Hex To Arm Converter 🔔

ARM processors often run in Thumb mode (16-bit instructions) for better code density.

Example: Hex 01 20 (little-endian byte order) → 0x2001 → MOVS R0, #1

To convert Thumb with capstone:

from capstone import Cs, CS_ARCH_ARM, CS_MODE_THUMB
md = Cs(CS_ARCH_ARM, CS_MODE_THUMB)

Most modern converters will auto-detect if you specify the mode.

As ARM moves toward AArch64 (ARMv8-A) and beyond, converters must support 64-bit instructions. Newer tools already handle both: hex to arm converter

Also, ARMv9 introduces more cryptographic and matrix instructions. A modern converter must stay updated.

rasm2 -a arm -d "e3a00001"
# Output: mov r0, 1

| Tool | Platform | Best For | |------|----------|----------| | Capstone (Python/Ruby/Node) | Cross-platform | Scripting & automation | | GNU objdump | Linux/macOS/WSL | Batch disassembly | | ARM Converter (Online) | Web | Quick 1-2 instructions | | Ghidra | Cross-platform | Full reverse engineering | | Radare2 | Cross-platform | Command-line ninjas |

for insn in md.disasm(hex_bytes, 0x1000): print(f"0xinsn.address:x:\tinsn.mnemonic\tinsn.op_str")

Output:

0x1000: mov r1, #42

Let’s convert a 32-bit ARM instruction manually.

Hex value: E3A00001 (little-endian dump: 01 00 A0 E3)

Step 1 – Write as binary: E3A00001 = 1110 0011 1010 0000 0000 0000 0000 0001

Step 2 – Split into ARM instruction fields (Data Processing format): ARM processors often run in Thumb mode (16-bit

| Bits | Field | Value | Meaning | |------|-------|-------|---------| | 31-28 | Cond | 1110 | Always (AL) | | 27-26 | Op0 | 00 | Data processing | | 25 | I | 1 | Immediate operand | | 24-21 | Opcode | 1010 | MOV | | 20 | S | 0 | No flags update | | 19-16 | Rn | 0000 | Not used | | 15-12 | Rd | 0000 | R0 | | 11-0 | Immediate | 00000001 | #1 |

Step 3 – Write assembly: MOV R0, #1

That’s it! Doing this for every instruction by hand is impractical, but it demystifies the process.

Note: For Thumb (16-bit) instructions, the field layout is different. For example, 0x2001 = MOVS R0, #1. Most modern converters will auto-detect if you specify

A hex file contains everything in the memory space, including data (images, strings, constants) and code.