Readme, makefile, clang-format

.clang-format

@@ -0,0 +1,8 @@
+BasedOnStyle: LLVM
+IndentWidth: 4
+TabWidth: 4
+UseTab: Never
+ColumnLimit: 80
+AllowShortLoopsOnASingleLine: true
+AlwaysBreakTemplateDeclarations: true
+BreakConstructorInitializers: BeforeComma

Makefile

@@ -0,0 +1,49 @@
+# Makefile for the Fusion operating system.
+# Make things fixable, not autocorrecting
+
+# TODO: Toolchain installation should be documented in the README
+# https://github.com/xpack-dev-tools/riscv-none-elf-gcc-xpack
+TOOLPREFIX = riscv-none-elf
+
+CC = $(TOOLPREFIX)-gcc
+AS = $(TOOLPREFIX)-gas
+LD = $(TOOLPREFIX)-ld
+OBJCOPY = $(TOOLPREFIX)-objcopy
+OBJDUMP = $(TOOLPREFIX)-objdump
+
+# TODO: Document these options with clear descriptions, it should be readable
+# by people not intimately familiar with machine code and/or gcc tooling.
+CFLAGS = -Wall -Werror -O -fno-omit-frame-pointer -ggdb -gdwarf-2
+CFLAGS += -MD
+CFLAGS += -mcmodel=medany
+CFLAGS += -ffreestanding -fno-common -nostdlib -mno-relax
+CFLAGS += -I.
+CFLAGS += -fno-pie -no-pie
+CFLAGS += -fno-stack-protector
+CFLAGS += -march=rv64gc -mabi=lp64
+
+LDFLAGS = -z max-page-size=4096
+LDFLAGS += -m elf64lriscv
+
+all: kernel.elf
+
+%.o: %.c
+	@echo CC $@
+	@$(CC) $(CFLAGS) -nostdinc -I. -c $< -o $@
+
+%.o: %.S
+	@echo CC-AS $@
+	@$(CC) $(CFLAGS) -c $< -o $@
+
+kernel.elf: trap.o kernelvec.o entry.o start.o kernel.o spinlock.o
+	@echo LD $@
+	@$(LD) $(LDFLAGS) -T kernel.ld -o $@ $^
+
+kernel.bin: kernel.elf
+	$(OBJCOPY) -O binary $< $@
+
+clean:
+	rm -f *.o *.d *.elf *.bin
+
+-include *.d
+

README.md

@@ -1,2 +1,8 @@
 # fusion
 
+For a quick reference on RISC-V assembly:
+- https://risc-v.guru/instructions/
+
+Toolchains:
+- https://github.com/xpack-dev-tools/riscv-none-elf-gcc-xpack
+- https://github.com/xpack-dev-tools/qemu-riscv-xpack/