Rewrite palloc code so that it only touches the first 4 MB of RAM.

[pintos-anon] / src / threads / init.c

diff --git a/src/threads/init.c b/src/threads/init.c
index 73a2e98305ffed99b683a9a350624e44c3f78717..3b313287183c06cd1f7286a246bd7518a766dda5 100644 (file)
--- a/src/threads/init.c
+++ b/src/threads/init.c
@@ -34,9 +34,6 @@
 #include "filesys/fsutil.h"
 #endif
 
-/* Amount of physical memory, in 4 kB pages. */
-size_t ram_pages;
-
 /* Page directory with kernel mappings only. */
 uint32_t *base_page_dir;
 
@@ -82,8 +79,8 @@ main (void)
 
   /* Initialize memory system. */
   palloc_init ();
-  malloc_init ();
   paging_init ();
+  malloc_init ();
 
   /* Segmentation. */
 #ifdef USERPROG
@@ -154,9 +151,6 @@ ram_init (void)
      linker as _start_bss and _end_bss.  See kernel.lds. */
   extern char _start_bss, _end_bss;
   memset (&_start_bss, 0, &_end_bss - &_start_bss);
-
-  /* Get RAM size from loader.  See loader.S. */
-  ram_pages = *(uint32_t *) ptov (LOADER_RAM_PAGES);
 }
 
 /* Populates the base page directory and page table with the
@@ -165,8 +159,8 @@ ram_init (void)
    directory it creates.
 
    At the time this function is called, the active page table
-   (set up by loader.S) only maps the first 4 MB of RAM, so we
-   should not try to use extravagant amounts of memory.
+   (set up by start.S) only maps the first 4 MB of RAM, so we
+   should not try to access memory beyond that limit.
    Fortunately, there is no need to do so. */
 static void
 paging_init (void)
@@ -237,7 +231,7 @@ argv_init (void)
     else if (!strcmp (argv[i], "-ex")) 
       initial_program = argv[++i];
     else if (!strcmp (argv[i], "-ul"))
-      user_page_limit = atoi (argv[++i]);
+      max_user_pages = atoi (argv[++i]);
 #endif
 #ifdef FILESYS
     else if (!strcmp (argv[i], "-f"))