# makefile - High-speed COMM.DRV replacement for MSVC 1.52
#
# Build: nmake
# Clean: nmake clean
#
# Prerequisites:
#   - MSVC 1.52 (cl, link in PATH)
#
# Output is COMM.DRV -- drop-in replacement for stock Windows 3.1 driver.
#
# Install:
#   1. Copy COMM.DRV to \WINDOWS\SYSTEM
#   2. Edit SYSTEM.INI [boot] section: comm.drv=comm.drv
#   3. Add to [386Enh] section: COM1FIFO=1 (for each port in use)
#   4. Restart Windows
#
# Key improvements over stock COMM.DRV:
#   - Both RX and TX FIFOs enabled (stock: RX only)
#   - RX trigger level 8 (stock: 14 -- only 2 bytes headroom)
#   - TX burst writes up to 16 bytes per THRE interrupt (stock: 1 byte)

CC      = cl
LINK    = link

# Compiler flags:
#   -c      Compile only
#   -W3     Warning level 3
#   -ASw    Small model, SS!=DS (Windows DLL)
#   -Gsw    No stack probes, Windows prolog/epilog
#   -Ow     Safe optimizations for Windows
#   -Zp1    Pack structures on 1-byte boundaries (hardware register layouts)
#   -Ze     Enable Microsoft extensions
CFLAGS  = -c -W3 -ASw -Gsw -Ow -Zp1 -Ze

# Linker flags:
#   /NOD    No default libraries
#   /NOE    No extended dictionary search
#   /AL:16  Segment alignment 16
LFLAGS  = /NOD /NOE /AL:16

# Libraries
#   sdllcew  Small model DLL C runtime (emulated math, Windows)
#   libw     Windows API import library
LIBS    = sdllcew libw

# Output
TARGET  = comm.drv

# Objects
OBJS    = commdrv.obj isr.obj

# -----------------------------------------------------------------------
# Build rules
# -----------------------------------------------------------------------
all: $(TARGET)

$(TARGET): $(OBJS) commdrv.def
	$(LINK) $(LFLAGS) $(OBJS), $(TARGET),,$(LIBS), commdrv.def

commdrv.obj: commdrv.c commdrv.h
	$(CC) $(CFLAGS) commdrv.c

isr.obj: isr.c commdrv.h
	$(CC) $(CFLAGS) isr.c

# -----------------------------------------------------------------------
# Clean
# -----------------------------------------------------------------------
clean:
	-del *.obj
	-del *.drv
	-del *.map