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Diffstat (limited to 'scripts/Kconfig.mk')
| -rw-r--r-- | scripts/Kconfig.mk | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/scripts/Kconfig.mk b/scripts/Kconfig.mk new file mode 100644 index 0000000..2bdc934 --- /dev/null +++ b/scripts/Kconfig.mk @@ -0,0 +1,238 @@ +# SPDX-License-Identifier: GPL-2.0-or-later +# Copyright (C) 2026 Richard Qin +# +# scripts/Kconfig.mk — Kernel Configuration Infrastructure +# +# This file is the heart of the LumeOS build-time configuration system. +# It mirrors the role of Linux's Kconfig + auto.conf pipeline: +# +# 1. Developer edits `.config` (or copies from arch/$(ARCH)/defconfig) +# 2. This file reads `.config`, applies defaults for anything missing, +# validates constraints, and exports two things: +# a) KCPPFLAGS — a set of -DCONFIG_xxx=value flags for the compiler +# b) $(BUILD)/generated/autoconf.h — the same values as C #defines +# +# Design Principles (matching Linux conventions): +# - Every CONFIG_ symbol has a default defined HERE, so a bare `make` +# with no .config still builds a sane kernel. +# - Boolean options use 'y' / 'n'. Numeric options are plain integers. +# - The generated autoconf.h uses the exact same names so that +# `#ifdef CONFIG_DEBUG` works identically in Makefile and C. +# ====================================================================== + +# ------------------------------------------------------------------ +# §1 Read user configuration (if it exists) +# ------------------------------------------------------------------ +-include .config + +# ------------------------------------------------------------------ +# §2 Provide defaults for every CONFIG_ symbol +# +# ?= means "set only if not already set (by .config or CLI)". +# This is the single source of truth for default values. +# ------------------------------------------------------------------ + +# --- Platform ------------------------------------------------------- +CONFIG_ARCH ?= riscv + +# --- CPU / SMP ------------------------------------------------------ +CONFIG_NR_CPUS ?= 8 + +# --- Scheduler ------------------------------------------------------ +CONFIG_HZ ?= 100 +CONFIG_NR_PRIORITIES ?= 32 + +# --- Memory Management ---------------------------------------------- +CONFIG_PAGE_SIZE ?= 4096 +CONFIG_MAX_ORDER ?= 11 +CONFIG_KERNEL_STACK_SIZE ?= 8192 + +# --- Security / Hardening ------------------------------------------- +CONFIG_KASLR ?= y +CONFIG_KASLR_POLICY_ID ?= 0 +CONFIG_KASLR_LOG_LEVEL ?= 1 +CONFIG_STACK_CANARY ?= y +CONFIG_KERNEL_COMPRESSED ?= y + +# --- Debug ----------------------------------------------------------- +CONFIG_DEBUG ?= y +CONFIG_DEBUG_LOCKS ?= y +CONFIG_SELFTEST ?= y +CONFIG_KLOG ?= y + +# --- Initramfs ------------------------------------------------------ +# Source for the initramfs image. Accepted forms (auto-detected by +# scripts/gen_initramfs.sh): +# - a listing file (gen_init_cpio format) → built into a cpio +# - a directory → packed recursively +# - a *.cpio file → used as-is +# Override on the command line or pin in .config: +# make all CONFIG_INITRAMFS_SOURCE=/path/to/rootfs +CONFIG_INITRAMFS_SOURCE ?= usr/default_cpio_list +CONFIG_INITRAMFS_ROOT_UID ?= 0 +CONFIG_INITRAMFS_ROOT_GID ?= 0 + +# ------------------------------------------------------------------ +# §3 Derived constants (computed from CONFIG_ symbols) +# +# These follow Linux's pattern of expressing dependent values +# so that C code never has to do its own derivation at runtime. +# ------------------------------------------------------------------ + +# Default priority = middle of the range +CONFIG_DEFAULT_PRIORITY = $(shell echo $$(( $(CONFIG_NR_PRIORITIES) / 2 ))) + +# Idle priority = lowest = NR_PRIORITIES - 1 +CONFIG_IDLE_PRIORITY = $(shell echo $$(( $(CONFIG_NR_PRIORITIES) - 1 ))) + +# Default time slice in ticks: 100ms worth of ticks +# (same as Linux CFS's sysctl_sched_min_granularity default) +CONFIG_DEFAULT_TIMESLICE = $(shell echo $$(( $(CONFIG_HZ) / 10 ))) + +# ------------------------------------------------------------------ +# §4 Export to C/C++ via -D flags +# +# KCPPFLAGS is appended to CFLAGS/CXXFLAGS in the main Makefile. +# Every CONFIG_xxx=<value> becomes -DCONFIG_xxx=<value>. +# Boolean 'y' options become -DCONFIG_xxx=1. +# ------------------------------------------------------------------ +KCPPFLAGS := + +# Numeric options — pass through as-is +KCPPFLAGS += -DCONFIG_NR_CPUS=$(CONFIG_NR_CPUS) +KCPPFLAGS += -DCONFIG_HZ=$(CONFIG_HZ) +KCPPFLAGS += -DCONFIG_NR_PRIORITIES=$(CONFIG_NR_PRIORITIES) +KCPPFLAGS += -DCONFIG_DEFAULT_PRIORITY=$(CONFIG_DEFAULT_PRIORITY) +KCPPFLAGS += -DCONFIG_IDLE_PRIORITY=$(CONFIG_IDLE_PRIORITY) +KCPPFLAGS += -DCONFIG_DEFAULT_TIMESLICE=$(CONFIG_DEFAULT_TIMESLICE) +KCPPFLAGS += -DCONFIG_PAGE_SIZE=$(CONFIG_PAGE_SIZE) +KCPPFLAGS += -DCONFIG_MAX_ORDER=$(CONFIG_MAX_ORDER) +KCPPFLAGS += -DCONFIG_KERNEL_STACK_SIZE=$(CONFIG_KERNEL_STACK_SIZE) + +# Boolean options — translate 'y' → 1 +ifeq ($(CONFIG_KASLR),y) +KCPPFLAGS += -DCONFIG_KASLR=1 +endif +KCPPFLAGS += -DCONFIG_KASLR_POLICY_ID=$(CONFIG_KASLR_POLICY_ID) +KCPPFLAGS += -DCONFIG_KASLR_LOG_LEVEL=$(CONFIG_KASLR_LOG_LEVEL) +ifeq ($(CONFIG_STACK_CANARY),y) +KCPPFLAGS += -DCONFIG_STACK_CANARY=1 +endif +ifeq ($(CONFIG_DEBUG),y) +KCPPFLAGS += -DCONFIG_DEBUG=1 +endif +ifeq ($(CONFIG_DEBUG_LOCKS),y) +KCPPFLAGS += -DCONFIG_DEBUG_LOCKS=1 +endif +ifeq ($(CONFIG_SELFTEST),y) +KCPPFLAGS += -DCONFIG_SELFTEST=1 +endif +ifeq ($(CONFIG_KLOG),y) +KCPPFLAGS += -DCONFIG_KLOG=1 +endif +ifeq ($(CONFIG_KERNEL_COMPRESSED),y) +KCPPFLAGS += -DCONFIG_KERNEL_COMPRESSED=1 +endif + +# ------------------------------------------------------------------ +# §5 Generate autoconf.h (analogous to Linux's include/generated/autoconf.h) +# +# This header is auto-generated at build time so that C code can +# #include <generated/autoconf.h> and see CONFIG_xxx macros without +# relying on -D flags alone. This is important for IDE integration. +# ------------------------------------------------------------------ +AUTOCONF_H := $(BUILD)/generated/autoconf.h + +define generate-autoconf + @mkdir -p $(dir $(AUTOCONF_H)) + @echo " GEN $(AUTOCONF_H)" + @echo "/* AUTO-GENERATED — DO NOT EDIT */" > $(AUTOCONF_H) + @echo "/* Generated by scripts/Kconfig.mk */" >> $(AUTOCONF_H) + @echo "#pragma once" >> $(AUTOCONF_H) + @echo "" >> $(AUTOCONF_H) + @echo "/* Platform */" >> $(AUTOCONF_H) + @echo "#define CONFIG_NR_CPUS $(CONFIG_NR_CPUS)" >> $(AUTOCONF_H) + @echo "" >> $(AUTOCONF_H) + @echo "/* Scheduler */" >> $(AUTOCONF_H) + @echo "#define CONFIG_HZ $(CONFIG_HZ)" >> $(AUTOCONF_H) + @echo "#define CONFIG_NR_PRIORITIES $(CONFIG_NR_PRIORITIES)" >> $(AUTOCONF_H) + @echo "#define CONFIG_DEFAULT_PRIORITY $(CONFIG_DEFAULT_PRIORITY)" >> $(AUTOCONF_H) + @echo "#define CONFIG_IDLE_PRIORITY $(CONFIG_IDLE_PRIORITY)" >> $(AUTOCONF_H) + @echo "#define CONFIG_DEFAULT_TIMESLICE $(CONFIG_DEFAULT_TIMESLICE)" >> $(AUTOCONF_H) + @echo "" >> $(AUTOCONF_H) + @echo "/* Memory Management */" >> $(AUTOCONF_H) + @echo "#define CONFIG_PAGE_SIZE $(CONFIG_PAGE_SIZE)" >> $(AUTOCONF_H) + @echo "#define CONFIG_MAX_ORDER $(CONFIG_MAX_ORDER)" >> $(AUTOCONF_H) + @echo "#define CONFIG_KERNEL_STACK_SIZE $(CONFIG_KERNEL_STACK_SIZE)" >> $(AUTOCONF_H) + @echo "" >> $(AUTOCONF_H) + @echo "/* Security */" >> $(AUTOCONF_H) + $(if $(filter y,$(CONFIG_KASLR)), @echo "#define CONFIG_KASLR 1" >> $(AUTOCONF_H)) + @echo "#define CONFIG_KASLR_POLICY_ID $(CONFIG_KASLR_POLICY_ID)" >> $(AUTOCONF_H) + @echo "#define CONFIG_KASLR_LOG_LEVEL $(CONFIG_KASLR_LOG_LEVEL)" >> $(AUTOCONF_H) + $(if $(filter y,$(CONFIG_STACK_CANARY)), @echo "#define CONFIG_STACK_CANARY 1" >> $(AUTOCONF_H)) + @echo "" >> $(AUTOCONF_H) + @echo "/* Debug */" >> $(AUTOCONF_H) + $(if $(filter y,$(CONFIG_DEBUG)), @echo "#define CONFIG_DEBUG 1" >> $(AUTOCONF_H)) + $(if $(filter y,$(CONFIG_DEBUG_LOCKS)), @echo "#define CONFIG_DEBUG_LOCKS 1" >> $(AUTOCONF_H)) + $(if $(filter y,$(CONFIG_SELFTEST)), @echo "#define CONFIG_SELFTEST 1" >> $(AUTOCONF_H)) + $(if $(filter y,$(CONFIG_KLOG)), @echo "#define CONFIG_KLOG 1" >> $(AUTOCONF_H)) + $(if $(filter y,$(CONFIG_KERNEL_COMPRESSED)), @echo "#define CONFIG_KERNEL_COMPRESSED 1" >> $(AUTOCONF_H)) +endef + +# ------------------------------------------------------------------ +# §6 Utility targets +# ------------------------------------------------------------------ + +# 'make defconfig' — reset .config to the arch default +.PHONY: defconfig savedefconfig showconfig + +defconfig: + @echo " DEFCFG arch/$(CONFIG_ARCH)/defconfig → .config" + @cp arch/$(CONFIG_ARCH)/defconfig .config + +# 'make savedefconfig' — save current effective config +savedefconfig: + @echo " SAVE .config" + @echo "# LumeOS Kernel Configuration (saved $$(date +%Y-%m-%d))" > .config + @echo "CONFIG_ARCH = $(CONFIG_ARCH)" >> .config + @echo "CONFIG_NR_CPUS = $(CONFIG_NR_CPUS)" >> .config + @echo "CONFIG_HZ = $(CONFIG_HZ)" >> .config + @echo "CONFIG_NR_PRIORITIES = $(CONFIG_NR_PRIORITIES)" >> .config + @echo "CONFIG_PAGE_SIZE = $(CONFIG_PAGE_SIZE)" >> .config + @echo "CONFIG_MAX_ORDER = $(CONFIG_MAX_ORDER)" >> .config + @echo "CONFIG_KERNEL_STACK_SIZE = $(CONFIG_KERNEL_STACK_SIZE)" >> .config + @echo "CONFIG_KASLR = $(CONFIG_KASLR)" >> .config + @echo "CONFIG_KASLR_POLICY_ID = $(CONFIG_KASLR_POLICY_ID)" >> .config + @echo "CONFIG_KASLR_LOG_LEVEL = $(CONFIG_KASLR_LOG_LEVEL)" >> .config + @echo "CONFIG_STACK_CANARY = $(CONFIG_STACK_CANARY)" >> .config + @echo "CONFIG_DEBUG = $(CONFIG_DEBUG)" >> .config + @echo "CONFIG_DEBUG_LOCKS = $(CONFIG_DEBUG_LOCKS)" >> .config + @echo "CONFIG_SELFTEST = $(CONFIG_SELFTEST)" >> .config + @echo "CONFIG_KLOG = $(CONFIG_KLOG)" >> .config + @echo "CONFIG_KERNEL_COMPRESSED = $(CONFIG_KERNEL_COMPRESSED)" >> .config + +# 'make showconfig' — print effective configuration +showconfig: + @echo "========================================" + @echo " LumeOS Effective Configuration" + @echo "========================================" + @echo " ARCH = $(CONFIG_ARCH)" + @echo " NR_CPUS = $(CONFIG_NR_CPUS)" + @echo " HZ = $(CONFIG_HZ)" + @echo " NR_PRIORITIES = $(CONFIG_NR_PRIORITIES)" + @echo " DEFAULT_PRIORITY = $(CONFIG_DEFAULT_PRIORITY)" + @echo " IDLE_PRIORITY = $(CONFIG_IDLE_PRIORITY)" + @echo " DEFAULT_TIMESLICE = $(CONFIG_DEFAULT_TIMESLICE)" + @echo " PAGE_SIZE = $(CONFIG_PAGE_SIZE)" + @echo " MAX_ORDER = $(CONFIG_MAX_ORDER)" + @echo " KERNEL_STACK_SIZE = $(CONFIG_KERNEL_STACK_SIZE)" + @echo " KASLR = $(CONFIG_KASLR)" + @echo " KASLR_POLICY_ID = $(CONFIG_KASLR_POLICY_ID)" + @echo " KASLR_LOG_LEVEL = $(CONFIG_KASLR_LOG_LEVEL)" + @echo " STACK_CANARY = $(CONFIG_STACK_CANARY)" + @echo " DEBUG = $(CONFIG_DEBUG)" + @echo " DEBUG_LOCKS = $(CONFIG_DEBUG_LOCKS)" + @echo " SELFTEST = $(CONFIG_SELFTEST)" + @echo " KLOG = $(CONFIG_KLOG)" + @echo " KERNEL_COMPRESSED = $(CONFIG_KERNEL_COMPRESSED)" + @echo "========================================" |