kern: Misc build system and dependency updates

kernel/GNUmakefile

@@ -1,6 +1,6 @@
 # GNUmakefile: Makefile of the kernel.
 # Code is governed by the GPL-2.0 license.
-# Copyright (C) 2021-2022 The Vinix authors.
+# Copyright (C) 2021-2024 The Vinix authors.
 
 # Nuke built-in rules and variables.
 MAKEFLAGS += -rR
@@ -13,6 +13,12 @@ override OUTPUT := vinix
 # Convenience macro to reliably declare user overridable variables.
 override USER_VARIABLE = $(if $(filter $(origin $(1)),default undefined),$(eval override $(1) := $(2)))
 
+# Destination directory on install (should always be empty by default).
+$(call USER_VARIABLE,DESTDIR,)
+
+# Install prefix; /usr/local is a good, standard default pick.
+$(call USER_VARIABLE,PREFIX,/usr/local)
+
 # User controllable C compiler command.
 $(call USER_VARIABLE,KCC,cc)
 
@@ -39,6 +45,13 @@ $(call USER_VARIABLE,KLDFLAGS,)
 
 $(call USER_VARIABLE,VINIX_PROD,)
 
+# Ensure the dependencies have been obtained.
+ifneq ($(shell ( test '$(MAKECMDGOALS)' = clean || test '$(MAKECMDGOALS)' = distclean ) && echo 1),1)
+ ifeq ($(shell ( ! test -d freestanding-headers || ! test -f c/cc-runtime.c || ! test -d c/flanterm || ! test -f c/printf/printf.c || ! test -f c/printf/printf.h ) && echo 1),1)
+ $(error Please run the ./get-deps script first)
+ endif
+endif
+
 # Internal C flags that should not be changed by the user.
 override KCFLAGS += \
  -g \
@@ -113,12 +126,6 @@ override ASFILES := $(shell cd asm && find -L * -type f -name '*.S' | LC_ALL=C s
 override OBJ := $(addprefix obj/,$(CFILES:.c=.c.o) $(ASFILES:.S=.S.o))
 override HEADER_DEPS := $(addprefix obj/,$(CFILES:.c=.c.d) $(ASFILES:.S=.S.d))
 
-# Ensure the dependencies have been obtained.
-override MISSING_DEPS := $(shell if ! test -d freestanding-headers || ! test -f c/cc-runtime.c || ! test -f c/printf/printf.c || ! test -f c/printf/printf.h; then echo 1; fi)
-ifeq ($(MISSING_DEPS),1)
- $(error Please run the ./get-deps script first)
-endif
-
 # Default target.
 .PHONY: all
 all: bin/$(OUTPUT)
@@ -166,3 +173,9 @@ distclean: clean
 install: all
  install -d "$(DESTDIR)$(PREFIX)/share/$(OUTPUT)"
  install -m 644 bin/$(OUTPUT) "$(DESTDIR)$(PREFIX)/share/$(OUTPUT)/"
+
+# Try to undo whatever the "install" target did.
+.PHONY: uninstall
+uninstall:
+ rm -f "$(DESTDIR)$(PREFIX)/share/$(OUTPUT)/$(OUTPUT)"
+ -rmdir "$(DESTDIR)$(PREFIX)/share/$(OUTPUT)"

kernel/get-deps

@@ -8,21 +8,24 @@ test -z "$srcdir" && srcdir=.
 cd "$srcdir"
 
 clone_repo_commit() {
- if test -d $2/.git; then
- git -C $2 reset --hard
- git -C $2 clean -fd
- if ! git -C $2 checkout $3; then
- rm -rf $2
+ if test -d "$2/.git"; then
+ git -C "$2" reset --hard
+ git -C "$2" clean -fd
+ if ! git -C "$2" checkout $3; then
+ rm -rf "$2"
  fi
  else
- if test -d $2; then
+ if test -d "$2"; then
  echo "error: '$2' is not a Git repository"
  exit 1
  fi
  fi
- if ! test -d $2; then
- git clone $1 $2
- git -C $2 checkout $3
+ if ! test -d "$2"; then
+ git clone $1 "$2"
+ if ! git -C "$2" checkout $3; then
+ rm -rf "$2"
+ exit 1
+ fi
  fi
 }
 
@@ -43,12 +46,15 @@ download_by_hash() {
  exit 1
  fi
  fi
- if ! test -f $2 || ! $SHA256_COMMAND $2 | grep $3 >/dev/null 2>&1; then
- rm -f $2
- mkdir -p $2 && rm -rf $2
- $DOWNLOAD_COMMAND $2 $1
- if ! $SHA256_COMMAND $2 | grep $3 >/dev/null 2>&1; then
+ if ! test -f "$2" || ! $SHA256_COMMAND "$2" | grep $3 >/dev/null 2>&1; then
+ rm -f "$2"
+ mkdir -p "$2" && rm -rf "$2"
+ $DOWNLOAD_COMMAND "$2" $1
+ if ! $SHA256_COMMAND "$2" | grep $3 >/dev/null 2>&1; then
  echo "error: Cannot download file '$2' by hash"
+ echo "incorrect hash:"
+ $SHA256_COMMAND "$2"
+ rm -f "$2"
  exit 1
  fi
  fi
@@ -58,7 +64,7 @@ if ! test -f version; then
  clone_repo_commit \
  https://github.com/osdev0/freestanding-headers.git \
  freestanding-headers \
- 4b8b78007533dec6ae3bd8dddcc302f22a21c140
+ f890bb927859719061fe020119f3d5439d90aecf
 
  download_by_hash \
  https://github.com/osdev0/cc-runtime/raw/dcdf5d82973e77edee597a047a3ef66300903de9/cc-runtime.c \