color_splash_gba.c

#include <gba_console.h>
#include <gba_video.h>
#include <gba_interrupt.h>
#include <gba_systemcalls.h>

#include <stdio.h>

typedef unsigned char      uint8;
typedef unsigned short     uint16;
typedef unsigned int       uint32;

#define VIDEOMODE_0    0x0000
#define BACKGROUND_0   0x0100

#define REG_DISPLAYCONTROL     *((volatile uint16*)(0x04000000))
#define REG_BG0_CONTROL        *((volatile uint32*)(0x04000008))

#define MEM_VRAM                ((volatile uint32*)0x6000000)
#define MEM_BG_PALETTE          ((uint16*)(0x05000000))
#define MEM_PALETTE             ((uint16*)(0x05000200))

inline uint16 RGB15(uint32 red, uint32 green, uint32 blue){
    
    return red | (green<<5) | (blue<<10);
}

void CreateBackground(){
    
    MEM_BG_PALETTE[0] = RGB15(12,0,50);

}

int main(){
	
	irqInit();
	irqEnable(IRQ_VBLANK);
    
    CreateBackground();

    REG_DISPLAYCONTROL =  VIDEOMODE_0 | BACKGROUND_0;

	while (1) {
		VBlankIntrWait();
	}
}