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
Radare's I/O subsystem allows you to map the contents of files into the same I/O space used to contain a loaded binary. New contents can be placed at random offsets.
The o command permits the user to open a file, this is mapped at offset 0 unless it has a known binary header and then the maps are created in virtual addresses.
Sometimes, we want to rebase a binary, or maybe we want to load or map the file in a different address.
When launching r2, the base address can be changed with the -B flag. But you must notice the difference when opening files with unknown headers, like bootloaders, so we need to map them using the -m flag (or specifying it as argument to the o command).
radare2 is able to open files and map portions of them at random places in memory specifying attributes like permissions and name. It is the perfect basic tooling to reproduce an environment like a core file, a debug session, by also loading and mapping all the libraries the binary depends on.
