Release Lab 1

.dir-locals.el

@@ -0,0 +1,12 @@
+((nil
+  (indent-tabs-mode . t)
+  (tab-width . 8))
+ (c-mode
+  (c-file-style . "bsd")
+  (c-basic-offset . 8))
+ (shell-mode
+  (sh-basic-offset . 8)
+  (sh-indentation . 8))
+ (python-mode
+  (indent-tabs-mode . nil))
+ )

.gdbinit.tmpl

@@ -0,0 +1,30 @@
+set $lastcs = -1
+
+define hook-stop
+  # There doesn't seem to be a good way to detect if we're in 16- or
+  # 32-bit mode, but we always run with CS == 8 in 32-bit mode.
+  if $cs == 8 || $cs == 27
+    if $lastcs != 8 && $lastcs != 27
+      set architecture i386
+    end
+    x/i $pc
+  else
+    if $lastcs == -1 || $lastcs == 8 || $lastcs == 27
+      set architecture i8086
+    end
+    # Translate the segment:offset into a physical address
+    printf "[%4x:%4x] ", $cs, $eip
+    x/i $cs*16+$eip
+  end
+  set $lastcs = $cs
+end
+
+echo + target remote localhost:1234\n
+target remote localhost:1234
+
+# If this fails, it's probably because your GDB doesn't support ELF.
+# Look at the tools page at
+#  http://pdos.csail.mit.edu/6.828/2009/tools.html
+# for instructions on building GDB with ELF support.
+echo + symbol-file obj/kern/kernel\n
+symbol-file obj/kern/kernel

.gitignore

@@ -0,0 +1,16 @@
+/obj
+/jos.in
+/jos.log
+/jos.out
+/jos.out.*
+/jos.cmd
+/.gdbinit
+/wget.log
+/qemu.pcap
+/qemu.pcap.*
+/qemu.out
+/qemu.log
+/gradelib.pyc
+/lab?-handin.tar.gz
+/lab?/
+/sol?/

CODING

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+JOS CODING STANDARDS
+
+It's easier on everyone if all authors working on a shared
+code base are consistent in the way they write their programs.
+We have the following conventions in our code:
+
+* No space after the name of a function in a call
+  For example, printf("hello") not printf ("hello").
+
+* One space after keywords "if", "for", "while", "switch".
+  For example, if (x) not if(x).
+
+* Space before braces.
+  For example, if (x) { not if (x){.
+
+* Function names are all lower-case separated by underscores.
+
+* Beginning-of-line indentation via tabs, not spaces.
+
+* Preprocessor macros are always UPPERCASE.
+  There are a few grandfathered exceptions: assert, panic,
+  static_assert, offsetof.
+
+* Pointer types have spaces: (uint16_t *) not (uint16_t*).
+
+* Multi-word names are lower_case_with_underscores.
+
+* Comments in imported code are usually C /* ... */ comments.
+  Comments in new code are C++ style //.
+
+* In a function definition, the function name starts a new line.
+  Then you can grep -n '^foo' */*.c to find the definition of foo.
+
+* Functions that take no arguments are declared f(void) not f().
+
+The included .dir-locals.el file will automatically set up the basic
+indentation style in Emacs.

GNUmakefile

@@ -0,0 +1,250 @@
+#
+# This makefile system follows the structuring conventions
+# recommended by Peter Miller in his excellent paper:
+#
+#	Recursive Make Considered Harmful
+#	http://aegis.sourceforge.net/auug97.pdf
+#
+OBJDIR := obj
+
+# Run 'make V=1' to turn on verbose commands, or 'make V=0' to turn them off.
+ifeq ($(V),1)
+override V =
+endif
+ifeq ($(V),0)
+override V = @
+endif
+
+-include conf/lab.mk
+
+-include conf/env.mk
+
+LABSETUP ?= ./
+
+TOP = .
+
+# Cross-compiler jos toolchain
+#
+# This Makefile will automatically use the cross-compiler toolchain
+# installed as 'i386-jos-elf-*', if one exists.  If the host tools ('gcc',
+# 'objdump', and so forth) compile for a 32-bit x86 ELF target, that will
+# be detected as well.  If you have the right compiler toolchain installed
+# using a different name, set GCCPREFIX explicitly in conf/env.mk
+
+# try to infer the correct GCCPREFIX
+ifndef GCCPREFIX
+GCCPREFIX := $(shell if i386-jos-elf-objdump -i 2>&1 | grep '^elf32-i386$$' >/dev/null 2>&1; \
+	then echo 'i386-jos-elf-'; \
+	elif objdump -i 2>&1 | grep 'elf32-i386' >/dev/null 2>&1; \
+	then echo ''; \
+	else echo "***" 1>&2; \
+	echo "*** Error: Couldn't find an i386-*-elf version of GCC/binutils." 1>&2; \
+	echo "*** Is the directory with i386-jos-elf-gcc in your PATH?" 1>&2; \
+	echo "*** If your i386-*-elf toolchain is installed with a command" 1>&2; \
+	echo "*** prefix other than 'i386-jos-elf-', set your GCCPREFIX" 1>&2; \
+	echo "*** environment variable to that prefix and run 'make' again." 1>&2; \
+	echo "*** To turn off this error, run 'gmake GCCPREFIX= ...'." 1>&2; \
+	echo "***" 1>&2; exit 1; fi)
+endif
+
+# try to infer the correct QEMU
+ifndef QEMU
+QEMU := $(shell if which qemu > /dev/null; \
+	then echo qemu; exit; \
+	else \
+	qemu=/Applications/Q.app/Contents/MacOS/i386-softmmu.app/Contents/MacOS/i386-softmmu; \
+	if test -x $$qemu; then echo $$qemu; exit; fi; fi; \
+	echo "***" 1>&2; \
+	echo "*** Error: Couldn't find a working QEMU executable." 1>&2; \
+	echo "*** Is the directory containing the qemu binary in your PATH" 1>&2; \
+	echo "*** or have you tried setting the QEMU variable in conf/env.mk?" 1>&2; \
+	echo "***" 1>&2; exit 1)
+endif
+
+# try to generate a unique GDB port
+GDBPORT	:= $(shell expr `id -u` % 5000 + 25000)
+
+CC	:= $(GCCPREFIX)gcc -pipe
+AS	:= $(GCCPREFIX)as
+AR	:= $(GCCPREFIX)ar
+LD	:= $(GCCPREFIX)ld
+OBJCOPY	:= $(GCCPREFIX)objcopy
+OBJDUMP	:= $(GCCPREFIX)objdump
+NM	:= $(GCCPREFIX)nm
+
+# Native commands
+NCC	:= gcc $(CC_VER) -pipe
+NATIVE_CFLAGS := $(CFLAGS) $(DEFS) $(LABDEFS) -I$(TOP) -MD -Wall
+TAR	:= gtar
+PERL	:= perl
+
+# Compiler flags
+# -fno-builtin is required to avoid refs to undefined functions in the kernel.
+# Only optimize to -O1 to discourage inlining, which complicates backtraces.
+CFLAGS := $(CFLAGS) $(DEFS) $(LABDEFS) -O1 -fno-builtin -I$(TOP) -MD
+CFLAGS += -fno-omit-frame-pointer
+CFLAGS += -Wall -Wno-format -Wno-unused -Werror -gstabs -m32
+
+# Add -fno-stack-protector if the option exists.
+CFLAGS += $(shell $(CC) -fno-stack-protector -E -x c /dev/null >/dev/null 2>&1 && echo -fno-stack-protector)
+
+# Common linker flags
+LDFLAGS := -m elf_i386
+
+# Linker flags for JOS user programs
+ULDFLAGS := -T user/user.ld
+
+GCC_LIB := $(shell $(CC) $(CFLAGS) -print-libgcc-file-name)
+
+# Lists that the */Makefrag makefile fragments will add to
+OBJDIRS :=
+
+# Make sure that 'all' is the first target
+all:
+
+# Eliminate default suffix rules
+.SUFFIXES:
+
+# Delete target files if there is an error (or make is interrupted)
+.DELETE_ON_ERROR:
+
+# make it so that no intermediate .o files are ever deleted
+.PRECIOUS: %.o $(OBJDIR)/boot/%.o $(OBJDIR)/kern/%.o \
+	   $(OBJDIR)/lib/%.o $(OBJDIR)/fs/%.o $(OBJDIR)/net/%.o \
+	   $(OBJDIR)/user/%.o
+
+KERN_CFLAGS := $(CFLAGS) -DJOS_KERNEL -gstabs
+USER_CFLAGS := $(CFLAGS) -DJOS_USER -gstabs
+
+# Update .vars.X if variable X has changed since the last make run.
+#
+# Rules that use variable X should depend on $(OBJDIR)/.vars.X.  If
+# the variable's value has changed, this will update the vars file and
+# force a rebuild of the rule that depends on it.
+$(OBJDIR)/.vars.%: FORCE
+	$(V)echo "$($*)" | cmp -s $@ || echo "$($*)" > $@
+.PRECIOUS: $(OBJDIR)/.vars.%
+.PHONY: FORCE
+
+
+# Include Makefrags for subdirectories
+include boot/Makefrag
+include kern/Makefrag
+
+
+QEMUOPTS = -hda $(OBJDIR)/kern/kernel.img -serial mon:stdio -gdb tcp::$(GDBPORT)
+QEMUOPTS += $(shell if $(QEMU) -nographic -help | grep -q '^-D '; then echo '-D qemu.log'; fi)
+IMAGES = $(OBJDIR)/kern/kernel.img
+QEMUOPTS += $(QEMUEXTRA)
+
+.gdbinit: .gdbinit.tmpl
+	sed "s/localhost:1234/localhost:$(GDBPORT)/" < $^ > $@
+
+pre-qemu: .gdbinit
+
+qemu: $(IMAGES) pre-qemu
+	$(QEMU) $(QEMUOPTS)
+
+qemu-nox: $(IMAGES) pre-qemu
+	@echo "***"
+	@echo "*** Use Ctrl-a x to exit qemu"
+	@echo "***"
+	$(QEMU) -nographic $(QEMUOPTS)
+
+qemu-gdb: $(IMAGES) pre-qemu
+	@echo "***"
+	@echo "*** Now run 'gdb'." 1>&2
+	@echo "***"
+	$(QEMU) $(QEMUOPTS) -S
+
+qemu-nox-gdb: $(IMAGES) pre-qemu
+	@echo "***"
+	@echo "*** Now run 'gdb'." 1>&2
+	@echo "***"
+	$(QEMU) -nographic $(QEMUOPTS) -S
+
+print-qemu:
+	@echo $(QEMU)
+
+print-gdbport:
+	@echo $(GDBPORT)
+
+# For deleting the build
+clean:
+	rm -rf $(OBJDIR) .gdbinit jos.in qemu.log
+
+realclean: clean
+	rm -rf lab$(LAB).tar.gz \
+		jos.out $(wildcard jos.out.*) \
+		qemu.pcap $(wildcard qemu.pcap.*)
+
+distclean: realclean
+	rm -rf conf/gcc.mk
+
+ifneq ($(V),@)
+GRADEFLAGS += -v
+endif
+
+grade:
+	@echo $(MAKE) clean
+	@$(MAKE) clean || \
+	  (echo "'make clean' failed.  HINT: Do you have another running instance of JOS?" && exit 1)
+	./grade-lab$(LAB) $(GRADEFLAGS)
+
+handin:
+	@if test -n "`git config remote.handin.url`"; then \
+		echo "Hand in to remote repository using 'git push handin HEAD' ..."; \
+		if ! git push -f handin HEAD; then \
+            echo ; \
+			echo "Hand in failed."; \
+			echo "As an alternative, please run 'make tarball'"; \
+			echo "and visit http://pdos.csail.mit.edu/6.828/submit/"; \
+			echo "to upload lab$(LAB)-handin.tar.gz.  Thanks!"; \
+			false; \
+		fi; \
+    else \
+		echo "Hand-in repository is not configured."; \
+		echo "Please run 'make handin-prep' first.  Thanks!"; \
+		false; \
+	fi
+
+handin-check:
+	@if test "$$(git symbolic-ref HEAD)" != refs/heads/lab$(LAB); then \
+		git branch; \
+		read -p "You are not on the lab$(LAB) branch.  Hand-in the current branch? [y/N] " r; \
+		test "$$r" = y; \
+	fi
+	@if ! git diff-files --quiet || ! git diff-index --quiet --cached HEAD; then \
+		git status; \
+		echo; \
+		echo "You have uncomitted changes.  Please commit or stash them."; \
+		false; \
+	fi
+	@if test -n "`git ls-files -o --exclude-standard`"; then \
+		git status; \
+		read -p "Untracked files will not be handed in.  Continue? [y/N] " r; \
+		test "$$r" = y; \
+	fi
+
+tarball: handin-check
+	git archive --format=tar HEAD | gzip > lab$(LAB)-handin.tar.gz
+
+handin-prep:
+	@./handin-prep
+
+
+# This magic automatically generates makefile dependencies
+# for header files included from C source files we compile,
+# and keeps those dependencies up-to-date every time we recompile.
+# See 'mergedep.pl' for more information.
+$(OBJDIR)/.deps: $(foreach dir, $(OBJDIRS), $(wildcard $(OBJDIR)/$(dir)/*.d))
+	@mkdir -p $(@D)
+	@$(PERL) mergedep.pl $@ $^
+
+-include $(OBJDIR)/.deps
+
+always:
+	@:
+
+.PHONY: all always \
+	handin tarball clean realclean distclean grade handin-prep handin-check

boot/Makefrag

@@ -0,0 +1,32 @@
+#
+# Makefile fragment for the JOS kernel.
+# This is NOT a complete makefile;
+# you must run GNU make in the top-level directory
+# where the GNUmakefile is located.
+#
+
+OBJDIRS += boot
+
+BOOT_OBJS := $(OBJDIR)/boot/boot.o $(OBJDIR)/boot/main.o
+
+$(OBJDIR)/boot/%.o: boot/%.c
+	@echo + cc -Os $<
+	@mkdir -p $(@D)
+	$(V)$(CC) -nostdinc $(KERN_CFLAGS) -Os -c -o $@ $<
+
+$(OBJDIR)/boot/%.o: boot/%.S
+	@echo + as $<
+	@mkdir -p $(@D)
+	$(V)$(CC) -nostdinc $(KERN_CFLAGS) -c -o $@ $<
+
+$(OBJDIR)/boot/main.o: boot/main.c
+	@echo + cc -Os $<
+	$(V)$(CC) -nostdinc $(KERN_CFLAGS) -Os -c -o $(OBJDIR)/boot/main.o boot/main.c
+
+$(OBJDIR)/boot/boot: $(BOOT_OBJS)
+	@echo + ld boot/boot
+	$(V)$(LD) $(LDFLAGS) -N -e start -Ttext 0x7C00 -o [email protected] $^
+	$(V)$(OBJDUMP) -S [email protected] >[email protected]
+	$(V)$(OBJCOPY) -S -O binary -j .text [email protected] $@
+	$(V)perl boot/sign.pl $(OBJDIR)/boot/boot
+