BugsResolved.txt

1. Misuse of region_alloc V.S. memset V.S memmove
     if(NIL == (pte = region_alloc(e, (void*)ph->p_va, ph->p_memsz)))
        {
            panic("pte not found!?\n");
            return ;
        }
        *pte = *pte | PTE_U | PTE_W;
        memset((void*)ROUNDDOWN(ph->p_va,PGSIZE),0 ,PGSIZE);
        memmove((void*)ph->p_va, (void*)((uint8_t*)binary + ph->p_offset), ph->p_filesz);    
    The list to be clarified
        A. region_alloc is to setup memory in sequence pages.
        B. pte just get only one page! 
            just set one page's privilege to PTE_U, PTE_W.
        C. If memmove will use the size than one page, then it will raise fault by CPU!
           Becuase the other PTEs(not the pte just get!) were not in the right privilege.
        
2. load_icode' lcr3' setup
    A. lcr3 uses the physical address!
    B. lcr3's right setup posistion!
        Before the time that all the memory you want to chage!

3. stack's growth direction
    memset((void*)(e->env_tf.tf_esp - PGSIZE),0 ,PGSIZE);)))
    Error : e->env_tf.tf_esp = USTACKTOP-PGSIZE;
    Right : e->env_tf.tf_esp = USTACKTOP;
    push :
          var = stack[esp-4] 
          esp = esp - 4

    pop :
          var = stack[esp]
          esp = esp + 4
       
4. boot_map_region
    It should at least have the permissions that lower lever PTE has.