统计 移植的库占据系统多少RAM

小贱贱接到 领导命令，系统占了多少RAM，小贱贱不会啊，浏览器疯狂搜索资料

RAM

RAM：Random Access Memory 随机存取存储器 也叫主存，是与CPU直接交换数据的内部存储器。它可以随时读写（刷新时除外），而且速度很快，主要用来存放操作系统、各种应用程序、数据等。它与ROM的最大区别是数据的易失性，RAM的工作特点是通电后，随时可在任意位置单元存取数据信息，断电后内部信息也随之消失,几乎是所有访问设备中写入和读取速度最快的

SRAM 静态随机存储器 常做cache
DRAM DRAM常用于作主存储器,平常所提到的计算机的内存指的是动态内存（即DRAM），动态内存中所谓的“动态”，指的是当我们将数据写入DRAM后，经过一段时间，数据会丢失，因此需要额外设一个电路进行内存刷新操作

统计

原来DRAM 就是系统跑起来占用的内存。那如何查看
readelf -S xxx elf 文件就可以实现 统计单位Byte

There are 49 section headers, starting at offset 0x107xxxx:

Section Headers:
  [Nr] Name              Type            Addr     Off    Size   ES Flg Lk Inf Al
  [ 0]                   NULL            xxxxxxxx xxxxxx 000000 00      0   0  0
  [ 1] .boot_struct      PROGBITS        xxxxxxxx xxxxxx 000010 00   A  0   0  4
  [ 2] .boot_text_flash  PROGBITS        xxxxxxxx xxxxxx 000d50 00  AX  0   0  8
  [ 3] .vector_table     NOBITS          xxxxxxxx xxxxxx 000100 00  WA  0   0  4
  [ 4] .reboot_param     NOBITS          xxxxxxxx xxxxxx 000040 00  WA  0   0  4
  [ 5] .boot_text_sram   PROGBITS        xxxxxxxx xxxxxx 001640 00  AX  0   0  8
  [ 6] .boot_data_sram   PROGBITS        xxxxxxxx xxxxxx 00007c 00  WA  0   0  4
  [ 7] .boot_bss_sram    NOBITS          xxxxxxxx xxxxxx 0000a0 00  WA  0   0  4
  [ 8] .sram_text        PROGBITS        xxxxxxxx xxxxxx 003e84 00  AX  0   0  8
  [ 9] .sram_data        PROGBITS        xxxxxxxx xxxxxx 000288 00  WA  0   0  4
  [10] .sram_bss         NOBITS          xxxxxxxx xxxxxx 005274 00  WA  0   0  4
  [11] .fast_text_sram   PROGBITS        xxxxxxxx xxxxxx 0005b0 00  AX  0   0  8
  [12] .overlay_text_end PROGBITS        xxxxxxxx xxxxxx 000004 00  WA  0   0  1
  [13] .overlay_data_end PROGBITS        xxxxxxxx xxxxxx 000004 00  WA  0   0  1
  [14] .userdata_pool    NOBITS          xxxxxxxx xxxxxx 002000 00  WA  0   0  4
  [15] .psram_text       PROGBITS        xxxxxxxx xxxxxx 000290 00  AX  0   0  8
  [16] .psram_data       PROGBITS        xxxxxxxx xxxxxx 003200 00  WA  0   0  4
  [17] .psram_bss        NOBITS          xxxxxxxx xxxxxx 2c7bd0 00  WA  0   0  8
  [18] .heap             NOBITS          xxxxxxxx xxxxxx 000100 00  WA  0   0  1
  [19] .text             PROGBITS        xxxxxxxx xxxxxx 10ada8 00  AX  0   0 16
  [20] .ARM.extab        PROGBITS        xxxxxxxx xxxxxx 000018 00   A  0   0  4
  [21] .ARM.exidx        ARM_EXIDX       xxxxxxxx xxxxxx 0000b8 00  AL 19   0  4
  [22] .rodata           PROGBITS        xxxxxxxx xxxxxx 108ed8 00   A  0   0 16
  [23] .custom.cmd.table PROGBITS        xxxxxxxx xxxxxx 000000 00   W  0   0  1
  [24] .thirdparty.event PROGBITS        xxxxxxxx xxxxxx 000000 00   W  0   0  1
  [25] .data             PROGBITS        xxxxxxxx xxxxxx 000034 00  WA  0   0  4
  [26] .bss              NOBITS          xxxxxxxx xxxxxx 0006b8 00  WA  0   0  8
  [27] .stack_dummy      PROGBITS        xxxxxxxx xxxxxx 002004 00   W  0   0  1
  [28] .system_info      PROGBITS        xxxxxxxx xxxxxx 000000 00   W  0   0  1
  [29] .build_info       PROGBITS        xxxxxxxx xxxxxx 0000f8 00   A  0   0  4
  [30] .code_start_addr  PROGBITS        xxxxxxxx xxxxxx 000008 00  WA  0   0  1
  [31] .custom_parameter NOBITS          xxxxxxxx xxxxxx 001000 00  WA  0   0  1
  [32] .userdata         NOBITS          xxxxxxxx xxxxxx 002000 00  WA  0   0  1
  [33] .factory          NOBITS          xxxxxxxx xxxxxx 001000 00  WA  0   0  1
  [34] .ARM.attributes   ARM_ATTRIBUTES  xxxxxxxx xxxxxx 000030 00      0   0  1
  [35] .comment          PROGBITS        xxxxxxxx xxxxxx 00007f 01  MS  0   0  1
  [36] .debug_info       PROGBITS        xxxxxxxx xxxxxx 79fe96 00      0   0  1
  [37] .debug_abbrev     PROGBITS        xxxxxxxx xxxxxx 09a76d 00      0   0  1
  [38] .debug_loc        PROGBITS        xxxxxxxx xxxxxx 27cf5e 00      0   0  1
  [39] .debug_aranges    PROGBITS        xxxxxxxx xxxxxx 0153b8 00      0   0  1
  [40] .debug_ranges     PROGBITS        xxxxxxxx xxxxxx 04dfc0 00      0   0  1
  [41] .debug_line       PROGBITS        xxxxxxxx xxxxxx 123c04 00      0   0  1
  [42] .debug_str        PROGBITS        xxxxxxxx xxxxxx 0d1d93 01  MS  0   0  1
  [43] .debug_frame      PROGBITS        xxxxxxxx xxxxxx 0505d8 00      0   0  4
  [44] .stab             PROGBITS        xxxxxxxx xxxxxx 0000cc 0c     45   0  4
  [45] .stabstr          STRTAB          xxxxxxxx xxxxxx 0001b7 00      0   0  1
  [46] .symtab           SYMTAB          xxxxxxxx xxxxxx 06d8a0 10     47 22131  4
  [47] .strtab           STRTAB          xxxxxxxx xxxxxx 035468 00      0   0  1
  [48] .shstrtab         STRTAB          xxxxxxxx xxxxxx 000253 00      0   0  1
Key to Flags:
  W (write), A (alloc), X (execute), M (merge), S (strings), I (info),
  L (link order), O (extra OS processing required), G (group), T (TLS),
  C (compressed), x (unknown), o (OS specific), E (exclude),
  y (purecode), p (processor specific)

上面的size就是 每个Section Headers占用的RAM大小统计的总数就是 占用情况

带有bss，text， data 段是我们一般需要统计