josh/hos
1
0
Fork 0
Code Issues 1 Pull Requests Projects Releases Wiki Activity

Import backup from 2003-08-11

Browse Source
This commit is contained in:
Josh Holtrop 2003-08-11 22:00:00 -04:00
parent 9035beda29
commit 1c3e9ebdc4
4 changed files with 184 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
bootdef.inc
View File

@ -1,9 +1,17 @@
%define BOOT_FAT_SEG 0x07E0 ;right after boot sector
%define BOOT_ROOT_SEG 0x0900 ;right after FAT
%define BOOT_STAGE2_SEG 0x0B00 ;right after KERNEL_SEG
%define BOOT_STAGE2_ADD 0xB000 ;address of stage2 to jump to, org at
%define BOOT_KERNEL_SEG 0x0AC0 ;right after ROOT_DIR
%define BOOT_KERNEL_ADD 0x100000 ;final pmode kernel destination - physical
%define VERSION "0.1.2" ;HOS version
%define BOOT_FAT_SEG 0x07E0 ;right after boot sector
%define BOOT_ROOT_SEG 0x0900 ;right after FAT
%define BOOT_KERNEL_SEG 0x0AC0 ;right after ROOT_DIR
%define BOOT_STAGE2_SEG 0x0B00 ;right after KERNEL_SEG
%define BOOT_STAGE2_ADD 0xB000 ;address of stage2 to jump to, org at
%define BOOT_KERNEL_ADD 0x100000 ;final pmode kernel destination - physical
%define BOOT_DATA_SEG 0x9000 ;data gathered by stage2 loader goes here
%define BOOT_HASRD 0x0000 ;1
%define BOOT_RD_ADD 0x200000 ;2mb for ram disk
%define BOOT_DRIVE 0x7C24 ;1 - boot drive

24
kernel.asm
View File

@ -1,7 +1,11 @@
%include "bootdef.inc"
bits 32
org 0x100000
org BOOT_KERNEL_ADD
call cls
mov esi, msg
mov edi, 0xb8000
@ -19,6 +23,24 @@ msg_done:
jmp $
cls:
push eax
push ecx
push edi
mov edi, 0xb8000
mov ecx, 2000
mov eax, 0x0700
cls_loop:
stosw
loop cls_loop
pop edi
pop ecx
pop eax
ret
msg:
db "This kernel is located at 0x100000! Aren't you glad?", 0

6
stage1.asm
View File

@ -33,6 +33,8 @@ brFSID DB 'FAT12 ' ; 0036h - File System ID
;------------------------------------------------------------------------
start:
jmp 0:jmphere ;ensure that cs=0 and ip=0x7c...
jmphere:
;dl=drive number, save it!
xor ax, ax
mov ds, ax
@ -133,6 +135,8 @@ error:
jmp $ ;halt! no kernel file found!
found_file: ;ds:si points to root dir entry
xor ax, ax
mov gs, ax
mov ax, BOOT_STAGE2_SEG
mov es, ax
@ -148,7 +152,7 @@ readstage2_loop:
push ax
call getCHSfromCluster
mov ax, 0x0201
mov dl, 0 ;[brDrive]
mov dl, [gs:BOOT_DRIVE]
xor bx, bx
int 0x13
mov bx, es

148
stage2.asm
View File

@ -33,6 +33,8 @@ error:
jmp $ ;halt! no kernel file found!
found_file: ;ds:si points to root dir entry of kernel file
xor ax, ax
mov gs, ax
mov ax, [ds:si+26]
mov bx, BOOT_FAT_SEG
mov ds, bx ;ds points to beginning of FAT
@ -44,7 +46,7 @@ readkernel_loop:
push ax
call getCHSfromCluster
mov ax, 0x0201
mov dl, 0 ;[brDrive]
mov dl, [gs:BOOT_DRIVE]
mov bx, BOOT_KERNEL_SEG
mov es, bx
xor bx, bx
@ -81,10 +83,146 @@ odd_cluster:
got_cluster:
jmp readkernel_loop
readkernel_done:
;------------------------------------------------------
readkernel_done: ;-------------put more real mode init stuff here!
;----ask to load RD from floppy
mov ax, 0xb800
mov es, ax
xor ax, ax
mov ds, ax
xor di, di
mov cx, 2000
mov ax, 0x0700
cls_loop:
stosw
loop cls_loop
mov dx, 0x3d4 ;move cursor off screen...
mov al, 0x0e
out dx, al
inc dx
mov al, 0xff
out dx, al
dec dx
mov al, 0x0f
out dx, al
inc dx
out dx, al
xor di, di
mov si, txt_welcome
mov ah, 0x1f
call puts
mov di, 160
mov si, txt_rd1
mov ah, 7
call puts
mov si, txt_rd2
mov di, 160*2
call puts
mov di, 160*3
mov si, txt_input
call puts
get_rd:
xor ax, ax
int 0x16
cmp al, '1'
jz got_rd
cmp al, '2'
jnz get_rd
got_rd:
stosb
sub al, '1'
push ds
mov bx, BOOT_DATA_SEG ;segment for data to send kernel
mov ds, bx
mov [ds:BOOT_HASRD], al
pop ds ;ds=0
cmp al, 0 ;dont load rd
jz no_rd
mov cx, 80
mov edi, 0xb8000+160*4
filler_loop:
mov word [ds:edi], 0x0400+176
inc edi
inc edi
loop filler_loop
mov cx, 80 ;80 cylinders to read
xor si, si
mov edi, BOOT_RD_ADD ;ram disk address
read_cylinder:
push cx
mov bx, 0x0100
mov es, bx
xor bx, bx
mov ax, 0x0224
mov cx, si
mov ch, cl
mov cl, 1
xor dx, dx
mov dl, [gs:BOOT_DRIVE]
int 0x13
mov ebx, 0xb8000
add bx, si
shl bl, 1
mov word [ds:ebx+160*4], 0x0200+219
push si
mov esi, 0x1000
mov cx, 0x2400
copydisk_loop:
mov ax, [ds:esi]
inc esi
inc esi
mov [ds:edi], ax
inc edi
inc edi
loop copydisk_loop
pop si ;what cylinder# we are on...
inc si
pop cx
loop read_cylinder
no_rd:
xor ax, ax
mov ds, ax
mov ax, 0xb800
mov es, ax
mov si, txt_vesa
mov di, 160*5
mov ah, 7
call puts
xor ax, ax
int 0x16
jmp go_pm
puts:
lodsb
or al, al
jz puts_done
stosb
mov al, ah
stosb
jmp puts
puts_done:
ret
txt_welcome: db " Welcome to HOS v", VERSION, "! ", 0
txt_rd1: db "1. Do not load an initial ram disk", 0
txt_rd2: db "2. Load initial ram disk from floppy", 0
txt_input: db "Enter your selection: ", 0
txt_vesa: db "VESA version: ", 0
;------------------------------------------------------
getCHSfromCluster:
;input: ax=lba of sector on floppy (0-2879)
@ -148,12 +286,10 @@ pmode:
mov ax, KERNEL_DATA
mov es, ax
mov ds, ax
mov fs, ax
mov gs, ax
jmp KERNEL_CODE:BOOT_KERNEL_ADD
kernel: db "KERNEL BIN"
k_count: dw 0
times 510-($-$$) db 0
db 0x55, 0xaa