Makefile

# OpenIMP Makefile
# Build system for libimp and libsysutils stub implementation

# Cross-compilation support
CROSS_COMPILE ?=

# Toolchain
CC = $(CROSS_COMPILE)gcc
AR = $(CROSS_COMPILE)ar
RANLIB = $(CROSS_COMPILE)ranlib
STRIP = $(CROSS_COMPILE)strip

# Directories
SRC_DIR = src
INC_DIR = include
BUILD_DIR = build
LIB_DIR = lib

# Installation
PREFIX ?= /usr/local
INSTALL_INC_DIR = $(PREFIX)/include
INSTALL_LIB_DIR = $(PREFIX)/lib

# Compiler flags
CFLAGS = -Wall -Wextra -O2 -fPIC -fno-stack-protector -I$(INC_DIR)
LDFLAGS = -shared -lpthread -lrt

# Platform detection (can be overridden)
PLATFORM ?= T31

# Add platform define
CFLAGS += -DPLATFORM_$(PLATFORM)

# Source files
#
# Build mode:
#   BUILD=legacy  (default) — original flat src/*.c stubs
#   BUILD=ported            — reverse-engineered port under src/{alcodec,audio,
#                             core,framesource,osd,ivs,isp,codec_c,fb,sys_wrap,
#                             video}/
#
BUILD ?= legacy

ifeq ($(BUILD),ported)

# Every ported .c under src/, excluding the legacy flat files so the two
# builds don't collide at link time.
# ALSO excluded: the reverse-engineered allocator chain under
# src/core/imp_alloc/ and src/core/mempool/ — on this Thingino T31
# kernel, the ported continuous_init's 30MB memset on /dev/rmem hangs
# the device. The legacy src/dma_alloc.c + src/kernel_interface.c +
# src/al_avpu.c have been confirmed by the user to get actual streams
# flowing. Use the legacy allocator/mempool/kernel-interface under the
# ported build too.
LEGACY_FILES := \
	src/imp_system.c src/imp_isp.c src/imp_framesource.c \
	src/imp_encoder.c src/imp_audio.c src/imp_dmic.c src/imp_osd.c \
	src/imp_ivs.c src/dma_alloc.c src/fifo.c src/hw_encoder.c \
	src/device_pool.c src/al_avpu.c src/kernel_interface.c \
	src/time64_shim.c src/codec.c src/al_encoder_compat.c src/su_base.c

# Ported files we EXCLUDE from BUILD=ported because they conflict with
# the legacy allocator or have caused runtime issues:
PORTED_DISABLED := \
	$(wildcard src/core/imp_alloc/*.c) \
	$(wildcard src/core/mempool/*.c) \
	src/video/imp_mempool.c \
	src/core/vbm.c

IMP_SOURCES := $(filter-out $(LEGACY_FILES) $(PORTED_DISABLED), \
                            $(shell find src -name '*.c'))

# Pull in the legacy allocator + kernel-interface + fifo etc. that the
# port's upper layers rely on. These provide:
#   dma_alloc.c        → IMP_Alloc / IMP_Free / IMP_PoolAlloc / IMP_Get_Info
#                        via direct /dev/rmem bump allocator (known working)
#   kernel_interface.c → VBM* frame pool + write_reg_32
#   fifo.c             → legacy fifo_* and Fifo_* dual API
#   al_avpu.c          → AL_EncCore_* ioctl wrappers
IMP_SOURCES += \
	$(SRC_DIR)/time64_shim.c \
	$(SRC_DIR)/kernel_interface.c \
	$(SRC_DIR)/dma_alloc.c

else

IMP_SOURCES = \
	$(SRC_DIR)/time64_shim.c \
	$(SRC_DIR)/imp_system.c \
	$(SRC_DIR)/imp_isp.c \
	$(SRC_DIR)/imp_framesource.c \
	$(SRC_DIR)/imp_encoder.c \
	$(SRC_DIR)/imp_audio.c \
	$(SRC_DIR)/imp_dmic.c \
	$(SRC_DIR)/imp_osd.c \
	$(SRC_DIR)/imp_ivs.c \
	$(SRC_DIR)/kernel_interface.c \
	$(SRC_DIR)/fifo.c \
	$(SRC_DIR)/al_avpu.c \
	$(SRC_DIR)/al_encoder_compat.c \
	$(SRC_DIR)/codec.c \
	$(SRC_DIR)/dma_alloc.c \
	$(SRC_DIR)/hw_encoder.c \
	$(SRC_DIR)/device_pool.c

endif

SU_SOURCES = \
	$(SRC_DIR)/su_base.c

# Object files — mirror src/ tree under build/
IMP_OBJECTS = $(patsubst $(SRC_DIR)/%.c,$(BUILD_DIR)/%.o,$(IMP_SOURCES))
SU_OBJECTS = $(SU_SOURCES:$(SRC_DIR)/%.c=$(BUILD_DIR)/%.o)

# ivs.c has a large GOT; compile with -mxgot to avoid R_MIPS_CALL16 overflow.
$(BUILD_DIR)/ivs/ivs.o: EXTRA_CFLAGS = -mxgot

# Allow -I src for files that include sibling headers like "kernel_interface.h"
CFLAGS += -I$(SRC_DIR)

# Library names
LIBIMP_SO = $(LIB_DIR)/libimp.so
LIBIMP_A = $(LIB_DIR)/libimp.a
LIBSU_SO = $(LIB_DIR)/libsysutils.so
LIBSU_A = $(LIB_DIR)/libsysutils.a

# Targets
.PHONY: all clean install test strip

all: $(LIBIMP_SO) $(LIBIMP_A) $(LIBSU_SO) $(LIBSU_A)

# Strip debug symbols for smaller binaries
strip: all
	$(STRIP) $(LIBIMP_SO) $(LIBSU_SO)

# Create directories
$(BUILD_DIR) $(LIB_DIR):
	mkdir -p $@

# Compile source files — pattern rule creates parent dirs for nested sources
$(BUILD_DIR)/%.o: $(SRC_DIR)/%.c
	@mkdir -p $(dir $@)
	$(CC) $(CFLAGS) $(EXTRA_CFLAGS) -c $< -o $@

# Build libimp shared library
# Links against libsysutils.so so imp_log_fun / IMP_Log_Get_Option resolve
# via DT_NEEDED at load time (the stock firmware's libimp does the same).
$(LIBIMP_SO): $(IMP_OBJECTS) $(LIBSU_SO) | $(LIB_DIR)
	$(CC) $(LDFLAGS) -L$(LIB_DIR) -o $@ $(IMP_OBJECTS) -lsysutils

# Build libimp static library
$(LIBIMP_A): $(IMP_OBJECTS) | $(LIB_DIR)
	$(AR) rcs $@ $^
	$(RANLIB) $@

# Build libsysutils shared library
$(LIBSU_SO): $(SU_OBJECTS) | $(LIB_DIR)
	$(CC) $(LDFLAGS) -o $@ $^

# Build libsysutils static library
$(LIBSU_A): $(SU_OBJECTS) | $(LIB_DIR)
	$(AR) rcs $@ $^
	$(RANLIB) $@

# Clean build artifacts
clean:
	rm -rf $(BUILD_DIR) $(LIB_DIR)

# Install libraries and headers
install: all
	install -d $(INSTALL_INC_DIR)/imp
	install -d $(INSTALL_INC_DIR)/sysutils
	install -d $(INSTALL_LIB_DIR)
	install -m 644 $(INC_DIR)/imp/*.h $(INSTALL_INC_DIR)/imp/
	install -m 644 $(INC_DIR)/sysutils/*.h $(INSTALL_INC_DIR)/sysutils/
	install -m 755 $(LIBIMP_SO) $(INSTALL_LIB_DIR)/
	install -m 644 $(LIBIMP_A) $(INSTALL_LIB_DIR)/
	install -m 755 $(LIBSU_SO) $(INSTALL_LIB_DIR)/
	install -m 644 $(LIBSU_A) $(INSTALL_LIB_DIR)/

# Test target
test: all
	@echo "Building test..."
	$(CC) $(CFLAGS) -L$(LIB_DIR) tests/api_test.c -o $(BUILD_DIR)/api_test -limp -lsysutils
	@echo "Running test..."
	LD_LIBRARY_PATH=$(LIB_DIR) $(BUILD_DIR)/api_test

# Help target
help:
	@echo "OpenIMP Build System"
	@echo ""
	@echo "Targets:"
	@echo "  all      - Build all libraries (default)"
	@echo "  clean    - Remove build artifacts"
	@echo "  strip    - Strip debug symbols from shared libraries"
	@echo "  install  - Install libraries and headers"
	@echo "  test     - Build and run tests"
	@echo "  help     - Show this help message"
	@echo ""
	@echo "Variables:"
	@echo "  CROSS_COMPILE - Cross-compiler prefix (e.g., mipsel-linux-)"
	@echo "  PREFIX        - Installation prefix (default: /usr/local)"
	@echo "  PLATFORM      - Target platform (default: T31)"
	@echo "                  Options: T21, T23, T31, C100, T40, T41"
	@echo ""
	@echo "Examples:"
	@echo "  make                                    # Build for host"
	@echo "  make CROSS_COMPILE=mipsel-linux-        # Cross-compile for MIPS"
	@echo "  make PLATFORM=T23                       # Build for T23"
	@echo "  make strip                              # Strip debug symbols"
	@echo "  make install PREFIX=~/.local            # Install to home directory"