why mapping beyond end "MAPPING_BEYOND_END"?
Wang Baisheng <[email protected]>
| Newsgroups | org.kernel.vger.linux-newbie |
|---|---|
| Message-ID | <CABymN7aq6zs47MKVuijcvRg5yggNkg_jUT_UJfOguUg2xv2f5A@mail.gmail.com> |
Hi All,
For x86, in arch/x86/kernel/head_32.S, for Initializing page tables,
why mapping beyond end by "MAPPING_BEYOND_END":
/*
* End condition: we must map up to the end + MAPPING_BEYOND_END.
*/
movl $pa(_end) + MAPPING_BEYOND_END + PTE_IDENT_ATTR, %ebp
cmpl %ebp,%eax
jb 10b
According vmlinux.lds.S, the paging table is between __brk_base and
_end. So why map MAPPING_BEYOND_END after _end ?
Regards,
Jacky
--
To unsubscribe from this list: send the line "unsubscribe linux-newbie" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.linux-learn.org/faqs