first part of stack setup

1 files changed, 24 insertions, 1 deletions

diff --git a/userprog/process.c b/userprog/process.c
index 8b6b86a..f5b7431 100644
--- a/userprog/process.c
+++ b/userprog/process.c
@@ -591,7 +591,8 @@ load_segment (struct file *file, off_t ofs, uint8_t *upage,
 static bool
 setup_stack (void **esp, const char *args)
 {
-  uint8_t *kpage = NULL;
+  uint8_t *kpage = NULL, stack_total;
+  const char *name = thread_current ()->name;
 
   kpage = palloc_get_page (PAL_USER | PAL_ZERO);
   if (kpage == NULL)
@@ -601,6 +602,28 @@ setup_stack (void **esp, const char *args)
       palloc_free_page (kpage);
       return false;
   }
+  printf("cmd=%s\n", name);
+  printf("args=%s\n", args);
+
+  *esp = PHYS_BASE;
+  printf("esp=%p\n", *esp);
+
+  /* copy arguments to stack */
+  *esp -= strlen(args) + 1;
+  memcpy(*esp, args, strlen(args) + 1);
+  printf("esp=%p, off=%d\n", *esp, strlen(args) + 1);
+
+  /* copy executable name to stack */
+  *esp -= strlen(name) + 1;
+  memcpy(*esp, name, strlen(name) + 1);
+  printf("esp=%p, off=%d\n", *esp, strlen(name) + 1);
+
+  /* word align our stack so far */
+  stack_total = PHYS_BASE - *esp;
+  printf("stack_total=%u\n", stack_total);
+  printf("unaligned=%p off=%d\n", *esp, PHYS_BASE - *esp);
+  *esp -= (4 - stack_total % sizeof(char *)); /* by thomas */
+  printf("aligned=%p off=%d\n", *esp, PHYS_BASE - *esp);
 
   /* Currently we assume that 'argc = 0' */
   *esp = PHYS_BASE - 12;