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development:csdk:1.0:debugging [2024/11/08 01:57] – removed - external edit (Unknown date) 127.0.0.1development:csdk:1.0:debugging [2024/11/08 01:57] (current) – ↷ Page moved from development:csdk:debugging to development:csdk:1.0:debugging clyde
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 +====== Debugging your Program ======
 +
 +The GameTank emulator contains a few tools to debug your program:
 +
 +  * The VRAM Viewer allows to check what is actually loaded in VRAM
 +  * The Memory Browser allows to look at the RAM. Its Variables tab allows to see the value of any global variable defined in C
 +  * The Code Stepper allows to set breakpoints and execute your program instruction by instruction
 +  * The Profiler allows to see how much time is being spent by the blitter and the CPU for each screen refresh. In order to keep a 60 FPS animation, the bar shown in the screen should stay well below 1
 +
 +===== Setting Breakpoints =====
 +
 +Setting breakpoints in Code Stepper isn't always easy when the program was written in C. Here is a tip to create breakpoints:
 +
 +  * Define an empty ''breakpoint()'' function
 +  * Call that function in the areas of your code that need debugging
 +
 +    void breakpoint() {}
 +    
 +    int main () {
 +       ...
 +       breakpoint();
 +       // Doing some stuff that needs to be debugged
 +       ...
 +    }
 +
 +  * In the Code Stepper, set a breakpoint on ''_breakpoint'' (don't forget to enable breakpoints)
 +  * Step out of the ''breakpoint()'' function
 +  * Step out of the interrupt handler function
 +  * You should now be right where you want to be
 +
 +===== Assembly to C =====
 +
 +In order to better understand how the assembly code shown in the Code Stepper relates to the original C code:
 +
 +  * Update the ''makefile'' and add ''--add-source'' to the ''CFLAGS'' value
 +  * Run ''make build/main.si''
 +  * Open ''build/main.si''. The original C lines will be inserted as comments, e.g.
 +
 +  ;
 +  ; if (tile_val & 0x20) {
 +  ;
 +  L000D: lda     _tile_val
 +  and     #$20
 +  beq     L000E
 +  ;
 +  ; tmp = 1;
 +  ;
 +  lda     #$01
 +  sta     _tmp