linux shared fill

#define RED     0xFF0000
#define GREEN       0x00FF00
#define BLUE        0x0000FF
#define CYAN        0x00FFFF
#define PINK        0xFF00FF
#define YELLOW      0xFFFF00
#define BLACK       0x000000
#define GREY        0x808080
#define WHITE       0xFFFFFF
#define ORANGE      0xFF9900
#define LIGHT_GREEN 0x00CC00
#define PURPLE      0x660033

#define EARLY_SHARED_BUF_PA (0x20000000)
#define SHARED_PA (EARLY_SHARED_BUF_PA - CONFIG_PHYS_OFFSET + CONFIG_PAGE_OFFSET)

void fillcolor(unsigned int color)
{
    volatile int i, sum;

    *(unsigned int *)SHARED_PA = color;

    __asm__ __volatile__(
        "mov r0, #0\n\t"
        "mcr p15, 0, r0, c7, c10, 0\n\t"
        : : : "r0"
    );

    for (i = 0; i < 10000000; i++)
        sum += i;
}