.vscode/c_cpp_properties.json

@@ -0,0 +1,16 @@
+{
+    "configurations": [
+        {
+            "name": "Linux",
+            "includePath": [
+                "${workspaceFolder}/**"
+            ],
+            "defines": [],
+            "compilerPath": "/usr/bin/gcc",
+            "cStandard": "gnu17",
+            "cppStandard": "gnu++14",
+            "intelliSenseMode": "linux-gcc-x64"
+        }
+    ],
+    "version": 4
+}

Makefile

@@ -24,7 +24,7 @@ all: clean build
 build: build_kernel run 
 
 run:
-	$(EMULATOR) -d int -kernel $(BUILD_DIR)/myos.bin -serial stdio -vga std
+	$(EMULATOR)  -kernel $(BUILD_DIR)/myos.bin -serial stdio -vga std
 
 build_kernel: $(OBJ_LINK_LIST)
 	

src/kernel/MMU.cpp

@@ -21,9 +21,9 @@ void MMU::enable(){
     //we will fill all 1024 entries in the table, mapping 4 megabytes
     for(unsigned int i = 0; i < 1024; i++)
     {
-    // As the address is page aligned, it will always leave 12 bits zeroed.
+        // As the address is page aligned, it will always leave 12 bits zeroed.
-    // Those bits are used by the attributes ;)
+        // Those bits are used by the attributes ;)
-    first_page_table[i] = (i * 0x1000) | 3; // attributes: supervisor level, read/write, present.
+        first_page_table[i] = (i * 0x1000) | 3; // attributes: supervisor level, read/write, present.
     }
 
     // attributes: supervisor level, read/write, present
@@ -33,3 +33,9 @@ void MMU::enable(){
     loadPageDirectory(this->page_directory);
     enablePaging();
 }
+
+
+uint32_t MMU::readTableEntry(int entry){
+    return this->page_directory[entry];
+
+}

src/kernel/MMU.h

@@ -7,6 +7,7 @@ extern "C" void enablePaging();
 class MMU {
     public:
     void enable ();
+    uint32_t readTableEntry(int);
 
     private:
     uint32_t page_directory[1024] __attribute__((aligned(4096)));

src/kernel/arch/i386/MMU/SlabAllocator.h

@@ -0,0 +1,33 @@
+#pragma once
+/**
+ *  We'll need something to this effect to allocate memory in the kernel
+ *  this will hopefully someday implement a full slab allocator 
+ **/
+enum SlabState {
+    empty,
+    partial,
+    full 
+};
+
+class CacheSlab {
+    const int SlabSize = 4000;
+    void* start = 0x0;
+};
+
+
+class Allocator {
+
+    public:
+        Allocator();
+        ~Allocator();
+
+        void* kmalloc( int size );
+        void kfree (void* address);
+
+    private:
+        CacheSlab** _cache;
+
+
+
+
+};

src/kernel/arch/i386/boot.s

@@ -471,6 +471,17 @@ _start:
 	/*Setup the stack pointer to point to the beginning of our stack */
 	/* I believe its a hight address growing down to lower adress for the stack on x86*/
 	mov $stack_top, %esp
+
+	/*Reset EFLAGS*/
+	pushl $0 
+	popf 
+
+	/* push the pointer to the Multiboot information structure*/
+	pushl %ebx
+
+	/* push the magic value */
+	pushl %eax
+	
 	call early_main
 	cli
 	load_gdt:

src/kernel/arch/i386/tty/kterm.c

@@ -88,7 +88,7 @@ void kterm_write(const char* data, size_t size) {
 }   
 
 void kterm_writestring(const char* data ){
-    AS_KERNEL();
+   // AS_KERNEL();
     kterm_write(data, strlen(data));
 }
 

src/kernel/kernel.cpp

@@ -97,20 +97,115 @@ void test_serial(){
 
 extern "C" {
 
-    void early_main(){
+    void early_main(unsigned long magic, unsigned long addr){
 
-       init_serial();
+        /** initialize terminal interface */ 
-       print_serial("\033[31;42mEarly main called!\n");
+        kterm_init();
       
+        multiboot_info_t *mbi;
+
+        if (magic != MULTIBOOT_BOOTLOADER_MAGIC){
+            printf("Invalid magic number: 0x%x\n", (unsigned) magic);
+            return;
+        }
+
+        /* Set MBI to the addresss of the multiboot information structure*/
+        mbi = (multiboot_info_t *) addr;
+
+        /* Print out the flags */
+        printf("flags = 0x%x\n", (unsigned) mbi->flags);
+
+        /* Are mem_* valid? */
+        if ( CHECK_FLAG(mbi->flags,0)){
+            printf("mem_lower = %uKB, mem_upper = %uKB\n");
+        }
+
+        /* is boot device valid ? */
+        if (CHECK_FLAG (mbi->flags, 1)){
+            printf("boot_device = 0x0%x\n", (unsigned) mbi->boot_device);
+        }
+
+        /* is the command line passed? */
+        if (CHECK_FLAG ( mbi->flags,2)){
+            printf("cmdline = %s\n", (char *) mbi->cmdline);
+        }
+
+        /* Are mods_* valid? */
+        if(CHECK_FLAG ( mbi->flags, 3)){
+            multiboot_module_t *mod;
+            int i;
+
+            printf("mods count = %d, mods_addr = 0x%x\n", (int) mbi->mods_count, (int) mbi->mods_addr);
+
+            for(i = 0, mod = (multiboot_module_t *) mbi->mods_addr; i < mbi->mods_count; i++ , mod++){
+                printf(" mod start = 0x%x, mod_end = 0x%x, cmdline = %s\n", (unsigned) mod->mod_start, (unsigned) mod->mod_end, (char*) mod->cmdline);
+            }
+        }
+
+        /* Bits 4 and 5 are mutually exclusive! */
+        if (CHECK_FLAG (mbi->flags, 4) && CHECK_FLAG(mbi->flags, 5)){
+            printf("Both bits 4 and 5 are set.\n");
+            return;
+        }
+
+        /* Is the symbol table of a.out valid? */
+        if (CHECK_FLAG(mbi->flags, 4)){
+            multiboot_aout_symbol_table_t *multiboot_aout_sym = &(mbi->u.aout_sym);
+
+            printf( "multiboot_aout_symbol_table: tabsize = 0x%0x, strsize = 0x%x, addr = 0x%x\n", 
+            (unsigned) multiboot_aout_sym->tabsize,
+            (unsigned) multiboot_aout_sym->strsize,
+            (unsigned) multiboot_aout_sym->addr);
+
+        }
+
+        /* Is the section header table of ELF valid? */
+        if (CHECK_FLAG(mbi->flags, 5)){
+            multiboot_elf_section_header_table_t *multiboot_elf_sec = &(mbi->u.elf_sec);
+
+            printf("multiboot_elf_sec: num = %u, size = 0x%x, addr = 0x%x, shnd = 0x%x\n",
+            (unsigned) multiboot_elf_sec->num, (unsigned) multiboot_elf_sec->size,
+            (unsigned) multiboot_elf_sec->addr, (unsigned)  multiboot_elf_sec->shndx);
+            
+        }
+
+
+        // AAAAAH memory map, Yes please!
+        /* Are mmap_* valid? */
+        if (CHECK_FLAG(mbi->flags, 6)){
+            multiboot_memory_map_t *mmap;
+            
+            printf("mmap_addr = 0x%x, mmap_length = 0x%x\n",
+            (unsigned) mbi->mmap_addr, (unsigned) mbi->mmap_length);
+            
+            for (mmap = (multiboot_memory_map_t *) mbi->mmap_addr; 
+                (unsigned long) mmap < mbi->mmap_addr + mbi->mmap_length; 
+                mmap = (multiboot_memory_map_t *) ((unsigned long) mmap + mmap->size + sizeof(mmap->size))){
+                    
+                    printf(
+                        "size = 0x%x, base_addr = 0x%x%08x, length = 0x%x%08x, type = 0x%x\n",
+                        (unsigned) mmap->size,
+                        (unsigned) (mmap->addr >> 32),
+                        (unsigned) (mmap->addr & 0xffffffff),
+                        (unsigned) (mmap->len >> 32),
+                        (unsigned) (mmap->len & 0xffffffff),
+                        (unsigned) mmap->type);
+                
+                }
+
+        }
+
+        /* Draw diagonal blue line */
+        if (CHECK_FLAG (mbi->flags, 12)){
+            printf("Can draw!");
+        } 
     }
 
     void kernel_main (void) {
 
-        print_serial("Kernel main called!\n");
 
+        init_serial();
 
-        /** initialize terminal interface */ 
-        kterm_init();
 
         /** Setup the MMU **/
         //kterm_writestring("Starting MMU...\n");
@@ -121,21 +216,7 @@ extern "C" {
         
 
        
-        /** Wrtite stuff to the screen to test the terminal**/ 
-        kterm_writestring("Hello world!\n");
-        kterm_writestring("We got newline support!\n");
        
-        /** Test scrolling **/
-        for(int i=0; i < 5; i++){
-            delay(500);
-            kterm_writestring("We have implemented terminal scrolling!\n");
-        }
-    
-
-        /** Test objective cpp **/
-        kterm_writestring("Testing C++ object support\n");
-        auto testObject = Test();
-        testObject.printMe();
     
  
 
@@ -147,7 +228,7 @@ extern "C" {
         while (true){
             //Read time indefinetely 
             read_rtc();
-            printf( "UTC time: %2d-%2d-%2d %2d:%2d:%2d  : (YY-MM-DD h:mm:ss)\r" ,year, month, day, hour, minute, second);
+            printf( "UTC time: %02d-%02d-%02d %02d:%02d:%02d  [ Formatted as YY-MM-DD h:mm:ss]\r" ,year, month, day, hour, minute, second);
             delay(1000);
         }
 

src/kernel/kernel.h

@@ -4,7 +4,11 @@ extern "C" {
     #include "arch/i386/tty/kterm.h"
 }
 
+#include "multiboot.h"
 #include "arch/i386/idt/idt.h"
 #include "MMU.h"
 #include "io.h"
 #include "time.h"
+
+
+#define CHECK_FLAG(flags, bit) ((flags) & (1 <<(bit)))

src/kernel/multiboot.h

@@ -0,0 +1,274 @@
+/* multiboot.h - Multiboot header file. */
+/* Copyright (C) 1999,2003,2007,2008,2009,2010  Free Software Foundation, Inc.
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to
+ *  deal in the Software without restriction, including without limitation the
+ *  rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ *  sell copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in
+ *  all copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL ANY
+ *  DEVELOPER OR DISTRIBUTOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ *  WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+ *  IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef MULTIBOOT_HEADER
+#define MULTIBOOT_HEADER 1
+
+/* How many bytes from the start of the file we search for the header. */
+#define MULTIBOOT_SEARCH                        8192
+#define MULTIBOOT_HEADER_ALIGN                  4
+
+/* The magic field should contain this. */
+#define MULTIBOOT_HEADER_MAGIC                  0x1BADB002
+
+/* This should be in %eax. */
+#define MULTIBOOT_BOOTLOADER_MAGIC              0x2BADB002
+
+/* Alignment of multiboot modules. */
+#define MULTIBOOT_MOD_ALIGN                     0x00001000
+
+/* Alignment of the multiboot info structure. */
+#define MULTIBOOT_INFO_ALIGN                    0x00000004
+
+/* Flags set in the ’flags’ member of the multiboot header. */
+
+/* Align all boot modules on i386 page (4KB) boundaries. */
+#define MULTIBOOT_PAGE_ALIGN                    0x00000001
+
+/* Must pass memory information to OS. */
+#define MULTIBOOT_MEMORY_INFO                   0x00000002
+
+/* Must pass video information to OS. */
+#define MULTIBOOT_VIDEO_MODE                    0x00000004
+
+/* This flag indicates the use of the address fields in the header. */
+#define MULTIBOOT_AOUT_KLUDGE                   0x00010000
+
+/* Flags to be set in the ’flags’ member of the multiboot info structure. */
+
+/* is there basic lower/upper memory information? */
+#define MULTIBOOT_INFO_MEMORY                   0x00000001
+/* is there a boot device set? */
+#define MULTIBOOT_INFO_BOOTDEV                  0x00000002
+/* is the command-line defined? */
+#define MULTIBOOT_INFO_CMDLINE                  0x00000004
+/* are there modules to do something with? */
+#define MULTIBOOT_INFO_MODS                     0x00000008
+
+/* These next two are mutually exclusive */
+
+/* is there a symbol table loaded? */
+#define MULTIBOOT_INFO_AOUT_SYMS                0x00000010
+/* is there an ELF section header table? */
+#define MULTIBOOT_INFO_ELF_SHDR                 0X00000020
+
+/* is there a full memory map? */
+#define MULTIBOOT_INFO_MEM_MAP                  0x00000040
+
+/* Is there drive info? */
+#define MULTIBOOT_INFO_DRIVE_INFO               0x00000080
+
+/* Is there a config table? */
+#define MULTIBOOT_INFO_CONFIG_TABLE             0x00000100
+
+/* Is there a boot loader name? */
+#define MULTIBOOT_INFO_BOOT_LOADER_NAME         0x00000200
+
+/* Is there a APM table? */
+#define MULTIBOOT_INFO_APM_TABLE                0x00000400
+
+/* Is there video information? */
+#define MULTIBOOT_INFO_VBE_INFO                 0x00000800
+#define MULTIBOOT_INFO_FRAMEBUFFER_INFO         0x00001000
+
+#ifndef ASM_FILE
+
+typedef unsigned char           multiboot_uint8_t;
+typedef unsigned short          multiboot_uint16_t;
+typedef unsigned int            multiboot_uint32_t;
+typedef unsigned long long      multiboot_uint64_t;
+
+struct multiboot_header
+{
+  /* Must be MULTIBOOT_MAGIC - see above. */
+  multiboot_uint32_t magic;
+
+  /* Feature flags. */
+  multiboot_uint32_t flags;
+
+  /* The above fields plus this one must equal 0 mod 2^32. */
+  multiboot_uint32_t checksum;
+
+  /* These are only valid if MULTIBOOT_AOUT_KLUDGE is set. */
+  multiboot_uint32_t header_addr;
+  multiboot_uint32_t load_addr;
+  multiboot_uint32_t load_end_addr;
+  multiboot_uint32_t bss_end_addr;
+  multiboot_uint32_t entry_addr;
+
+  /* These are only valid if MULTIBOOT_VIDEO_MODE is set. */
+  multiboot_uint32_t mode_type;
+  multiboot_uint32_t width;
+  multiboot_uint32_t height;
+  multiboot_uint32_t depth;
+};
+
+/* The symbol table for a.out. */
+struct multiboot_aout_symbol_table
+{
+  multiboot_uint32_t tabsize;
+  multiboot_uint32_t strsize;
+  multiboot_uint32_t addr;
+  multiboot_uint32_t reserved;
+};
+typedef struct multiboot_aout_symbol_table multiboot_aout_symbol_table_t;
+
+/* The section header table for ELF. */
+struct multiboot_elf_section_header_table
+{
+  multiboot_uint32_t num;
+  multiboot_uint32_t size;
+  multiboot_uint32_t addr;
+  multiboot_uint32_t shndx;
+};
+typedef struct multiboot_elf_section_header_table multiboot_elf_section_header_table_t;
+
+struct multiboot_info
+{
+  /* Multiboot info version number */
+  multiboot_uint32_t flags;
+
+  /* Available memory from BIOS */
+  multiboot_uint32_t mem_lower;
+  multiboot_uint32_t mem_upper;
+
+  /* "root" partition */
+  multiboot_uint32_t boot_device;
+
+  /* Kernel command line */
+  multiboot_uint32_t cmdline;
+
+  /* Boot-Module list */
+  multiboot_uint32_t mods_count;
+  multiboot_uint32_t mods_addr;
+
+  union
+  {
+    multiboot_aout_symbol_table_t aout_sym;
+    multiboot_elf_section_header_table_t elf_sec;
+  } u;
+
+  /* Memory Mapping buffer */
+  multiboot_uint32_t mmap_length;
+  multiboot_uint32_t mmap_addr;
+
+  /* Drive Info buffer */
+  multiboot_uint32_t drives_length;
+  multiboot_uint32_t drives_addr;
+
+  /* ROM configuration table */
+  multiboot_uint32_t config_table;
+
+  /* Boot Loader Name */
+  multiboot_uint32_t boot_loader_name;
+
+  /* APM table */
+  multiboot_uint32_t apm_table;
+
+  /* Video */
+  multiboot_uint32_t vbe_control_info;
+  multiboot_uint32_t vbe_mode_info;
+  multiboot_uint16_t vbe_mode;
+  multiboot_uint16_t vbe_interface_seg;
+  multiboot_uint16_t vbe_interface_off;
+  multiboot_uint16_t vbe_interface_len;
+
+  multiboot_uint64_t framebuffer_addr;
+  multiboot_uint32_t framebuffer_pitch;
+  multiboot_uint32_t framebuffer_width;
+  multiboot_uint32_t framebuffer_height;
+  multiboot_uint8_t framebuffer_bpp;
+#define MULTIBOOT_FRAMEBUFFER_TYPE_INDEXED 0
+#define MULTIBOOT_FRAMEBUFFER_TYPE_RGB     1
+#define MULTIBOOT_FRAMEBUFFER_TYPE_EGA_TEXT     2
+  multiboot_uint8_t framebuffer_type;
+  union
+  {
+    struct
+    {
+      multiboot_uint32_t framebuffer_palette_addr;
+      multiboot_uint16_t framebuffer_palette_num_colors;
+    };
+    struct
+    {
+      multiboot_uint8_t framebuffer_red_field_position;
+      multiboot_uint8_t framebuffer_red_mask_size;
+      multiboot_uint8_t framebuffer_green_field_position;
+      multiboot_uint8_t framebuffer_green_mask_size;
+      multiboot_uint8_t framebuffer_blue_field_position;
+      multiboot_uint8_t framebuffer_blue_mask_size;
+    };
+  };
+};
+typedef struct multiboot_info multiboot_info_t;
+
+struct multiboot_color
+{
+  multiboot_uint8_t red;
+  multiboot_uint8_t green;
+  multiboot_uint8_t blue;
+};
+
+struct multiboot_mmap_entry
+{
+  multiboot_uint32_t size;
+  multiboot_uint64_t addr;
+  multiboot_uint64_t len;
+#define MULTIBOOT_MEMORY_AVAILABLE              1
+#define MULTIBOOT_MEMORY_RESERVED               2
+#define MULTIBOOT_MEMORY_ACPI_RECLAIMABLE       3
+#define MULTIBOOT_MEMORY_NVS                    4
+#define MULTIBOOT_MEMORY_BADRAM                 5
+  multiboot_uint32_t type;
+} __attribute__((packed));
+typedef struct multiboot_mmap_entry multiboot_memory_map_t;
+
+struct multiboot_mod_list
+{
+  /* the memory used goes from bytes ’mod_start’ to ’mod_end-1’ inclusive */
+  multiboot_uint32_t mod_start;
+  multiboot_uint32_t mod_end;
+
+  /* Module command line */
+  multiboot_uint32_t cmdline;
+
+  /* padding to take it to 16 bytes (must be zero) */
+  multiboot_uint32_t pad;
+};
+typedef struct multiboot_mod_list multiboot_module_t;
+
+/* APM BIOS info. */
+struct multiboot_apm_info
+{
+  multiboot_uint16_t version;
+  multiboot_uint16_t cseg;
+  multiboot_uint32_t offset;
+  multiboot_uint16_t cseg_16;
+  multiboot_uint16_t dseg;
+  multiboot_uint16_t flags;
+  multiboot_uint16_t cseg_len;
+  multiboot_uint16_t cseg_16_len;
+  multiboot_uint16_t dseg_len;
+};
+
+#endif /* ! ASM_FILE */
+
+#endif /* ! MULTIBOOT_HEADER */