X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fthreads%2Finit.c;h=0d9c69984603eaaa6a69bf4fac58c4af9e54ce54;hb=f0612244c44f4b4f0bc79e3fc882e9f74bd4a3f4;hp=49b26a9bae3b636daf3bdea790c3b19b7367ab70;hpb=5539377e713d0b7424a15547ca0242518e86ea9b;p=pintos-anon

diff --git a/src/threads/init.c b/src/threads/init.c
index 49b26a9..0d9c699 100644
--- a/src/threads/init.c
+++ b/src/threads/init.c
@@ -17,11 +17,11 @@
 #include "threads/loader.h"
 #include "threads/malloc.h"
 #include "threads/mmu.h"
-#include "threads/paging.h"
 #include "threads/palloc.h"
 #include "threads/test.h"
 #include "threads/thread.h"
 #ifdef USERPROG
+#include "userprog/process.h"
 #include "userprog/exception.h"
 #include "userprog/gdt.h"
 #include "userprog/syscall.h"
@@ -36,22 +36,25 @@
 /* Amount of physical memory, in 4 kB pages. */
 size_t ram_pages;
 
+/* Page directory with kernel mappings only. */
+uint32_t *base_page_dir;
+
 #ifdef FILESYS
-/* Format the filesystem? */
+/* -f: Format the filesystem? */
 static bool format_filesys;
 #endif
 
 #ifdef USERPROG
-/* Initial program to run. */
+/* -ex: Initial program to run. */
 static char *initial_program;
 #endif
 
-/* Power off after running requested actions? */
-static bool power_off;
+/* -q: Power off after running requested actions? */
+static bool do_power_off;
 
 static void ram_init (void);
+static void paging_init (void);
 static void argv_init (void);
-static void do_power_off (void);
 
 int main (void) NO_RETURN;
 
@@ -110,14 +113,14 @@ main (void)
   if (initial_program != NULL)
     {
       printf ("\nExecuting '%s':\n", initial_program);
-      thread_execute (initial_program); 
+      process_execute (initial_program); 
     }
 #else
   test ();
 #endif
 
-  if (power_off) 
-    do_power_off ();
+  if (do_power_off) 
+    power_off ();
 
   /* Terminate this thread. */
   thread_exit ();
@@ -140,6 +143,42 @@ ram_init (void)
   ram_pages = *(uint32_t *) ptov (LOADER_RAM_PAGES);
 }
 
+/* Populates the base page directory and page table with the
+   kernel virtual mapping, and then sets up the CPU to use the
+   new page directory.  Points base_page_dir to the page
+   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.
+   Fortunately, there is no need to do so. */
+static void
+paging_init (void)
+{
+  uint32_t *pd, *pt;
+  size_t page;
+
+  pd = base_page_dir = palloc_get (PAL_ASSERT | PAL_ZERO);
+  pt = NULL;
+  for (page = 0; page < ram_pages; page++) 
+    {
+      uintptr_t paddr = page * PGSIZE;
+      void *vaddr = ptov (paddr);
+      size_t pde_idx = pd_no (vaddr);
+      size_t pte_idx = pt_no (vaddr);
+
+      if (pd[pde_idx] == 0)
+        {
+          pt = palloc_get (PAL_ASSERT | PAL_ZERO);
+          pd[pde_idx] = pde_create (pt);
+        }
+
+      pt[pte_idx] = pte_create_kernel (vaddr, true);
+    }
+
+  asm volatile ("movl %0,%%cr3" :: "r" (vtop (base_page_dir)));
+}
+
 /* Parses the command line. */
 static void
 argv_init (void) 
@@ -173,7 +212,7 @@ argv_init (void)
     else if (!strcmp (argv[i], "-d")) 
       debug_enable (argv[++i]);
     else if (!strcmp (argv[i], "-q"))
-      power_off = true;
+      do_power_off = true;
 #ifdef USERPROG
     else if (!strcmp (argv[i], "-ex")) 
       initial_program = argv[++i];
@@ -220,14 +259,16 @@ argv_init (void)
           " -q                  Power off after doing requested actions.\n"
           " -u                  Print this help message and power off.\n"
           );
-        do_power_off ();
+        power_off ();
       }
     else 
       PANIC ("unknown option `%s' (use -u for help)", argv[i]);
 }
 
+/* Powers down the machine we're running on,
+   as long as we're running on Bochs or qemu. */
 void
-do_power_off (void) 
+power_off (void) 
 {
   const char s[] = "Shutdown";
   const char *p;