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(New page: Бут сектор загрузки для FDD. Рассмотрим код и опишем логику работы. ;======================================================= ;= boot p...) |
(Fixes for <asm> tags - replaced with <syntaxhighlight>) |
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(7 intermediate revisions by 4 users not shown) | |||
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Рассмотрим код и опишем логику работы. | Рассмотрим код и опишем логику работы. | ||
− | + | <syntaxhighlight lang="asm"> | |
− | ;= boot program for | + | ;== boot program for Kolibri OS version 1.00 == |
− | ; | + | ; January 2002 |
− | ; | + | ; |
− | ; | + | ; Copyright (C) Alex Nogueira Teixeira |
− | ; | + | ; E-Mail : alexwal{dog_}siteplanet.com.br |
− | ; | + | ; |
− | ; | + | ; Distributed under GPL, see file COPYING for details |
− | ; | + | ; |
− | ; | + | ; equates for program |
− | ; | + | ; |
− | ; | + | ; added support of config save |
− | lf equ 0ah | + | lf equ 0ah |
− | cr equ 0dh | + | cr equ 0dh |
− | + | ||
− | pos_read_tmp equ 0700h ;position for temporary read | + | pos_read_tmp equ 0700h ;position for temporary read |
− | boot_program equ 07c00h ;position for boot code | + | boot_program equ 07c00h ;position for boot code |
− | seg_read_kernel equ 01000h ;seguiment to kernel read | + | seg_read_kernel equ 01000h ;seguiment to kernel read |
− | + | ||
− | + | jmp start_program | |
− | + | nop | |
− | + | ||
− | oemname db 'KOLIBRI ' | + | oemname db 'KOLIBRI ' |
− | bytespersector dw 512 | + | bytespersector dw 512 |
− | sectorspercluster db 1 | + | sectorspercluster db 1 |
− | ressectors dw 1 | + | ressectors dw 1 |
− | numcopiesfat db 2 | + | numcopiesfat db 2 |
− | maxallocrootdir dw 224 | + | maxallocrootdir dw 224 |
− | maxsectors dw 2880 ;for 1.44 mbytes disk | + | maxsectors dw 2880 ;for 1.44 mbytes disk |
− | mediadescriptor db 0f0h ;fd = 2 sides 18 sectors | + | mediadescriptor db 0f0h ;fd = 2 sides 18 sectors |
− | sectorsperfat dw 9 | + | sectorsperfat dw 9 |
− | sectorspertrack dw 18 | + | sectorspertrack dw 18 |
− | heads dw 2 | + | heads dw 2 |
− | hiddensectors dd 0 | + | hiddensectors dd 0 |
− | hugesectors dd 0 ;if sectors > 65536 | + | hugesectors dd 0 ;if sectors > 65536 |
− | drivenumber db 0 | + | drivenumber db 0 |
− | + | db 0 | |
− | bootsignature db 029h ;extended boot signature | + | bootsignature db 029h ;extended boot signature |
− | volumeid dd 0 | + | volumeid dd 0 |
− | volumelabel db 'KOLIBRI ' | + | volumelabel db 'KOLIBRI ' |
− | filesystemtype db 'FAT12 ' | + | filesystemtype db 'FAT12 ' |
+ | |||
+ | |||
+ | start_program: | ||
+ | |||
+ | xor ax,ax | ||
+ | mov ss,ax | ||
+ | mov sp,boot_program | ||
+ | push ss | ||
+ | pop ds | ||
+ | mov si,loading+boot_program | ||
+ | loop_loading: | ||
+ | lodsb | ||
+ | or al,al | ||
+ | jz procura_arquivo_novamente | ||
+ | mov ah,0eh | ||
+ | mov bx,07h | ||
+ | int 010h | ||
+ | jmp loop_loading | ||
+ | |||
+ | |||
+ | procura_arquivo_novamente: | ||
− | + | push ss | |
+ | pop es | ||
− | + | mov bp,16 | |
− | + | ||
− | + | newtry: | |
− | + | ||
− | + | dec bp | |
− | + | jz mensagem_erro_arquivo | |
− | + | ||
− | + | mov ax,020eh ;read, 14 sectors for directory | |
− | + | mov bx,pos_read_tmp ;es:bx read position | |
− | + | mov cx,02h ;track 0, sector 2 | |
− | + | mov dx,0100h ;head 1, drive 0 (a:) | |
− | + | call read_sector | |
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | newtry: | ||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
; int 013h ;read sectors | ; int 013h ;read sectors | ||
; jc newtry ; mensagem_erro_arquivo | ; jc newtry ; mensagem_erro_arquivo | ||
+ | |||
+ | mov si,bx | ||
− | + | loop_compara_entrada_diretorio: | |
− | |||
− | loop_compara_entrada_diretorio: | ||
push si | push si | ||
Line 99: | Line 99: | ||
jb loop_compara_entrada_diretorio | jb loop_compara_entrada_diretorio | ||
− | mensagem_erro_arquivo: | + | mensagem_erro_arquivo: |
mov si,mens_erro+boot_program | mov si,mens_erro+boot_program | ||
− | loop_envio_mensagem: | + | loop_envio_mensagem: |
lodsb | lodsb | ||
Line 113: | Line 113: | ||
jmp loop_envio_mensagem | jmp loop_envio_mensagem | ||
− | espera_digitar_tecla: | + | espera_digitar_tecla: |
− | jmp $ | + | jmp $ ;зацикливание остановка пк. |
− | ; load kernel | + | ;load kernel |
− | le_arquivo_kernel: | + | le_arquivo_kernel: |
mov bp,[si+01ah] | mov bp,[si+01ah] | ||
Line 134: | Line 134: | ||
xor bx,bx | xor bx,bx | ||
− | ; \begin{diamond}[02.12.2005] | + | ; \begin{diamond}[02.12.2005] |
mov [cluster1st+boot_program], bp | mov [cluster1st+boot_program], bp | ||
− | ; \end{diamond}[02.12.2005] | + | ; \end{diamond}[02.12.2005] |
; read kernel to es:bx | ; read kernel to es:bx | ||
− | loop_obtem_dados_kernel: | + | loop_obtem_dados_kernel: |
call le_setor_dados | call le_setor_dados | ||
jc mensagem_erro_arquivo | jc mensagem_erro_arquivo | ||
− | ; | + | ; add bx,0200h ;add one sector |
push bx | push bx | ||
Line 161: | Line 161: | ||
and ax,0fffh | and ax,0fffh | ||
jmp verifica_fim_setores | jmp verifica_fim_setores | ||
− | desloca_4_direita: | + | desloca_4_direita: |
mov cl,4 | mov cl,4 | ||
shr ax,cl | shr ax,cl | ||
− | verifica_fim_setores: | + | verifica_fim_setores: |
cmp ax,0ff8h | cmp ax,0ff8h | ||
jae executa_kernel | jae executa_kernel | ||
Line 170: | Line 170: | ||
jmp loop_obtem_dados_kernel | jmp loop_obtem_dados_kernel | ||
− | executa_kernel: | + | executa_kernel: |
− | ; \begin{diamond}[02.12.2005] | + | ; \begin{diamond}[02.12.2005] |
mov ax, 'KL' | mov ax, 'KL' | ||
push 0 | push 0 | ||
pop ds | pop ds | ||
mov si, loader_block+boot_program | mov si, loader_block+boot_program | ||
− | ; \end{diamond}[02.12.2005] | + | ; \end{diamond}[02.12.2005] |
push word seg_read_kernel | push word seg_read_kernel | ||
push word 00h | push word 00h | ||
Line 182: | Line 182: | ||
− | le_setor_dados: ;es:bx -> position in read buffer | + | le_setor_dados: ;es:bx -> position in read buffer |
− | + | ;bp -> logical sector to read | |
− | + | ;carry <- 0 read OK | |
− | + | ;carry <- 1 read error | |
push bx | push bx | ||
mov ax,0e2eh ;decimal point | mov ax,0e2eh ;decimal point | ||
Line 193: | Line 193: | ||
pop bx | pop bx | ||
mov ax,bp ;data sector to read | mov ax,bp ;data sector to read | ||
− | writesec: | + | writesec: |
add ax,31 ;get logical sector | add ax,31 ;get logical sector | ||
mov cx,36 ;sector/track | mov cx,36 ;sector/track | ||
Line 204: | Line 204: | ||
sub dl,18 | sub dl,18 | ||
inc dh ;head 1 | inc dh ;head 1 | ||
− | cabeca_correta: | + | cabeca_correta: |
inc dl | inc dl | ||
mov cl,dl | mov cl,dl | ||
xor dl,dl ;drive 0 (a:) | xor dl,dl ;drive 0 (a:) | ||
− | patchhere: | + | patchhere: |
mov ax,0201h ;read 1 sector | mov ax,0201h ;read 1 sector | ||
call read_sector | call read_sector | ||
Line 214: | Line 214: | ||
retn | retn | ||
− | read_sector: | + | read_sector: |
push bp | push bp | ||
mov bp,20 | mov bp,20 | ||
− | + | newread: | |
dec bp | dec bp | ||
jz mensagem_erro_arquivo | jz mensagem_erro_arquivo | ||
Line 228: | Line 228: | ||
retn | retn | ||
− | loading db 13,10,'Starting system ',00h | + | loading db 13,10,'Starting system ',00h |
− | mens_erro: | + | mens_erro: |
db 13,10 | db 13,10 | ||
− | arq_boot: | + | arq_boot: |
db 'KERNEL MNT ?',cr,lf,00h | db 'KERNEL MNT ?',cr,lf,00h | ||
− | errors db 16 | + | errors db 16 |
− | ; \begin{diamond}[02.12.2005] | + | ; \begin{diamond}[02.12.2005] |
− | write1st: | + | write1st: |
push cs | push cs | ||
pop ds | pop ds | ||
Line 248: | Line 248: | ||
retf | retf | ||
− | cluster1st dw ? | + | cluster1st dw ? |
− | loader_block: | + | loader_block: |
db 1 | db 1 | ||
dw 0 | dw 0 | ||
dw write1st+boot_program | dw write1st+boot_program | ||
dw 0 | dw 0 | ||
− | ; \end{diamond}[02.12.2005] | + | ; \end{diamond}[02.12.2005] |
− | times 0x1fe-$ db 00h | + | times 0x1fe-$ db 00h |
db 55h,0aah ;boot signature | db 55h,0aah ;boot signature | ||
+ | </syntaxhighlight> | ||
+ | |||
+ | [[Category:Coding]] |
Latest revision as of 12:50, 22 April 2012
Бут сектор загрузки для FDD. Рассмотрим код и опишем логику работы.
;== boot program for Kolibri OS version 1.00 ==
; January 2002
;
; Copyright (C) Alex Nogueira Teixeira
; E-Mail : alexwal{dog_}siteplanet.com.br
;
; Distributed under GPL, see file COPYING for details
;
; equates for program
;
; added support of config save
lf equ 0ah
cr equ 0dh
pos_read_tmp equ 0700h ;position for temporary read
boot_program equ 07c00h ;position for boot code
seg_read_kernel equ 01000h ;seguiment to kernel read
jmp start_program
nop
oemname db 'KOLIBRI '
bytespersector dw 512
sectorspercluster db 1
ressectors dw 1
numcopiesfat db 2
maxallocrootdir dw 224
maxsectors dw 2880 ;for 1.44 mbytes disk
mediadescriptor db 0f0h ;fd = 2 sides 18 sectors
sectorsperfat dw 9
sectorspertrack dw 18
heads dw 2
hiddensectors dd 0
hugesectors dd 0 ;if sectors > 65536
drivenumber db 0
db 0
bootsignature db 029h ;extended boot signature
volumeid dd 0
volumelabel db 'KOLIBRI '
filesystemtype db 'FAT12 '
start_program:
xor ax,ax
mov ss,ax
mov sp,boot_program
push ss
pop ds
mov si,loading+boot_program
loop_loading:
lodsb
or al,al
jz procura_arquivo_novamente
mov ah,0eh
mov bx,07h
int 010h
jmp loop_loading
procura_arquivo_novamente:
push ss
pop es
mov bp,16
newtry:
dec bp
jz mensagem_erro_arquivo
mov ax,020eh ;read, 14 sectors for directory
mov bx,pos_read_tmp ;es:bx read position
mov cx,02h ;track 0, sector 2
mov dx,0100h ;head 1, drive 0 (a:)
call read_sector
; int 013h ;read sectors
; jc newtry ; mensagem_erro_arquivo
mov si,bx
loop_compara_entrada_diretorio:
push si
mov cx,11 ;file name
mov di,arq_boot+boot_program
rep cmpsb
pop si
je le_arquivo_kernel
add si,32
cmp si,pos_read_tmp+(512*14) ;end of directory
jb loop_compara_entrada_diretorio
mensagem_erro_arquivo:
mov si,mens_erro+boot_program
loop_envio_mensagem:
lodsb
or al,al
jz espera_digitar_tecla
mov ah,0eh
mov bx,07h
int 010h
jmp loop_envio_mensagem
espera_digitar_tecla:
jmp $ ;зацикливание остановка пк.
;load kernel
le_arquivo_kernel:
mov bp,[si+01ah]
mov ax,0209h ;read, 9 sectors
mov bx,pos_read_tmp ;es:bx read position
mov cx,02h ;track 0, sector 2
xor dx,dx ;head 0, drive 0 (a:)
call read_sector
; int 013h ;read sectorsv
jc mensagem_erro_arquivo
mov ax,seg_read_kernel
mov es,ax
xor bx,bx
; \begin{diamond}[02.12.2005]
mov [cluster1st+boot_program], bp
; \end{diamond}[02.12.2005]
; read kernel to es:bx
loop_obtem_dados_kernel:
call le_setor_dados
jc mensagem_erro_arquivo
; add bx,0200h ;add one sector
push bx
mov bx,es
add bx,0x20
mov es,bx
pop bx
mov di,bp
shr di,01h
pushf
add di,bp
add di,pos_read_tmp
mov ax,[di]
popf
jc desloca_4_direita
and ax,0fffh
jmp verifica_fim_setores
desloca_4_direita:
mov cl,4
shr ax,cl
verifica_fim_setores:
cmp ax,0ff8h
jae executa_kernel
mov bp,ax
jmp loop_obtem_dados_kernel
executa_kernel:
; \begin{diamond}[02.12.2005]
mov ax, 'KL'
push 0
pop ds
mov si, loader_block+boot_program
; \end{diamond}[02.12.2005]
push word seg_read_kernel
push word 00h
retf
le_setor_dados: ;es:bx -> position in read buffer
;bp -> logical sector to read
;carry <- 0 read OK
;carry <- 1 read error
push bx
mov ax,0e2eh ;decimal point
xor bh,bh
int 010h
pop bx
mov ax,bp ;data sector to read
writesec:
add ax,31 ;get logical sector
mov cx,36 ;sector/track
xor dx,dx
div cx
mov ch,al ;track transfer
xor dh,dh ;head 0
cmp dl,18
jb cabeca_correta
sub dl,18
inc dh ;head 1
cabeca_correta:
inc dl
mov cl,dl
xor dl,dl ;drive 0 (a:)
patchhere:
mov ax,0201h ;read 1 sector
call read_sector
; int 013h
retn
read_sector:
push bp
mov bp,20
newread:
dec bp
jz mensagem_erro_arquivo
push ax bx cx dx
int 0x13
pop dx cx bx ax
jc newread
pop bp
retn
loading db 13,10,'Starting system ',00h
mens_erro:
db 13,10
arq_boot:
db 'KERNEL MNT ?',cr,lf,00h
errors db 16
; \begin{diamond}[02.12.2005]
write1st:
push cs
pop ds
mov byte [patchhere+2+boot_program], 3
mov ax, [cluster1st+boot_program]
push 1000h
pop es
xor bx, bx
call writesec
mov byte [patchhere+2+boot_program], 2
retf
cluster1st dw ?
loader_block:
db 1
dw 0
dw write1st+boot_program
dw 0
; \end{diamond}[02.12.2005]
times 0x1fe-$ db 00h
db 55h,0aah ;boot signature