map 0x00-0xFF, 0x00-0xD7 to U+0000 using little-endian
map 0x00-0xFF, 0xE0-0xFF to U+E000 using little-endian
map 0x00-0xFF <<< 2, 0xD8-0xDB <<< 3,\
    0x00-0xFF <<< 0, 0xDC-0xDF <<< 1 to U+010000