a minimal working demo on bare metal

1 files changed, 232 insertions, 0 deletions

diff --git a/_Makefile b/_Makefile
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+# This is the makefile goal ... TODO integrate the rust project into this...
+
+
+# -----------------------------------------------------------------------------
+# 
+#                              M A K E F I L E
+# 
+# for building OOStuBS, the teaching OS for "Operating-System Construction"
+# -----------------------------------------------------------------------------
+#
+# By entering 'make', the system's source codes get compiled and linked.
+# 'make bootdisk' writes the system image to an USB stick that allows to boot
+# the system on a real machine.
+# 'make clean' cleans up the directory.
+# The targets 'qemu', 'qemu-smp' and 'qemu-gdb' start the QEMU emulator in
+# single-core mode, multi-core mode (2 CPUs), respectively in single-core mode
+# waiting for a debugger to attach before starting the system.
+# The targets 'gdb', 'ddd' and 'cgdb' each run one of these three debuggers
+# that automatically connect to the GDB stub of an already started 'qemu-gdb'
+# (see above).
+#
+# -----------------------------------------------------------------------------
+
+# -----------------------------------------------------------------------------
+# source-code files
+
+STARTUP_SOURCE = ./startup.asm
+CC_SOURCES = $(shell find . -name "*.cc")
+C_SOURCES = $(shell find . -name "*.c")
+ASM_SOURCES = $(shell find ./machine -name "*.asm")
+
+# build settings
+#
+#    ASMOBJFORMAT: assembler output format (must match the format of the used
+#                  C++ compiler to make linking possible)
+#    OBJDIR:       directory for storing object files
+#    DEPDIR:       directory for storing dependency files
+#    DRIVE_HD:     HDD/USB device the system image gets written to
+#                  with 'make bootdisk'
+#    DELETE:       file-deletion command
+#    ASM:          assembler command
+#    CC/CXX:       C/C++ compiler command
+#    CFLAGS:       C-compiler flags
+#    CXXFLAGS:     C++-compiler flags
+#    QEMU:         architecture-specific name of the QEMU command
+#    MKRESCUE:     name of the GRUB mkrescue program
+
+VERBOSE = @
+ASMOBJFORMAT = elf64
+OBJDIR = ./build
+DEPDIR = ./dep
+# ATTENTION: using the wrong device name here will destroy data on the specified
+# device! Do not run with root privileges!
+DRIVE_HD = /dev/sdz
+DELETE = rm
+ASM = nasm
+QEMU ?= qemu-system-x86_64
+CC ?= gcc
+CXX ?= g++
+CFLAGS := $(CFLAGS) -m64 -mno-red-zone -Wall -Wno-write-strings -fno-stack-protector -nostdlib -mno-sse -I. -g #-DDEBUG
+CXXFLAGS := $(CFLAGS) -Wno-non-virtual-dtor -fno-threadsafe-statics -fno-use-cxa-atexit -fno-rtti -fno-exceptions -std=c++11
+
+# enforce i386-pc grub variant also on EFI systems
+ifneq ($(wildcard /usr/lib/grub/i386-pc/.),)
+        MKRESCUE_OPTION ?= /usr/lib/grub/i386-pc
+else ifneq ($(wildcard /usr/share/grub2/i386-pc/.),)
+        MKRESCUE_OPTION ?= /usr/share/grub2/i386-pc
+else
+        MKRESCUE_OPTION ?=
+endif
+
+ifneq ($(shell which grub-mkrescue 2> /dev/null),)
+MKRESCUE = grub-mkrescue $(MKRESCUE_OPTION)
+endif
+ifneq ($(shell which grub2-mkrescue 2> /dev/null),)
+MKRESCUE = grub2-mkrescue $(MKRESCUE_OPTION)
+endif
+
+# -------------------------------------------------------------------------
+# names of sub-directories with source-code files
+
+VPATH = $(sort $(dir $(STARTUP_SOURCE) $(CC_SOURCES) $(C_SOURCES) $(ASM_SOURCES)))
+
+# -------------------------------------------------------------------------
+# lists of object files that are generated during compilation
+
+FIRST_OBJECT = $(addprefix $(OBJDIR)/,$(patsubst %.asm,_%.o, $(notdir $(STARTUP_SOURCE))))
+C_OBJECTS = $(notdir $(C_SOURCES:.c=.o))
+CC_OBJECTS = $(notdir $(CC_SOURCES:.cc=.o))
+
+DEP_FILES = $(patsubst %.o,$(DEPDIR)/%.d,$(C_OBJECTS))
+DEP_FILES += $(patsubst %.o,$(DEPDIR)/%.d,$(CC_OBJECTS))
+
+ASM_OBJECTS = $(patsubst %.asm,_%.o, $(notdir $(ASM_SOURCES)))
+OBJPRE = $(addprefix $(OBJDIR)/,$(ASM_OBJECTS) $(C_OBJECTS) $(CC_OBJECTS))
+
+# --------------------------------------------------------------------------
+# Default target: the image file for USB sticks and QEMU
+
+
+
+all: $(OBJDIR)/bootdisk.iso
+
+# --------------------------------------------------------------------------
+# rules for generating dependency files
+
+
+$(DEPDIR)/%.d : %.c
+	@echo "DEP		$@"
+	@if test \( ! \( -d $(@D) \) \) ;then mkdir -p $(@D);fi
+	$(VERBOSE) $(CC) $(CFLAGS) -MM -MT $(OBJDIR)/$*.o -MF $@ $<
+
+$(DEPDIR)/%.d : %.cc
+	@echo "DEP		$@"
+	@if test \( ! \( -d $(@D) \) \) ;then mkdir -p $(@D);fi
+	$(VERBOSE) $(CXX) $(CXXFLAGS) -MM -MT $(OBJDIR)/$*.o -MF $@ $<
+
+# --------------------------------------------------------------------------
+# rules for generating object files
+
+$(OBJDIR)/%.o : %.c
+	@echo "CC		$@"
+	@if test \( ! \( -d $(@D) \) \) ;then mkdir -p $(@D);fi
+	$(VERBOSE) $(CC) -c $(CFLAGS) -o $@ $<
+
+$(OBJDIR)/%.o : %.cc
+	@echo "CXX		$@"
+	@if test \( ! \( -d $(@D) \) \) ;then mkdir -p $(@D);fi
+	$(VERBOSE) $(CXX) -c $(CXXFLAGS) -o $@ $<
+
+$(OBJDIR)/_%.o : %.asm
+	@echo "ASM		$@"
+	@if test \( ! \( -d $(@D) \) \) ;then mkdir -p $(@D);fi
+	$(VERBOSE) $(ASM) -f $(ASMOBJFORMAT) -o $@ $<
+
+# --------------------------------------------------------------------------
+# linked system
+
+$(OBJDIR)/system: $(FIRST_OBJECT) $(OBJPRE)
+	@echo "LD		$@"
+	@if test \( ! \( -d $(@D) \) \) ;then mkdir -p $(@D);fi
+	$(VERBOSE) $(CXX) $(CXXFLAGS) -static -z max-page-size=0x1000 -e startup -T sections -o $(OBJDIR)/system $(FIRST_OBJECT) $(OBJPRE)
+
+# --------------------------------------------------------------------------
+# 'bootdisk.iso' consists of the system and a boot loader (GRUB) with boot
+# block and setup code. The system gets started via Multiboot, so we don't
+# have to care about switching to protected mode or how to deal with the BIOS.
+
+$(OBJDIR)/bootdisk.iso : $(OBJDIR)/system
+	@echo "BUILD		$@"
+	@if test \( ! \( -d $(@D) \) \) ;then mkdir -p $(@D);fi
+	$(VERBOSE) cp $< isofiles/boot/system
+	$(VERBOSE) $(MKRESCUE) -o $@ isofiles
+
+# --------------------------------------------------------------------------
+# 'clean' deletes the generated system, the object files, and the dependency
+# files.
+
+clean:	
+	@echo "RM		$(OBJDIR)"
+	$(VERBOSE) rm -rf $(OBJDIR)
+	@echo "RM		$(DEPDIR)"
+	$(VERBOSE) rm -rf $(DEPDIR)
+
+# 'list' shows the OBJS for debuging linker
+
+list:
+	@echo "C_OBJECTS $(C_OBJECTS)"
+	@echo "CC_OBJECTS $(CC_OBJECTS)"
+	@echo "OBJDIR $(OBJDIR)"
+	@echo "OBJPRE $(OBJPRE)"
+	@echo "FIRST_OBJECT $(FIRST_OBJECT)"
+
+
+# --------------------------------------------------------------------------
+# 'bootdisk' depends on bootdisk.iso, which in turn depends on the system. The
+# ISO image gets written to the specified drive, which can be a HDD/SSD or an
+# USB stick.
+# ATTENTION: using the wrong device name here will destroy data on the specified
+# device! Do not run with root privileges!
+
+bootdisk: $(OBJDIR)/bootdisk.iso
+	@echo "CP		$<"
+	$(VERBOSE) cp $< $(DRIVE_HD)
+
+# --------------------------------------------------------------------------
+# 'qemu' runs the QEMU emulator with the system
+
+qemu: $(OBJDIR)/bootdisk.iso
+	$(QEMU) -drive file=build/bootdisk.iso,format=raw -k en-us
+
+# --------------------------------------------------------------------------
+# 'qemu-smp' runs QEMU in SMP (symmetric multi-processing) mode with 2 CPUs
+
+qemu-smp: $(OBJDIR)/bootdisk.iso
+	$(QEMU) -drive file=build/bootdisk.iso,format=raw -k en-us -smp 2
+
+# --------------------------------------------------------------------------
+# 'qemu-gdb' runs QEMU with an activated GDB stub, which waits for a debugger
+# (GDB, DDD, CGDB, etc.) to connect before starting the system.
+
+qemu-gdb: $(OBJDIR)/bootdisk.iso
+	$(VERBOSE) echo "target remote localhost:$(shell echo $$(( $$(id -u) % (65536 - 1024) + 1024 )))" > /tmp/gdbcommands.$(shell id -u)
+	$(QEMU) -drive file=build/bootdisk.iso,format=raw -k en-us -S -gdb tcp::$(shell echo $$(( $$(id -u) % (65536 - 1024) + 1024 )))
+
+# --------------------------------------------------------------------------
+# 'gdb' starts the GDB debugger and makes it connect to an already started
+# 'qemu-gdb'.
+
+gdb:
+	gdb -x /tmp/gdbcommands.$(shell id -u) $(OBJDIR)/system
+
+# --------------------------------------------------------------------------
+# 'ddd': same as 'gdb' but uses the 'ddd' debugger
+
+ddd:
+	ddd --gdb -x /tmp/gdbcommands.$(shell id -u) $(OBJDIR)/system
+
+# --------------------------------------------------------------------------
+# 'cgdb': same as 'gdb' but uses the 'cgdb' debugger
+
+cgdb:
+	cgdb -x /tmp/gdbcommands.$(shell id -u) $(OBJDIR)/system
+
+# --------------------------------------------------------------------------
+# include dependency files
+
+ifneq ($(MAKECMDGOALS),clean)
+-include $(DEP_FILES)
+endif
+
+.PHONY: clean bootdisk gdb ddd qemu qemu-smp qemu-gdb qemu-ddd qemu-cgdb