stecman

This is a technique for extracting all imported modules from a packaged Python application as .pyc files, then decompiling them. The target program needs to be run from scratch, but no debugging symbols are necessary (assuming an unmodified build of Python is being used).

This was performed on 64-bit Linux with a Python 3.6 target.

Theory

In Python we can leverage the fact that any module import involving a .py* file will eventually arrive as ready-to-execute Python code object at this function:

PyObject* PyEval_EvalCode(PyObject *co, PyObject *globals, PyObject *locals);

stecman

#!/usr/bin/env python3

# Convert hackaday posts to markdown with images stored nearby
#
# This needs the following modules to run:
#
#  - https://github.com/matthewwithanm/python-markdownify
#  - https://2.python-requests.org/en/master/
#  - https://www.crummy.com/software/BeautifulSoup/

stecman

-- LR imports
local LrApplication = import("LrApplication")
local LrApplicationView = import("LrApplicationView")
local LrBinding = import("LrBinding")
local LrDevelopController = import("LrDevelopController")
local LrDialogs = import("LrDialogs")
local LrExportSession = import("LrExportSession")
local LrFileUtils = import("LrFileUtils")
local LrFunctionContext = import("LrFunctionContext")
local LrLogger = import("LrLogger")

stecman

Date/time from GPS without storing NMEA string

This is a first pass at reading the date and time from a serial GPS device on a tiny microcontroller. The target device is an ATTiny13A with only 64 bytes of RAM, which isn't enough to store the full 79 characters of a NMEA sentence, so something like minmea wouldn't work (their API passes around full sentence strings).

When compiled with avr-gcc -Os, this is around 500 bytes of program space. The size can be reduced by 100 bytes if the handling of checksums is removed.

stecman

<?php

use Phalcon\Mvc\Model;

/**
 * Configuration and behaviours for all models
 */
abstract class BaseModel extends Model
{
    /**

stecman

/**
 * Thrown together program to dump 512 kbit EPROMs from an AVR ATMega64A/128A
 * More specifically, a bunch of ST M27C512 from the early 90's
 *
 * Connections:
 *
 *   Port A 0-7: low address byte (output)
 *   Port B 0-7: high address byte (output)
 *   Port D 0-7: data (input)
 *

stecman

#include <avr/interrupt.h>
#include <avr/io.h>
#include <avr/wdt.h>

#include <stdlib.h>
#include <string.h>

void init_usart(void)
{
    cli();

stecman

# Show file from Git tree at a certain point in the history
function hist() {
    local ref=$1
    local query=$2

    if [ -z $ref ]; then
        echo "Please specify a ref";
        return;
    fi

stecman

DEVICE = atmega328p
CLOCK  = 16000000
PROGRAMMER = -c arduino -P /dev/ttyUSB0 -b57600

AVRDUDE = avrdude $(PROGRAMMER) -p $(DEVICE)

SOURCES = $(shell find . -name '*.c')
OBJECTS = $(SOURCES:.c=.o)

# Automatic dependency resolution

stecman

import os

# Device definition for the stm8s.h header
# This enables available features of the device library.
STM8_DEVICE_DEFINE = "STM8S003"

# Programmer argument for stm8flash (stlink or stlinkv2)
STM8_PROGRAMMER = "stlinkv2"

# Target device argument for stm8flash