6.828: Operating System Engineering (43)

以下なソレですが、

    //////////////////////////////////////////////////////////////////////
    // Recursively insert PD in itself as a page table, to form
    // a virtual page table at virtual address VPT.
    // (For now, you don't have understand the greater purpose of the
    // following two lines.)

    // Permissions: kernel RW, user NONE
    pgdir[PDX(VPT)] = PADDR(pgdir)|PTE_W|PTE_P;

    // same for UVPT
    // Permissions: kernel R, user R 
    pgdir[PDX(UVPT)] = PADDR(pgdir)|PTE_U|PTE_P;

これが、pgdir の中身を誤解しているらしいワタシの認識を改めて頂けることを切に願う。