hi, In the following code of i386 arch, I have a very simple question. Why does it store the higher address of the PDE to the page global table instead of the starting lower address? And the size of each PDE is 8 bytes, right? I assume this happens on line 122 and 123. Thanks, Neo 116 page_pde_offset = (__PAGE_OFFSET >> 20); 117 118 movl $(pg0 - __PAGE_OFFSET), %edi 119 movl $(swapper_pg_dir - __PAGE_OFFSET), %edx 120 movl $0x007, %eax /* 0x007 = PRESENT+RW+USER */ 121 10: 122 leal 0x007(%edi),%ecx /* Create PDE entry */ 123 movl %ecx,(%edx) /* Store identity PDE entry */ 124 movl %ecx,page_pde_offset(%edx) /* Store kernel PDE entry */ 125 addl $4,%edx 126 movl $1024, %ecx 127 11: 128 stosl 129 addl $0x1000,%eax 130 loop 11b 131 /* End condition: we must map up to and including INIT_MAP_BEYOND_END */ 132 /* bytes beyond the end of our own page tables; the +0x007 is the attribute bits */ 133 leal (INIT_MAP_BEYOND_END+0x007)(%edi),%ebp 134 cmpl %ebp,%eax 135 jb 10b 136 movl %edi,(init_pg_tables_end - __PAGE_OFFSET) -- I would remember that if researchers were not ambitious probably today we haven't the technology we are using! -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
