refactor: reorganize bootloader source code

Makefile

@@ -4,12 +4,13 @@ TOPDIR     := $(dir $(realpath $(lastword $(MAKEFILE_LIST))))
 SYSROOTDIR := $(TOPDIR)/sysroot
 TOOLSDIR   := $(TOPDIR)/tools
 
-RM = echo
+AS = fasm
+RM = rm -f
 
 MK_BUGREPORT := \"https://git.cute.engineering/d0p1/StupidOS/issues\"
 MK_COMMIT    := \"$(shell git rev-parse --short HEAD)\"
 
-SUBDIRS	:= tools include boot kernel lib bin
+SUBDIRS	:= external tools include boot kernel lib bin
 
 TARGET	= stupid.tar.gz floppy_boot.img
 ifneq ($(OS),Windows_NT)
@@ -28,7 +29,7 @@ clean: GOAL:=clean
 .PHONY: $(SUBDIRS)
 $(SUBDIRS):
 	@echo "📁 $@"
-	DESTDIR=$(SYSROOTDIR) $(MAKE) -C $@ $(GOAL)
+	@DESTDIR=$(SYSROOTDIR) $(MAKE) -C $@ $(GOAL)
 
 .PHONY: stupid.iso
 stupid.iso: $(SUBDIRS)
@@ -46,8 +47,8 @@ stupid.tar.gz: $(SUBDIRS)
 floppy_boot.img: $(SUBDIRS)
 	dd if=/dev/zero of=$@ bs=512 count=1440
 	mformat -C -f 1440 -i $@
-	dd if=boot/bootsector.bin of=$@ conv=notrunc
-	mcopy -i $@ boot/stpdboot.sys ::/STPDBOOT.SYS
+	dd if=boot/bootsect/bootsector.bin of=$@ conv=notrunc
+	mcopy -i $@ boot/loader/stpdldr.sys ::/STPDLDR.SYS
 	mcopy -i $@ kernel/vmstupid.sys ::/VMSTUPID.SYS
 
 .PHONY: run
@@ -63,4 +64,4 @@ run: all
 
 .PHONY: clean
 clean: $(SUBDIRS)
-	$(RM) $(TARGET) $(SYSROOTDIR)
+	$(RM) $(TARGET) 

bin/Makefile

@@ -1,13 +1,11 @@
-SUBDIRS = cmd
-
 TOPGOALS = all clean install
 
 SUBDIRS = cmd
 
 .PHONY: $(SUBDIRS)
 $(SUBDIRS):
 	@echo "📁 bin/$@"
-	DESTDIR=$(DESTDIR)/bin $(MAKE) -C $@ $(MAKECMDGOALS)
+	@DESTDIR=$(DESTDIR)/bin $(MAKE) -C $@ $(MAKECMDGOALS)
 
 .PHONY: $(TOPGOALS)
 $(TOPGOALS): $(SUBDIRS)

bin/cmd/cmd.asm

@@ -1,11 +1,13 @@
-	format COFF
-
-	section '.text' code
-
-	public main
-main:
-	int 0x2A
-
-	section '.data' data
-
-	INCLUDE 'builtins.inc'
+	format COFF
+
+	section '.text' code
+
+	public main
+	public _start
+_start:	
+main:
+	int 0x2A
+
+	section '.data' data
+
+	INCLUDE 'builtins.inc'

boot/Makefile

@@ -1,39 +1,11 @@
-AS = fasm
-RM = rm
+TOPGOALS = all clean install
 
-TARGET = bootsector.bin stpdboot.sys bootia32.efi
+SUBDIRS = bootsect loader efi
 
-STAGE0_SRCS	= boot0.asm \
-			const.inc \
-			fat12.inc
+.PHONY: $(SUBDIRS)
+$(SUBDIRS):
+	@echo "📁 boot/$@"
+	@DESTDIR=$(DESTDIR) $(MAKE) -C $@ $(MAKECMDGOALS)
 
-STAGE1_SRCS	= boot1.asm \
-			const.inc \
-			a20.inc \
-			multiboot.inc
-
-BOOTIA32_EFI_SRCS = bootia32.asm \
-					uefi.inc
-
-.PHONY: all
-all: $(TARGET)
-
-bootsector.bin: $(STAGE0_SRCS)
-	$(AS) boot0.asm $@
-
-stpdboot.sys: $(STAGE1_SRCS)
-	$(AS) boot1.asm $@
-
-bootia32.efi: $(BOOTIA32_EFI_SRCS)
-	$(AS) bootia32.asm $@
-
-.PHONY: clean
-clean:
-	$(RM) $(TARGET)
-
-.PHONY: install
-install: $(TARGET)
-	@ mkdir -p $(DESTDIR)
-	install stpdboot.sys $(DESTDIR)
-	@ mkdir -p $(DESTDIR)/EFI/BOOT
-	install bootia32.efi $(DESTDIR)/EFI/BOOT
+.PHONY: $(TOPGOALS)
+$(TOPGOALS): $(SUBDIRS)

boot/bootsect/Makefile

@@ -0,0 +1,18 @@
+TARGET = bootsector.bin
+
+FLOPPY_SRCS	= floppy.asm \
+			../common/const.inc \
+			../common/fat12.inc
+
+.PHONY: all
+all: $(TARGET)
+
+bootsector.bin: $(FLOPPY_SRCS)
+	$(AS) floppy.asm $@
+
+.PHONY: clean
+clean:
+	$(RM) $(TARGET)
+
+.PHONY: install
+install: $(TARGET)

boot/bootsect/floppy.asm

@@ -0,0 +1,122 @@
+	format binary
+	use16
+
+	include '../common/const.inc'
+
+	org BOOTSECT_BASE
+
+	jmp short _start
+	nop
+
+	; Boot Record
+OEM_identifier      db 'STUPID  '
+bytes_per_sector    dw 512
+sectors_per_cluster db 1
+reserved_sectors    dw 1
+FAT_count           db 2
+root_dir_entries    dw 224
+total_sectors       dw 2880
+media_desc_type     db 0xF0
+sectors_per_FAT     dw 9
+sectors_per_track   dw 18
+heads_per_cylinder  dw 2
+hidden_sectors      dd 0
+large_sector_count  dd 0
+
+	; Extended Boot Record
+drive_number db 0x0
+reserved     db 0x0
+signature    db 0x29   		; 0x28 or 0x29
+volume_id    dd 0xB00B135 	; hope mine will grow :'(
+volume_label db 'Stupid Boot'
+system_id    db 'FAT12  '
+
+
+_start:
+	cli
+	cld
+	jmp 0x0:.canonicalize_cs
+
+.canonicalize_cs:
+	xor ax, ax
+	mov ds, ax
+	mov ss, ax
+	mov es, ax
+	mov sp, 0x7c00
+
+	mov [drive_number], dl
+
+	; reset floppy disk
+@@:
+	mov dl, [drive_number]
+	xor ah, ah
+	int 0x13
+	jc @b
+
+	call fat_load_root
+
+	; search in root directory
+
+	mov si, kernel_file
+	call fat_search_root
+	jc .error_not_found
+	mov [kernel_start], ax
+
+	mov si, stage1_file
+	call fat_search_root
+	jc .error_not_found
+	mov [stage1_start], ax
+
+	; load fat
+	xor ax, ax
+	mov al, [FAT_count]
+	mul word [sectors_per_FAT]
+	mov cx, ax
+	mov ax, [reserved_sectors]
+
+	xor bx, bx
+
+	call disk_read_sectors
+
+	; preload kernel
+	mov ax, KERNEL_PRELOAD/0x10
+	mov es, ax
+	mov ax, [kernel_start]
+	xor bx, bx
+	call fat_load_binary
+
+	; load stage 2
+	mov ax, LOADER_BASE/0x10
+	mov es, ax
+	mov ax, [stage1_start]
+	xor bx, bx
+	call fat_load_binary
+
+	jmp 0x0:LOADER_BASE
+
+.error_not_found:
+	push si
+	mov si, msg_error
+	call bios_print
+	pop si
+	call bios_print
+	mov si, msg_not_found
+	call bios_print
+	hlt
+	jmp $
+
+	include '../common/bios.inc'
+	include '../common/fat12.inc'
+
+msg_error                  db "ERROR: ", 0
+msg_not_found              db " not found", CR, LF, 0
+
+kernel_file db "VMSTUPIDSYS", 0
+stage1_file db "STPDLDR SYS", 0
+
+kernel_start dw 0x0
+stage1_start dw 0x0
+
+
+	rb 0x7C00+512-2-$
+	db 0x55, 0xAA