commit d19025bbc9f33010d7d0e5234b2ed3098d232644
Author: Lephe <sebastien.mld@numericable.fr>
Date:   Thu Mar 21 22:54:06 2019 +0100

    fxsdk: initial push for gint v2 (WIP but mostly done)

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..79b3941
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,17 @@
+# Configuration file
+Makefile.cfg
+
+# Build directory
+build/
+
+# Binaries
+bin/
+
+# Test icons
+icons/
+
+# Documentation drafts
+doc/
+
+# Python cache
+__pycache__
diff --git a/Makefile b/Makefile
new file mode 100755
index 0000000..b0a6bcb
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,119 @@
+#! /usr/bin/make -f
+
+# Require config file if not cleaning up
+ifeq "$(filter clean distclean,$(MAKECMDGOALS))" ""
+include Makefile.cfg
+endif
+
+# Compiler flags
+cflags = -Wall -Wextra -std=c11 -O2 -I $(dir $<) -D_GNU_SOURCE \
+         -DFXSDK_PREFIX='"$(PREFIX)"' $(CFLAGS)
+# Linker flags
+lflags = -lpng
+# Bison generation flags
+# bflags = -L C --defines=$(@:.c=.h) --verbose
+# Dependency generation flags
+dflags = -MT $@ -MMD -MP -MF $(@:%.o=%.d)
+
+#
+#  Main targets and symbolic targets
+#  $TARGETS is provided by Makefile.cfg.
+#
+
+TARGETS := $(filter-out fxconv,$(TARGETS))
+bin = $(TARGETS:%=bin/%)
+
+# fxconv has no sources files because it's written in Python
+src = $(wildcard $1/*.c)
+src-fxsdk  := $(call src,fxsdk)
+src-fxg1a  := $(call src,fxg1a)
+src-fxos   := $(call src,fxos)
+
+obj = $(src-$1:%=build/%.o)
+obj-fxsdk  := $(call obj,fxsdk)
+obj-fxg1a  := $(call obj,fxg1a)
+obj-fxos   := $(call obj,fxos)
+
+# Symbolic targets
+
+all: $(bin)
+
+all-fxsdk: bin/fxsdk
+all-fxg1a: bin/fxg1a
+all-fxos: bin/fxos
+
+# Explicit targets
+
+bin/fxsdk: $(obj-fxsdk) | bin/
+	gcc $^ -o $@ $(lflags)
+bin/fxg1a: $(obj-fxg1a) | bin/
+	gcc $^ -o $@ $(lflags)
+bin/fxos: $(obj-fxos) | bin/
+	gcc $^ -o $@ $(lflags)
+
+bin/:
+	mkdir -p $@
+
+#
+#  Source rules
+#
+
+build/%.c.o: %.c
+	@mkdir -p $(dir $@)
+	gcc -c $< -o $@ $(cflags) $(dflags)
+
+# Flex lexers (unused since fxconv is written in Python)
+# build/%/lexer.yy.c: %/lexer.l build/%/parser.tab.c
+#	flex -o $@ -s $<
+# build/%/lexer.yy.c.o: build/%/lexer.yy.c
+#	gcc -c $< -o $@ $(cflags) -Wno-unused-function $(dflags) -I $*
+
+# Bison parsers (unused since fxconv is written in Python)
+# build/%/parser.tab.c: %/parser.y
+#	bison $< -o $@ $(bflags)
+# build/%/parser.tab.c.o: build/%/parser.tab.c
+#	gcc -c $< -o $@ $(cflags) $(dflags) -I $*
+
+#
+#  Dependency system, misc.
+#
+
+include $(wildcard build/*/*.d)
+
+# Dependency on configuration file
+Makefile.cfg:
+	@ if [[ ! -f Makefile.cfg ]]; then \
+	  echo "error: Makefile.cfg is missing, did you ./configure?" >&2; \
+	  false; \
+	fi
+
+.PHONY: all clean distclean
+
+#
+#  Installing
+#
+
+install: $(bin)
+	install -d $(PREFIX)/bin
+	install $(bin) -m 755 $(PREFIX)/bin
+	install fxconv/fxconv-main.py -m 755 $(PREFIX)/bin/fxconv
+	install fxconv/fxconv.py -m 644 $(PREFIX)/bin
+
+#
+#  Cleaning
+#
+
+clean-fxsdk:
+	@rm -rf build/fxsdk
+clean-fxconv:
+	@rm -rf build/fxconv
+clean-fxg1a:
+	@rm -rf build/fxg1a
+clean-fxos:
+	@rm -rf build/fxos
+
+clean:
+	@rm -rf build
+distclean: clean
+	@rm -rf bin
+	@rm -f Makefile.cfg
diff --git a/configure b/configure
new file mode 100755
index 0000000..8c01f87
--- /dev/null
+++ b/configure
@@ -0,0 +1,112 @@
+#! /usr/bin/bash
+
+#
+#  Output variables
+#
+
+# Path parameters
+PREFIX="/usr"
+# Individual component selection
+BUILD_fxsdk=1
+BUILD_fxconv=1
+BUILD_fxg1a=1
+BUILD_fxos=1
+
+#
+#  Tool name checking
+#
+
+check()
+{
+	[[ $1 = "fxsdk"  ]] ||
+	[[ $1 = "fxconv" ]] ||
+	[[ $1 = "fxg1a"  ]] ||
+	[[ $1 = "fxos"   ]]
+}
+
+#
+#  Usage
+#
+
+help()
+{
+	cat << EOF
+Configuration options for the fxSDK (fx9860g and fxcg50 development tools).
+
+Tool selection:
+  <tool> may be one of the following:
+    "fxsdk"          Command-line options (you generally want this)
+    "fxconv"         Asset conversion for gint (or any 4-aligned-VRAM system)
+    "fxg1a"          G1A file wrapper, editor and analyzer
+    "fxos"           OS fiddling tool, including syscall disassembly
+
+  --enable-<tool>    Build and install the selected tool [default]
+  --disable-<tool>   Do not build or install the selected tool
+
+Install folders:
+  Executables will be installed in <prefix>/bin and runtime data in
+  <prefix>/share/fxsdk.
+
+  --prefix=<prefix>  Base install folder [default /usr]
+EOF
+	exit 0
+}
+
+#
+#  Argument parsing
+#
+
+for arg; do case "$arg" in
+	-h | -? | --help)
+		help;;
+
+	--prefix=*)
+		PREFIX=${arg#--prefix=};;
+
+	--enable-*)
+		tool="${arg#--enable-}"
+		if ! check $tool; then
+			echo "error: cannot enable $tool: unknown tool"
+			exit 1
+		fi
+
+		eval "BUILD_${tool}=1";;
+
+	--disable-*)
+		tool="${arg#--disable-}"
+		if ! check $tool; then
+			echo "error: cannot disable $tool: unknown tool"
+			exit 1
+		fi
+
+		eval "BUILD_${tool}=0";;
+
+	*)
+		echo "error: unrecognized option $arg"
+		exit 1;;
+esac; done
+
+#
+#  Makefile generation
+#
+
+gen()
+{
+	echo "PREFIX  = $PREFIX"
+	echo -n "TARGETS ="
+
+	[[ $BUILD_fxsdk  = 1 ]] && echo -n " fxsdk"
+	[[ $BUILD_fxconv = 1 ]] && echo -n " fxconv"
+	[[ $BUILD_fxg1a  = 1 ]] && echo -n " fxg1a"
+	[[ $BUILD_fxos   = 1 ]] && echo -n " fxos"
+
+	echo ""
+}
+
+echo "Configuration complete, the following has been saved in Makefile.cfg:"
+echo ""
+
+gen | tee Makefile.cfg
+
+echo ""
+echo "You can now 'make'."
diff --git a/fxconv/fxconv-main.py b/fxconv/fxconv-main.py
new file mode 100755
index 0000000..a665163
--- /dev/null
+++ b/fxconv/fxconv-main.py
@@ -0,0 +1,112 @@
+#! /usr/bin/python3
+
+import getopt
+import sys
+import os
+import fxconv
+
+help_string = """
+usage: fxconv [-s] <python script> [files...]
+       fxconv  -b  <bin file> -o <object file> [parameters...]
+       fxconv  -i  <png file> -o <object file> [parameters...]
+       fxconv  -f  <png file> -o <object file> [parameters...]
+
+fxconv converts data files such as images and fonts into gint formats
+optimized for fast execution, or into object files.
+
+Operating modes:
+  -s, --script   Expose the fxconv module and run this Python script
+  -b, --binary   Turn data into an object file, no conversion
+  -i, --image    Convert to gint's image format
+  -f, --font     Convert to gint's font format
+
+When using -s, additional arguments are stored in the [fxconv.args] variable of
+the module. This is intended to be a restricted list of file names specified by
+a Makefile, used to convert only a subset of the files in the script.
+
+The -b, -i and -f modes are shortcuts to convert single files without a script.
+They accept parameters with a "category.key:value" syntax, for example:
+  fxconv -f myfont.png -o myfont.o charset:ascii grid.padding:1 height:7
+""".strip()
+
+# Simple error-warnings system
+def err(msg):
+	print("error:", msg, file=sys.stderr)
+def warn(msg):
+	print("warning:", msg, file=sys.stderr)
+
+def main():
+	# Default execution mode is to run a Python script for conversion
+	modes = "script binary image font"
+	mode = "s"
+	output = None
+
+	# Parse command-line arguments
+
+	if len(sys.argv) == 1:
+		print(help_string, file=sys.stderr)
+		sys.exit(1)
+
+	try:
+		opts, args = getopt.gnu_getopt(sys.argv[1:], "hsbifo:",
+			("help output="+modes).split())
+	except getopt.GetoptError as error:
+		err(error)
+		sys.exit(1)
+
+	for name, value in opts:
+		# Print usage
+		if name == "--help":
+			err(help_string, file=sys.stderr)
+			sys.exit(0)
+		# TODO: fxconv: verbose mode
+		elif name == "--verbose":
+			pass
+		elif name in [ "-o", "--output" ]:
+			output = value
+		# Other names are modes
+		else:
+			mode = name[1] if len(name)==2 else name[2]
+
+	# Remaining arguments
+	if args == []:
+		err(f"execution mode -{mode} expects an input file")
+		sys.exit(1)
+	input = args.pop(0)
+
+	# In --script mode, run the Python script with an augmented PYTHONPATH
+
+	if mode == "s":
+		if output is not None:
+			warn("option --output is ignored in script mode")
+		args = None if args == [] else args
+
+		err("script mode not currently implemented (TODO) x_x")
+		sys.exit(1)
+
+	# In shortcut conversion modes, read parameters from the command-line
+
+	else:
+		def check(arg):
+			if ':' not in arg:
+				warn(f"argument {arg} is not a valid parameter (ignored)")
+			return ':' in arg
+
+		def insert(params, path, value):
+			if len(path) == 1:
+				params[path[0]] = value
+				return
+			if not path[0] in params:
+				params[path[0]] = {}
+			insert(params[path[0]], path[1:], value)
+
+		args = [ arg.split(':', 1) for arg in args if check(arg) ]
+		params = {}
+		for (name, value) in args:
+			insert(params, name.split("."), value)
+
+		params["type"] = { "b": "binary", "i": "image", "f": "font" }[mode]
+
+		fxconv.convert(input, params, output)
+
+main()
diff --git a/fxconv/fxconv.py b/fxconv/fxconv.py
new file mode 100644
index 0000000..a91563e
--- /dev/null
+++ b/fxconv/fxconv.py
@@ -0,0 +1,497 @@
+"""
+fxconv: Convert data files into gint formats or object files
+"""
+
+import os
+import tempfile
+import subprocess
+
+from PIL import Image
+
+#
+# Color quantification
+#
+
+# Colors
+FX_BLACK  = (  0,   0,   0, 255)
+FX_DARK   = ( 85,  85,  85, 255)
+FX_LIGHT  = (170, 170, 170, 255)
+FX_WHITE  = (255, 255, 255, 255)
+FX_ALPHA  = (  0,   0,   0,   0)
+
+# Profiles
+
+FX_PROFILES = [
+	{ # Usual black-and-white bitmaps without transparency, as in MonochromeLib
+	  "name":   "mono",
+	  "gray":   False,
+	  "colors": { FX_BLACK, FX_WHITE },
+	  "layers": [ lambda c: (c == FX_BLACK) ]
+	},
+    { # Black-and-white with transparency, equivalent of two bitmaps in ML
+	  "name":   "mono_alpha",
+	  "gray":   False,
+	  "colors": { FX_BLACK, FX_WHITE, FX_ALPHA },
+	  "layers": [ lambda c: (c != FX_ALPHA),
+	              lambda c: (c == FX_BLACK) ]
+	},
+	{ # Gray engine bitmaps, reference could have been Eiyeron's Gray Lib
+	  "name":   "gray",
+	  "gray":   True,
+	  "colors": { FX_BLACK, FX_DARK, FX_LIGHT, FX_WHITE },
+	  "layers": [ lambda c: (c in [FX_BLACK, FX_LIGHT]),
+	              lambda c: (c in [FX_BLACK, FX_DARK]) ]
+	},
+	{ # Gray images with transparency, unfortunately 3 layers since 5 colors
+	  "name":   "gray_alpha",
+	  "gray":   True,
+	  "colors": { FX_BLACK, FX_DARK, FX_LIGHT, FX_WHITE, FX_ALPHA },
+	  "layers": [ lambda c: (c != FX_ALPHA),
+	              lambda c: (c in [FX_BLACK, FX_LIGHT]),
+	              lambda c: (c in [FX_BLACK, FX_DARK]) ]
+	},
+]
+
+#
+# Character sets
+#
+
+class _Charset:
+	def __init__(self, id, name, count):
+		self.id = id
+		self.name = name
+		self.count = count
+
+FX_CHARSETS = [
+	# Digits 0...9
+	_Charset(0x0, "numeric", 10),
+	# Uppercase letters A...Z
+	_Charset(0x1, "upper", 26),
+	# Upper and lowercase letters A..Z, a..z
+	_Charset(0x2, "alpha", 52),
+	# Letters and digits A..Z, a..z, 0..9
+	_Charset(0x3, "alnum", 62),
+	# All printable characters from 0x20 to 0x7e
+	_Charset(0x4, "print", 95),
+	# All 128 ASII characters
+	_Charset(0x5, "ascii", 128),
+]
+
+#
+# Internal routines
+#
+
+# normalize_area(): Expand area.size and set defaults for all values.
+def _normalize_area(area, img):
+	default = { "x": 0, "y": 0, "width": img.width, "height": img.height }
+	if area is None:
+		area = default
+	else:
+		if "size" in area:
+			area["width"], area["height"] = area["size"].split("x")
+		area = { **default, **area }
+
+	return (int(area[key]) for key in "x y width height".split())
+
+class _Grid:
+	# [grid] is a dictionary of parameters. Relevant keys:
+	#   "border", "padding", "width", "height", "size"
+	def __init__(self, grid):
+		self.border  = int(grid.get("border",  1))
+		self.padding = int(grid.get("padding", 0))
+
+		self.w = int(grid.get("width", "-1"))
+		self.h = int(grid.get("height", "-1"))
+
+		if "size" in grid:
+			self.w, self.h = map(int, grid["size"].split("x"))
+
+		if self.w <= 0 or self.h <= 0:
+			raise FxconvError("size of grid unspecified or invalid")
+
+	# size(): Number of elements in the grid
+	def size(self, img):
+		b, p, w, h =  self.border, self.padding, self.w, self.h
+
+		# Padding-extended parameters
+		W = w + 2 * p
+		H = h + 2 * p
+
+		columns = (img.width  - b) // (W + b)
+		rows    = (img.height - b) // (H + b)
+		return columns * rows
+
+
+	# iter(): Iterator on all rectangles of the grid
+	def iter(self, img):
+		b, p, w, h =  self.border, self.padding, self.w, self.h
+
+		# Padding-extended parameters
+		W = w + 2 * p
+		H = h + 2 * p
+
+		columns = (img.width  - b) // (W + b)
+		rows    = (img.height - b) // (H + b)
+
+		for r in range(rows):
+			for c in range(columns):
+				x = b + c * (W + b) + p
+				y = b + r * (H + b) + p
+				yield (x, y, x + w, y + h)
+
+#
+# Binary conversion
+#
+
+def _convert_binary(input, output, params):
+	raise FxconvError("TODO: binary mode x_x")
+
+#
+# Image conversion
+#
+
+def _profile_find(name):
+	gen = ((i,pr) for (i,pr) in enumerate(FX_PROFILES) if pr["name"] == name)
+	return next(gen, (None,None))
+
+def _convert_image(input, output, params):
+	img = Image.open(input)
+	if img.width >= 4096 or img.height >= 4096:
+		raise FxconvError(f"'{input}' is too large (max. 4095*4095)")
+
+	# Expand area.size and get the defaults. Crop image to resulting area.
+	params["area"] = _normalize_area(params.get("area", None), img)
+	img = img.crop(params["area"])
+
+	# Quantize the image and check the profile
+	img = quantize(img, dither=False)
+
+	# If profile is provided, check its validity, otherwise use the smallest
+	# compatible profile
+
+	colors = { y for (x,y) in img.getcolors() }
+
+	if "profile" in params:
+		p = params["profile"]
+		pid, p = _profile_find(p)
+		if p is None:
+			raise FxconvError(f"unknown profile {p} in conversion '{input}'")
+		if colors - profiles[p]:
+			raise FxconvError(f"'{input}' has more colors than profile '{p}'")
+	else:
+		p = "gray" if FX_LIGHT in colors or FX_DARK in colors else "mono"
+		if FX_ALPHA in colors: p += "_alpha"
+		pid, p = _profile_find(p)
+
+	# Make the image header
+
+	header = bytes ([(0x80 if p["gray"] else 0) + pid])
+	encode24bit = lambda x: bytes([ x >> 16, (x & 0xff00) >> 8, x & 0xff ])
+	header += encode24bit((img.size[0] << 12) + img.size[1])
+
+	# Split the image into layers depending on the profile and zip them all
+
+	layers = [ _image_project(img, layer) for layer in p["layers"] ]
+	count  = len(layers)
+	size   = len(layers[0])
+
+	data = bytearray(count * size)
+	n = 0
+
+	for longword in range(size // 4):
+		for layer in layers:
+			for i in range(4):
+				data[n] = layer[4 * longword + i]
+				n += 1
+
+	# Generate the object file
+
+	elf(header + data, output, "_" + params["name"])
+
+def _image_project(img, f):
+	# New width and height
+	w = (img.size[0] + 31) // 32
+	h = (img.size[1])
+
+	data = bytearray(4 * w * h)
+	im = img.load()
+
+	# Now generate a 32-bit byte sequence
+	for y in range(img.size[1]):
+		for x in range(img.size[0]):
+			bit = int(f(im[x, y]))
+			data[4 * y * w + (x >> 3)] |= (bit << (~x & 7))
+
+	return data
+
+#
+# Font conversion
+#
+
+def _charset_find(name):
+	gen = (cs for cs in FX_CHARSETS if cs.name == name)
+	return next(gen, None)
+
+def _convert_font(input, output, params):
+
+	#--
+	# Image area and grid
+	#--
+
+	img = Image.open(input)
+	params["area"] = _normalize_area(params.get("area", None), img)
+	img = img.crop(params["area"])
+
+	grid = _Grid(params.get("grid", {}))
+
+	# Quantize image (any profile will do)
+	img = quantize(img, dither=False)
+
+	#--
+	# Character set
+	#--
+
+	if "charset" not in params:
+		raise FxconvError("'charset' attribute is required and missing")
+
+	charset = _charset_find(params["charset"])
+	if charset is None:
+		raise FxconvError(f"unknown character set '{charset}'")
+	if charset.count > grid.size(img):
+		raise FxconvError(f"not enough elements in grid (got {grid.size()}, "+
+			f"need {charset.count} for '{charset.name}'")
+
+	#--
+	# Proportionality and metadata
+	#--
+
+	proportional = (params.get("proportional", "false") == "true")
+
+	title = params.get("title", "")
+	if len(title) > 31:
+		raise FxconvError(f"font title {title} is too long (max. 31 bytes)")
+	# Pad title to 4 bytes
+	title = bytes(title, "utf-8") + bytes(((4 - len(title) % 4) % 4) * [0])
+
+	flags = set(params.get("flags", "").split(","))
+	flags.remove("")
+	flags_std = { "bold", "italic", "serif", "mono" }
+
+	if flags - flags_std:
+		raise FxconvError(f"unknown flags: {', '.join(flags - flags_std)}")
+
+	bold   = int("bold" in flags)
+	italic = int("italic" in flags)
+	serif  = int("serif" in flags)
+	mono   = int("mono" in flags)
+	header = bytes([
+		(len(title) << 3) | (bold << 2) | (italic << 1) | serif,
+		(mono << 7) | (int(proportional) << 6) | (charset.id & 0xf),
+		params.get("height", grid.h),
+		grid.h,
+	])
+
+	encode16bit = lambda x: bytes([ x >> 8, x & 255 ])
+	fixed_header = encode16bit(grid.w) + encode16bit((grid.w*grid.h + 31) >> 5)
+
+	#--
+	# Encoding glyphs
+	#--
+
+	data_glyphs = []
+	data_widths = bytearray()
+	data_index  = bytearray()
+
+	for (number, region) in enumerate(grid.iter(img)):
+		# Upate index
+		if not (number % 8):
+			idx = len(data_glyphs) // 4
+			data_index += encode16bit(idx)
+
+		# Get glyph area
+		glyph = img.crop(region)
+		glyph.save(f"/tmp/img{number}.png")
+		if proportional:
+			glyph = _trim(glyph)
+			data_widths.append(glyph.width)
+
+		length = 4 * ((glyph.width * glyph.height + 31) >> 5)
+		bits = bytearray(length)
+		offset = 0
+		px = glyph.load()
+
+		for y in range(glyph.size[1]):
+			for x in range(glyph.size[0]):
+				color = (px[x,y] == FX_BLACK)
+				bits[offset >> 3] |= ((color * 0x80) >> (offset & 7))
+				offset += 1
+
+		data_glyphs.append(bits)
+
+	data_glyphs = b''.join(data_glyphs)
+
+	#---
+	#  Object file generation
+	#---
+
+	if proportional:
+		data = header + data_index + data_widths + data_glyphs + title
+	else:
+		data = header + fixed_header + data_glyphs + title
+
+	elf(data, output, "_" + params["name"])
+
+#
+# Exceptions
+#
+
+FxconvError = Exception
+
+#
+# API
+#
+
+def quantize(img, dither=False):
+	"""
+	Convert a PIL.Image.Image into an RGBA image whose only colors are:
+	* FX_BLACK  = (  0,   0,   0, 255)
+	* FX_DARK   = ( 85,  85,  85, 255)
+	* FX_LIGHT  = (170, 170, 170, 255)
+	* FX_WHITE  = (255, 255, 255, 255)
+	* FX_ALPHA  = (  0,   0,   0,   0)
+
+	The alpha channel is first flattened to either opaque of full transparent,
+	then all colors are quantized into the 4-shade scale. Floyd-Steinberg
+	dithering can be used, although most applications will prefer nearest-
+	neighbor coloring.
+
+	Arguments:
+	img     -- Input image, in any format
+	dither  -- Enable Floyd-Steinberg dithering [default: False]
+
+	Returns a quantized PIL.Image.Image.
+	"""
+
+	# Our palette will have only 4 colors for the gray engine
+	colors = [ FX_BLACK, FX_DARK, FX_LIGHT, FX_WHITE ]
+
+	# Create the palette
+	palette = Image.new("RGBA", (len(colors), 1))
+	for (i, c) in enumerate(colors):
+		palette.putpixel((i, 0), c)
+	palette = palette.convert("P")
+	palette.save("/tmp/palette.png")
+
+	# Save the alpha channel, and make it either full transparent or opaque
+	try:
+		alpha_channel = img.getchannel("A").convert("1", dither=Image.NONE)
+	except:
+		alpha_channel = Image.new("L", img.size, 255)
+
+	# Apply the palette to the original image (transparency removed)
+	img = img.convert("RGB")
+
+	# Let's do an equivalent of the following, but with a dithering setting:
+	# img = img.quantize(palette=palette)
+
+	img.load()
+	palette.load()
+	im = img.im.convert("P", int(dither), palette.im)
+	img = img._new(im)
+
+	# Put back the alpha channel
+	img.putalpha(alpha_channel)
+
+	# Premultiply alpha
+	pixels = img.load()
+	for y in range(img.size[1]):
+		for x in range(img.size[0]):
+			r, g, b, a = pixels[x, y]
+			if a == 0:
+				r, g, b, = 0, 0, 0
+			pixels[x, y] = (r, g, b, a)
+
+	return img
+
+def convert(input, params, output=None):
+	"""
+	Convert a data file into an object that exports the following symbols:
+	* _<varname>
+	* _<varname>_end
+	* _<varname>_size
+	The variable name is obtained from the parameter dictionary <params>.
+
+	Arguments:
+	input   -- Input file path
+	params  -- Parameter dictionary
+	output  -- Output file name [default: <input> with suffix '.o']
+
+	Produces an output file and returns nothing.
+	"""
+
+	if output is None:
+		output = os.path.splitext(input)[0] + '.o'
+
+	if "name" not in params:
+		raise FxconvError(f"no name specified for conversion '{input}'")
+
+	if "type" not in params:
+		raise FxconvError(f"missing type in conversion '{input}'")
+	elif params["type"] == "binary":
+		_convert_binary(input, output, params)
+	elif params["type"] == "image":
+		_convert_image(input, output, params)
+	elif params["type"] == "font":
+		_convert_font(input, output, params)
+
+def elf(data, output, symbol, section=None, arch="sh3"):
+	"""
+	Call objcopy to create an object file from the specified data. The object
+	file will export three symbols:
+	* <symbol>
+	* <symbol>_end
+	* <symbol>_size
+
+	The symbol name must have a leading underscore if it is to be declared and
+	used from a C program.
+
+	The section name can be specified, along with its flags. A typical example
+	would be section=".rodata,contents,alloc,load,readonly,data", which is the
+	default.
+
+	The architecture can be either "sh3" or "sh4". This affects the choice of
+	the toolchain (sh3eb-elf-objcopy versus sh4eb-nofpu-elf-objcopy) and the
+	--binary-architecture flag of objcopy.
+
+	Arguments:
+	data     -- A bytes-like object with data to embed into the object file
+	output   -- Name of output file
+	symbol   -- Chosen symbol name
+	section  -- Target section [default: above variation of .rodata]
+	arch     -- Target architecture: "sh3" or "sh4" [default: "sh3"]
+
+	Produces an output file and returns nothing.
+	"""
+
+	toolchain = { "sh3": "sh3eb-elf", "sh4": "sh4eb-nofpu-elf" }[arch]
+	if section is None:
+		section = ".rodata,contents,alloc,load,readonly,data"
+
+	with tempfile.NamedTemporaryFile() as fp:
+		fp.write(data)
+		fp.flush()
+
+		sybl = "_binary_" + fp.name.replace("/", "_")
+
+		objcopy_args = [
+			f"{toolchain}-objcopy", "-I", "binary", "-O", "elf32-sh",
+			"--binary-architecture", arch, "--file-alignment", "4",
+			"--rename-section", f".data={section}",
+			"--redefine-sym", f"{sybl}_start={symbol}",
+			"--redefine-sym", f"{sybl}_end={symbol}_end",
+			"--redefine-sym", f"{sybl}_size={symbol}_size",
+			fp.name, output ]
+
+		proc = subprocess.run(objcopy_args)
+		if proc.returncode != 0:
+			raise FxconvError(f"objcopy returned {proc.returncode}")
diff --git a/fxg1a/dump.c b/fxg1a/dump.c
new file mode 100644
index 0000000..cb6ed4c
--- /dev/null
+++ b/fxg1a/dump.c
@@ -0,0 +1,146 @@
+#include <stdio.h>
+#include <string.h>
+#include <endian.h>
+
+#include <fxg1a.h>
+#include <g1a.h>
+
+/* check(): Check validity of a g1a control or fixed field
+
+   This function checks a single field of a g1a header (depending on the value
+   of @test, from 0 up) and returns:
+   * 0 if the field is valid
+   * 1 if there is a minor error (wrong fixed-byte entry)
+   * 2 if there is a major error (like not a g1a, bad checksum, etc)
+   * -1 if the value of @test is out of bounds
+
+   It produces a description of the check in @status (even if the test is
+   passed); the string should have room for at least 81 bytes.
+
+   @test    Test number
+   @g1a     G1A file being manipulated
+   @size    File size
+   @status  Array row, at least 81 bytes free */
+static int check(int test, struct g1a const *g1a, size_t size, char *status)
+{
+	#define m(msg, ...) sprintf(status, msg, ##__VA_ARGS__)
+
+	struct header const *h = &g1a->header;
+	uint8_t const *raw = (void *)h;
+
+	uint16_t sum;
+	uint8_t ctrl;
+
+	switch(test)
+	{
+	case 0:
+		m("Signature    \"USBPower\"    \"########\"");
+		strncpy(status + 28, h->magic, 8);
+		return strncmp(h->magic, "USBPower", 8) ? 2:0;
+	case 1:
+		m("MCS Type     0xf3          0x%02x", h->mcs_type);
+		return (h->mcs_type != 0xf3) ? 2:0;
+	case 2:
+		m("Sequence 1   0x0010001000  0x%02x%02x%02x%02x%02x",
+		h->seq1[0], h->seq1[1], h->seq1[2], h->seq1[3], h->seq1[4]);
+		return strncmp((const char *)h->seq1, "\x00\x01\x00\x01\x00",
+			5) ? 1:0;
+	case 3:
+		ctrl = raw[0x13] + 0x41;
+		m("Control 1    0x%02x          0x%02x", ctrl, h->control1);
+		return (h->control1 != ctrl) ? 2:0;
+	case 4:
+		m("Sequence 2   0x01          0x%02x", h->seq2);
+		return (h->seq2 != 0x01) ? 1:0;
+	case 5:
+		m("File size 1  %-8zu      %u", size,
+			be32toh(h->filesize_be1));
+		return (be32toh(h->filesize_be1) != size) ? 2:0;
+	case 6:
+		ctrl = raw[0x13] + 0xb8;
+		m("Control 2    0x%02x          0x%02x", ctrl, h->control2);
+		return (h->control2 != ctrl) ? 2:0;
+	case 7:
+		sum = checksum(g1a, size);
+		m("Checksum     0x%02x        0x%02x", sum,
+			be16toh(h->checksum));
+		return (be16toh(h->checksum) != sum) ? 2:0;
+	case 8:
+		m("File size 2  %-8zu      %u", size,
+			be32toh(h->filesize_be2));
+		return (be32toh(h->filesize_be2) != size) ? 2:0;
+	default:
+		return -1;
+	}
+}
+
+/* unknown(): Print an unknown field
+   @data    Address of field
+   @offset  Offset of field in header
+   @size    Number of consecutive unknown bytes */
+static void unknown(uint8_t const *data, size_t offset, size_t size)
+{
+	printf("  0x%03zx   %-4zd  0x", offset, size);
+	for(size_t i = 0; i < size; i++) printf("%02x", data[offset + i]);
+	printf("\n");
+}
+
+/* field(): Print a text field with limited size
+   @field  Address of text field
+   @size   Maximum number of bytes to print */
+static void field(const char *field, size_t size)
+{
+	for(size_t i = 0; i < size && field[i]; i++) putchar(field[i]);
+	printf("\n");
+}
+
+/* dump(): Print the detailed header fields of a g1a file */
+void dump(struct g1a const *g1a, size_t size)
+{
+	struct header const *header = &g1a->header;
+	uint8_t const *raw = (void *)header;
+
+	/* Checks for g1a files */
+	char status[81];
+	int ret = 0;
+	int passed = 0;
+
+	printf("G1A signature checks:\n\n");
+	printf("  Sta.  Field        Expected      Value\n");
+
+	for(int test = 0; ret >= 0; test++)
+	{
+		ret = check(test, g1a, size, status);
+		passed += !ret;
+		if(ret < 0) break;
+
+		printf("  %s  %s\n", ret ? "FAIL" : "OK  ", status);
+	}
+
+	printf("\nFields with unknown meanings:\n\n");
+	printf("  Offset  Size  Value\n");
+
+	unknown(raw, 0x015, 1);
+	unknown(raw, 0x018, 6);
+	unknown(raw, 0x028, 3);
+	unknown(raw, 0x02c, 4);
+	unknown(raw, 0x03a, 2);
+	unknown(raw, 0x04a, 2);
+	unknown(raw, 0x1d0, 4);
+	unknown(raw, 0x1dc, 20);
+	unknown(raw, 0x1f4, 12);
+
+	printf("\nApplication metadata:\n\n");
+
+	printf("  Program name:   ");
+	field(header->name, 8);
+	printf("  Internal name:  ");
+	field(header->internal, 8);
+	printf("  Version:        ");
+	field(header->version, 10);
+	printf("  Build date:     ");
+	field(header->date, 14);
+
+	printf("\nProgram icon:\n\n");
+	icon_print(header->icon);
+}
diff --git a/fxg1a/edit.c b/fxg1a/edit.c
new file mode 100644
index 0000000..60286ad
--- /dev/null
+++ b/fxg1a/edit.c
@@ -0,0 +1,71 @@
+#include <fxg1a.h>
+#include <stdio.h>
+#include <string.h>
+
+/* sign(): Sign header by filling fixed fields and checksums */
+void sign(struct g1a *g1a, size_t size)
+{
+	struct header *header = &g1a->header;
+
+	/* Fixed elements */
+
+	memcpy(header->magic, "USBPower", 8);
+	header->mcs_type = 0xf3;
+	memcpy(header->seq1, "\x00\x10\x00\x10\x00", 5);
+	header->seq2 = 0x01;
+
+	header->filesize_be1 = htobe32(size);
+	header->filesize_be2 = htobe32(size);
+
+	/* Control bytes and checksums */
+
+	header->control1 = size + 0x41;
+	header->control2 = size + 0xb8;
+	header->checksum = htobe16(checksum(g1a, size));
+}
+
+/* edit_name(): Set application name */
+void edit_name(struct g1a *g1a, const char *name)
+{
+	memset(g1a->header.name, 0, 8);
+	if(!name) return;
+
+	for(int i = 0; name[i] && i < 8; i++)
+		g1a->header.name[i] = name[i];
+}
+
+/* edit_internal(): Set internal name */
+void edit_internal(struct g1a *g1a, const char *internal)
+{
+	memset(g1a->header.internal, 0, 8);
+	if(!internal) return;
+
+	for(int i = 0; internal[i] && i < 8; i++)
+		g1a->header.internal[i] = internal[i];
+}
+
+/* edit_version(): Set version string */
+void edit_version(struct g1a *g1a, const char *version)
+{
+	memset(g1a->header.version, 0, 10);
+	if(!version) return;
+
+	for(int i = 0; version[i] && i < 10; i++)
+		g1a->header.version[i] = version[i];
+}
+
+/* edit_date(): Set build date */
+void edit_date(struct g1a *g1a, const char *date)
+{
+	memset(g1a->header.date, 0, 14);
+	if(!date) return;
+
+	for(int i = 0; date[i] && i < 14; i++)
+		g1a->header.date[i] = date[i];
+}
+
+/* edit_icon(): Set icon from monochrome bitmap */
+void edit_icon(struct g1a *g1a, uint8_t const *mono)
+{
+	memcpy(g1a->header.icon, mono, 68);
+}
diff --git a/fxg1a/file.c b/fxg1a/file.c
new file mode 100644
index 0000000..da59116
--- /dev/null
+++ b/fxg1a/file.c
@@ -0,0 +1,111 @@
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <fxg1a.h>
+
+/* invert_header(): Bit-invert a standard header
+   Part of the header is stored inverted in files for obfuscation purposes. */
+static void invert_header(struct g1a *g1a)
+{
+	uint8_t *data = (void *)&g1a->header;
+	for(size_t i = 0; i < 0x20; i++) data[i] = ~data[i];
+}
+
+#define fail(msg, ...) {						\
+	fprintf(stderr, "error: " msg ": %m\n", ##__VA_ARGS__);		\
+	close(fd);							\
+	free(data);							\
+	return NULL;							\
+}
+
+/* load(): Fully load a file into memory
+   Allocates a buffer with @prepend leading bytes initialized to zero. */
+static void *load(const char *filename, size_t *size, size_t prepend)
+{
+	int fd;
+	struct stat statbuf;
+	void *data = NULL;
+	size_t filesize;
+
+	fd = open(filename, O_RDONLY);
+	if(fd < 0) fail("cannot open %s", filename);
+
+	int x = fstat(fd, &statbuf);
+	if(x > 0) fail("cannot stat %s", filename);
+
+	filesize = statbuf.st_size;
+	data = malloc(prepend + filesize);
+	if(!data) fail("cannot load %s", filename);
+
+	size_t remaining = filesize;
+	while(remaining > 0)
+	{
+		size_t offset = prepend + filesize - remaining;
+		ssize_t y = read(fd, data + offset, remaining);
+
+		if(y < 0) fail("cannot read from %s", filename);
+		remaining -= y;
+	}
+	close(fd);
+
+	memset(data, 0, prepend);
+
+	if(size) *size = prepend + filesize;
+	return data;
+}
+
+/* load_g1a(): Load a g1a file into memory */
+struct g1a *load_g1a(const char *filename, size_t *size)
+{
+	struct g1a *ret = load(filename, size, 0);
+	if(ret) invert_header(ret);
+	return ret;
+}
+
+/* load_binary(): Load a binary file into memory */
+struct g1a *load_binary(const char *filename, size_t *size)
+{
+	struct g1a *ret = load(filename, size, 0x200);
+	if(ret) memset(ret, 0xff, 0x20);
+	return ret;
+}
+
+#undef fail
+#define fail(msg, ...) {						\
+	fprintf(stderr, "error: " msg ": %m\n", ##__VA_ARGS__);		\
+	close(fd);							\
+	invert_header(g1a);						\
+	return 1;							\
+}
+
+/* save_g1a(): Save a g1a file to disk */
+int save_g1a(const char *filename, struct g1a *g1a, size_t size)
+{
+	/* Invert header before saving */
+	invert_header(g1a);
+
+	int fd = creat(filename, 0644);
+	if(fd < 0) fail("cannot open %s", filename);
+
+	void const *raw = g1a;
+	ssize_t status;
+
+	size_t written = 0;
+	while(written < size)
+	{
+		status = write(fd, raw + written, size - written);
+		if(status < 0) fail("cannot write to %s", filename);
+		written += status;
+	}
+	close(fd);
+
+	/* Before returning, re-invert header for further use */
+	invert_header(g1a);
+	return 0;
+}
diff --git a/fxg1a/fxg1a.h b/fxg1a/fxg1a.h
new file mode 100644
index 0000000..b084fa6
--- /dev/null
+++ b/fxg1a/fxg1a.h
@@ -0,0 +1,168 @@
+//---
+//	fxg1a:fxg1a - Main interfaces
+//---
+
+#ifndef FX_FXG1A
+#define FX_FXG1A
+
+#include <stdlib.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <g1a.h>
+
+/*
+**  Header dumping (dump.c)
+*/
+
+/* dump(): Print the detailed header fields of a g1a file
+   This function takes as argument the full file loaded into memory and the
+   size of the file. It does various printing to stdout as main job.
+
+   @g1a   Full file data
+   @size  Size of g1a file */
+void dump(struct g1a const *g1a, size_t size);
+
+
+/*
+**  Header manipulation (edit.c)
+*/
+
+/* sign(): Sign header by filling fixed fields and checksums
+   This function fills the fixed fields and various checksums of a g1a file. To
+   do this it accesses some of the binary data. To set the user-customizable
+   field, use the edit_*() functions. (The value of the customizable fields
+   does not influence the checksums so it's okay to not call this function
+   afterwards.)
+
+   @g1a   Header to sign
+   @size  Size of raw file data */
+void sign(struct g1a *g1a, size_t size);
+
+/* edit_*(): Set various fields of a g1a header */
+
+void edit_name     (struct g1a *g1a, const char *name);
+void edit_internal (struct g1a *g1a, const char *internal);
+void edit_version  (struct g1a *g1a, const char *version);
+void edit_date     (struct g1a *g1a, const char *date);
+
+/* edit_icon(): Set monochrome icon of a g1a header
+   The icon parameter must be loaded in 1-bit bitmap format. */
+void edit_icon(struct g1a *header, uint8_t const *mono);
+
+
+/*
+**  Utility functions (util.c)
+*/
+
+/* checksum(): Sum of 8 big-endian shorts at 0x300
+   Computes the third checksum by summing bytes from the data part of the file.
+
+   @g1a   Add-in file whose checksum is requested
+   @size  Size of file */
+uint16_t checksum(struct g1a const *g1a, size_t size);
+
+/* default_output(): Calculate default output file name
+   This function computes a default file name by replacing the extension of
+   @name (if it exists) or adding one. The extension is specified as a suffix,
+   usually in the form ".ext".
+
+   The resulting string might be as long as the length of @name plus that of
+   @suffix (plus one NUL byte); the provided buffer must point to a suitably-
+   large allocated space.
+
+   @name    Input file name
+   @suffix  Suffix to add or replace @name's extension with
+   @output  Output file name */
+void default_output(const char *name, const char *suffix, char *output);
+
+
+/*
+**  File manipulation (file.c)
+*/
+
+/* load_g1a(): Load a g1a file into memory
+   This function loads @filename into a dynamically-allocated buffer and
+   returns the address of that buffer; it must be free()'d after use. When
+   loading the file, if @size is not NULL, it receives the size of the file.
+   On error, load() prints a message an stderr and returns NULL. The header
+   is inverted before this function returns.
+
+   @filename  File to load
+   @size      If non-NULL, receives the file size
+   Returns a pointer to a buffer with loaded data, or NULL on error. */
+struct g1a *load_g1a(const char *filename, size_t *size);
+
+/* load_binary(): Load a binary file into memory
+   This function operates like load_g1a() but reserves space for an empty
+   header. The header is initialized with all zeros.
+
+   @filename  File to load
+   @size      If non-NULL, receives the file size
+   Returns a pointer to a buffer with loaded data, or NULL on error. */
+struct g1a *load_binary(const char *filename, size_t *size);
+
+/* save_g1a(): Save a g1a file to disk
+   This functions creates @filename, then writes a g1a header and a chunk of
+   raw data to it. Since it temporarily inverts the header to comply with
+   Casio's obfuscated format, it needs write access to @g1a. Returns non-zero
+   on error.
+
+   @filename  File to write (it will be overridden if it exists)
+   @g1a       G1A data to write
+   @size      Size of data
+   Returns zero on success and a nonzero error code otherwise. */
+int save_g1a(const char *filename, struct g1a *g1a, size_t size);
+
+
+/*
+**  Icon management (icon.c)
+*/
+
+/* icon_print(): Show a monochrome 30*17 icon on stdout
+   The buffer should point to a 68-byte array. */
+void icon_print(uint8_t const *icon);
+
+/* icon_load(): Load a monochrome PNG image into an array
+   This function loads a PNG image into a 1-bit buffer; each row is represented
+   by a fixed number of bytes, each byte being 8 pixels. Rows are loaded from
+   top to bottom, and from left to right.
+
+   If the image is not a PNG image or a reading error occurs, this functions
+   prints an error message on stderr and returns NULL.
+
+   @filename  PNG file to load
+   @width     If non-NULL, receives image width
+   @height    If non-NULL, receives image height
+   Returns a pointer to a free()able buffer with loaded data, NULL on error. */
+uint8_t *icon_load(const char *filename, size_t *width, size_t *height);
+
+/* icon_save(): Save an 8-bit array to a PNG image
+   Assumes 8-bit GRAY format.
+
+   @filename  Target filename
+   @input     An 8-bit GRAY image
+   @width     Width of input, should be equal to stride
+   @height    Height of input
+   Returns non-zero on error. */
+int icon_save(const char *filename, uint8_t *input, size_t width,
+	size_t height);
+
+/* icon_conv_8to1(): Convert an 8-bit icon to 1-bit
+   The returned 1-bit icon is always of size 30*17, if the input size does not
+   match it is adjusted.
+
+   @input   8-bi data
+   @width   Width of input image
+   @height  Height of input image
+   Returns a free()able buffer with a 1-bit icon on success, NULL on error. */
+uint8_t *icon_conv_8to1(uint8_t const *input, size_t width, size_t height);
+
+/* icon_conv_1to8(): Convert an 1-bit icon to 8-bit
+   Input 1-bit is assumed to be 30*17 in size, this function returns an 8-bit
+   buffer with the same dimensions.
+
+   @mono  Input monochrome icon (from a g1a header, for instance)
+   Returns a free()able buffer, or NULL on error. */
+uint8_t *icon_conv_1to8(uint8_t const *mono);
+
+#endif /* FX_FXG1A */
diff --git a/fxg1a/g1a.h b/fxg1a/g1a.h
new file mode 100644
index 0000000..862c74b
--- /dev/null
+++ b/fxg1a/g1a.h
@@ -0,0 +1,59 @@
+//---
+//	fxg1a:g1a - Add-in header for Casio's G1A format
+//---
+
+#ifndef FX_G1A
+#define FX_G1A
+
+#include <stdint.h>
+
+/* TODO: eStrips are not supported yet */
+struct estrip
+{
+	uint8_t data[80];
+};
+
+/* G1A file header with 0x200 bytes. When output to a file the standard part
+   (first 0x20 bytes) of this header is bit-inverted, but the non-inverted
+   version makes a lot more sens so we'll be using it. */
+struct header
+{				/* Offset Size  Value                       */
+	char     magic[8];	/* 0x000  8     "USBPower"                  */
+	uint8_t  mcs_type;	/* 0x008  1     0xf3 (AddIn)                */
+	uint8_t  seq1[5];	/* 0x009  5     0x0010001000                */
+	uint8_t  control1;	/* 0x00e  1     *0x13 + 0x41                */
+	uint8_t  seq2;		/* 0x00f  1     0x01                        */
+	uint32_t filesize_be1;	/* 0x010  4     File size, big endian       */
+	uint8_t  control2;	/* 0x014  1     *0x13 + 0xb8                */
+	uint8_t  _1;		/* 0x015  1     ???                         */
+	uint16_t checksum;	/* 0x016  2     BE sum of 8 shorts at 0x300 */
+	uint8_t  _2[6];		/* 0x018  6     ???                         */
+	uint16_t mcs_objects;	/* 0x01e  2     MCS-only, unused            */
+	char     internal[8];	/* 0x020  8     Internal app name with '@'  */
+	uint8_t  _3[3];		/* 0x028  3     ???                         */
+	uint8_t  estrips;	/* 0x02b  1     Number of estrips (0..4)    */
+	uint8_t  _4[4];		/* 0x02c  4     ???                         */
+	char     version[10];	/* 0x030  10    Version "MM.mm.pppp"        */
+	uint8_t  _5[2];		/* 0x03a  2     ???                         */
+	char     date[14];	/* 0x03c  14    Build date "yyyy.MMdd.hhmm" */
+	uint8_t  _6[2];		/* 0x04a  2     ???                         */
+	uint8_t  icon[68];      /* 0x04c  68    30*17 monochrome icon       */
+	struct estrip estrip1;	/* 0x090  80    eStrip 1                    */
+	struct estrip estrip2;	/* 0x0e0  80    eStrip 2                    */
+	struct estrip estrip3;	/* 0x130  80    eStrip 3                    */
+	struct estrip estrip4;	/* 0x180  80    eStrip 4                    */
+	uint8_t  _7[4];		/* 0x1d0  4     ???                         */
+	char     name[8];	/* 0x1d4  8     Add-in name                 */
+	uint8_t  _8[20];	/* 0x1dc  20    ???                         */
+	uint32_t filesize_be2;	/* 0x1f0  4     File size, big endian       */
+	uint8_t  _9[12];        /* 0x1f4  12    ???                         */
+};
+
+/* A full g1a file, suitable for use with pointers */
+struct g1a
+{
+	struct header header;
+	uint8_t code[];
+};
+
+#endif /* FX_G1A */
diff --git a/fxg1a/icon.c b/fxg1a/icon.c
new file mode 100644
index 0000000..79a21ee
--- /dev/null
+++ b/fxg1a/icon.c
@@ -0,0 +1,132 @@
+#include <stdio.h>
+#include <string.h>
+
+#include <fxg1a.h>
+#include <png.h>
+
+/* icon_print(): Show a monochrome 30*17 icon on stdout */
+void icon_print(uint8_t const *icon)
+{
+	for(int y = 0; y < 17; y++)
+	{
+		for(int x = 0; x < 30; x++)
+		{
+			int v = icon[(y << 2) + (x >> 3)] & (0x80 >> (x & 7));
+			putchar(v ? '#' : ' ');
+			putchar(v ? '#' : ' ');
+		}
+
+		putchar('\n');
+	}
+}
+
+/* icon_load(): Load a monochrome PNG image into an array */
+uint8_t *icon_load(const char *filename, size_t *width, size_t *height)
+{
+	png_image img;
+	memset(&img, 0, sizeof img);
+	img.opaque = NULL;
+	img.version = PNG_IMAGE_VERSION;
+
+	png_image_begin_read_from_file(&img, filename);
+	if(img.warning_or_error)
+	{
+		fprintf(stderr, "libpng %s: %s\n", img.warning_or_error == 1
+			? "warning": "error", img.message);
+		if(img.warning_or_error > 1)
+		{
+			png_image_free(&img);
+			return NULL;
+		}
+	}
+
+	img.format = PNG_FORMAT_GRAY;
+
+	void *buffer = calloc(img.width * img.height, 1);
+	if(!buffer)
+	{
+		fprintf(stderr, "error: cannot read %s: %m\n", filename);
+		png_image_free(&img);
+		return NULL;
+	}
+
+	png_image_finish_read(&img, NULL, buffer, img.width, NULL);
+	if(width) *width = img.width;
+	if(height) *height = img.height;
+
+	png_image_free(&img);
+	return buffer;
+}
+
+/* icon_save(): Save an 8-bit array to a PNG image */
+int icon_save(const char *filename, uint8_t *input, size_t width,
+	size_t height)
+{
+	png_image img;
+	memset(&img, 0, sizeof img);
+
+	img.version = PNG_IMAGE_VERSION;
+	img.width = width;
+	img.height = height;
+	img.format = PNG_FORMAT_GRAY;
+
+	png_image_write_to_file(&img, filename, 0, input, 0, NULL);
+	png_image_free(&img);
+
+	if(img.warning_or_error)
+	{
+		fprintf(stderr, "libpng %s: %s\n", img.warning_or_error == 1
+			? "warning": "error", img.message);
+		if(img.warning_or_error > 1) return 1;
+	}
+
+	return 0;
+}
+
+/* icon_conv_8to1(): Convert an 8-bit icon to 1-bit */
+uint8_t *icon_conv_8to1(uint8_t const *input, size_t width, size_t height)
+{
+	if(!input) return NULL;
+	uint8_t *mono = calloc(68, 1);
+	if(!mono) return NULL;
+	size_t stride = width;
+
+	/* If the image is wider than 30 pixels, ignore columns at the right */
+	if(width > 30) width = 30;
+
+	/* Skip the first line if there is enough rows, because in standard
+	   30*19 icons, the first and last lines are skipped */
+	if(height > 17) input += stride, height--;
+
+	/* If height is still larger than 17, ignore rows at the bottom */
+	if(height > 17) height = 17;
+
+	/* Then copy individual pixels on the currently-blank image */
+	for(size_t y = 0; y < height; y++)
+	for(size_t x = 0; x < width; x++)
+	{
+		int offset = (y << 2) + (x >> 3);
+		int color = input[y * stride + x] < 128;
+		uint8_t mask = color << (~x & 7);
+		mono[offset] |= mask;
+	}
+
+	return mono;
+}
+
+/* icon_conv_1to8(): Convert an 1-bit icon to 8-bit */
+uint8_t *icon_conv_1to8(uint8_t const *mono)
+{
+	uint8_t *data = calloc(30 * 17, 1);
+	if(!data) return NULL;
+
+	for(int y = 0; y < 17; y++)
+	for(int x = 0; x < 30; x++)
+	{
+		int offset = (y << 2) + (x >> 3);
+		int bit = mono[offset] & (0x80 >> (x & 7));
+		data[y * 30 + x] = (bit ? 0x00 : 0xff);
+	}
+
+	return data;
+}
diff --git a/fxg1a/main.c b/fxg1a/main.c
new file mode 100644
index 0000000..c45ed29
--- /dev/null
+++ b/fxg1a/main.c
@@ -0,0 +1,266 @@
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+#include <getopt.h>
+
+#include <fxg1a.h>
+#include <g1a.h>
+
+static const char *help_string =
+"usage: %1$s [-g] <binary file> [options...]\n"
+"       %1$s  -e  <g1a file> [options...]\n"
+"       %1$s  -d  <g1a file>\n"
+"       %1$s  -r  <g1a file> [-o <g1a file>]\n"
+"       %1$s  -x  <g1a file> [-o <png file>]\n"
+"\n"
+"fxg1a creates or edits g1a files (add-in applications for Casio fx9860g\n"
+"calculator series) that consist of a g1a header followed by binary code.\n"
+"\n"
+"Operating modes:\n"
+"  -g, --g1a             Generate a g1a file (default)\n"
+"  -e, --edit            Edit header of an existing g1a file\n"
+"  -d, --dump            Dump header of an existing g1a file\n"
+"  -r, --repair          Recalculate control bytes and checksums\n"
+"  -x, --extract         Extract icon into a PNG file\n"
+"\n"
+"General options:\n"
+"  -o, --output=<file>   Output file (default: input file with .g1a suffix\n"
+"                        [-g]; with .png suffix [-x]; input file [-e, -r])\n"
+"\n"
+"Generation and edition options:\n"
+"  -i, --icon=<png>      Program icon, in PNG format (default: blank icon)\n"
+"  -n, --name=<name>     Add-in name, 8 bytes (default: output file name)\n"
+"  --version=<text>      Program version, MM.mm.pppp format (default: empty)\n"
+"  --internal=<name>     Internal name, eg. '@NAME' (default: empty)\n"
+"  --date=<date>         Date of build, yyyy.MMdd.hhmm (default: now)\n";
+
+/*
+**  Field customization
+*/
+
+/* A set of user-defined fields, often taken on the command-line
+   Default values are NULL and indicate "no value" (-g) or "no change" (-e). */
+struct fields
+{
+	/* New values for basic fields */
+	const char *name;
+	const char *version;
+	const char *internal;
+	const char *date;
+	/* Icon file name */
+	const char *icon;
+};
+
+/* fields_edit(): Set the value of some fields altogether
+   @header  Header to edit, is assumed checksumed and filled
+   @fields  New values for fields, any members can be NULL */
+void fields_edit(struct g1a *header, struct fields const *fields)
+{
+	/* For easy fields, just call the appropriate edition function */
+	if(fields->name)     edit_name(header, fields->name);
+	if(fields->version)  edit_version(header, fields->version);
+	if(fields->internal) edit_internal(header, fields->internal);
+	if(fields->date)     edit_date(header, fields->date);
+
+	/* Load icon from PNG file */
+	if(fields->icon)
+	{
+		size_t width, height;
+		uint8_t *data = icon_load(fields->icon, &width, &height);
+		if(!data) return;
+
+		uint8_t *mono = icon_conv_8to1(data, width, height);
+		free(data);
+
+		if(!mono) return;
+		edit_icon(header, mono);
+	}
+}
+
+/*
+**  Tool implementation
+*/
+
+int main(int argc, char **argv)
+{
+	/* Result of option parsing */
+	int mode = 'g', error = 0;
+	struct fields fields = { 0 };
+	const char *output = NULL;
+
+	const struct option longs[] = {
+		{ "help",     no_argument,       NULL, 'h' },
+		{ "g1a",      no_argument,       NULL, 'g' },
+		{ "edit",     no_argument,       NULL, 'e' },
+		{ "dump",     no_argument,       NULL, 'd' },
+		{ "repair",   no_argument,       NULL, 'r' },
+		{ "extract",  no_argument,       NULL, 'x' },
+		{ "output",   required_argument, NULL, 'o' },
+		{ "icon",     required_argument, NULL, 'i' },
+		{ "name",     required_argument, NULL, 'n' },
+		{ "version",  required_argument, NULL, 'v' },
+		{ "internal", required_argument, NULL, 't' },
+		{ "date",     required_argument, NULL, 'a' },
+		{ NULL,       0,                 NULL, 0   },
+	};
+
+	int option = 0;
+	while(option >= 0 && option != '?')
+	switch((option = getopt_long(argc, argv, "hgedrxo:i:n:", longs, NULL)))
+	{
+	case 'h':
+		fprintf(stderr, help_string, argv[0]);
+		return 0;
+	case 'g':
+	case 'e':
+	case 'd':
+	case 'r':
+	case 'x':
+		mode = option;
+		break;
+	case 'o':
+		output = optarg;
+		break;
+	case 'i':
+		fields.icon = optarg;
+		break;
+	case 'n':
+		fields.name = optarg;
+		break;
+	case 'v':
+		fields.version = optarg;
+		break;
+	case 't':
+		fields.internal = optarg;
+		break;
+	case 'a':
+		fields.date = optarg;
+		break;
+	case '?':
+		error = 1;
+		break;
+	}
+
+	if(error) return 1;
+
+	if(argv[optind] == NULL)
+	{
+		fprintf(stderr, help_string, argv[0]);
+		return 1;
+	}
+	if(mode == 'g')
+	{
+		/* Load binary file into memory */
+		size_t size;
+		struct g1a *g1a = load_binary(argv[optind], &size);
+		if(!g1a) return 1;
+
+		/* If [output] is set, use it, otherwise compute a default */
+		char *alloc = NULL;
+		if(!output)
+		{
+			alloc = malloc(strlen(argv[optind]) + 5);
+			if(!alloc) {fprintf(stderr, "error: %m\n"); return 1;}
+			default_output(argv[optind], ".g1a", alloc);
+		}
+
+		/* Start with output file name as application name */
+		edit_name(g1a, output ? output : alloc);
+
+		/* Start with "now" as build date */
+		char date[15];
+		time_t t = time(NULL);
+		struct tm *now = localtime(&t);
+		strftime(date, 15, "%Y.%m%d.%H%M", now);
+		edit_date(g1a, date);
+
+		/* Edit the fields with user-customized values */
+		fields_edit(g1a, &fields);
+
+		/* Set fixed fields and calculate checksums */
+		sign(g1a, size);
+
+		save_g1a(output ? output : alloc, g1a, size);
+		free(alloc);
+
+		/* Write output file */
+		free(g1a);
+	}
+	if(mode == 'e')
+	{
+		/* Load g1a file into memory */
+		size_t size;
+		struct g1a *g1a = load_g1a(argv[optind], &size);
+		if(!g1a) return 1;
+
+		/* Edit the fields with user-customized values */
+		fields_edit(g1a, &fields);
+
+		/* We don't reset fixed fields or recalculate checksums because
+		   we only want to edit what was requested by the user.
+		   Besides, the control bytes and checksums do *not* depend on
+		   the value of user-customizable fields. */
+
+		/* Regenerate input file, or output somewhere else */
+		if(!output) output = argv[optind];
+		save_g1a(output, g1a, size);
+		free(g1a);
+	}
+	if(mode == 'd')
+	{
+		/* Load and dump the g1a */
+		size_t size;
+		struct g1a *g1a = load_g1a(argv[optind], &size);
+		if(!g1a) return 1;
+
+		dump(g1a, size);
+		free(g1a);
+	}
+	if(mode == 'r')
+	{
+		/* Load g1a file into memory */
+		size_t size;
+		struct g1a *g1a = load_g1a(argv[optind], &size);
+		if(!g1a) return 1;
+
+		/* Repair file by recalculating fixed fields and checksums */
+		sign(g1a, size);
+
+		/* Regenerate input file, or output somewhere else */
+		if(!output) output = argv[optind];
+		save_g1a(output, g1a, size);
+		free(g1a);
+	}
+	if(mode == 'x')
+	{
+		/* Load g1a file into memory */
+		size_t size;
+		struct g1a *g1a = load_g1a(argv[optind], &size);
+		if(!g1a) return 1;
+
+		/* Generate 8-bit icon from g1a 1-bit */
+		uint8_t *data = icon_conv_1to8(g1a->header.icon);
+		if(!data)
+		{
+			fprintf(stderr, "error: %m\n");
+			return 1;
+		}
+
+		/* Calculate a default output name if none is provided */
+		if(output)
+		{
+			icon_save(output, data, 30, 17);
+		}
+		else
+		{
+			char *alloc = malloc(strlen(argv[optind]) + 5);
+			if(!alloc) {fprintf(stderr, "error: %m\n"); return 1;}
+			default_output(argv[optind], ".png", alloc);
+
+			icon_save(alloc, data, 30, 17);
+			free(alloc);
+		}
+	}
+
+	return 0;
+}
diff --git a/fxg1a/util.c b/fxg1a/util.c
new file mode 100644
index 0000000..7dc3b72
--- /dev/null
+++ b/fxg1a/util.c
@@ -0,0 +1,47 @@
+#include <string.h>
+#include <fxg1a.h>
+
+/*
+**  Public API
+*/
+
+/* checksum(): Sum of 8 big-endian shorts at 0x300 */
+uint16_t checksum(struct g1a const *g1a, size_t size)
+{
+	uint16_t shorts[16] = { 0 };
+
+	/* Extract 16 bytes from the file (maybe less are available) */
+	int available = size - 0x300;
+	if(available < 0) available = 0;
+	if(available > 16) available = 16;
+	memcpy(shorts, g1a->code + 0x100, available);
+
+	/* Do the big-endian sum */
+	uint16_t sum = 0;
+	for(int i = 0; i < 8; i++) sum += htobe16(shorts[i]);
+
+	return sum;
+}
+
+/* default_output(): Calculate default output file name */
+void default_output(const char *name, const char *suffix, char *output)
+{
+	/* Check if there is a dot at the end of @name, before the last '/'.
+	   The dot must also not be in first position (hidden files) */
+	size_t end = strlen(name) - 1;
+	while(end >= 1 && name[end] != '/' && name[end] != '.') end--;
+
+	/* If we don't have a dot in the file name, append the extension */
+	if(end < 1 || name[end] != '.')
+	{
+		strcpy(output, name);
+		strcat(output, suffix);
+	}
+
+	/* If we found a dot before the last slash, replace the extension */
+	else
+	{
+		memcpy(output, name, end);
+		strcpy(output + end, suffix);
+	}
+}
diff --git a/fxos/fxos.h b/fxos/fxos.h
new file mode 100644
index 0000000..5c5f2a6
--- /dev/null
+++ b/fxos/fxos.h
@@ -0,0 +1,154 @@
+//---
+//	fxos:fxos - Main interfaces
+//---
+
+#ifndef FX_FXOS
+#define FX_FXOS
+
+#include <stdint.h>
+#include <stddef.h>
+
+/* Microprocessor platforms */
+enum mpu
+{
+	mpu_unknown = 0,
+	mpu_sh7705  = 1,
+	mpu_sh7305  = 2,
+};
+
+
+/*
+**  Data tables (tables.c)
+*/
+
+/* tables_add_asm(): Append an instruction table to the table list
+   This function adds a new instruction table to fetch instructions from; it
+   will be consulted if searching any of the previously-declared tables fails.
+
+   @filename  Name of instruction table file
+   Returns non-zero on error (and prints a message on stderr) */
+int tables_add_asm(const char *filename);
+
+/* tables_add_syscall(): Append a syscall table to the table list
+   This function adds a new syscall table to fetch syscalls information from;
+   if will be consulted if searching any of the previously-declared tables
+   fails.
+
+   @filename  Name of instruction table file
+   Returns non-zero on error (and prints a message on stderr) */
+int tables_add_syscall(const char *filename);
+
+
+/*
+**  RAM dumps (ram.c)
+*/
+
+/* Region for a single RAM dump */
+struct region
+{
+	uint32_t start;
+	uint32_t length;
+	void *data;
+};
+
+/* RAM dump */
+struct ram_sh7705
+{
+	struct region RAM;	/* Usual RAM (256k) */
+};
+struct ram_sh7305
+{
+	struct region RAM;	/* Usual RAM (512k) */
+	struct region IL;	/* On-chip instruction storage (16k) */
+	struct region RS;	/* On-chip generic storage (2k) */
+};
+
+
+/*
+**  File identification (info.c)
+*/
+
+/* Info options */
+struct info
+{
+	/* OS file (0) or binary file (1) */
+	int binary;
+	/* Force underlying architecture */
+	enum mpu mpu;
+
+	/* RAM dumps, if any */
+	union {
+		struct ram_sh7705 ram3;
+		struct ram_sh7305 ram4;
+	};
+};
+
+
+/*
+**  Disassembling (disassembly.c)
+*/
+
+/* Disassembly options */
+struct disassembly
+{
+	/* OS file (0) or binary file (1) */
+	int binary;
+	/* Force underlying architecture */
+	enum mpu mpu;
+
+	/* RAM dumps, if any */
+	union {
+		struct ram_sh7705 ram3;
+		struct ram_sh7305 ram4;
+	};
+
+	/* Start address */
+	uint32_t start;
+	/* Length of disassembled region */
+	uint32_t length;
+};
+
+
+/*
+**  Blind analysis (analysis.c)
+*/
+
+/* Analysis options */
+struct analysis
+{
+	/* Force underlying architecture */
+	enum mpu mpu;
+
+	/* RAM dumps, if any */
+	union {
+		struct ram_sh7705 ram3;
+		struct ram_sh7305 ram4;
+	};
+
+	/* Analysis mode */
+	enum {
+		ANALYSIS_FULL = 0,
+		ANALYSIS_SYSCALL = 1,
+		ANALYSIS_ADDRESS = 2,
+		ANALYSIS_REGISTER = 3,
+	} type;
+
+	/* Max number of printed occurrences */
+	int occurrences;
+};
+
+
+/*
+**  Utility functions (util.c)
+*/
+
+/* integer(): Convert base 8, 10 or 16 into integers
+   Prints an error message and sets *error to 1 in case of conversion error or
+   overflow.
+
+   @str    Original integer representation ("10", "0x1f", "07")
+   @error  Set to 1 on error, otherwise unchanged (can be NULL)
+   Returns result of conversion (valid if *error is not 1) */
+long long integer(const char *str, int *error);
+
+#endif /* FX_FXOS */
diff --git a/fxos/main.c b/fxos/main.c
new file mode 100644
index 0000000..cc364fd
--- /dev/null
+++ b/fxos/main.c
@@ -0,0 +1,183 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <getopt.h>
+
+#include <fxos.h>
+
+static const char *help_string =
+"usage: %1$s info    (<os file> | -b <binary file>)\n"
+"       %1$s disasm  <os file> (-a <address> | -s <syscall id>) [options...]\n"
+"       %1$s disasm  -b <binary file> [options...]\n"
+"       %1$s analyze [-f|-s|-a|-r] <number> <os file> [options...]\n"
+"\n"
+"fxos disassembles or analyzes binary and OS files for efficient reverse-\n"
+"engineering. It currently only supports fx9860g binaries.\n"
+"\n"
+"Commands:\n"
+"  info     Identify an OS image: version, platform, date, checksums...\n"
+"           Identify the architecture of a binary file.\n"
+"  disasm   Disassemble and annotate code with relative address targets,\n"
+"           syscall invocations and hints about memory structure.\n"
+"  analyze  Dig an address or syscall number, finding syscall call graph,\n"
+"           4-aligned occurrences, memory region and probable role.\n"
+"\n"
+"General options:\n"
+"  -b                   Disassemble any binary file, not an OS file\n"
+"  -3, --sh3            Assume SH3 OS and platform (default: guess)\n"
+"  -4, --sh4            Assume SH4 OS and platform (default: guess)\n"
+"  --ram <folder>       Read RAM dumps from <folder>\n"
+"  --table-asm <file>   Read more instruction patterns in <file>\n"
+"  --table-call <file>  Read more syscall prototypes in <file>\n"
+"\n"
+"Disassembly region options:\n"
+"  -a <address>         Start disassembling at this address\n"
+"  -s <syscall id>      Start disassembling at this syscall's address\n"
+"  -l <length>          Length of region\n"
+"\n"
+"Analysis modes:\n"
+"  -f, --full           Find everything that can be known about <number>\n"
+"  -s, --syscall        <number> is a syscall ID\n"
+"  -a, --address        <number> is a code/data address in ROM or RAM\n"
+"  -r, --register       <number> is a register or peripheral address\n"
+"\n"
+"Analysis options:\n"
+"  --occurrences <num>  Show at most <num> occurrences (integer or \"all\")\n";
+
+/* "Low-level" command-line option set */
+struct options
+{
+	const char *input;
+
+	int target;
+	const char *ram;
+
+	const char *a;
+	const char *s;
+	size_t l;
+
+	int f;
+	int r;
+	const char *occ;
+};
+
+int main(int argc, char **argv)
+{
+	int command = 0, error = 0;
+	struct options opt = { 0 };
+	/* For string -> int conversions, first non-int character */
+
+
+	/* Get command name */
+	if(argc >= 2)
+	{
+		if(!strcmp(argv[1], "info")) command = 'i';
+		if(!strcmp(argv[1], "disasm")) command = 'd';
+		if(!strcmp(argv[1], "analyze")) command = 'a';
+
+		if(!command && argv[1][0] != '-')
+		{
+			fprintf(stderr, "invalid operation: '%s'\n", argv[1]);
+			fprintf(stderr, "Try '%s --help'.\n", argv[0]);
+			return 1;
+		}
+
+		if(command) argv[1] = "";
+	}
+
+	enum {
+		OPT_RAM  = 1,
+		OPT_ASM  = 2,
+		OPT_CALL = 3,
+		OPT_OCC  = 4,
+	};
+	const struct option longs[] = {
+		{ "help",        no_argument,       NULL, 'h'      },
+		{ "sh3",         no_argument,       NULL, '3'      },
+		{ "sh4",         no_argument,       NULL, '4'      },
+		{ "ram",         required_argument, NULL, OPT_RAM  },
+		{ "table-asm",   required_argument, NULL, OPT_ASM  },
+		{ "table-call",  required_argument, NULL, OPT_CALL },
+		{ "full",        no_argument,       NULL, 'f'      },
+		{ "syscall",     no_argument,       NULL, 's'      },
+		{ "address",     no_argument,       NULL, 'a'      },
+		{ "register",    no_argument,       NULL, 'r'      },
+		{ "occurrences", required_argument, NULL, OPT_OCC  },
+	};
+
+	int option = 0;
+	while(option >= 0 && option != '?')
+	switch((option = getopt_long(argc, argv, "hb34a::s::l:fr",longs,NULL)))
+	{
+	case 'h':
+		fprintf(stderr, help_string, argv[0]);
+		return 0;
+	case '3':
+	case '4':
+		opt.target = option;
+		break;
+	case OPT_RAM:
+		opt.ram = optarg;
+		break;
+	case OPT_ASM:
+		tables_add_asm(optarg);
+		break;
+	case OPT_CALL:
+		tables_add_syscall(optarg);
+		break;
+	case 'f':
+		opt.f = 1;
+		break;
+	case 's':
+		opt.s = optarg;
+		break;
+	case 'a':
+		opt.a = optarg;
+		break;
+	case 'l':
+		opt.l = integer(optarg, &error);
+		break;
+	case 'r':
+		opt.r = 1;
+		break;
+	case OPT_OCC:
+		opt.occ = optarg;
+		break;
+	case '?':
+		error = 1;
+		break;
+	}
+
+	if(error) return 1;
+	opt.input = argv[optind];
+
+	if(!opt.input)
+	{
+		fprintf(stderr, help_string, argv[0]);
+		return 1;
+	}
+
+	/* Load default tables (user-specified tables will override them) */
+	tables_add_asm    (FXSDK_PREFIX "/share/assembly-sh3.txt");
+	tables_add_syscall(FXSDK_PREFIX "/share/syscalls.txt");
+
+	/* Change interpretation of arguments depending on mode */
+
+	printf("Operation is '%c'\n", command);
+	printf("  input=%s\n", opt.input);
+	printf("  target='%c'\n", opt.target);
+	printf("  ram=%s\n", opt.ram);
+	printf("  a=%s\n", opt.a);
+	printf("  s=%s\n", opt.s);
+	printf("  l=%zu\n", opt.l);
+	printf("  f=%d\n", opt.f);
+	printf("  r=%d\n", opt.r);
+	printf("  occ=%s\n", opt.occ);
+
+	/* TODO: Execution procedure:
+	   TODO: 1. Identify architecture
+	   TODO: 2. Load RAM data, syscall tables, peripheral modules, etc
+	   TODO: 3. Execute command */
+
+	return 0;
+}
diff --git a/fxos/tables.c b/fxos/tables.c
new file mode 100644
index 0000000..032b05c
--- /dev/null
+++ b/fxos/tables.c
@@ -0,0 +1,59 @@
+#include <stdlib.h>
+#include <fxos.h>
+
+/* A linked list of pointers (either file names or tables) */
+struct element
+{
+	void *data;
+	struct element *next;
+};
+
+/* list_append(): Append a pointer to a linked list
+   Returns a pointer to the new node, NULL on error. */
+struct element *list_append(struct element **head, void *data)
+{
+	struct element *el = malloc(sizeof *el);
+	if(!el) return NULL;
+	el->data = data;
+	el->next = NULL;
+
+	while(*head) head = &((*head)->next);
+	*head = el;
+
+	return el;
+}
+
+/* list_free(): Free a linked list */
+void list_free(struct element *head, void (*destructor)(void *))
+{
+	struct element *next;
+	while(head)
+	{
+		destructor(head->data);
+		next = head->next;
+		free(head);
+		head = next;
+	}
+}
+
+/* Table of assembly instruction listings */
+static struct element *tasm = NULL;
+/* Table of system call information listings */
+static struct element *tcall = NULL;
+
+
+/*
+**  Public API
+*/
+
+/* tables_add_asm(): Append an instruction table to the table list */
+int tables_add_asm(const char *filename)
+{
+	return !list_append(&tasm, (void *)filename);
+}
+
+/* tables_add_syscall(): Append a syscall table to the table list */
+int tables_add_syscall(const char *filename)
+{
+	return !list_append(&tcall, (void *)filename);
+}
diff --git a/fxos/util.c b/fxos/util.c
new file mode 100644
index 0000000..2c380c9
--- /dev/null
+++ b/fxos/util.c
@@ -0,0 +1,30 @@
+#include <fxos.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+
+/* integer(): Convert base 8, 10 or 16 into integers */
+long long integer(const char *str, int *error)
+{
+	char *end;
+	errno = 0;
+
+	long long ll = strtoll(str, &end, 0);
+	if(errno == ERANGE)
+	{
+		fprintf(stderr, "error: integer is too large: '%s'\n", str);
+		if(error) *error = 1;
+
+		/* In my situation this is often better than LLONG_MIN/MAX */
+		return 0;
+	}
+
+	if(*end)
+	{
+		fprintf(stderr, "invalid integer: '%s'\n", str);
+		if(error) *error = 1;
+		return 0;
+	}
+
+	return ll;
+}
diff --git a/fxsdk/main.c b/fxsdk/main.c
new file mode 100644
index 0000000..31dbf45
--- /dev/null
+++ b/fxsdk/main.c
@@ -0,0 +1,4 @@
+int main(void)
+{
+	return 0;
+}