move to grub

.build/iso/boot/grub/grub.cfg

@@ -0,0 +1,4 @@
+menuentry "nub-os" {
+    multiboot /boot/kernel.bin
+    boot
+}

.gitignore

@@ -1,2 +1,3 @@
 *.bin
 *.o
+*.iso

grub.cfg

@@ -0,0 +1,4 @@
+menuentry "nub-os" {
+    multiboot /boot/kernel.bin
+    boot
+}

makefile

@@ -0,0 +1,28 @@
+CC = i386-elf-gcc -ffreestanding -m32
+
+.build/nub-os.iso: .build/kernel.bin
+	mkdir -p .build/iso/boot/grub
+	cp grub.cfg .build/iso/boot/grub
+	cp .build/kernel.bin .build/iso/boot/
+	grub-mkrescue -o .build/nub-os.iso .build/iso/
+
+.build/kernel.bin: .build/entry.o .build/kernel.o .build/mem.o .build/print.o
+	i386-elf-ld -Ttext 0x100000 -o .build/kernel.bin .build/entry.o .build/kernel.o .build/mem.o .build/print.o
+
+.build/kernel.o: src/kernel.c
+	$(CC) -c -o .build/kernel.o src/kernel.c
+
+.build/mem.o: src/mem.c
+	$(CC) -c -o .build/mem.o src/mem.c
+
+.build/print.o: src/print.c
+	$(CC) -c -o .build/print.o src/print.c
+
+.build/entry.o: src/entry.asm
+	nasm -f elf -o .build/entry.o src/entry.asm
+
+run: .build/nub-os.iso
+	qemu-system-x86_64 -cdrom .build/nub-os.iso
+
+clean:
+	@rm -r .build/* 2>/dev/null || true

src/boot/bootloader.asm

@@ -1,84 +0,0 @@
-[org 0x7c00]
-[bits 16]
-
-KERNEL_INIT equ 0x1000
-
-mov [BOOT_DISK], dl
-
-xor ax, ax
-mov es, ax
-mov ds, ax
-mov bp, 0x8000
-mov sp, bp
-
-mov bx, KERNEL_INIT
-mov dh, 2
-
-mov ah, 0x02
-mov al, dh
-mov ch, 0x00
-mov dh, 0x00
-mov cl, 0x02
-mov dl, [BOOT_DISK]
-int 0x13
-
-mov ah, 0x0
-mov al, 0x3
-int 0x10
-
-CODE_SEG equ gdt_code - gdt_start
-DATA_SEG equ gdt_data - gdt_start
-
-cli
-lgdt [gdt_descriptor]
-mov eax, cr0
-or eax, 1
-mov cr0, eax
-jmp CODE_SEG:start_protected_mode
-jmp $
-
-BOOT_DISK: db 0
-
-gdt_start:
-    dd 0x0
-    dd 0x0
-
-    gdt_code:
-        dw 0xffff
-        dw 0x0
-        db 0x0
-        db 0b10011010
-        db 0b11001111
-        db 0x0
-
-    gdt_data:
-        dw 0xffff
-        dw 0x0
-        db 0x0
-        db 0b10010010
-        db 0b11001111
-        db 0x0
-
-gdt_end:
-
-gdt_descriptor:
-    dw gdt_end - gdt_start - 1
-    dd gdt_start
-
-[bits 32]
-start_protected_mode:
-    mov ax, DATA_SEG
-	mov ds, ax
-	mov ss, ax
-	mov es, ax
-	mov fs, ax
-	mov gs, ax
-
-	mov ebp, 0x90000
-	mov esp, ebp
-
-    jmp KERNEL_INIT
-    hlt
-
-times 510-($-$$) db 0
-dw 0xaa55

src/boot/makefile

@@ -1,5 +0,0 @@
-bootloader.bin: bootloader.asm
-	nasm -f bin -o bootloader.bin bootloader.asm
-
-clean:
-	@rm *.o *.bin 2>/dev/null || true

src/entry.asm

@@ -0,0 +1,21 @@
+extern kernel_init
+
+section .multiboot
+align 4
+    dd 0x1BADB002          ; multiboot magic number
+    dd 0x0                 ; flags
+    dd -(0x1BADB002+0x0)   ; checksum
+
+section .text
+global _start
+_start:
+    cli
+    mov esp, stack_top
+    call kernel_init
+.hang:
+    hlt
+    jmp .hang
+
+section .bss
+resb 8192
+stack_top:

src/kernel/entry.asm

@@ -1,4 +0,0 @@
-[extern kernel_init]
-[bits 32]
-call kernel_init
-hlt

src/kernel/linker.ld

@@ -1,22 +0,0 @@
-ENTRY(kernel_init)
-
-SECTIONS {
-    . = 0x1000;
-
-    .text : {
-        *(.text)
-    }
-
-    .rodata : {
-        *(.rodata)
-    }
-
-    .data : {
-        *(.data)
-    }
-
-    .bss : {
-        *(.bss)
-        *(COMMON)
-    }
-}

src/kernel/makefile

@@ -1,19 +0,0 @@
-CC = i386-elf-gcc -ffreestanding -m32
-
-kernel.bin: entry.o kernel.o linker.ld mem.o print.o
-	i386-elf-ld -o kernel.bin -T linker.ld entry.o kernel.o mem.o print.o --oformat binary
-
-kernel.o: kernel.c
-	$(CC) -c -o kernel.o kernel.c
-
-mem.o: mem.c
-	$(CC) -c -o mem.o mem.c
-
-print.o: print.c
-	$(CC) -c -o print.o print.c
-
-entry.o: entry.asm
-	nasm -f elf entry.asm
-
-clean:
-	@rm *.o *.bin 2>/dev/null || true

src/makefile

@@ -1,19 +0,0 @@
-.PHONY: kernel/kernel.bin boot/bootloader.bin
-
-os.bin: boot/bootloader.bin kernel/kernel.bin
-	dd if=/dev/zero of=zeroes.bin bs=1 count=10240
-	cat boot/bootloader.bin kernel/kernel.bin zeroes.bin > os.bin
-
-kernel/kernel.bin:
-	pushd kernel; make kernel.bin; popd
-
-boot/bootloader.bin:
-	pushd boot; make bootloader.bin; popd
-
-run: os.bin
-	qemu-system-x86_64 -drive file=os.bin,format=raw,index=0,media=disk
-
-clean:
-	pushd kernel; make clean; popd
-	pushd boot; make clean; popd
-	@rm *.o *.bin 2>/dev/null || true