rasm2 - Radare2 Assembler and Disassembler Tool
NAME
rasm2 — Radare2 Assembler and Disassembler Tool
SYNOPSIS
rasm2 [−ACdDehHjLvwrNqxp] [−a arch] [−b bits] [−c cpu] [−F parser] [−k kernel] [−o ofile] [−s addr] [−@ addr] [−S syntax] [−i len] [−l len] [code|hex|-]
DESCRIPTION
Assembles and disassembles code or hexpair strings for multiple architectures and syntax formats.
−a arch
Set architecture plugin
−A
Show analysis information of given hexpair string
−b bits
Set architecture bits (8, 16, 32, 64)
−B
Binary input/output (−l is mandatory for binary input)
−c cpu
Select specific CPU (depends on −a arch)
−C
Output in C format
−d
Disassemble hexpair bytes. rasm2 −d 9090
−D
Disassemble showing hexpair and opcode
−e
Use big endian instead of little endian
−E
Output disassembled instructions in ESIL format
−f file
Read data from file instead of ARG
−F parser
Specify parse plugin to be used (pseudo)
−h
Show usage help message
−hh
Show long help message including supported assembler directives
−H [var]
Display variable
−i len
Ignore/skip N bytes from the beginning of the input buffer
−j
Output in json format
−k kernel
Select operating system (linux, windows, darwin, android, ios, ...)
−l len
Input/Output length
−L [name]
List RArch plugins: (a=asm, d=disasm, e=esil)
−LL [name]
List RAsm parse plugins
−N
Don’t load any plugin, same as R2_NOPLUGINS=1 or r2 -N
−o ofile
Output to file, for example ’rasm2 −Bf a.asm’
−p
Run SPP over input for assembly
−q
Quiet output (handy for -L, -v, ...)
−r
Show output in r2 script
−s addr
Define initial start/seek address (default 0)
−@ addr
Alias for -s
−S syntax
Select syntax output (intel, att, masm, ...)
−v
Show version information
−w
Describe opcode (what’s op)
−x
Use hex dwords instead of hexpairs in the assembler output
ENVIRONMENT
R2_NOPLUGINS
Do not load shared plugins (speedup loading)
R2_LOG_LEVEL
Change the log level
R2_DEBUG
If defined, show error messages and crash signal
R2_DEBUG_ASSERT
Enables runtime assertions for debugging
RASM2_ARCH
Same as rasm2 -a
RASM2_BITS
Same as rasm2 -b
DIRECTIVES
List the supported assembler and preprocessor directives with:
$ rasm2 -hh
EXAMPLES
Assemble opcode:
$ rasm2 −a x86 −b 32 ’mov eax, 33’
Disassemble opcode:
$ rasm2 −d 90
Show all supported architectures:
$ rasm2 -L
Assemble with specific syntax:
$ rasm2 -a x86 -b 32 -S att ’mov eax, 33’
Output in JSON format:
$ rasm2 -j -a x86 -b 32 ’mov eax, 33’
Use big endian:
$ rasm2 -e -a arm -b 32 ’add r0, r0, r1’
Disassemble and show ESIL output:
$ rasm2 -d -E 90
SEE ALSO
radare2(1)
AUTHORS
pancake <[email protected]> Jul 10, 2025 RASM2(1)