fxos/fxos/main.cpp

#include "fxos-cli.h"

#include <fxos/disassembly.h>
#include <fxos/library.h>
#include <fxos/errors.h>
#include <fxos/target.h>
#include <fxos/load.h>
#include <fxos/log.h>
#include <fxos/os.h>

#include <getopt.h>

#include <filesystem>
#include <fstream>
#include <sstream>
#include <string>
#include <vector>
#include <map>

namespace fs = std::filesystem;
using namespace FxOS;
using namespace FxOS::Log;

static char const *help_string = R"(
usage: fxos library [-t] [-a]
       fxos info    <target>
       fxos disasm  <target> <region or function> [options...]
       fxos analyze [-f] [-s] [-a] [-r] <number> <os file> [options...]

fxos is a reverse-engineering tool that disassembles and analyzes SuperH
programs and OS dumps for fx9860g and fxcg50-like CASIO calculators, using an
editable database of platform, syscall, and OS knowledge.

General options:
  -3, --sh3         Assume SH3 OS and platform (default: SH4)
  -4, --sh4         Assume SH4 OS and platform (default: SH4)
  -v, --verbose     Print logs about what's happening

A <target> is either:
  <targetname>      A target in library (eg "fx@3.10")
  -f <file>         An arbitrary file which is loaded as ROM

LIBRARY COMMAND

Prints out the contents of the library. If an option is set, the results are
printed in a simple easily-parsable form without header.

Selectors:
  -t, --targets     Print all targets
  -a, --asm         Print all assembler instruction sets

INFO COMMAND

Identify an OS image: version, platform, date, checksums...

DISASM COMMAND

Disassemble and annotate code with relative address targets, syscalls, control
flow, propagated constants and hints about memory structure.

Location specifiers:
  <address>         Start disassembling at this address (hexa)
  <address>:<len>   Disassemble exactly the specified region. <len> is an
                    hexadecimal number optionally followed by k, M, or G.
  %<syscall id>     Start disassembling at this syscall's address (hexa)
  <symbol>          Disassemble this library symbol (typically a syscall name).
                    Note that <address> takes precedence if ambiguous.

Disassembly options:
  -p <list>         Execute the specified comma-separated list of passes

Available passes:
  cfg               Build the control flow graph (always required)
  pcrel             Resolve PC-relative references as their target address
  cstprop           Propagate constants by abstract interpretation
  syscall           Annotate code with reverse syscalls

The default sequence of passes is cfg,pcrel,cstprop,syscall. When disassembling
a function (ie. no size specified on the command-line), the cfg pass is always
executed to explore the function.

ANALYZE COMMAND

Dig an address or syscall number. Finds syscall references, 4-aligned
occurrences, memory region...

Analysis modes:
  -f, --full        Run all analysis passes on <number> (same as -sar)
  -s, --syscall     Run syscall ID analysis
  -a, --address     Run code/data address analyis
  -r, --register    Run peripheral register analysis

Analysis options:
  --occurrences <num>  Show at most <num> occurrences (integer or "all")
)"+1;

#define usage(exitcode) {		\
	std::cerr << help_string;	\
	return exitcode;		\
}

//---
//  Configuration
//---

void loadconfig(Library &lib)
{
	std::string home = getenv("HOME");
	fs::path configpath = home + "/.config/fxos/config";

	if(!fs::exists(configpath)) return;

	std::ifstream stream(configpath);

	/* Read line by line and register paths for the library or load files
	   from the database */
	while(stream)
	{
		char path[256];
		std::string line;
		std::getline(stream, line);

		if(std::sscanf(line.c_str(), "library: %256s", path) == 1)
		{
			lib.add_path(path);
		}
		else if(std::sscanf(line.c_str(), "load: %256s", path) == 1)
		{
			lib.explore(path);
		}
	}
}

//---
//  Main routines
//---

int main_library(int argc, char **argv)
{
	int error=0, option=0;
	bool show_targets = false;
	bool show_asm = false;

	struct option const longs[] = {
		{ "help",     no_argument,  NULL,  'h' },
		{ "targets",  no_argument,  NULL,  't' },
		{ "asm",      no_argument,  NULL,  'a' },
	};

	while(option >= 0 && option != '?')
	switch((option = getopt_long(argc, argv, "hta", longs, NULL)))
	{
	case 'h':
		usage(0);
	case 't':
		show_targets = true;
		break;
	case 'a':
		show_asm = true;
		break;
	case '?':
		error = 1;
	}

	if(error) return 1;

	/* If no option is given, display everything */
	if(!show_targets && !show_asm)
	{
		show_targets = true;
		show_asm = true;
	}

	/* Load the library */
	Library lib;
	loadconfig(lib);

	show_library(lib, show_targets, show_asm);
	return 0;
}

int main_info(int argc, char **argv)
{
	int error=0, option=0;
	std::string path;

	struct option const longs[] = {
		{ "help",     no_argument,  NULL,  'h' },
		{ "sh3",      no_argument,  NULL,  '3' },
		{ "sh4",      no_argument,  NULL,  '4' },
		{ "verbose",  no_argument,  NULL,  'v' },
	};

	while(option >= 0 && option != '?')
	switch((option = getopt_long(argc, argv, "h34f:p:v", longs, NULL)))
	{
	case 'h':
		usage(0);
	case '3':
	case '4':
		/* TODO: Use sh3/sh4 information in [fxos info]? */
		break;
	case 'f':
		path = optarg;
		break;
	case 'v':
		log_setminlevel(LEVEL_LOG);
		break;
	case '?':
		error = 1;
	}

	if(error) return 1;

	//~

	/* Load the configuration and library */
	Library lib;
	loadconfig(lib);

	/* Load from path if one is specified */
	if(path.size())
	{
		try {
			/* Load the file in ROM over 8M */
			Buffer romfile(path, MemoryRegion::ROM.size());
			Target t;
			t.bind_region(MemoryRegion::ROM, romfile);
			t.bind_region(MemoryRegion::ROM_P2, romfile);
			os_info(t);
		}
		catch(std::exception &e) {
			log(ERR "%s", e.what());
			return 1;
		}
	}
	/* Load from target otherwise */
	else
	{
		if(!argv[optind + 1]) usage(1);

		std::string tname = argv[optind + 1];
		if(!lib.targets().count(tname))
		{
			log(ERR "no target '%s' in library", tname);
			return 1;
		}

		try {
			Target t(lib.targets().at(tname), lib.paths());
			os_info(t);
		}
		catch(std::exception &e) {
			log(ERR "%s", e.what());
			return 1;
		}
	}

	return 0;
}

int main_disassembly(int argc, char **argv)
{
	int error=0, option=0;
	__attribute__((unused)) int mpu='4';
	std::vector<std::string> passes {
		"cfg", "pcrel", "constprop", "syscall", "print"
	};
	std::string file;

	struct option const longs[] = {
		{ "help",     no_argument,  NULL,  'h' },
		{ "sh3",      no_argument,  NULL,  '3' },
		{ "sh4",      no_argument,  NULL,  '4' },
		{ "verbose",  no_argument,  NULL,  'v' },
	};

	while(option >= 0 && option != '?')
	switch((option = getopt_long(argc, argv, "h34p:f:v", longs, NULL)))
	{
	case 'h':
		usage(0);
	case '3':
	case '4':
		mpu = option;
		break;
	case 'p':
	{
		passes.clear();

		std::istringstream in(optarg);
		std::string pass;

		while(std::getline(in, pass, ',')) {
			passes.push_back(pass);
		}

		if(!passes.size()) error = 1, log(ERR "no pass specified");
		if(passes.back() != "print") passes.push_back("print");
		break;
	}
	case 'f':
		file = optarg;
		break;
	case 'v':
		log_setminlevel(LEVEL_LOG);
		break;
	case '?':
		error = 1;
	}

	int remaining_args = (file.size() ? 1 : 2);

	if(argc < optind + remaining_args + 1)
	{
		log(ERR "missing file or address");
		error = 1;
	}
	else if(argc > optind + remaining_args + 1)
	{
		log(ERR "excess argument");
		error = 1;
	}
	if(error) return 1;

	//~

	/* Load the configuration and library */
	Library lib;
	loadconfig(lib);

	Target target;
	char const *ref;

	if(!file.size())
	{
		std::string tname = argv[optind + 1];

		if(!lib.targets().count(tname))
		{
			log(ERR "no target '%s' in library", tname);
			return 1;
		}

		target = Target(lib.targets().at(tname), lib.paths());

		ref = argv[optind + 2];
		log(LOG "Disassembling target %s at %s", tname, ref);

	}
	else
	{
		/* Load the file in ROM over 8M */
		Buffer romfile(file, MemoryRegion::ROM.size());
		target = Target();
		target.bind_region(MemoryRegion::ROM, romfile);
		target.bind_region(MemoryRegion::ROM_P2, romfile);

		ref = argv[optind + 1];
		log(LOG "Disassembling file %s at %s", file, ref);
	}

	try
	{
		return disassembly(lib, target, ref, passes);
	}
	catch(LangError &e)
	{
		log(ERR "%08x: %s", e.addr(), e.what());
		return 1;
	}
	catch(AddressError &e)
	{
		log(ERR "%08x[%d]: %s", e.addr(), e.size(), e.what());
		return 1;
	}
}

#define UN __attribute__((unused))
int main_analyze(UN int argc, UN char **argv)
{
	std::cerr << "doing main_analyze, which is incomplete x_x\n";
	return 0;
}

int main(int argc, char **argv)
{
	if(argc < 2) usage(1);

	std::string cmd = argv[1];
	argv[1] = (char *)"";

	try
	{
		if(cmd == "library")
			return main_library(argc, argv);
		else if(cmd == "info")
			return main_info(argc, argv);
		else if(cmd == "disasm")
			return main_disassembly(argc, argv);
//		else if(cmd == "analyze")
//			return main_analyze(argc, argv);

		else if(cmd == "-?" || cmd == "-h" || cmd == "--help")
			usage(0);

		std::cerr << "invalid operation '" << cmd << "'\n";
		std::cerr << "Try '" << argv[0] << " --help'.\n";
	}
	catch(std::logic_error &e)
	{
		log(ERR "%s o(x_x)o", e.what());
	}
	catch(std::runtime_error &e)
	{
		log(ERR "%s", e.what());
	}
	catch(FxOS::LimitError &e)
	{
		log(ERR "%s _(x_x)_", e.what());
	}

	return 1;
}