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static volatile int status;

void process_to_usermode(uint64_t rip)
{
   asm volatile("cli");
   asm volatile("mov $0x23, %ax");
   asm volatile("mov %ax, %ds");
   asm volatile("mov %ax, %es");
   asm volatile("mov %ax, %fs");
   asm volatile("mov %ax, %gs");
   asm volatile("mov %rsp, %rax");
   asm volatile("push $0x23");
   asm volatile("push %rax");
   asm volatile("pushf");
   asm volatile("pop %rax");
   asm volatile("or $0x200, %rax");
   asm volatile("push %rax");
   asm volatile("push $0x1B");
   asm volatile("push %%rdx" :: "d"(rip));
   asm volatile("iretq");

// IT WORKS IF I USE A SIMPLE JUMP AND LEAVE THEM RUNNING IN KERNEL MODE (CODE BELOW)
//       void (*init)();
//       init = (void*)rip;
//       init();
}

void process_init(args_t *args)
{
   uint64_t addr, entry;

   addr = elf64_load(args->path, 0);
   if(!addr) // File not loaded
   {
      status = 0;
      printf("ELF loading failed!\n");
      process_exit(1);
   }

   entry = elf64_prepare(addr);
   if(!entry) // Linking failed
   {
      status = 0;
      printf("ELF linking failed!\n");
      process_exit(1);
   }

   // Allocate a new stack in user space
   if(!alloc_page(get_page(USER_STACK_ADDR, 1)))
   {
      printf("Failed to allocate memory for stack!\n");
      process_exit(1);
   }
   memset((void*)USER_STACK_ADDR, 0, USER_STACK_SIZE);
   asm volatile("movq %0, %%rsp" :: "r"(USER_STACK_ADDR+USER_STACK_SIZE));
   
   status = 2; // All good!
   
   kfree((void*)addr);
   process_to_usermode(entry);
}

int process_spawn(char *path, char *str, char *cwd, int modal)
{
   stream_t *file = vfs_open(path, "r");
   int value;

   if(file)
   {
      vfs_close(file);
      args_t *args = (args_t*)kmalloc(sizeof(args_t));
      strcpy(args->path, path);
      strcpy(args->param, str);
      strcpy(args->cwd, cwd);
      
      if(modal)
      {
         args->parent = smp_get_thread();
         args->modal = modal;
      }
      else
      {
         args->parent = 0;
         args->modal = 0;
      }

      status = 1;
      uint64_t pml4 = vmm_create_user_space();
      new_thread(&process_init, args, pml4);
      while(status == 1); // THE FIRST PROCESS CRASHES HERE WHILE WAITING ON THE SECOND PROCESS
      value = status;
      
      if(!value)
      {
         return 0;
      }
      else
      {
         if(args->modal)
         {
            // This is a temporary solution (the parent process should be put to sleep in this case)
            status = 1; 
            while(status == 1);
         }

         return 1;
      }
   }

   return 0;
}