docker run -u root --volume /data/webapp/smallproject/rvld/:/code -it golang:1.19.2-bullseye
apt update
apt install -y gcc-10-riscv64-linux-gnu qemu-user file bsdmainutils
ln -sf /usr/bin/riscv64-linux-gnu-gcc-10 /usr/bin/riscv64-linux-gnu-gcc
如果关闭了容器怎么重新进入容器
容器参看: docker container ls -a
启动容器: docker container start 容器ID
进入容器: docker exec -it 容器ID bash
- Program header table: 固定长度的数组，可以直接映射到数组中去。用于运行时
- Section header table: 用于链接的时候
readelf -S out/tests/hello/a.o
There are 11 section headers, starting at offset 0x2c0:
Section Headers:
[Nr] Name Type Address Offset
Size EntSize Flags Link Info Align
[ 0] NULL 0000000000000000 00000000
0000000000000000 0000000000000000 0 0 0
[ 1] .text PROGBITS 0000000000000000 00000040
0000000000000024 0000000000000000 AX 0 0 2
[ 2] .rela.text RELA 0000000000000000 000001d8
0000000000000090 0000000000000018 I 8 1 8
[ 3] .data PROGBITS 0000000000000000 00000064
0000000000000000 0000000000000000 WA 0 0 1
[ 4] .bss NOBITS 0000000000000000 00000064
0000000000000000 0000000000000000 WA 0 0 1
[ 5] .rodata PROGBITS 0000000000000000 00000068
000000000000000d 0000000000000000 A 0 0 8
[ 6] .comment PROGBITS 0000000000000000 00000075
0000000000000028 0000000000000001 MS 0 0 1
[ 7] .note.GNU-stack PROGBITS 0000000000000000 0000009d
0000000000000000 0000000000000000 0 0 1
[ 8] .symtab SYMTAB 0000000000000000 000000a0
0000000000000120 0000000000000018 9 10 8
[ 9] .strtab STRTAB 0000000000000000 000001c0
0000000000000015 0000000000000000 0 0 1
[10] .shstrtab STRTAB 0000000000000000 00000268
0000000000000052 0000000000000000 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),
p (processor specific)
root@4ec3c2798e0f:/code# readelf -s out/tests/hello/a.o
Symbol table '.symtab' contains 12 entries:
Num: Value Size Type Bind Vis Ndx Name
0: 0000000000000000 0 NOTYPE LOCAL DEFAULT UND
1: 0000000000000000 0 FILE LOCAL DEFAULT ABS
2: 0000000000000000 0 SECTION LOCAL DEFAULT 1
3: 0000000000000000 0 SECTION LOCAL DEFAULT 3
4: 0000000000000000 0 SECTION LOCAL DEFAULT 4
5: 0000000000000000 0 SECTION LOCAL DEFAULT 5
6: 0000000000000000 0 SECTION LOCAL DEFAULT 7
7: 0000000000000000 0 NOTYPE LOCAL DEFAULT 5 .LC0
8: 0000000000000008 0 NOTYPE LOCAL DEFAULT 1 .L0
9: 0000000000000000 0 SECTION LOCAL DEFAULT 6
10: 0000000000000000 36 FUNC GLOBAL DEFAULT 1 main
11: 0000000000000000 0 NOTYPE GLOBAL DEFAULT UND puts
Symbol Table 包含了一组 Symbol。这些 Symbol 在程序中，要么表示定义，要么表示引用，它们的作用是在编译和链接的过程中，进行定位或者重定位
readelf -SW out/tests/hello/a.o
Section Headers:
[Nr] Name Type Address Off Size ES Flg Lk Inf Al
[ 8] .symtab SYMTAB 0000000000000000 0000a0 000120 18 9 10 8
由上可知 Symbol Table Section
- 名字叫 “.symtab”
- 类型是 SYMTAB
- offset = 0xa0 = 160 bytes
- size = 0x120 = 288 bytes
- 每个 Symbol 的 size = 0x18 = 24
- Symbol 数为: 288 / 24 = 12
通过与GCC联动
[./ld -plugin /usr/lib/gcc-cross/riscv64-linux-gnu/10/liblto_plugin.so -plugin-opt=/usr/lib/gcc-cross/riscv64-linux-gnu/10/lto-wrapper -plugin-opt=-fresolution=/tmp/ccDYhVfE.res -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lgcc_eh -plugin-opt=-pass-through=-lc --sysroot=/ --build-id -hash-style=gnu -as-needed -melf64lriscv -static -o out/tests/hello/out /usr/lib/gcc-cross/riscv64-linux-gnu/10/../../../../riscv64-linux-gnu/lib/crt1.o /usr/lib/gcc-cross/riscv64-linux-gnu/10/crti.o /usr/lib/gcc-cross/riscv64-linux-gnu/10/crtbeginT.o -L. -L/usr/lib/gcc-cross/riscv64-linux-gnu/10 -L/usr/lib/gcc-cross/riscv64-linux-gnu/10/../../../../riscv64-linux-gnu/lib -L/usr/lib/riscv64-linux-gnu out/tests/hello/a.o --start-group -lgcc -lgcc_eh -lc --end-group /usr/lib/gcc-cross/riscv64-linux-gnu/10/crtend.o /usr/lib/gcc-cross/riscv64-linux-gnu/10/crtn.o]