Sections（分节）

The concept of sections is tied to the information extracted from the binary. We can display this information by using the i command.

Displaying information about sections:

[0x00005310]> iS
[Sections]
00 0x00000000     0 0x00000000     0 ----
01 0x00000238    28 0x00000238    28 -r-- .interp
02 0x00000254    32 0x00000254    32 -r-- .note.ABI_tag
03 0x00000278   176 0x00000278   176 -r-- .gnu.hash
04 0x00000328  3000 0x00000328  3000 -r-- .dynsym
05 0x00000ee0  1412 0x00000ee0  1412 -r-- .dynstr
06 0x00001464   250 0x00001464   250 -r-- .gnu.version
07 0x00001560   112 0x00001560   112 -r-- .gnu.version_r
08 0x000015d0  4944 0x000015d0  4944 -r-- .rela.dyn
09 0x00002920  2448 0x00002920  2448 -r-- .rela.plt
10 0x000032b0    23 0x000032b0    23 -r-x .init
...

As you may know, binaries have sections and maps. The sections define the contents of a portion of the file that can be mapped in memory (or not). What is mapped is defined by the segments.

Before the IO refactoring done by condret, the S command was used to manage what we now call maps. Currently the S command is deprecated because iS and om should be enough.

Firmware images, bootloaders and binary files usually place various sections of a binary at different addresses in memory. To represent this behavior, radare offers the iS. Use iS? to get the help message. To list all created sections use iS (or iSj to get the json format). The iS= will show the region bars in ascii-art.

You can create a new mapping using the om subcommand as follows:

om fd vaddr [size] [paddr] [rwx] [name]

For Example:

[0x0040100]> om 4 0x00000100 0x00400000 0x0001ae08 rwx test

You can also use om command to view information about mapped sections:

[0x00401000]> om
 6 fd: 4 +0x0001ae08 0x00000100 - 0x004000ff rwx test
 5 fd: 3 +0x00000000 0x00000000 - 0x0000055f r-- fmap.LOAD0
 4 fd: 3 +0x00001000 0x00001000 - 0x000011e4 r-x fmap.LOAD1
 3 fd: 3 +0x00002000 0x00002000 - 0x0000211f r-- fmap.LOAD2
 2 fd: 3 +0x00002de8 0x00003de8 - 0x0000402f r-- fmap.LOAD3
 1 fd: 4 +0x00000000 0x00004030 - 0x00004037 rw- mmap.LOAD3

Use om? to get all the possible subcommands. To list all the defined maps use om (or omj to get the json format or om* to get the r2 commands format). To get the ascii art view use om=.

It is also possible to delete the mapped section using the om-mapid command.

For Example:

[0x00401000]> om-6