pythoncode-tutorials/general/assembly-code/arm_assembly.py at master · popoting/pythoncode-tutorials · GitHub

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# We need to emulate ARM

from unicorn import Uc, UC_ARCH_ARM, UC_MODE_ARM, UcError

# for accessing the R0 and R1 registers

from unicorn.arm_const import UC_ARM_REG_R0, UC_ARM_REG_R1

# We need to assemble ARM code

from keystone import Ks, KS_ARCH_ARM, KS_MODE_ARM, KsError

ARM_CODE = """

// n is r0, we will pass it from python, ans is r1

mov r1, 1 // ans = 1

loop:

cmp r0, 0 // while n >= 0:

mulgt r1, r1, r0 // ans *= n

subgt r0, r0, 1 // n = n - 1

bgt loop //

// answer is in r1

"""

print("Assembling the ARM code")

try:

# initialize the keystone object with the ARM architecture

ks = Ks(KS_ARCH_ARM, KS_MODE_ARM)

# Assemble the ARM code

ARM_BYTECODE, _ = ks.asm(ARM_CODE)

# convert the array of integers into bytes

ARM_BYTECODE = bytes(ARM_BYTECODE)

print(f"Code successfully assembled (length = {len(ARM_BYTECODE)})")

print("ARM bytecode:", ARM_BYTECODE)

except KsError as e:

print("Keystone Error: %s" % e)

exit(1)

# memory address where emulation starts

ADDRESS = 0x1000000

print("Emulating the ARM code")

try:

# Initialize emulator in ARM mode

mu = Uc(UC_ARCH_ARM, UC_MODE_ARM)

# map 2MB memory for this emulation

mu.mem_map(ADDRESS, 2 * 1024 * 1024)

# write machine code to be emulated to memory

mu.mem_write(ADDRESS, ARM_BYTECODE)

# Set the r0 register in the code, let's calculate factorial(5)

mu.reg_write(UC_ARM_REG_R0, 5)

# emulate code in infinite time and unlimited instructions

mu.emu_start(ADDRESS, ADDRESS + len(ARM_BYTECODE))

# now print out the R0 register

print("Emulation done. Below is the result")

# retrieve the result from the R1 register

r1 = mu.reg_read(UC_ARM_REG_R1)

print(">> R1 = %u" % r1)

except UcError as e:

print("Unicorn Error: %s" % e)

pythoncode-tutorials/general/assembly-code/arm_assembly.py at master · popoting/pythoncode-tutorials · GitHub

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