example_peek.cpp

00001 #include "MicroBit.h"
00002 #include "MicroBitPin.h"
00003 #include "cppNorm.h"
00004 #include "common.h"
00005 
00006 
00007 /**
00008   * conclusion: items incl char and char[] are on stack 4 byte alligned (0,4,8,c)
00009   * on global data char isn't aligned.
00010   * int8_t[] seems to 2 aligned, but it would demand a  clean global date area to find out
00011   * variables are not source code ordered!
00012   */
00013 void typeSizeAndAlignment() {
00014 #define outputscreeen1
00015 #ifdef outputscreeen1
00016     double d1;
00017     int8_t int8[3];
00018     int16_t int16;
00019     int32_t int32;
00020     int32_t i32;
00021                 // ADRESS   bytes in decimal 
00022                 //               
00023     void                                    *addresses[] = {
00024      int8       // b8       4         
00025     ,&int8[3]   // bb       3  
00026     ,&int16     // bc       4  
00027     ,&d1        // c0       8         
00028     ,&int32     // c8       4 
00029     ,&i32};     // cc         
00030     char names[][8] = {
00031          "int8"
00032         ,"int8[3]"
00033         ,"int16"
00034         ,"d1"
00035         ,"int32"
00036         ,"i32"
00037         };
00038 #else
00039     int   i;
00040     float f;
00041     char  ch1;
00042     char  chre[9];
00043     char  chr3[3];
00044     char  chr4[4];
00045     char  chr2[2];
00046                 // ADRESS   bytes(decimal)
00047     void                           *addresses[] = {
00048      chre    //     ac      12
00049     ,&i      //     b8      4
00050     ,&f      //     bc      4
00051     ,&ch1    //     c0      4
00052     ,chr3    //     c4      4
00053     ,chr4    //     c8      4
00054     ,chr2 }; //     cc
00055     char names[][8] = {
00056         "chre[9]"
00057         ,"i"
00058         ,"f"
00059         ,"ch1"
00060         ,"chr3[3]"
00061         ,"chr4[4]"
00062         ,"chr2[2]"
00063         };
00064     
00065 #endif
00066 
00067     for (int i=0; i < sizeof(addresses)/4; i++)
00068         oled.printf("%-8s %p\n",names[i],addresses[i]);
00069 }    
00070 struct  {
00071     const static int isConstStatic=0;
00072     } HasConstStatic;
00073 
00074 int csint;
00075 
00076 void isGlobalConstStaticFlashed() {
00077     static int k=2;
00078     oled.printf("const static \naddr:%p\n",&csint);
00079     oled.printf("addr:%p\n",&HasConstStatic.isConstStatic);
00080     oled.printf("addr:%p\n",&k);
00081     oled.printf("%d",csint);
00082 }
00083 
00084 void  example_peek() {
00085     oled.init();
00086     //typeSizeAndAlignment();
00087     isGlobalConstStaticFlashed();
00088     release_fiber();
00089 }
00090 
00091