MemScan.java

/*
 * Copyright (c) Steven P. Goldsmith. All rights reserved.
 */
package com.codeferm.periphery.mmio;

import static com.codeferm.periphery.Common.cString;
import com.codeferm.periphery.Gpio;
import static com.codeferm.periphery.Gpio.GPIO_BIAS_DEFAULT;
import static com.codeferm.periphery.Gpio.GPIO_BIAS_DISABLE;
import static com.codeferm.periphery.Gpio.GPIO_BIAS_PULL_DOWN;
import static com.codeferm.periphery.Gpio.GPIO_BIAS_PULL_UP;
import static com.codeferm.periphery.Gpio.GPIO_DIR_IN;
import static com.codeferm.periphery.Gpio.GPIO_DIR_OUT;
import static com.codeferm.periphery.Gpio.GPIO_DRIVE_DEFAULT;
import static com.codeferm.periphery.Gpio.GPIO_EDGE_NONE;
import com.codeferm.periphery.Mmio;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Callable;
import org.apache.logging.log4j.LogManager;
import picocli.CommandLine;

/**
 * Scan memory for changes based on start address, range and GPIO chip and line.
 *
 * Make sure you disable all hardware in armbian-config System, Hardware and remove console=serial from /boot/armbianEnv.txt. You
 * want multi-function pins to act as GPIO pins.
 *
 * @author Steven P. Goldsmith
 * @version 1.0.0
 * @since 1.0.0
 */
@CommandLine.Command(name = "memscan", mixinStandardHelpOptions = true, version = "memscan 1.0.0",
 description = "Use GPIO device to detect memory changes")
public class MemScan implements Callable<Integer> {

 /**
 * Logger.
 */
 private final org.apache.logging.log4j.Logger logger = LogManager.getLogger(MemScan.class);
 /**
 * MMIO path.
 */
 @CommandLine.Option(names = {"-p", "--path"}, description = "Path defaults to /dev/mem")
 private String path = "/dev/mem";
 /**
 * Memory address.
 */
 @CommandLine.Option(names = {"-a", "--address"}, description = "Memorry address defaults to 0x00")
 private long address = 0x00;
 /**
 * Memory size to scan.
 */
 @CommandLine.Option(names = {"-w", "--words"}, description = "32 bit words to read defaults to 0x01")
 private long words = 0x01;
 /**
 * Device option.
 */
 @CommandLine.Option(names = {"-d", "--device"}, description = "GPIO device defaults to 0")
 private int device = 0;
 /**
 * Line option.
 */
 @CommandLine.Option(names = {"-l", "--line"}, description = "GPIO line defaults to 1")
 private int line = 1;

 /**
 * Return values from all registers.
 *
 * @param mmioHandle MMIO handle.
 * @return List of register values.
 */
 public List<Integer> getRegValues(final Long mmioHandle) {
 final var list = new ArrayList<Integer>();
 final var value = new int[1];
 for (long i = 0; i < words; i++) {
 Mmio.mmioRead32(mmioHandle, i * 4, value);
 list.add(value[0]);
 }
 return list;
 }

 /**
 * Compare list values and log difference.
 *
 * @param list1 First list.
 * @param list2 Second list.
 * @param text Description text.
 */
 public void listDiff(final List<Integer> list1, final List<Integer> list2, final String text) {
 for (int i = 0; i < list1.size(); i++) {
 if (!list1.get(i).equals(list2.get(i))) {
 int diff;
 if (list1.get(i) > list2.get(i)) {
 diff = list1.get(i) - list2.get(i);
 } else {
 diff = list2.get(i) - list1.get(i);
 }
 logger.info(String.format("%s difference found at offset 0x%08x before 0x%08x after 0x%08x difference 0x%08x", text,
 i * 4, list1.get(i), list2.get(i), diff));
 }
 }
 }

 /**
 * Use GPIO device to detect configuration changes.
 *
 * @param mmioHandle MMIO handle.
 */
 public void detectMode(final long mmioHandle) {
 final var dev = String.format("/dev/gpiochip%d", device);
 // Set pin for input, output and look for delta
 try (final var gpio = new Gpio(dev, line, new Gpio.GpioConfig().setBias(GPIO_BIAS_DEFAULT).setDirection(GPIO_DIR_IN).setDrive(
 GPIO_DRIVE_DEFAULT).setEdge(GPIO_EDGE_NONE).setInverted(false).setLabel(cString(
 MemScan.class.getSimpleName())))) {
 final var list1 = getRegValues(mmioHandle);
 Gpio.gpioSetDirection(gpio.getHandle(), GPIO_DIR_OUT);
 final var list2 = getRegValues(mmioHandle);
 // Show the register delta
 listDiff(list1, list2, "Mode");
 } catch (RuntimeException e) {
 logger.error(String.format("Device %d line %d Error %s", device, line, e.getMessage()));
 }
 }

 /**
 * Use GPIO device to detect data changes.
 *
 * @param mmioHandle MMIO handle.
 */
 public void detectData(final long mmioHandle) {
 final var dev = String.format("/dev/gpiochip%d", device);
 // Set pin for input, output and look for delta
 try (final var gpio = new Gpio(dev, line, new Gpio.GpioConfig().setBias(GPIO_BIAS_DEFAULT).setDirection(GPIO_DIR_OUT).setDrive(
 GPIO_DRIVE_DEFAULT).setEdge(GPIO_EDGE_NONE).setInverted(false).setLabel(cString(
 MemScan.class.getSimpleName())))) {
 Gpio.gpioWrite(gpio.getHandle(), false);
 final var list1 = getRegValues(mmioHandle);
 Gpio.gpioWrite(gpio.getHandle(), true);
 final var list2 = getRegValues(mmioHandle);
 // Show the register delta
 listDiff(list1, list2, "Data");
 } catch (RuntimeException e) {
 logger.error(String.format("Device %d line %d Error %s", device, line, e.getMessage()));
 }
 }

 /**
 * Use GPIO device to detect pull changes.
 *
 * @param mmioHandle MMIO handle.
 */
 public void detectPull(final long mmioHandle) {
 final var dev = String.format("/dev/gpiochip%d", device);
 // Set pin for input, output and look for delta
 try (final var gpio = new Gpio(dev, line, new Gpio.GpioConfig().setBias(GPIO_BIAS_DISABLE).setDirection(GPIO_DIR_IN).setDrive(
 GPIO_DRIVE_DEFAULT).setEdge(GPIO_EDGE_NONE).setInverted(false).setLabel(cString(
 MemScan.class.getSimpleName())))) {
 var list1 = getRegValues(mmioHandle);
 Gpio.gpioSetBias(gpio.getHandle(), GPIO_BIAS_PULL_UP);
 var list2 = getRegValues(mmioHandle);
 // Show the register delta
 listDiff(list1, list2, "Pull up");
 list1 = getRegValues(mmioHandle);
 Gpio.gpioSetBias(gpio.getHandle(), GPIO_BIAS_PULL_DOWN);
 list2 = getRegValues(mmioHandle);
 // Show the register delta
 listDiff(list1, list2, "Pull down");
 } catch (RuntimeException e) {
 logger.error(String.format("Device %d line %d Error %s", device, line, e.getMessage()));
 }
 }

 /**
 * Detect changes made by GPIO at register level.
 *
 * @return Exit code.
 * @throws InterruptedException Possible exception.
 */
 @Override
 public Integer call() throws InterruptedException {
 var exitCode = 0;
 logger.debug(String.format("Memory address 0x%08x words 0x%08x", address, words));
 try (final var mmio = new Mmio(address, words * 4, path)) {
 detectMode(mmio.getHandle());
 detectData(mmio.getHandle());
 detectPull(mmio.getHandle());
 } catch (RuntimeException e) {
 logger.error(e.getMessage());
 exitCode = 1;
 }
 return exitCode;
 }

 /**
 * Main parsing, error handling and handling user requests for usage help or version help are done with one line of code.
 *
 * @param args Argument list.
 */
 public static void main(String... args) {
 System.exit(new CommandLine(new MemScan()).registerConverter(Long.class, Long::decode).registerConverter(Long.TYPE,
 Long::decode).execute(args));
 }
}