6 +21,8 @@ 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
new file mode 100644
index 0000000..154ae46
--- /dev/null
+++ b/Source/Kernel/MemoryManager/KernelSegment.class.cpp
@@ -0,0 +1,51 @@
+#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
new file mode 100644
index 0000000..4d8205a
--- /dev/null
+++ b/Source/Kernel/MemoryManager/KernelSegment.class.h
@@ -0,0 +1,25 @@
+#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 a0809b0..712c0f3 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) kernelPageDirectory->allocFrame(i, false, false);
+		if (pagingEnabled) PhysMem::keSeg.allocFrame(i);
 	}
 	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) {
-		kernelPageDirectory->allocFrame(i, false, false);
+		PhysMem::keSeg.allocFrame(i);
 	}
 
 	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 d8ede2a..1b9a322 100644
--- a/Source/Kernel/MemoryManager/PageAlloc.ns.cpp
+++ b/Source/Kernel/MemoryManager/PageAlloc.ns.cpp
@@ -29,13 +29,10 @@ void* alloc(u32int* phys) {
 			next = Mem::alloc(0x1000, true);
 		} else {
 			u32int i = 0xFFFFF000;
-			page_t *p;
 			while (1) {
-				p = kernelPageDirectory->getPage(i, true);
-				if (p->frame == 0) break;
+				if (PhysMem::keSeg.allocFrame(i)) break;
 				i -= 0x1000;
 			}
-			PhysMem::allocFrame(p, true, false);
 			next = (void*)i;
 		}
 		freePage[freec] = next;
@@ -52,7 +49,7 @@ void* alloc(u32int* phys) {
 		if (p == 0) {	//THIS SHOULD NEVER HAPPEN
 			PANIC("Cached free page does not exist.");
 		} else if (p->frame == 0) {
-			PhysMem::allocFrame(p, true, false);
+			PageDirectory::map(p, PhysMem::getFrame(), true, false);
 		} else {
 			*phys = (p->frame * 0x1000);
 		}
@@ -61,7 +58,7 @@ void* alloc(u32int* phys) {
 }
 
 void free(void *ptr) {
-	kernelPageDirectory->freeFrame((u32int)ptr);
+	PhysMem::keSeg.freeFrame((u32int)ptr);
 	return;
 }
 
diff --git a/Source/Kernel/MemoryManager/PageDirectory.class.cpp b/Source/Kernel/MemoryManager/PageDirectory.class.cpp
index 064b423..575b14c 100644
--- a/Source/Kernel/MemoryManager/PageDirectory.class.cpp
+++ b/Source/Kernel/MemoryManager/PageDirectory.class.cpp
@@ -5,6 +5,23 @@
 
 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++) {
@@ -24,7 +41,7 @@ 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.
-				PhysMem::allocFrame(&tables[i]->pages[j], true, true);
+				map(&tables[i]->pages[j], PhysMem::getFrame(), 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;
@@ -44,58 +61,48 @@ 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 e93524b..c3403aa 100644
--- a/Source/Kernel/MemoryManager/PageDirectory.class.h
+++ b/Source/Kernel/MemoryManager/PageDirectory.class.h
@@ -2,6 +2,8 @@
 #define DEF_PAGEDIRECTORY_CLASS_H
 
 #include <common.h>
+#include <Vector.class.h>
+#include <MemoryManager/Segment.proto.h>
 
 struct page_t {
 	u32int present		: 1;
@@ -22,14 +24,21 @@ 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();
-	page_t *getPage(u32int address, bool make);
-	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();
+	page_t *getPage(u32int address, bool make);
+
+	//For mapping memory segments to the page directory
+	void map(Segment* seg);
+	void unmap(Segment* seg);
 
 	private:
 	PageDirectory(const PageDirectory& other);
diff --git a/Source/Kernel/MemoryManager/PhysMem.ns.cpp b/Source/Kernel/MemoryManager/PhysMem.ns.cpp
index 54eb4de..d3ce0b9 100644
--- a/Source/Kernel/MemoryManager/PhysMem.ns.cpp
+++ b/Source/Kernel/MemoryManager/PhysMem.ns.cpp
@@ -9,17 +9,21 @@ 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) {
-		page_t *p2 = kernelPageDirectory->getPage(i, true);
-		allocFrame(p2, false, false);
+		keSeg.identityMap(i);
 		i += 0x1000;
 	}
 	//Also map thoses pages at begning of virtual memory
@@ -42,30 +46,15 @@ void removeTemporaryPages() {
 	}
 }
 
-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;
-	}
+u32int getFrame() {
+	u32int idx = frames->firstFreeBit();
+	if (idx == (u32int) - 1) PANIC("No more free frames !");
+	frames->setBit(idx);
+	return idx;
 }
 
-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;
-	}
+void freeFrame(u32int frame) {
+	frames->clearBit(frame);
 }
 
 u32int free() {
diff --git a/Source/Kernel/MemoryManager/PhysMem.ns.h b/Source/Kernel/MemoryManager/PhysMem.ns.h
index 258591a..3e6ec55 100644
--- a/Source/Kernel/MemoryManager/PhysMem.ns.h
+++ b/Source/Kernel/MemoryManager/PhysMem.ns.h
@@ -3,17 +3,21 @@
 
 #include <MemoryManager/PageDirectory.class.h>
 
+#include <MemoryManager/KernelSegment.class.h>
+
 extern PageDirectory* kernelPageDirectory;
 
 namespace PhysMem {
 	void initPaging(u32int mem_size);
 	void removeTemporaryPages();
 
-	void allocFrame(page_t *page, bool is_user, bool is_writable);
-	void freeFrame(page_t *page);
+	u32int getFrame();
+	void freeFrame(u32int frame);
 
 	u32int free();
 	u32int total();
+
+	extern KernelSegment keSeg;
 }
 
 #endif
diff --git a/Source/Kernel/MemoryManager/Segment.proto.h b/Source/Kernel/MemoryManager/Segment.proto.h
new file mode 100644
index 0000000..780cd10
--- /dev/null
+++ b/Source/Kernel/MemoryManager/Segment.proto.h
@@ -0,0 +1,24 @@
+#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
new file mode 100644
index 0000000..e82a94c
--- /dev/null
+++ b/Source/Kernel/MemoryManager/V86Segment.class.cpp
@@ -0,0 +1,16 @@
+#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
new file mode 100644
index 0000000..665506d
--- /dev/null
+++ b/Source/Kernel/MemoryManager/V86Segment.class.h
@@ -0,0 +1,12 @@
+#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 f70728c..f6cc641 100644
--- a/Source/Kernel/TaskManager/V86/V86.ns.cpp
+++ b/Source/Kernel/TaskManager/V86/V86.ns.cpp
@@ -19,13 +19,6 @@ 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 ec8e928..d30c08e 100644
--- a/Source/Kernel/TaskManager/V86/V86.ns.h
+++ b/Source/Kernel/TaskManager/V86/V86.ns.h
@@ -26,7 +26,6 @@ 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);
 }