Make Austin happier

2011

Make Austin happier
d9818bdd · Frans Kaashoek · a4b213cf · d9818bdd · d9818bdd
--- a/README
+++ b/README
@@ -26,7 +26,7 @@ In addition, we are grateful for the patches contributed by Greg
 Price, Yandong Mao, and Hitoshi Mitake.
 The code in the files that constitute xv6 is
-Copyright 2006-2007 Frans Kaashoek, Robert Morris, and Russ Cox.
+Copyright 2006-2011 Frans Kaashoek, Robert Morris, and Russ Cox.
 ERROR REPORTS

--- a/vm.c
+++ b/vm.c
@@ -18,7 +18,7 @@ seginit(void)
 {
  struct cpu *c;
-  // Map virtual addresses to linear addresses using identity map.
+  // Map "logical" addresses to virtual addresses using identity map.
  // Cannot share a CODE descriptor for both kernel and user
  // because it would have to have DPL_USR, but the CPU forbids
  // an interrupt from CPL=0 to DPL=3.
@@ -40,7 +40,7 @@ seginit(void)
 }
 // Return the address of the PTE in page table pgdir
-// that corresponds to linear address va.  If alloc!=0,
+// that corresponds to virtual address va.  If alloc!=0,
 // create any required page table pages.
 static pte_t *
 walkpgdir(pde_t *pgdir, const void *va, char* (*alloc)(void))
@@ -64,17 +64,17 @@ walkpgdir(pde_t *pgdir, const void *va, char* (*alloc)(void))
  return &pgtab[PTX(va)];
 }
-// Create PTEs for linear addresses starting at la that refer to
+// Create PTEs for virtual addresses starting at la that refer to
 // physical addresses starting at pa. la and size might not
 // be page-aligned.
 static int
-mappages(pde_t *pgdir, void *la, uint size, uint pa, int perm, char* (*alloc)(void))
+mappages(pde_t *pgdir, void *va, uint size, uint pa, int perm, char* (*alloc)(void))
 {
  char *a, *last;
  pte_t *pte;
-  a = PGROUNDDOWN(la);
+  a = PGROUNDDOWN(va);
-  last = PGROUNDDOWN(la + size - 1);
+  last = PGROUNDDOWN(va + size - 1);
  for(;;){
    pte = walkpgdir(pgdir, a, alloc);
    if(pte == 0)
@@ -90,7 +90,7 @@ mappages(pde_t *pgdir, void *la, uint size, uint pa, int perm, char* (*alloc)(vo
  return 0;
 }
-// The mappings from logical to linear are one to one (i.e.,
+// The mappings from logical to virtual are one to one (i.e.,
 // segmentation doesn't do anything).
 // There is one page table per process, plus one that's used
 // when a CPU is not running any process (kpgdir).
@@ -98,7 +98,6 @@ mappages(pde_t *pgdir, void *la, uint size, uint pa, int perm, char* (*alloc)(vo
 // page protection bits prevent it from using anything other
 // than its memory.
 // 
-//
 // setupkvm() and exec() set up every page table like this:
 //   0..USERTOP      : user memory (text, data, stack, heap), mapped to some unused phys mem
 //   KERNBASE..KERNBASE+1M: mapped to 0..1M
@@ -112,9 +111,9 @@ mappages(pde_t *pgdir, void *la, uint size, uint pa, int perm, char* (*alloc)(vo
 // (which is inaccessible in user mode).  The user program sits in
 // the bottom of the address space, and the kernel at the top at KERNBASE.
 static struct kmap {
-  void *l;
+  void *virt;
-  uint p;
+  uint phys_start;
-  uint e;
+  uint phys_end;
  int perm;
 } kmap[] = {
  { P2V(0), 0, 1024*1024, PTE_W},  // First 1Mbyte contains BIOS and some IO devices
@@ -135,7 +134,8 @@ setupkvm(char* (*alloc)(void))
  memset(pgdir, 0, PGSIZE);
  k = kmap;
  for(k = kmap; k < &kmap[NELEM(kmap)]; k++)
-    if(mappages(pgdir, k->l, k->e - k->p, (uint)k->p, k->perm, alloc) < 0)
+    if(mappages(pgdir, k->virt, k->phys_end - k->phys_start, (uint)k->phys_start, 
+		k->perm, alloc) < 0)
      return 0;
  return pgdir;