Diff: example_peek.cpp

Revision:

7:7b225c565fe6

Child:

8:5972683a7190

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/example_peek.cpp	Mon Feb 24 14:34:14 2020 +0000
@@ -0,0 +1,88 @@
+#include "MicroBit.h"
+#include "MicroBitPin.h"
+#include "cppNorm.h"
+#include "common.h"
+
+
+/**
+  * conclusion: items incl char and char[] are on stack 4 byte alligned (0,4,8,c)
+  * on global data char isn't aligned.
+  * int8_t[] seems to 2 aligned, but it would demand a  clean global date area to find out
+  * variables are not source code ordered!
+  */
+void typeSizeAndAlignment() {
+#define outputscreeen1
+#ifdef outputscreeen1
+    double d1;
+    int8_t int8[3];
+    int16_t int16;
+    int32_t int32;
+    int32_t i32;
+                // ADRESS   bytes in decimal 
+                //               
+    void                                    *addresses[] = {
+     int8       // b8       4         
+    ,&int8[3]   // bb       3  
+    ,&int16     // bc       4  
+    ,&d1        // c0       8         
+    ,&int32     // c8       4 
+    ,&i32};     // cc         
+    char names[][8] = {
+         "int8"
+        ,"int8[3]"
+        ,"int16"
+        ,"d1"
+        ,"int32"
+        ,"i32"
+        };
+#else
+    int   i;
+    float f;
+    char  ch1;
+    char  chre[9];
+    char  chr3[3];
+    char  chr4[4];
+    char  chr2[2];
+                // ADRESS   bytes(decimal)
+    void                           *addresses[] = {
+     chre    //     ac      12
+    ,&i      //     b8      4
+    ,&f      //     bc      4
+    ,&ch1    //     c0      4
+    ,chr3    //     c4      4
+    ,chr4    //     c8      4
+    ,chr2 }; //     cc
+    char names[][8] = {
+        "chre[9]"
+        ,"i"
+        ,"f"
+        ,"ch1"
+        ,"chr3[3]"
+        ,"chr4[4]"
+        ,"chr2[2]"
+        };
+    
+#endif
+
+    for (int i=0; i < sizeof(addresses)/4; i++)
+        oled.printf("%-8s %p\n",names[i],addresses[i]);
+}    
+struct  {
+    const static int isConstStatic=0;
+    } HasConstStatic;
+
+const static int csint=0;
+
+void isGlobalConstStaticFlashed() {
+    oled.printf("const static \naddr:%p\n",&csint);
+    oled.printf("addr:%p\n",&HasConstStatic.isConstStatic);
+}
+
+void  example_peek() {
+    oled.init();
+    //typeSizeAndAlignment();
+    isGlobalConstStaticFlashed();
+    release_fiber();
+}
+
+