HWC_MEM_SIZE
short x = (HWC_MEM_SIZE / (4*4)) - 1;
short x = (HWC_MEM_SIZE / (4*4*2)) - 1;
image = malloc(HWC_MEM_SIZE, M_TEMP, M_WAITOK);
mask = image + HWC_MEM_SIZE/2;
#define HWC_MEM_OFF ((PAT_MEM_OFF - HWC_MEM_SIZE) & 0xffffff00)