下载校验与命令行
MD5
9fef687371962542331332985472a225
SHA256
d9291b33b3ea4f4895488b23d2d18cf7491f7663f3f960c052e9a1d760872551
curl -O http://appldnld.apple.com/iOS8.1/031-09552.20141020.HUR2S/iPhone7,2_8.1_12B411_Restore.ipsw
# 校验文件完整性
md5sum iPhone7,2_8.1_12B411_Restore.ipsw # 期望 9fef687371962542331332985472a225