From: Ben Pfaff Date: Wed, 5 Apr 2006 19:56:02 +0000 (+0000) Subject: Clarify need for virt-to-phys translation table. X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3dd12e6dd3f49b42ec9b3dcadeb8506ecf8b17c0;p=pintos-anon Clarify need for virt-to-phys translation table. Thanks to Nico R Benitez for the question. --- diff --git a/doc/vm.texi b/doc/vm.texi index 8afc49c..3703a94 100644 --- a/doc/vm.texi +++ b/doc/vm.texi @@ -316,12 +316,12 @@ Some way of translating in software from virtual page frames to physical page frames. Pintos provides a hash table that you may find useful for this purpose (@pxref{Hash Table}). -It is possible to do this translation without adding a new data -structure, by modifying the code in @file{userprog/pagedir.c}. However, -if you do that you'll need to carefully study and understand section -3.7, ``Page Translation Using 32-Bit Physical Addressing,'' in -@bibref{IA32-v3a}, and in practice it is probably easier to add a new -data structure. +You don't strictly need a new data structure for this. You could +instead modify the code in @file{userprog/pagedir.c}. If you do that +you'll need to thoroughly understand how 80@var{x}86 page tables work +by, e.g.,@: studying section 3.7, ``Page Translation Using 32-Bit +Physical Addressing,'' in @bibref{IA32-v3a}. In practice, most groups +use a separate data structure. @item Some way of finding a page on disk (in a file or in swap) if it is not