feat: scheduling, usermode, shell

programs/GNUmakefile

@@ -0,0 +1,74 @@
+# Nuke built-in rules and variables.
+MAKEFLAGS += -rR
+.SUFFIXES:
+
+# Target architecture.
+ARCH := x86_64
+
+# Auto-detect cross compiler from toolchain/local/.
+TOOLCHAIN_PREFIX := $(shell cd .. && pwd)/toolchain/local/bin/x86_64-elf-
+ifneq ($(wildcard $(TOOLCHAIN_PREFIX)gcc),)
+    CXX := $(TOOLCHAIN_PREFIX)g++
+else
+    CXX := g++
+endif
+
+# Compiler flags: freestanding, no stdlib, kernel-mode compatible.
+override CXXFLAGS := \
+    -std=gnu++20 \
+    -g -O2 -pipe \
+    -Wall \
+    -Wextra \
+    -nostdinc \
+    -ffreestanding \
+    -fno-stack-protector \
+    -fno-stack-check \
+    -fno-PIC \
+    -fno-rtti \
+    -fno-exceptions \
+    -ffunction-sections \
+    -fdata-sections \
+    -m64 \
+    -march=x86-64 \
+    -mno-80387 \
+    -mno-mmx \
+    -mno-sse \
+    -mno-sse2 \
+    -mno-red-zone \
+    -mcmodel=small \
+    -I include \
+    -isystem ../kernel/freestnd-c-hdrs/x86_64/include \
+    -isystem ../kernel/freestnd-cxx-hdrs/x86_64/include
+
+# Linker flags: freestanding static ELF.
+override LDFLAGS := \
+    -nostdlib \
+    -static \
+    -Wl,--build-id=none \
+    -Wl,--gc-sections \
+    -Wl,-m,elf_x86_64 \
+    -z max-page-size=0x1000 \
+    -T link.ld
+
+# Output directory.
+BINDIR := bin
+
+# Discover all programs (each subdirectory under src/ is a program).
+PROGRAMS := $(notdir $(wildcard src/*))
+
+# Build targets: one ELF per program.
+TARGETS := $(addprefix $(BINDIR)/,$(addsuffix .elf,$(PROGRAMS)))
+
+.PHONY: all clean
+
+all: $(TARGETS)
+
+# Build each program from its source files.
+# For now each program is a single .cpp file compiled and linked directly.
+$(BINDIR)/%.elf: src/%/main.cpp link.ld GNUmakefile
+	mkdir -p $(BINDIR) obj/$*
+	$(CXX) $(CXXFLAGS) -c src/$*/main.cpp -o obj/$*/main.o
+	$(CXX) $(CXXFLAGS) $(LDFLAGS) obj/$*/main.o -o $@
+
+clean:
+	rm -rf $(BINDIR) obj