static int callback_tick(volatile int *tick){*tick = 1;return TIMER_CONTINUE;}

pierre@dragon:~$ cat $(sh-elf-gcc -print-file-name=include/gint/timer.h) | grep -B17 "timer_callback_t;"
typedef union
{
    /* No argument, returns either TIMER_CONTINUE or TIMER_STOP */
    int (*v)(void);
    /* Single integer argument */
    int (*i)(int);
    /* Single pointer argument, cv-qualified as needed */
    int (*pv)  (void *);
    int (*pVv) (volatile void *);
    int (*pCv) (const void *);
    int (*pCVv)(volatile const void *);
    /* Integer pointer argument, cv-qualified as needed */
    int (*pi)  (int *);
    int (*pVi) (volatile int *);
    int (*pCi) (const int *);
    int (*pCVi)(volatile const int *);

} GTRANSPARENT timer_callback_t;

int (*)(volatile int*)

git checkout master
git pull
make -B
make install

#---
# fxSDK project configuration file for folia
#---

# Project name, should be at most 8 bytes long.
# (You can also specify NAME_G1A or NAME_G3A to override individually.)
NAME := folia

# Internal name, should be '@' followed by at most 7 uppercase letters.
# WARNING: If this convention is not followed, the add-in might not appear in
#          the main menu of the calculator!
INTERNAL := @foliaeg

# Output file name. The default is to take <NAME>, replace spaces with dashes,
# and add .g1a (or .g3a). You can specify a different folder if you want.
TARGET_FX :=
TARGET_CG :=

# fx-9860G icon location
ICON_FX = assets-fx/icon-fx.png
# fx-CG 50 icon locations
ICON_CG_UNS = assets-cg/icon-cg-uns.png
ICON_CG_SEL = assets-cg/icon-cg-sel.png

#---
# Toolchain selection
#---

# Toolchain for fx9860g. Please see also CFLAGS_FX below.
TOOLCHAIN_FX := sh-elf

# Toolchain for fxcg50. Please see also CFLAGS_CG below.
TOOLCHAIN_CG := sh-elf

#---
# Compiler flags
#---

# Base compiler flags for the fxSDK, you usually want to keep these.
CFLAGS := -mb -ffreestanding -nostdlib -fstrict-volatile-bitfields

# Platform-specific compiler flags.
# <> If you are using sh3eb-elf, use -m3. (You can do this on both FX and CG.)
# <> If you are using sh4eb-elf, use -m4-nofpu. (Not ideal on FX but works.)
# <> If you are using sh4eb-nofpu-elf, then your compiler will likely use the
#    FPU and cause problems on the calculator. Consider another configuration.
# <> If you are using an sh-elf with several targets, specify whichever you
#    support. I recommend -m3 on FX and -m4-nofpu on CG.
# Please see also TOOLCHAIN_FX and TOOLCHAIN_CG above.
CFLAGS_FX := -D FX9860G -m3
CFLAGS_CG := -D FXCG50  -m4-nofpu

# Additional compiler flags, change to your own taste!
CFLAGS += -Wall -Wextra -Wno-missing-field-initializers -Os

# Include paths. Add one -I option for each folder from which you want to
# be able to include files with #include<>. The Makefile provides a variable
# GCC_INCLUDE_FX/GCC_INCLUDE_CG that represents the default include folder,
# which is useful for some libraries such as OpenLibm.
INCLUDE_FX = -I include
INCLUDE_CG = -I include

# Libraries. Add one -l option for each library you are using, and also
# suitable -L options if you have library files in custom folders. To use
# fxlib, add libfx.a to the project directory and use "-L . -lfx".
LIBS_FX :=
LIBS_CG :=

# Base linker flags for the fxSDK, you usually want to keep these.
LDFLAGS_FX := -T fx9860g.ld -lgint-fx $(LIBS_FX) -lgint-fx -lgcc
LDFLAGS_CG := -T fxcg50.ld  -lgint-cg $(LIBS_CG) -lgint-cg -lgcc

# Additional linker flags, if you need any.
LDFLAGS :=

# Additional platform-specific linker flags.
LDFLAGS_FX += -Wl,-Map=build-fx/map
LDFLAGS_CG += -Wl,-Map=build-cg/map

#---
# File conversion parameters
#---

# Here you can add fxconv options for each converted file, individually.
# The syntax is "<type>.<file>". For example, to specify the parameters for a
# font named "hexa.png", you might write:

#! /usr/bin/make -f
#  Default Makefile for fxSDK add-ins. This file was probably copied there by
#  the [fxsdk] program.
#---

#
#  Configuration
#

include project.cfg

# Compiler flags
CFLAGSFX = $(CFLAGS) $(CFLAGS_FX) $(INCLUDE_FX)
CFLAGSCG = $(CFLAGS) $(CFLAGS_CG) $(INCLUDE_CG)

# Linker flags
LDFLAGSFX := $(LDFLAGS) $(LDFLAGS_FX)
LDFLAGSCG := $(LDFLAGS) $(LDFLAGS_CG)

# Dependency list generation flags
depflags = -MMD -MT $@ -MF $(@:.o=.d) -MP
# ELF to binary flags
BINFLAGS := -R .bss -R .gint_bss

# G1A and G3A generation flags
NAME_G1A ?= $(NAME)
NAME_G3A ?= $(NAME)
G1AF := -i "$(ICON_FX)" -n "$(NAME_G1A)" --internal="$(INTERNAL)"
G3AF := -n basic:"$(NAME_G3A)" -i uns:"$(ICON_CG_UNS)" -i sel:"$(ICON_CG_SEL)"

ifeq "$(TOOLCHAIN_FX)" ""
TOOLCHAIN_FX := sh3eb-elf
endif

ifeq "$(TOOLCHAIN_CG)" ""
TOOLCHAIN_CG := sh4eb-elf
endif

# fxconv flags
FXCONVFX := --fx --toolchain=$(TOOLCHAIN_FX)
FXCONVCG := --cg --toolchain=$(TOOLCHAIN_CG)

# Determine the compiler install and include path
g++_BASE_FX := $(shell $(TOOLCHAIN_FX)-g++ --print-search-dirs | grep install | sed 's/install: //')
g++_BASE_CG := $(shell $(TOOLCHAIN_CG)-g++ --print-search-dirs | grep install | sed 's/install: //')
g++_INCLUDE_FX := $(g++_BASE_FX)/include
g++_INCLUDE_CG := $(g++_BASE_CG)/include

#
#  File listings
#

NULL   :=
TARGET := $(subst $(NULL) $(NULL),-,$(NAME))

ifeq "$(TARGET_FX)" ""
TARGET_FX := $(TARGET).g1a
endif

ifeq "$(TARGET_CG)" ""
TARGET_CG := $(TARGET).g3a
endif

ELF_FX := build-fx/$(shell basename "$(TARGET_FX)" .g1a).elf
BIN_FX := $(ELF_FX:.elf=.bin)

ELF_CG := build-cg/$(shell basename "$(TARGET_CG)" .g3a).elf
BIN_CG := $(ELF_CG:.elf=.bin)

# Source files
src       := $(wildcard src/*.[csS] \
                        src/*/*.[csS] \
                        src/*/*/*.[csS] \
                        src/*/*/*/*.[csS])
assets-fx := $(wildcard assets-fx/*/*)
assets-cg := $(wildcard assets-cg/*/*)

# Object files
obj-fx  := $(src:%=build-fx/%.o) \
           $(assets-fx:assets-fx/%=build-fx/assets/%.o)
obj-cg  := $(src:%=build-cg/%.o) \
           $(assets-cg:assets-cg/%=build-cg/assets/%.o)

# Additional dependencies
deps-fx := $(ICON_FX)
deps-cg := $(ICON_CG_UNS) $(ICON_CG_SEL)

# All targets
all :=
ifneq "$(wildcard build-fx)" ""
all += all-fx
endif
ifneq "$(wildcard build-cg)" ""
all += all-cg
endif

#
#  Build rules
#

all: $(all)

all-fx: $(TARGET_FX)
all-cg: $(TARGET_CG)

$(TARGET_FX): $(obj-fx) $(deps-fx)
    @ mkdir -p $(dir $@)
    $(TOOLCHAIN_FX)-g++ -o $(ELF_FX) $(obj-fx) $(CFLAGSFX) $(LDFLAGSFX)
    $(TOOLCHAIN_FX)-objcopy -O binary $(BINFLAGS) $(ELF_FX) $(BIN_FX)
    fxg1a $(BIN_FX) -o $@ $(G1AF)

$(TARGET_CG): $(obj-cg) $(deps-cg)
    @ mkdir -p $(dir $@)
    $(TOOLCHAIN_CG)-g++ -o $(ELF_CG) $(obj-cg) $(CFLAGSCG) $(LDFLAGSCG)
    $(TOOLCHAIN_CG)-objcopy -O binary $(BINFLAGS) $(ELF_CG) $(BIN_CG)
    mkg3a $(G3AF) $(BIN_CG) $@

# C sources
build-fx/%.c.o: %.c
    @ mkdir -p $(dir $@)
    $(TOOLCHAIN_FX)-g++ -c $< -o $@ $(CFLAGSFX) $(depflags)
build-cg/%.c.o: %.c
    @ mkdir -p $(dir $@)
    $(TOOLCHAIN_CG)-g++ -c $< -o $@ $(CFLAGSCG) $(depflags)

# Assembler sources
build-fx/%.s.o: %.s
    @ mkdir -p $(dir $@)
    $(TOOLCHAIN_FX)-g++ -c $< -o $@
build-cg/%.s.o: %.s
    @ mkdir -p $(dir $@)
    $(TOOLCHAIN_CG)-g++ -c $< -o $@

# Preprocessed assembler sources
build-fx/%.S.o: %.S
    @ mkdir -p $(dir $@)
    $(TOOLCHAIN_FX)-g++ -c $< -o $@ $(INCLUDE_FX)
build-cg/%.S.o: %.S
    @ mkdir -p $(dir $@)
    $(TOOLCHAIN_CG)-g++ -c $< -o $@ $(INCLUDE_CG)

# Images
build-fx/assets/img/%.o: assets-fx/img/%
    @ mkdir -p $(dir $@)
    fxconv --bopti-image $< -o $@ $(FXCONVFX) name:img_$(basename $*) $(IMG.$*)
build-cg/assets/img/%.o: assets-cg/img/%
    @ mkdir -p $(dir $@)
    fxconv --bopti-image $< -o $@ $(FXCONVCG) name:img_$(basename $*) $(IMG.$*)

# Fonts
build-fx/assets/fonts/%.o: assets-fx/fonts/%
    @ mkdir -p $(dir $@)
    fxconv -f $< -o $@ $(FXCONVFX) name:font_$(basename $*) $(FONT.$*)
build-cg/assets/fonts/%.o: assets-cg/fonts/%
    @ mkdir -p $(dir $@)
    fxconv -f $< -o $@ $(FXCONVCG) name:font_$(basename $*) $(FONT.$*)

# Binaries
build-fx/assets/bin/%.o: assets-fx/bin/%
    @ mkdir -p $(dir $@)
    fxconv -b $< -o $@ $(FXCONVFX) name:bin_$(basename $*) $(BIN.$*)
build-cg/assets/bin/%.o: assets-cg/bin/%
    @ mkdir -p $(dir $@)
    fxconv -b $< -o $@ $(FXCONVCG) name:bin_$(basename $*) $(BIN.$*)

# Custom conversions
build-fx/assets/%.o: assets-fx/%
    @ mkdir -p $(dir $@)
    fxconv --custom $< -o $@ $(FXCONVFX) type:$(subst /,,$(dir $*)) name:$(subst /,_,$(basename $*))
build-cg/assets/%.o: assets-cg/%
    @ mkdir -p $(dir $@)
    fxconv --custom $< -o $@ $(FXCONVCG) type:$(subst /,,$(dir $*)) name:$(subst /,_,$(basename $*))

#
#  Cleaning and utilities
#

# Dependency information
-include $(shell find build* -name *.d 2> /dev/null)
build-fx/%.d: ;
build-cg/%.d: ;
.PRECIOUS: build-fx build-cg build-fx/%.d build-cg/%.d %/

clean-fx:
    @ rm -rf build-fx/
clean-cg:
    @ rm -rf build-cg/

distclean-fx: clean-fx
    @ rm -f $(TARGET_FX)
distclean-cg: clean-cg
    @ rm -f $(TARGET_CG)

clean: clean-fx clean-cg

distclean: distclean-fx distclean-cg

install-fx: $(TARGET_FX)
    p7 send -f $<
install-cg: $(TARGET_CG)
    @ while [[ ! -h /dev/Prizm1 ]]; do sleep 0.25; done
    @ while ! mount /dev/Prizm1; do sleep 0.25; done
    @ rm -f /mnt/prizm/$<
    @ cp $< /mnt/prizm
    @ umount /dev/Prizm1
    @- eject /dev/Prizm1

.PHONY: all all-fx all-cg clean distclean install-fx install-cg

% fxsdk
usage: fxsdk (new|build|build-fx|build-cg|send|send-fx|send-cg) [ARGUMENTS...]

This program is a command-line helper for the fxSDK, a set of tools used in
conjunction with gint to develop add-ins for CASIO fx-9860G and fx-CG 50.

fxsdk new <FOLDER> [--makefile|--cmake] [<NAME>]
  Create a new project in the specified folder. The default build system is
  CMake. Project name can be specified now or in the project files later.

fxsdk (build|build-fx|build-cg) [-c] [-s] [--] [<ARGS>...]
  Build the current project for fx-9860G (usually for .g1a add-ins) or fx-CG 50
  (usually for .g3a add-ins). The first form compiles in every existing build
  folder, and configures for both if none exists.

  With -c, reconfigure but don't build (CMake only).
  With -s, also sends the resulting program to the calculator.
  Other arguments are passed to CMake (if using -c) or make (otherwise). You
  can pass -c or -s to CMake/make by specifying --.

fxsdk (send|send-fx|send-cg)
  Sends the target file to the calculator. Uses p7 (which must be installed
  externally) for fx-9860G. Currently not implemented for fx-CG 50, as it
  requires detecting and mounting the calculator (same for the Graph 35+E II).