From fc00c656c96528112d05cf0edf8631bd5eaea446 Mon Sep 17 00:00:00 2001
From: Kacper <kacper@mail.openlinux.dev>
Date: Sun, 7 Dec 2025 20:10:31 +0100
Subject: Add build system scaffolding and libc headers

---
 makefile | 142 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 142 insertions(+)
 create mode 100644 makefile

(limited to 'makefile')

diff --git a/makefile b/makefile
new file mode 100644
index 00000000..7e530f28
--- /dev/null
+++ b/makefile
@@ -0,0 +1,142 @@
+-include Kbuild
+
+# Disable builti-n rules and variables
+MAKEFLAGS += -r -R
+
+# Disable output of entering/leaving directory messages
+MAKEFLAGS += --no-print-directory
+
+export MSG = @printf '\033[34m%-8s\033[0m %s\n'
+
+this-makefile = $(lastword $(MAKEFILE_LIST))
+srctree = $(realpath $(dir $(this-makefile)))
+
+LLVM ?= 1
+ifneq ($(LLVM),1)
+  ifneq ($(filter %/,$(LLVM)),)
+    LLVM_PREFIX = $(LLVM)
+  else ifneq ($(filter -%,$(LLVM)),)
+    LLVM_SUFFIX = $(LLVM)
+  endif
+endif
+
+# Variables
+ifeq ($(LLVM),1)
+  CC      = $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
+  LD      = $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX)
+  AR      = $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX)
+  STRIP   = $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX)
+else
+  CC = $(CROSS_COMPILE)gcc
+  LD = $(CROSS_COMPILE)ld
+  AR = $(CROSS_COMPILE)ar
+  STRIP = $(CROSS_COMPILE)strip
+endif
+
+ifndef ARCH
+  ARCH := x86_64
+endif
+
+export CC LD AR STRIP CROSS_COMPILE ARCH
+
+ifeq ($(V),1)
+  Q :=
+else
+  Q := @
+  MAKEFLAGS += -s
+endif
+
+ifdef M
+  obj = $(M)/
+endif
+
+# CFLAGS
+
+KBUILD_CFLAGS :=
+
+KBUILD_CFLAGS += -Wall -Wextra
+KBUILD_CFLAGS += -nostdinc
+KBUILD_CFLAGS += -target $(ARCH)-linux-eabi
+KBUILD_CFLAGS += -I$(srctree)/include
+KBUILD_CFLAGS += -I$(srctree)/include/arch/$(ARCH)
+
+KBUILD_CFLAGS += -std=c11
+KBUILD_CFLAGS += -fno-common
+KBUILD_CFLAGS += -fno-PIE
+KBUILD_CFLAGS += -fstrict-aliasing
+
+KBUILD_CFLAGS += -fno-delete-null-pointer-checks
+KBUILD_CFLAGS += -flto
+
+# Disable overflow optimizations
+KBUILD_CFLAGS += -fno-strict-overflow
+
+# Disable stack check
+KBUILD_CFLAGS += -fno-stack-check
+
+# Weird loops transformations to wcslen
+KBUILD_CFLAGS += -fno-builtin-wcslen
+
+KBUILD_ASFLAGS :=
+
+# Assembly does not need -nostdinc; clang warns it is unused.
+KBUILD_ASFLAGS += -target $(ARCH)-linux-eabi
+KBUILD_ASFLAGS += -I$(srctree)/include
+KBUILD_ASFLAGS += -I$(srctree)/include/arch/$(ARCH)
+
+# LDFLAGS
+KBUILD_LDFLAGS :=
+
+KBUILD_LDFLAGS += --gc-sections
+KBUILD_LDFLAGS += --build-id=none
+KBUILD_LDFLAGS += --as-needed
+
+PHONY :=
+
+KCONFIG_CONFIG ?= .config
+
+export Q srctree MAKEFLAGS KCONFIG_CONFIG \
+       KBUILD_CFLAGS KBUILD_ASFLAGS KBUILD_LDFLAGS
+
+all: $(srctree)/include/config/auto.conf $(srctree)/include/generated/autoconf.h
+	$(Q)$(MAKE) -f scripts/makefile.build obj=$(obj)
+
+clean:
+	$(Q)$(MAKE) -f scripts/makefile.build obj=$(obj) clean
+	rm -f $(srctree)/include/config/auto.conf
+	rm -f $(srctree)/include/generated/autoconf.h
+	rm -f compile_commands.json
+
+distclean: clean
+	$(Q)$(MAKE) -C scripts/kconfig clean
+
+$(KCONFIG_CONFIG):
+	@echo >&2 '***'
+	@echo >&2 '*** Configuration file "$@" not found!'
+	@echo >&2 '***'
+	@echo >&2 '*** Please run some configurator'
+	@echo >&2 '*** (e.g. "make oldconfig" or "make menuconfig"'
+	@echo >&2 '***'
+	@false
+
+compile_commands.json:
+	$(Q)bear -- $(MAKE) -f scripts/makefile.build obj=$(obj)
+
+PHONY += menuconfig
+menuconfig:
+	$(Q)$(MAKE) -f scripts/kconfig/makefile menuconfig
+
+PHONY += defconfig
+defconfig:
+	$(Q)$(MAKE) -f scripts/kconfig/makefile defconfig
+
+clang-tidy: compile_commands.json
+	$(Q)clang-tidy -p=. $(shell find . -name '*.c' -o -name '*.h' | grep -v './scripts/')
+
+clang-format:
+	$(Q)clang-format -i $(shell find . -name '*.c' -o -name '*.h' | grep -v './scripts/')
+
+%/include/config/auto.conf %/include/generated/autoconf.h: $(KCONFIG_CONFIG) compile_commands.json
+	$(Q)$(MAKE) -f scripts/kconfig/makefile syncconfig
+
+.PHONY: $(PHONY)
-- 
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