Merge changes from Lab 2

kern/pmap.c

@@ -185,8 +185,6 @@ mem_init(void)
 	boot_map_region(kern_pgdir,
 			UPAGES, ROUNDUP(pages_size, PGSIZE),
 			PADDR(pages), PTE_U);
-	kern_pgdir[PDX(UPAGES)] |= PTE_U;
-	kern_pgdir[PDX(UPAGES)] &= ~PTE_W;
 
 	//////////////////////////////////////////////////////////////////////
 	// Map the 'envs' array read-only by the user at linear address UENVS
@@ -198,8 +196,6 @@ mem_init(void)
 	boot_map_region(kern_pgdir,
 		UENVS, ROUNDUP(envs_size, PGSIZE),
 		PADDR(envs), PTE_U);
-	kern_pgdir[PDX(UENVS)] |= PTE_U;
-	kern_pgdir[PDX(UPAGES)] &= ~PTE_W;
 
 	//////////////////////////////////////////////////////////////////////
 	// Use the physical memory that 'bootstack' refers to as the kernel
@@ -215,8 +211,11 @@ mem_init(void)
 	boot_map_region(kern_pgdir,
 			KSTACKTOP-KSTKSIZE, KSTKSIZE,
 			PADDR(bootstack), PTE_W);
+<<<<<<< HEAD
 	kern_pgdir[PDX(KSTACKTOP-KSTKSIZE)] |= PTE_W;
 	kern_pgdir[PDX(KSTACKTOP-KSTKSIZE)] &= ~PTE_U;
+=======
+>>>>>>> lab2
 
 	//////////////////////////////////////////////////////////////////////
 	// Map all of physical memory at KERNBASE.
@@ -229,9 +228,6 @@ mem_init(void)
 	boot_map_region(kern_pgdir,
 			KERNBASE, 0x100000000 - KERNBASE,
 			0, PTE_W);
-	kern_pgdir[PDX(KERNBASE)] |= PTE_W | PTE_P;
-	kern_pgdir[PDX(KERNBASE)] &= ~PTE_U;
-
 
 	// Check that the initial page directory has been set up correctly.
 	check_kern_pgdir();