Moved processes to be in ring 3

src/kernel/datatypes/hashtable.h

@@ -36,11 +36,9 @@ namespace xnoe {
       
       if (exists)
         current->elem = xnoe::tuple<key, value>(k, v);
-      else {
+      else
-        printf("Appended.\n");
         list->append(xnoe::tuple<key, value>(k, v));
     }
-    }
 
     xnoe::Maybe<value> get(key k) {
       xnoe::linkedlist<xnoe::tuple<key, value>>* list = &table[xnoe::hash<key>(k) % 4096];

src/kernel/gdt.cpp

@@ -1,47 +1,45 @@
 #include "gdt.h"
 
-constexpr tss_struct::tss_struct() :
+tss_struct tss = (tss_struct) {
-  link(0),
+  .link = 0,
-  _reserved0(0),
+  ._reserved0 = 0,
-  esp0(0),
+  .esp0 = 0xc1006000,
-  ss0(0),
+  .ss0 = 0x10,
-  _reserved1(0),
+  ._reserved1 = 0,
-  esp1(0),
+  .esp1 = 0,
-  ss1(0),
+  .ss1 = 0,
-  _reserved2(0),
+  ._reserved2 = 0,
-  esp2(0),
+  .esp2 = 0,
-  ss2(0),
+  .ss2 = 0,
-  _reserved3(0),
+  ._reserved3 = 0,
-  cr3(0),
+  .cr3 = 0,
-  eip(0),
+  .eip = 0,
-  eflags(0),
+  .eflags = 0,
-  eax(0),
+  .eax = 0,
-  ebx(0),
+  .ebx = 0,
-  ecx(0),
+  .ecx = 0,
-  edx(0),
+  .edx = 0,
-  esp(0),
+  .esp = 0,
-  ebp(0),
+  .ebp = 0,
-  esi(0),
+  .esi = 0,
-  edi(0),
+  .edi = 0,
-  es(0),
+  .es = 0,
-  _reserved4(0),
+  ._reserved4 = 0,
-  cs(0),
+  .cs = 0,
-  _reserved5(0),
+  ._reserved5 = 0,
-  ss(0),
+  .ss = 0,
-  _reserved6(0),
+  ._reserved6 = 0,
-  ds(0),
+  .ds = 0,
-  _reserved7(0),
+  ._reserved7 = 0,
-  fs(0),
+  .fs = 0,
-  _reserved8(0),
+  ._reserved8 = 0,
-  gs(0),
+  .gs = 0,
-  _reserved9(0),
+  ._reserved9 = 0,
-  ldtr(0),
+  .ldtr = 0,
-  _reserved10(0),
+  ._reserved10 = 0,
-  _reserved11(0),
+  ._reserved11 = 0,
-  iopb(0)
+  .iopb = 104
-{}
+};
-
-tss_struct tss = tss_struct();
 
 constexpr gdt_entry::gdt_entry(uint32_t limit, uint32_t base, bool rw, bool exec, bool system, uint8_t ring) :
   limit_lo(limit & 0xffff),
@@ -81,9 +79,13 @@ constexpr gdt_entry::gdt_entry() :
 
 gdt_entry gdt[] = {
   gdt_entry(), // Null Segment
-  gdt_entry(0xfffff, 0, 1, 1, 1, 0), // Code Segment
+  gdt_entry(0xfffff, 0, 1, 1, 1, 0), // Kernel Code Segment
-  gdt_entry(0xfffff, 0, 1, 0, 1, 0), // Data Segment
+  gdt_entry(0xfffff, 0, 1, 0, 1, 0), // Kernel Data Segment
-  gdt_entry(sizeof(tss), &tss, 0, 1, 0, 0) // Task State Segment 1
+
+  gdt_entry(0xfffff, 0, 1, 1, 1, 3), // User Code Segment
+  gdt_entry(0xfffff, 0, 1, 0, 1, 3), // User Data Segment
+
+  gdt_entry() // Empty Task State Segment
 };
 
 gdt_descr descr = (gdt_descr){
@@ -92,9 +94,12 @@ gdt_descr descr = (gdt_descr){
 };
 
 void init_gdt() {
+  gdt[5] = gdt_entry(sizeof(tss), &tss, 0, 1, 0, 0); // Initialise the TSS.
+  gdt[5].accessed = 1;
   asm volatile("lgdt %0;"
                "mov $0x10, %%eax;"
                "mov %%eax, %%ss;"
-               "mov $0x10, %%eax;"
+               "mov %%eax, %%ds;"
-               "mov %%eax, %%ds" : : "m" (descr));
+               "mov $0x28, %%ax;"
+               "ltr %%ax" : : "m" (descr));
 }

src/kernel/gdt.h

@@ -42,9 +42,10 @@ struct __attribute__((packed)) tss_struct {
   uint16_t _reserved10;
   uint16_t _reserved11;
   uint16_t iopb;
-  constexpr tss_struct();
 };
 
+extern tss_struct tss;
+
 struct __attribute__((packed)) gdt_entry {
   uint32_t limit_lo : 16;
   uint32_t base_lo : 16;

src/kernel/idt.cpp

@@ -2,14 +2,17 @@
 
 GateEntry idt[256];
 
-void set_entry(uint8_t interrupt_number, uint16_t code_segment, void* handler, uint8_t type) {
+void set_entry(uint8_t interrupt_number, uint16_t code_segment, void* handler, uint8_t type, uint8_t privilege) {
   uint32_t handler_addr = (uint32_t)handler;
   uint16_t* handler_halves = (uint16_t*)&handler_addr;
-  idt[interrupt_number] = (GateEntry){
+  idt[interrupt_number] = (GateEntry) {
     .offset_low = handler_halves[0],
     .selector = code_segment,
     .zero = 0,
     .type = type,
+    .zero1 = 0,
+    .privilege = privilege,
+    .present = 1,
     .offset_high = handler_halves[1]
   };
 }
@@ -31,7 +34,7 @@ __attribute__((interrupt)) void ignore_interrupt(interrupt_frame* frame) {
 }
 
 __attribute__((interrupt)) void gpf(interrupt_frame* frame, uint32_t err_code) {
-  printf("General Protection Fault %d\n", err_code);
+  printf("General Protection Fault %x\n", err_code);
   while (1) asm("hlt");
 }
 
@@ -168,10 +171,10 @@ void init_idt() {
   for (int i=0; i<256; i++)
     set_entry(i, 0x08, &ignore_interrupt, 0x8E);
   
-  set_entry(0x20, 0x08, &context_switch, 0x8E);
+  set_entry(0x20, 0x08, &context_switch, 0xE);
-  set_entry(0xD, 0x08, &gpf, 0x8E);
+  set_entry(0xD, 0x08, &gpf, 0xE);
-  set_entry(0xE, 0x08, &page_fault, 0x8E);
+  set_entry(0xE, 0x08, &page_fault, 0xE);
-  set_entry(0x7f, 0x08, &syscall, 0x8E);
+  set_entry(0x7f, 0x08, &syscall, 0xE, 3);
 
   outb(0x20, 0x11);
   outb(0xA0, 0x11);

src/kernel/idt.h

@@ -13,7 +13,7 @@ struct interrupt_frame {
     uint32_t eflags;
 };
 extern void load_idt();
-void set_entry(uint8_t interrupt_number, uint16_t code_segment, void* handler, uint8_t type);
+void set_entry(uint8_t interrupt_number, uint16_t code_segment, void* handler, uint8_t type, uint8_t privilege = 0);
 void init_idt();
 void enable_idt();
 
@@ -21,7 +21,10 @@ struct __attribute__((packed)) GateEntry{
   uint16_t offset_low;
   uint16_t selector;
   uint8_t zero;
-  uint8_t type;
+  uint8_t type : 4;
+  uint8_t zero1 : 1;
+  uint8_t privilege : 2;
+  uint8_t present : 1;
   uint16_t offset_high;
 } ;
 

src/kernel/kmain.cpp

@@ -47,8 +47,6 @@ int main() {
   Global::currentProc = &kernel;
 
   Process* p1 = kernel.createProcess("WORLD   BIN");
-  Process* p2 = kernel.createProcess("HELLO   BIN");
-  kernel.destroyProcess(p2);
 
   init_keyboard();
   

src/kernel/memory.cpp

@@ -104,11 +104,11 @@ PageTable::~PageTable() {
   delete page_table;
 }
 
-void PageTable::map_table(uint32_t index, uint32_t addr) {
+void PageTable::map_table(uint32_t index, uint32_t addr, uint8_t privilege) {
   page_table[index] = (PTE){
     .present = 1,
     .read_write = 1,
-    .privilege = 0,
+    .privilege = privilege,
     .write_through_cache = 0,
     .disable_cache = 0,
     .accessed = 0,
@@ -168,7 +168,7 @@ PageDirectory::~PageDirectory() {
   delete page_directory;
 }
 
-void PageDirectory::map(uint32_t phys, uint32_t virt) {
+void PageDirectory::map(uint32_t phys, uint32_t virt, uint8_t privilege) {
   split_addr* split = (split_addr*)&virt;
 
   if (!page_tables[split->pd_index].virt_addr)
@@ -177,7 +177,7 @@ void PageDirectory::map(uint32_t phys, uint32_t virt) {
   page_directory[split->pd_index] = (PDE){
     .present = 1,
     .read_write = 1,
-    .privilege = 0,
+    .privilege = privilege,
     .write_through_cache = 0,
     .disable_cache = 0,
     .accessed = 0,
@@ -188,7 +188,7 @@ void PageDirectory::map(uint32_t phys, uint32_t virt) {
     .address = page_tables[split->pd_index].phys_addr
   };
 
-  page_tables[split->pd_index].map_table(split->pt_index, phys >> 12);
+  page_tables[split->pd_index].map_table(split->pt_index, phys >> 12, privilege);
   asm volatile ("invlpg (%0)" : : "r" (virt) : "memory");
 }
 
@@ -217,11 +217,12 @@ Allocator::Allocator(PageDirectory* page_directory, PageMap* phys, PageMap* virt
   this->virt_alloc_base = virt_alloc_base;
 }
 
-Allocator::Allocator(PageDirectory* page_directory, PageMap* virt, uint32_t virt_alloc_base) {
+Allocator::Allocator(PageDirectory* page_directory, PageMap* virt, uint32_t virt_alloc_base, uint8_t privilege) {
   this->PD = page_directory;
   this->virt = virt;
 
   this->virt_alloc_base = virt_alloc_base;
+  this->privilege = privilege;
 }
 
 Allocator::~Allocator() {
@@ -238,7 +239,7 @@ void* Allocator::allocate(uint32_t size) {
   for (int i=0; i<count; i++) {
     uint32_t phys_addr = this->phys->find_next_available_from(0);
     this->phys->mark_unavailable(phys_addr);
-    this->PD->map(phys_addr, virt_addr + 4096 * i);
+    this->PD->map(phys_addr, virt_addr + 4096 * i, this->privilege);
   }
 
   return virt_addr;

src/kernel/memory.h

@@ -47,7 +47,7 @@ struct PageTable {
 
   ~PageTable(); // Delete page_table
 
-  void map_table(uint32_t index, uint32_t addr);
+  void map_table(uint32_t index, uint32_t addr, uint8_t privilege=0);
   void unmap_table(uint32_t index);
 
   uint32_t get_physical_address(uint32_t index);
@@ -68,7 +68,7 @@ public:
 
   ~PageDirectory(); // Delete the page tables and page_directory
 
-  void map(uint32_t phys, uint32_t virt);
+  void map(uint32_t phys, uint32_t virt, uint8_t privilege=0);
   void unmap(uint32_t virt);
 
   uint32_t virtual_to_physical(uint32_t virt);
@@ -82,11 +82,12 @@ protected:
   PageMap* virt;
 
   uint32_t virt_alloc_base;
+  uint8_t privilege;
 public:
   PageDirectory* PD;
 
   Allocator(PageDirectory* page_directory, PageMap* phys, PageMap* virt, uint32_t virt_alloc_base);
-  Allocator(PageDirectory* page_directory, PageMap* virt, uint32_t virt_alloc_base);
+  Allocator(PageDirectory* page_directory, PageMap* virt, uint32_t virt_alloc_base, uint8_t privilege);
 
   ~Allocator(); // Delete virt and PD
 

src/kernel/process.cpp

@@ -23,7 +23,7 @@ Process::Process(uint32_t PID, void* stack, PageDirectory* page_directory, PageM
 }
 
 Process::Process(uint32_t PID)
-: Allocator(new PageDirectory, new PageMap, 0) {
+: Allocator(new PageDirectory, new PageMap, (uint32_t)0, 3) {
   this->PID = PID;
   this->page_remaining = 0;
   this->last_page_pointer = 0;
@@ -31,7 +31,7 @@ Process::Process(uint32_t PID)
 }
 
 Process::Process(uint32_t PID, PageDirectory* inherit, uint32_t inheritBase, char* filename)
-: Allocator(new PageDirectory, new PageMap, 0) {
+: Allocator(new PageDirectory, new PageMap, (uint32_t)0, 3) {
   this->PID = PID;
   this->page_remaining = 0;
   this->last_page_pointer = 0;
@@ -50,9 +50,13 @@ Process::Process(uint32_t PID, PageDirectory* inherit, uint32_t inheritBase, cha
   // We also need to initialise ESP and the stack
   uint32_t* stack32 = ((uint32_t)this->stack + 0x8000);
   stack32--;
+  *stack32 = 0x23;
+  stack32--;
+  *stack32 = ((uint32_t)this->stack + 0x8000);
+  stack32--;
   *stack32 = 0x200; // EFLAGS
   stack32--;
-  *stack32 = 8; // CS 0x08
+  *stack32 = 27; // CS 0x08
   stack32--;
   *stack32 = (uint32_t)program_data;
 

src/program/world.c

@@ -80,6 +80,8 @@ void readline(int max, char* buffer) {
 }
 
 int main() {
+  print ("Hello from Ring 3!\n");
+
   char buffer[128];
   while (1) {
     for (int i=0; i<128; i++)