From abfb601db6e6d80f90d99a23c3b12c6522d642f7 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Tue, 12 May 2015 18:01:13 +1000
Subject: [PATCH] AP_Progmem: added pgm_read_block()

---
 libraries/AP_Progmem/AP_Progmem_AVR.h      | 18 +++++++++---------
 libraries/AP_Progmem/AP_Progmem_Identity.h |  6 ++++++
 2 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/libraries/AP_Progmem/AP_Progmem_AVR.h b/libraries/AP_Progmem/AP_Progmem_AVR.h
index 77906d43d6..d6fa76b241 100644
--- a/libraries/AP_Progmem/AP_Progmem_AVR.h
+++ b/libraries/AP_Progmem/AP_Progmem_AVR.h
@@ -56,6 +56,12 @@ static inline char *strncpy_P(char *buffer, const prog_char_t *pstr, size_t buff
     return strncpy_P(buffer, (const prog_char *)pstr, buffer_size);
 }
 
+static inline void pgm_read_block(const void *s, void *dest, uint8_t len) {
+    uint8_t *dp = (uint8_t *)dest;
+    for (uint8_t i=0; i<len; i++) {
+        dp[i] = pgm_read_byte(i + (const prog_char *)s);
+    }
+}
 
 // read something the size of a pointer. This makes the menu code more
 // portable
@@ -64,15 +70,9 @@ static inline uintptr_t pgm_read_pointer(const void *s)
     if (sizeof(uintptr_t) == sizeof(uint16_t)) {
         return (uintptr_t)pgm_read_word(s);
     } else {
-        union {
-            uintptr_t p;
-            uint8_t a[sizeof(uintptr_t)];
-        } u;
-        uint8_t        i;
-        for (i=0; i< sizeof(uintptr_t); i++) {
-            u.a[i] = pgm_read_byte(i + (const prog_char *)s);
-        }
-        return u.p;
+        uintptr_t p;
+        pgm_read_block(s, &p, sizeof(p));
+        return p;
     }
 }
 
diff --git a/libraries/AP_Progmem/AP_Progmem_Identity.h b/libraries/AP_Progmem/AP_Progmem_Identity.h
index 7b81419de3..408bbb6b05 100644
--- a/libraries/AP_Progmem/AP_Progmem_Identity.h
+++ b/libraries/AP_Progmem/AP_Progmem_Identity.h
@@ -80,5 +80,11 @@ static inline uintptr_t pgm_read_pointer(const void *s) {
 	return *(const uintptr_t *)s;
 }
 
+// read something the size of a pointer. This makes the menu code more
+// portable
+static inline void pgm_read_block(const void *s, void *dest, uint8_t len) {
+    memcpy(dest, s, len);
+}
+
 #endif // __AP_PROGMEM_IDENTITY__