diff --git a/.gitignore b/.gitignore index de756d76..127eb5d8 100644 --- a/.gitignore +++ b/.gitignore @@ -2,17 +2,17 @@ *.bin *.ZXE *.MAP -src/Boot/ +/src/Boot *.ELF *.elf *.sys *.SYS -src/EFI/ -build/limine -build/ovmf +/src/EFI +/build/limine +/build/ovmf *.iso *.raw *.hdd *.o *.d -zealbooter/limine.h +/zealbooter/limine.h diff --git a/zealbooter/GNUmakefile b/zealbooter/GNUmakefile index ff39eaf3..d8f30e28 100644 --- a/zealbooter/GNUmakefile +++ b/zealbooter/GNUmakefile @@ -1,8 +1,11 @@ +# Nuke built-in rules and variables. +override MAKEFLAGS += -rR + # This is the name that our final kernel executable will have. # Change as needed. override KERNEL := zealbooter.elf -# Convenience macro to reliably declare overridable command variables. +# Convenience macro to reliably declare user overridable variables. define DEFAULT_VAR = ifeq ($(origin $1),default) override $(1) := $(2) @@ -20,49 +23,54 @@ $(eval $(call DEFAULT_VAR,CC,cc)) # Same thing for "ld" (the linker). $(eval $(call DEFAULT_VAR,LD,ld)) -# User controllable CFLAGS. -CFLAGS ?= -g -O2 -pipe -Wall -Wextra +# User controllable C flags. +$(eval $(call DEFAULT_VAR,CFLAGS,-g -O2 -pipe -Wall -Wextra)) -# User controllable preprocessor flags. We set none by default. -CPPFLAGS ?= +# User controllable C preprocessor flags. We set none by default. +$(eval $(call DEFAULT_VAR,CPPFLAGS,)) # User controllable nasm flags. -NASMFLAGS ?= -F dwarf -g +$(eval $(call DEFAULT_VAR,NASMFLAGS,-F dwarf -g)) # User controllable linker flags. We set none by default. -LDFLAGS ?= +$(eval $(call DEFAULT_VAR,LDFLAGS,)) # Internal C flags that should not be changed by the user. -override CFLAGS += \ - -std=gnu11 \ - -ffreestanding \ +override CFLAGS += \ + -std=gnu11 \ + -ffreestanding \ -fno-stack-protector \ - -fno-stack-check \ - -fno-lto \ - -fno-pie \ - -fno-pic \ - -m64 \ - -march=x86-64 \ - -mabi=sysv \ - -mno-80387 \ - -mno-mmx \ - -mno-sse \ - -mno-sse2 \ - -mno-red-zone \ - -mcmodel=kernel \ - -MMD \ - -I. \ - -I./lib + -fno-stack-check \ + -fno-lto \ + -fno-pie \ + -fno-pic \ + -m64 \ + -march=x86-64 \ + -mabi=sysv \ + -mno-80387 \ + -mno-mmx \ + -mno-sse \ + -mno-sse2 \ + -mno-red-zone \ + -mcmodel=kernel + +# Internal C preprocessor flags that should not be changed by the user. +override CPPFLAGS := \ + -I. \ + -I./lib \ + $(CPPFLAGS) \ + -MMD \ + -MP # Internal linker flags that should not be changed by the user. -override LDFLAGS += \ - -nostdlib \ - -static \ - -m elf_x86_64 \ +override LDFLAGS += \ + -nostdlib \ + -static \ + -m elf_x86_64 \ -z max-page-size=0x1000 \ -T linker.ld -# Check if the linker supports -no-pie and enable it if it does +# Check if the linker supports -no-pie and enable it if it does. ifeq ($(shell $(LD) --help 2>&1 | grep 'no-pie' >/dev/null 2>&1; echo $$?),0) override LDFLAGS += -no-pie endif @@ -71,10 +79,11 @@ endif override NASMFLAGS += \ -f elf64 -# Use find to glob all *.c, *.S, and *.asm files in the directory and extract the object names. -override CFILES := $(shell find . -type f -name '*.c') -override ASFILES := $(shell find . -type f -name '*.S') -override NASMFILES := $(shell find . -type f -name '*.asm') +# Use "find" to glob all *.c, *.S, and *.asm files in the tree and obtain the +# object and header dependency file names. +override CFILES := $(shell find -L . -type f -name '*.c') +override ASFILES := $(shell find -L . -type f -name '*.S') +override NASMFILES := $(shell find -L . -type f -name '*.asm') override OBJ := $(CFILES:.c=.o) $(ASFILES:.S=.o) $(NASMFILES:.asm=.o) override HEADER_DEPS := $(CFILES:.c=.d) $(ASFILES:.S=.d) @@ -83,7 +92,7 @@ override HEADER_DEPS := $(CFILES:.c=.d) $(ASFILES:.S=.d) all: $(KERNEL) limine.h: - curl https://raw.githubusercontent.com/limine-bootloader/limine/trunk/limine.h -o $@ || cp ../build/limine/limine.h limine.h || echo "ERROR" + curl -Lo $@ https://github.com/limine-bootloader/limine/raw/trunk/limine.h || cp ../build/limine/limine.h limine.h || echo "ERROR" # Link rules for the final kernel executable. $(KERNEL): $(OBJ) @@ -94,11 +103,11 @@ $(KERNEL): $(OBJ) # Compilation rules for *.c files. %.o: %.c limine.h - $(CC) $(CPPFLAGS) $(CFLAGS) -c $< -o $@ + $(CC) $(CFLAGS) $(CPPFLAGS) -c $< -o $@ # Compilation rules for *.S files. %.o: %.S limine.h - $(CC) $(CPPFLAGS) $(CFLAGS) -c $< -o $@ + $(CC) $(CFLAGS) $(CPPFLAGS) -c $< -o $@ # Compilation rules for *.asm (nasm) files. %.o: %.asm diff --git a/zealbooter/linker.ld b/zealbooter/linker.ld index 36452585..529a4dd1 100644 --- a/zealbooter/linker.ld +++ b/zealbooter/linker.ld @@ -40,6 +40,10 @@ SECTIONS *(.data .data.*) } :data + /* NOTE: .bss needs to be the last thing mapped to :data, otherwise lots of */ + /* unnecessary zeros will be written to the binary. */ + /* If you need, for example, .init_array and .fini_array, those should be placed */ + /* above this. */ .bss : { *(COMMON) *(.bss .bss.*)