可通过readelf指令，分析文.a .so .bin 文件是在什么系统上编译的，文件格式是32位还是64位，数据是大端还是小端，运行在 arm 上还是 x86上

1：格式读取说明

通过 readelf -a libbrd.a 读取文件的格式内容

File: libbrd.a(brd_audio.o)
ELF Header:Magic:   7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00 Class:                             ELF32Data:                              2's complement, little endianVersion:                           1 (current)OS/ABI:                            UNIX - System VABI Version:                       0Type:                              REL (Relocatable file)Machine:                           ARMVersion:                           0x1Entry point address:               0x0Start of program headers:          0 (bytes into file)Start of section headers:          10924 (bytes into file)Flags:                             0x5000000, Version5 EABISize of this header:               52 (bytes)Size of program headers:           0 (bytes)Number of program headers:         0Size of section headers:           40 (bytes)Number of section headers:         22Section header string table index: 21

2：关键内容说明

2.1 Class

ELF32：说明该文件格式是32位系统格式

2.2 Data

2’s complement, little endian：说明数据格式位为小端

2.3 Machine

ARM：说明当前文件运行在 arm架构 的系统上