#!/usr/bin/env ruby

require 'unicorn'
require 'unicorn/arm_const'

include Unicorn

# code to be emulated
ARM_CODE   = "\x37\x00\xa0\xe3\x03\x10\x42\xe0" # mov r0, #0x37; sub r1, r2, r3
THUMB_CODE = "\x83\xb0" # sub    sp, #0xc
# memory address where emulation starts
ADDRESS    = 0x10000


# callback for tracing basic blocks
$hook_block = Proc.new do |uc, address, size, user_data|
    puts(">>> Tracing basic block at 0x%x, block size = 0x%x" % [address, size])
end


# callback for tracing instructions
$hook_code = Proc.new do |uc, address, size, user_data|
    puts(">>> Tracing instruction at 0x%x, instruction size = %u" % [address, size])
end


# Test ARM
def test_arm()
    puts("Emulate ARM code")
    begin
        # Initialize emulator in ARM mode
        mu = Uc.new 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_CODE)

        # initialize machine registers
        mu.reg_write(UC_ARM_REG_R0, 0x1234)
        mu.reg_write(UC_ARM_REG_R2, 0x6789)
        mu.reg_write(UC_ARM_REG_R3, 0x3333)

        # tracing all basic blocks with customized callback
        mu.hook_add(UC_HOOK_BLOCK, $hook_block)

        # tracing all instructions with customized callback
        mu.hook_add(UC_HOOK_CODE, $hook_code)

        # emulate machine code in infinite time
        mu.emu_start(ADDRESS, ADDRESS + ARM_CODE.bytesize)

        # now print out some registers
        puts(">>> Emulation done. Below is the CPU context")

        r0 = mu.reg_read(UC_ARM_REG_R0)
        r1 = mu.reg_read(UC_ARM_REG_R1)
        puts(">>> R0 = 0x%x" % r0)
        puts(">>> R1 = 0x%x" % r1)

    rescue UcError => e
        puts("ERROR: %s" % e)
    end
end


def test_thumb()
    puts("Emulate THUMB code")
    begin
        # Initialize emulator in thumb mode
        mu = Uc.new UC_ARCH_ARM, UC_MODE_THUMB

        # 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, THUMB_CODE)

        # initialize machine registers
        mu.reg_write(UC_ARM_REG_SP, 0x1234)

        # tracing all basic blocks with customized callback
        mu.hook_add(UC_HOOK_BLOCK, $hook_block)

        # tracing all instructions with customized callback
        mu.hook_add(UC_HOOK_CODE, $hook_code)

        # emulate machine code in infinite time
        mu.emu_start(ADDRESS, ADDRESS + THUMB_CODE.bytesize)

        # now print out some registers
        puts(">>> Emulation done. Below is the CPU context")

        sp = mu.reg_read(UC_ARM_REG_SP)
        puts(">>> SP = 0x%x" % sp)

    rescue UcError => e
        puts("ERROR: %s" % e)
    end
end


test_arm()
puts("=" * 20)
test_thumb()