`rasm2` is an inline assembler/disassembler. Initially, `rasm` tool was designed to be used for binary patching. Its main function is to get bytes corresponding to given machine instruction opcode.
$ rasm2 -h
Usage: rasm2 [-ACdDehLBvw] [-a arch] [-b bits] [-o addr] [-s syntax]
[-f file] [-F fil:ter] [-i skip] [-l len] 'code'|hex|-
-a [arch] Set architecture to assemble/disassemble (see -L)
-A Show Analysis information from given hexpairs
-b [bits] Set cpu register size (8, 16, 32, 64) (RASM2_BITS)
-B Binary input/output (-l is mandatory for binary input)
-c [cpu] Select specific CPU (depends on arch)
-C Output in C format
-d, -D Disassemble from hexpair bytes (-D show hexpairs)
-e Use big endian instead of little endian
-E Display ESIL expression (same input as in -d)
-f [file] Read data from file
-F [in:out] Specify input and/or output filters (att2intel, x86.pseudo, ...)
-h, -hh Show this help, -hh for long
-i [len] ignore/skip N bytes of the input buffer
-j output in json format
-k [kernel] Select operating system (linux, windows, darwin, ..)
-l [len] Input/Output length
-L List Asm plugins: (a=asm, d=disasm, A=analyze, e=ESIL)
-o [offset] Set start address for code (default 0)
-O [file] Output file name (rasm2 -Bf a.asm -O a)
-p Run SPP over input for assembly
-q quiet mode
-r output in radare commands
-s [syntax] Select syntax (intel, att)
-v Show version information
-w What's this instruction for? describe opcode
If '-l' value is greater than output length, output is padded with nops
If the last argument is '-' reads from stdin
Environment:
RASM2_NOPLUGINS do not load shared plugins (speedup loading)
RASM2_ARCH same as rasm2 -a
RASM2_BITS same as rasm2 -b
R_DEBUG if defined, show error messages and crash signal
Plugins for supported target architectures can be listed with the `-L` option. Knowing a plugin name, you can use it by specifying its name to the `-a` option
$ rasm2 -L _dAe 8 16 6502 LGPL3 6502/NES/C64/Tamagotchi/T-1000 CPU _dAe 8 8051 PD 8051 Intel CPU _dA_ 16 32 arc GPL3 Argonaut RISC Core a___ 16 32 64 arm.as LGPL3 as ARM Assembler (use ARM_AS environment) adAe 16 32 64 arm BSD Capstone ARM disassembler _dA_ 16 32 64 arm.gnu GPL3 Acorn RISC Machine CPU _d__ 16 32 arm.winedbg LGPL2 WineDBG's ARM disassembler adAe 8 16 avr GPL AVR Atmel adAe 16 32 64 bf LGPL3 Brainfuck (by pancake, nibble) v4.0.0 _dA_ 32 chip8 LGPL3 Chip8 disassembler _dA_ 16 cr16 LGPL3 cr16 disassembly plugin _dA_ 32 cris GPL3 Axis Communications 32-bit embedded processor adA_ 32 64 dalvik LGPL3 AndroidVM Dalvik ad__ 16 dcpu16 PD Mojang's DCPU-16 _dA_ 32 64 ebc LGPL3 EFI Bytecode adAe 16 gb LGPL3 GameBoy(TM) (z80-like) _dAe 16 h8300 LGPL3 H8/300 disassembly plugin _dAe 32 hexagon LGPL3 Qualcomm Hexagon (QDSP6) V6 _d__ 32 hppa GPL3 HP PA-RISC _dAe i4004 LGPL3 Intel 4004 microprocessor _dA_ 8 i8080 BSD Intel 8080 CPU adA_ 32 java Apache Java bytecode _d__ 32 lanai GPL3 LANAI _d__ 8 lh5801 LGPL3 SHARP LH5801 disassembler _d__ 32 lm32 BSD disassembly plugin for Lattice Micro 32 ISA _dA_ 16 32 m68k BSD Capstone M68K disassembler _dA_ 32 malbolge LGPL3 Malbolge Ternary VM _d__ 16 mcs96 LGPL3 condrets car adAe 16 32 64 mips BSD Capstone MIPS disassembler adAe 32 64 mips.gnu GPL3 MIPS CPU _dA_ 16 msp430 LGPL3 msp430 disassembly plugin _dA_ 32 nios2 GPL3 NIOS II Embedded Processor _dAe 8 pic LGPL3 PIC disassembler _dAe 32 64 ppc BSD Capstone PowerPC disassembler _dA_ 32 64 ppc.gnu GPL3 PowerPC _d__ 32 propeller LGPL3 propeller disassembly plugin _dA_ 32 64 riscv GPL RISC-V _dAe 32 rsp LGPL3 Reality Signal Processor _dAe 32 sh GPL3 SuperH-4 CPU _dA_ 8 16 snes LGPL3 SuperNES CPU _dAe 32 64 sparc BSD Capstone SPARC disassembler _dA_ 32 64 sparc.gnu GPL3 Scalable Processor Architecture _d__ 16 spc700 LGPL3 spc700, snes' sound-chip _d__ 32 sysz BSD SystemZ CPU disassembler _dA_ 32 tms320 LGPLv3 TMS320 DSP family (c54x,c55x,c55x+,c64x) _d__ 32 tricore GPL3 Siemens TriCore CPU _dAe 32 v810 LGPL3 v810 disassembly plugin _dAe 32 v850 LGPL3 v850 disassembly plugin _dAe 8 32 vax GPL VAX adA_ 32 wasm MIT WebAssembly (by cgvwzq) v0.1.0 _dA_ 32 ws LGPL3 Whitespace esotheric VM a___ 16 32 64 x86.as LGPL3 Intel X86 GNU Assembler _dAe 16 32 64 x86 BSD Capstone X86 disassembler a___ 16 32 64 x86.nasm LGPL3 X86 nasm assembler a___ 16 32 64 x86.nz LGPL3 x86 handmade assembler _dA_ 16 xap PD XAP4 RISC (CSR) _dA_ 32 xcore BSD Capstone XCore disassembler _dAe 32 xtensa GPL3 XTensa CPU adA_ 8 z80 GPL Zilog Z80
Note that "ad" in the first column means both assembler and disassembler are offered by a corresponding plugin. "_d" indicates disassembler, "a_" means only assembler is available.