From 546b293cb9369c9c421981c71577af29d83b925a Mon Sep 17 00:00:00 2001
From: Rob Landley <rob@landley.net>
Date: Mon, 21 Jul 2014 19:56:53 -0500
Subject: Little endian and big endian versions of peek (for host.c).

---
 lib/lib.c | 38 ++++++++++++++++++++++++--------------
 lib/lib.h |  4 +++-
 2 files changed, 27 insertions(+), 15 deletions(-)

(limited to 'lib')

diff --git a/lib/lib.c b/lib/lib.c
index bda69931..e16873f0 100644
--- a/lib/lib.c
+++ b/lib/lib.c
@@ -372,21 +372,31 @@ void msleep(long miliseconds)
   nanosleep(&ts, &ts);
 }
 
-int64_t peek(void *ptr, int size)
+// Inefficient, but deals with unaligned access
+int64_t peek_le(void *ptr, unsigned size)
 {
-  if (size & 8) {
-    volatile int64_t *p = (int64_t *)ptr;
-    return *p;
-  } else if (size & 4) {
-    volatile int *p = (int *)ptr;
-    return *p;
-  } else if (size & 2) {
-    volatile short *p = (short *)ptr;
-    return *p;
-  } else {
-    volatile char *p = (char *)ptr;
-    return *p;
-  }
+  int64_t ret = 0;
+  char *c = ptr;
+  int i;
+
+  for (i=0; i<size; i++) ret |= ((int64_t)c[i])<<i;
+
+  return ret;
+}
+
+int64_t peek_be(void *ptr, unsigned size)
+{
+  int64_t ret = 0;
+  char *c = ptr;
+
+  while (size--) ret = (ret<<8)|c[size];
+
+  return ret;
+}
+
+int64_t peek(void *ptr, unsigned size)
+{
+  return IS_BIG_ENDIAN ? peek_be(ptr, size) : peek_le(ptr, size);
 }
 
 void poke(void *ptr, uint64_t val, int size)
diff --git a/lib/lib.h b/lib/lib.h
index 9deacf22..11a1018c 100644
--- a/lib/lib.h
+++ b/lib/lib.h
@@ -138,7 +138,9 @@ int mkpathat(int atfd, char *dir, mode_t lastmode, int flags);
 struct string_list **splitpath(char *path, struct string_list **list);
 char *readfile(char *name, char *buf, off_t len);
 void msleep(long miliseconds);
-int64_t peek(void *ptr, int size);
+int64_t peek_le(void *ptr, unsigned size);
+int64_t peek_be(void *ptr, unsigned size);
+int64_t peek(void *ptr, unsigned size);
 void poke(void *ptr, uint64_t val, int size);
 struct string_list *find_in_path(char *path, char *filename);
 long atolx(char *c);
-- 
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