Merge pull request #100 from Zeal-Operating-System/zealbooter-update

zealbooter: Rebase on latest limine-barebones code

.gitignore

@@ -2,17 +2,17 @@
 *.bin
 *.ZXE
 *.MAP
-src/Boot/
+/src/Boot
 *.ELF
 *.elf
 *.sys
 *.SYS
-src/EFI/
+/src/EFI
-build/limine
+/build/limine
-build/ovmf
+/build/ovmf
 *.iso
 *.raw
 *.hdd
 *.o
 *.d
-zealbooter/limine.h
+/zealbooter/limine.h

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)
@@ -20,17 +23,17 @@ $(eval $(call DEFAULT_VAR,CC,cc))
 # Same thing for "ld" (the linker).
 $(eval $(call DEFAULT_VAR,LD,ld))
 
-# User controllable CFLAGS.
+# User controllable C flags.
-CFLAGS ?= -g -O2 -pipe -Wall -Wextra
+$(eval $(call DEFAULT_VAR,CFLAGS,-g -O2 -pipe -Wall -Wextra))
 
-# User controllable preprocessor flags. We set none by default.
+# User controllable C preprocessor flags. We set none by default.
-CPPFLAGS ?=
+$(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 += \
@@ -49,10 +52,15 @@ override CFLAGS +=       \
     -mno-sse \
     -mno-sse2 \
     -mno-red-zone \
-    -mcmodel=kernel      \
+    -mcmodel=kernel
-    -MMD                 \
+
+# Internal C preprocessor flags that should not be changed by the user.
+override CPPFLAGS := \
     -I. \
-    -I./lib
+    -I./lib \
+    $(CPPFLAGS) \
+    -MMD \
+    -MP
 
 # Internal linker flags that should not be changed by the user.
 override LDFLAGS += \
@@ -62,7 +70,7 @@ override LDFLAGS +=         \
     -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.
+# Use "find" to glob all *.c, *.S, and *.asm files in the tree and obtain the
-override CFILES := $(shell find . -type f -name '*.c')
+# object and header dependency file names.
-override ASFILES := $(shell find . -type f -name '*.S')
+override CFILES := $(shell find -L . -type f -name '*.c')
-override NASMFILES := $(shell find . -type f -name '*.asm')
+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

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.*)