d0p1/StupidOS
d0p1/StupidOS
2
3
Fork 0
Code Issues 26 Pull requests Packages Projects 3 Releases Wiki Activity

refactor: move multiboot struct from kernel to loader

Browse source
This commit is contained in:
d0p1 🏳️‍⚧️ 2024-03-03 16:38:35 +01:00
parent e71c7ce555
commit 060c2835f6
11 changed files with 308 additions and 241 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

5
boot/Makefile
View file

@ -9,7 +9,8 @@ STAGE0_SRCS = boot0.asm \
STAGE1_SRCS = boot1.asm \
const.inc \
a20.inc
a20.inc \
multiboot.inc
.PHONY: all
all: $(TARGET)
@ -27,3 +28,5 @@ clean:
.PHONY: install
install: $(TARGET)
@ mkdir -p $(DESTDIR)
install stpdboot.sys $(DESTDIR)

31
boot/README.org
View file

@ -1,2 +1,33 @@
#+TITLE: StupidOS Bootloader
#+begin_src
0x100000 +-----------------------+
| |
| Reserved |
| |
0x080000 +-----------------------+
| |
| Kernel preload |
| |
0x00F000 +-----------------------+
| |
| buffer |
| |
0x008000 +-----------------------+
| |
| Boot0 |
| |
0x007000 +-----------------------+
| |
| Real mode stack |
| |
0x006000 +-----------------------+
| |
| Boot1 |
| |
0x001000 +-----------------------+
| |
| Reserved (BIOS & IVT) |
| |
0x000000 +-----------------------+
#+end_src

43
boot/boot1.asm
View file

@ -1,9 +1,18 @@
INCLUDE 'const.inc'
INCLUDE 'multiboot.inc'
ORG STAGE1_BASE
USE16
stage2:
jmp _start
mb_header MultibootHeader mb_header
_start:
cmp eax, MULTIBOOT_MAGIC
je .multiboot
;; non multiboot process
push cs
pop ds
@ -13,9 +22,22 @@ stage2:
call a20_enable
jc .error_a20
; detect memory
call memory_get_map
jc .error_memory
xchg bx, bx
call video_setup
.multiboot:
jmp .hang
.error_memory:
mov si, msg_error_memory
jmp .error
.error_a20:
mov si, msg_error_a20
.error:
call bios_print
.hang:
hlt
@ -23,6 +45,21 @@ stage2:
INCLUDE 'a20.inc'
INCLUDE 'utils.inc'
INCLUDE 'memory.inc'
INCLUDE 'video.inc'
msg_stage2 db "StupidOS Bootloader (Stage 1)", 0x0D, 0x0A, 0
msg_error_a20 db "ERROR: can't enable a20 line", 0x0D, 0x0A, 0
msg_stage2 db "StupidOS Bootloader (Stage 1)", CR, LF, 0
msg_error_a20 db "ERROR: can't enable a20 line", CR, LF, 0
msg_error_memory db "ERROR: can't detect available memory", CR, LF, 0
;;
bi_screen_width: dw 0
bi_screen_height: dw 0
_edata:
; BSS
rb 0x4000
_end:

5
boot/const.inc
View file

@ -1,5 +1,6 @@
CR = 0x0D
LF = 0x0A
; -------- Address ----------
STAGE0_BASE = 0x7C00
STAGE1_BASE = 0x1000
@ -7,3 +8,7 @@ DISK_BUFFER = 0x8000
KERNEL_PRELOAD = 0xF000
STACK_TOP = 0x7000
; ---------- Video ------------
VIDEO_WIDTH = 1024
VIDEO_HEIGHT = 768
VIDEO_DEPTH = 32

28
boot/memory.inc Normal file
View file

@ -0,0 +1,28 @@
; 0xE820 Get System Memory Map
; EAX=0x0000E820
; EDX=0x534D4150
; EBX=0x0 or continuation value
; ECX=buffer size
; ES:SI = buffer
memory_do_E820:
ret
memory_get_map:
call memory_do_E820
jnc .end
; try 0x88
clc
mov ah, 0x88
int 0x15
jc .error
test ax, ax
je .error
.end:
clc
ret
.error:
stc
ret

19
kernel/boot/multiboot.inc → boot/multiboot.inc
View file

@ -4,25 +4,26 @@ MULTIBOOT_MAGIC = 0x2BADB002
MULTIBOOT_HDR_ALIGN = 0x1
MULTIBOOT_HDR_MEMINFO = 0x2
MULTIBOOT_HDR_VIDEO = 0x4
MULTIBOOT_FLAGS = MULTIBOOT_HDR_ALIGN or MULTIBOOT_HDR_MEMINFO or MULTIBOOT_HDR_VIDEO
struc MultibootHeader flags,addr,width,height,depth
struc MultibootHeader addr
{
.magic dd MULTIBOOT_HDR_MAGIC
.flags dd flags
.checksum dd -(MULTIBOOT_HDR_MAGIC + flags)
.flags dd MULTIBOOT_FLAGS
.checksum dd -(MULTIBOOT_HDR_MAGIC + MULTIBOOT_FLAGS)
; address fields (we'll just skip them)
.header_addr dd addr
.load_addr dd 0x100000
.load_end_addr dd _edata - KBASE
.bss_end_addr dd _end - KBASE
.load_addr dd STAGE1_BASE
.load_end_addr dd _edata - STAGE1_BASE
.bss_end_addr dd _end - STAGE1_BASE
.entry_addr dd _start
; Video mode
.mode_type dd 0x0
.width dd width
.height dd height
.depth dd depth
.width dd VIDEO_WIDTH
.height dd VIDEO_HEIGHT
.depth dd VIDEO_DEPTH
}
struc MultibootData

3
boot/video.inc Normal file
View file

@ -0,0 +1,3 @@
video_setup:
ret

4
kernel/Makefile
View file

@ -2,11 +2,9 @@ AS = fasm
RM = rm -f
INSTALL = install
KERNEL = vmstupid
KERNEL = vmstupid.sys
SRCS = kernel.asm \
const.inc \
boot/multiboot.inc \
boot/boot.inc \
mm/mm.inc
.PHONY: all

35
kernel/boot/boot.inc
View file

@ -1,35 +0,0 @@
ORG 0x100000
ALIGN 4
USE32
INCLUDE 'boot/multiboot.inc'
INCLUDE 'const.inc'
mb_header MultibootHeader MB_FLAGS, mb_header, VIDEO_WIDTH, VIDEO_HEIGHT, VIDEO_DEPTH
_start:
cli
cmp eax, MULTIBOOT_MAGIC
jne hang
; iterate over memory
;
;
xor esi, esi
mov edi, kernel_page_table - KBASE
mov ecx, kernel_page_directory - KBASE
mov cr3, ecx
mov ecx, cr0
hang:
hlt
jmp $-1
; SEGMENT readable writable
boot_struct dd 0x0

7
kernel/const.inc
View file

@ -5,13 +5,6 @@ PSIZE = 0x1000
VERSION_MAJOR = 1
VERSION_MINOR = 0
; --------- BOOT PARAMS ---------
MB_FLAGS = MULTIBOOT_HDR_ALIGN or MULTIBOOT_HDR_MEMINFO or MULTIBOOT_HDR_VIDEO
VIDEO_WIDTH = 1024
VIDEO_HEIGHT = 768
VIDEO_DEPTH = 32
; --------- Registers ------------
CR0_PE = 0x00000001
CR0_MP = 0x00000002

7
kernel/kernel.asm
View file

@ -1,6 +1,9 @@
INCLUDE 'boot/boot.inc'
INCLUDE 'const.inc'
ORG $ + KBASE
ORG KBASE
USE32
jmp kmain
INCLUDE 'mm/mm.inc'