Add base source code

Author: SamyPesse

README.md

@@ -13,6 +13,8 @@ How to Make a Computer Operating System
 
 The goal is to build a very simple UNIX-based operating system in C++, but the goal is not to just build a "proof-of-concept". The OS should be able to boot, start an userland shell and be extensible.
 
+[![Screen](https://raw.github.com/SamyPesse/How-to-Make-a-Computer-Operating-System/master/preview.png)](https://raw.github.com/SamyPesse/How-to-Make-a-Computer-Operating-System/master/preview.png)
+
 ### Summary
 
 #### [Chapter 1: Introduction about the x86 architecture and about our OS](Chapter-1/README.md)

preview.png

@@ -0,0 +1,29 @@
+SDKDIR=./sdk
+
+help:
+	@echo "Makefile for Building Dev Operating System."
+	@echo "Usage: make [ all | clean | help | build | run] " 
+	@echo ""
+	@echo
+
+all: 
+	@echo "Building Kernel"
+	make -C ./kernel
+	@echo "Building SDK"
+	make -C ./sdk
+	@echo "Building Userland"
+	make -C ./userland
+	
+
+build:
+	zip -r devos-$(VERSION).zip ./
+
+
+run:
+	@echo "Running Dev Operating System."
+	cd ./sdk && sudo ./diskimage.sh
+	cd ./sdk && ./qemu.sh
+
+clean:
+	make -C ./kernel clean
+	make -C ./userland clean

src/Makefile

@@ -124,4 +124,4 @@ Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
   # chef-validator, unless you changed the configuration.
   #
   #   chef.validation_client_name = "ORGNAME-validator"
-end
+end

src/Vagrantfile

@@ -0,0 +1,71 @@
+ARCH=x86
+KERNEL=kernel.elf
+SDKDIR=../sdk
+INCDIR= -I ./ -I ./modules -I ./core -I ./arch/$(ARCH)
+
+
+include ./arch/$(ARCH)/config.make
+
+include ./runtime/Makefile
+include ./core/Makefile
+include ./modules/Makefile
+include ./arch/$(ARCH)/Makefile
+
+FLAG :=$(FLAG) -D__$(ARCH)__
+PLATFORMS= `find ./arch/ -type d | sed "s/.*\///" | sort`
+
+
+all: $(KERNEL)
+
+$(KERNEL): $(OBJS)
+	$(LD) $(LDFLAG) -o $@ $^ 
+	cp $(KERNEL) $(SDKDIR)/bootdisk/
+	
+help:
+	@echo "Makefile for Kernel."
+	@echo "Please see COPYING for licensing information."
+	@echo "Output should be: "$(KERNEL)
+	@echo "Usage: make [ all | clean] " 
+	@echo "Currently supported platforms:"
+	@echo $(PLATFORMS)
+	@echo
+
+tosdk:
+	cp $(KERNEL) $(SDKDIR)/disk/
+
+install:
+	sudo cp $(KERNEL) /boot/
+	
+debug:
+	$(NM) -n $(KERNEL)
+
+	
+hinfo:
+	$(OBJDUMP) -f $(KERNEL)
+	
+dasm:
+	$(OBJDUMP) -d $(KERNEL) > dasm.txt
+	
+				
+run:
+	cd $(SDKDIR) &&	sh ./diskimage.sh
+	cd $(SDKDIR) &&	sh ./qemu.sh
+	
+geniso:
+	cd $(SDKDIR) &&	sh ./cdrom.sh
+
+%.o: %.cc
+	$(SC) $(FLAG) -c $< -o  $@
+	
+%.o: %.S
+	$(SC) $(FLAG) -c $< -o  $@
+	
+%.o: %.asm
+	$(ASM) $(ASMFLAG)  -c $< -o  $@
+
+
+clean:
+	rm -f $(OBJS)  $(KERNEL) dasm.txt
+	
+	
+

src/kernel/Makefile

@@ -0,0 +1,2 @@
+OBJS:= arch/$(ARCH)/start.o  $(OBJS) arch/$(ARCH)/alloc.o arch/$(ARCH)/architecture.o \
+	arch/$(ARCH)/io.o arch/$(ARCH)/vmm.o arch/$(ARCH)/x86.o arch/$(ARCH)/switch.o arch/$(ARCH)/x86int.o

src/kernel/arch/x86/Makefile

@@ -0,0 +1,143 @@
+
+#include <os.h>
+
+
+extern "C" {
+	
+/* change size of a memory segment */
+void *ksbrk(int n)
+{
+	struct kmalloc_header *chunk;
+	char *p_addr;
+	int i;
+
+	if ((kern_heap + (n * PAGESIZE)) > (char *) KERN_HEAP_LIM) {
+		io.print
+		    ("PANIC: ksbrk(): no virtual memory left for kernel heap !\n");
+		return (char *) -1;
+	}
+
+	chunk = (struct kmalloc_header *) kern_heap;
+
+	/* Allocation d'une page libre */
+	for (i = 0; i < n; i++) {
+		p_addr = get_page_frame();
+		if ((int)(p_addr) < 0) {
+			io.print
+			    ("PANIC: ksbrk(): no free page frame available !\n");
+			return (char *) -1;
+		}
+
+		/* Ajout dans le repertoire de pages */
+		pd0_add_page(kern_heap, p_addr, 0);
+
+		kern_heap += PAGESIZE;
+	}
+
+	/* Marquage pour kmalloc */
+	chunk->size = PAGESIZE * n;
+	chunk->used = 0;
+
+	return chunk;
+}
+
+/* allocate memory block */
+void *kmalloc(unsigned long size)
+{
+	if (size==0)
+		return 0;
+		
+	unsigned long realsize;	/* taille totale de l'enregistrement */
+	struct kmalloc_header *chunk, *other;
+
+	if ((realsize =
+	     sizeof(struct kmalloc_header) + size) < KMALLOC_MINSIZE)
+		realsize = KMALLOC_MINSIZE;
+
+	/* 
+	 * On recherche un bloc libre de 'size' octets en parcourant le HEAP
+	 * kernel a partir du debut
+	 */
+	chunk = (struct kmalloc_header *) KERN_HEAP;
+	while (chunk->used || chunk->size < realsize) {
+		if (chunk->size == 0) {
+			io.print
+			    ("\nPANIC: kmalloc(): corrupted chunk on %x with null size (heap %x) !\nSystem halted\n",
+			     chunk, kern_heap);
+				 //error
+				 asm("hlt");
+				 return 0;
+		}
+
+		chunk =
+		    (struct kmalloc_header *) ((char *) chunk +
+					       chunk->size);
+
+		if (chunk == (struct kmalloc_header *) kern_heap) {
+			if ((int)(ksbrk((realsize / PAGESIZE) + 1)) < 0) {
+				io.print
+				    ("\nPANIC: kmalloc(): no memory left for kernel !\nSystem halted\n");
+				 asm("hlt");
+				return 0;
+			}
+		} else if (chunk > (struct kmalloc_header *) kern_heap) {
+			io.print
+			    ("\nPANIC: kmalloc(): chunk on %x while heap limit is on %x !\nSystem halted\n",
+			     chunk, kern_heap);
+			 asm("hlt");
+			return 0;
+		}
+	}
+
+	/* 
+	 * On a trouve un bloc libre dont la taille est >= 'size'
+	 * On fait de sorte que chaque bloc est une taille minimale
+	 */
+	if (chunk->size - realsize < KMALLOC_MINSIZE)
+		chunk->used = 1;
+	else {
+		other =
+		    (struct kmalloc_header *) ((char *) chunk + realsize);
+		other->size = chunk->size - realsize;
+		other->used = 0;
+
+		chunk->size = realsize;
+		chunk->used = 1;
+	}
+
+	kmalloc_used += realsize;
+
+	/* retourne un pointeur sur la zone de donnees */
+	return (char *) chunk + sizeof(struct kmalloc_header);
+}
+
+/* free memory block */
+void kfree(void *v_addr)
+{
+	if (v_addr==(void*)0)
+		return;
+		
+	struct kmalloc_header *chunk, *other;
+
+	/* On libere le bloc alloue */
+	chunk =
+	    (struct kmalloc_header *) ((u32)v_addr -
+				       sizeof(struct kmalloc_header));
+	chunk->used = 0;
+
+	kmalloc_used -= chunk->size;
+
+	/* 
+	 * On merge le bloc nouvellement libere avec le bloc suivant ci celui-ci
+	 * est aussi libre
+	 */
+	while ((other =
+		(struct kmalloc_header *) ((char *) chunk + chunk->size))
+	       && other < (struct kmalloc_header *) kern_heap
+	       && other->used == 0)
+		chunk->size += other->size;
+}
+
+
+
+}