#include <stdint.h>

enum {
  DISPH = 480,
  DISPW = 800,
};

void cstart(void)
{
  uint16_t * const dptr = (uint16_t *)0x14800000;

  for (int y = 0; y < DISPH; y++) {
    for (int x = 0; x < DISPW; x++) {
      dptr[y*DISPW+x] = ((x&1)^(y&1)) ? 0 : 0xffff;
    }
  }
}