main.c

typedef unsigned short uint16_t;
typedef unsigned int uint32_t;

#include "nyan.h"

#define WIDTH 240
#define HEIGHT 320

#define CWIDTH 8
#define CHEIGHT 15

struct frame_descriptor {
	void* FDADR;
	void* FSADR;
	uint32_t FIDR;
	uint32_t LCDCMD;
};

void draw_char(uint16_t *fb, char c, int x0, int y0)
{
	char *font = (void*)0x80008f50;
	char *glyph = font + (c*15);
	for (int dy=0; dy<CHEIGHT; dy++) {
		for (int dx=0; dx<CWIDTH; dx++) {
			if ((glyph[dy] >> (7-dx)) & 1) {
				fb[(y0+dy)*WIDTH+(x0+dx)] = 0xffff;
			}
		}
	}
}

void draw_str(uint16_t *fb, char *str, int x0, int y0)
{
	while (*str) {
		draw_char(fb, *str++, x0, y0);
		x0 += CWIDTH;
	}
}

static int lut[] = {0, 1608, 3215, 4821, 6423, 8022, 9616, 11204, 12785, 14359, 15923, 17479, 19024, 20557, 22078, 23586, 25079, 26557, 28020, 29465, 30893, 32302, 33692, 35061, 36409, 37736, 39039, 40319, 41575, 42806, 44011, 45189, 46340, 47464, 48558, 49624, 50660, 51665, 52639, 53581, 54491, 55368, 56212, 57022, 57797, 58538, 59243, 59913, 60547, 61144, 61705, 62228, 62714, 63162, 63571, 63943, 64276, 64571, 64826, 65043, 65220, 65358, 65457, 65516, 65536, 65516, 65457, 65358, 65220, 65043, 64826, 64571, 64276, 63943, 63571, 63162, 62714, 62228, 61705, 61144, 60547, 59913, 59243, 58538, 57797, 57022, 56212, 55368, 54491, 53581, 52639, 51665, 50660, 49624, 48558, 47464, 46340, 45189, 44011, 42806, 41575, 40319, 39039, 37736, 36409, 35061, 33692, 32302, 30893, 29465, 28020, 26557, 25079, 23586, 22078, 20557, 19024, 17479, 15923, 14359, 12785, 11204, 9616, 8022, 6423, 4821, 3215, 1608, 0, -1609, -3216, -4822, -6424, -8023, -9617, -11205, -12786, -14360, -15924, -17480, -19025, -20558, -22079, -23587, -25080, -26558, -28021, -29466, -30894, -32303, -33693, -35062, -36410, -37737, -39040, -40320, -41576, -42807, -44012, -45190, -46341, -47465, -48559, -49625, -50661, -51666, -52640, -53582, -54492, -55369, -56213, -57023, -57798, -58539, -59244, -59914, -60548, -61145, -61706, -62229, -62715, -63163, -63572, -63944, -64277, -64572, -64827, -65044, -65221, -65359, -65458, -65517, -65536, -65517, -65458, -65359, -65221, -65044, -64827, -64572, -64277, -63944, -63572, -63163, -62715, -62229, -61706, -61145, -60548, -59914, -59244, -58539, -57798, -57023, -56213, -55369, -54492, -53582, -52640, -51666, -50661, -49625, -48559, -47465, -46341, -45190, -44012, -42807, -41576, -40320, -39040, -37737, -36410, -35062, -33693, -32303, -30894, -29466, -28021, -26558, -25080, -23587, -22079, -20558, -19025, -17480, -15924, -14360, -12786, -11205, -9617, -8023, -6424, -4822, -3216, -1609};

int main(void)
{

	void (*sleep)(int duration) = (void(*)(int))0x8000ece8;
	
	struct frame_descriptor *fd = (void*)0xa400a000;
	
	uint16_t *fb = (void*)0xa400a280;
	//volatile void **FDADR0 = (void*)0x9e200200;
	
	
	//volatile uint32_t *CCCR = (volatile uint32_t*)0xad300000;
	
	//*CCCR = 0b0101100101;
	
	// Enter Frequency Change Sequence
	//__asm__ __volatile__ ("MCR p14, 0, %0, c6, c0, 0" ::"r"(0b10));
	
	*(uint32_t*)&fb ^= 0x40000;
	
	int ni=0;
	
	for (int i=0;; i=((i+2)&0xff)) {
		
		
		for (int y=0; y<HEIGHT; y++) {
			for (int x=0; x<WIDTH; x++) {
				fb[y*WIDTH+x] = ((x+i)^(y+i))/4;
			}
		}
		
		char msg[] = "Hello baremetal armv5te world!";
		
		/*draw_str(fb, msg, 0, 0);
		
		for (int y=0; y<16; y++) {
			for (int x=0; x<16; x++) {
				draw_char(fb, y*16+x, x*CWIDTH, (y+2)*CHEIGHT);
			}
		}*/
		for (int x=0; x<30; x++) {
			draw_char(fb, msg[x], x*CWIDTH, 80 + lut[(i*4+(x*8))&0xff]/0x1000);
		}
		
		for (int y=0; y<NYAN_HEIGHT*4; y++) {
			for (int x=0; x<NYAN_WIDTH*4; x++) {
				if (nyana[ni][y/4][x/4]) {
					fb[(180+y)*WIDTH+x+52] = nyan[ni][y/4][x/4];
				}
			}
		}
		
		if (i&2) {
			ni++;
			if (ni>=NYAN_FRAMES) ni = 0;
		}
		
		*(uint32_t*)&fd->FSADR ^= 0x40000;
		*(uint32_t*)&fb ^= 0x40000;
		
		sleep(20);

	}
}