kolibrios/kernel/trunk/boot/parsers.inc

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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; ;;
;; Copyright (C) KolibriOS team 2011-2015. All rights reserved. ;;
;; Distributed under terms of the GNU General Public License ;;
;; ;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
$Revision$
; All parsers are called with ds:si -> value of the variable,
; possibly with spaces before, and dx = limit of config file.
; Three subroutines parse_char, parse_number and parse_bool set CF
; if something has failed, otherwise return the value in al/ax.
parse_timeout:
; timeout is a number not greater than 9
call parse_number
jc .nothing
cmp ax, 9
jbe @f
mov ax, 9
@@:
imul ax, 18
mov [es:preboot_timeout], ax
.nothing:
ret
parse_resolution:
; resolution is <width>*<height>, 'x' can be used instead of '*'
; parse width
call parse_number
jc .nothing
; save width
xchg ax, bx
; test for 'x' or '*'
call parse_char
cmp al, 'x'
jz @f
cmp al, '*'
jnz .nothing
@@:
; parse height
call parse_number
jc .nothing
; write width and height
mov [es:x_save], bx
mov [es:y_save], ax
.nothing:
ret
parse_vbemode:
; vbemode is a number
call parse_number
jc .nothing
mov [es:number_vm], ax
.nothing:
ret
;parse_vrr:
;; vrr is a boolean setting
; call parse_bool
; jc .nothing
;; convert 0 to 2, 1 to 1
; inc ax
; xor al, 3
; mov [es:preboot_vrrm], al
;.nothing:
; ret
parse_biosdisks:
; using biosdisks is a boolean setting
call parse_bool
jc .nothing
; convert 0 to 2, 1 to 1
inc ax
xor al, 3
mov [es:preboot_biosdisk], al
.nothing:
ret
parse_imgfrom:
; boot device (1-floppy 2-kolibri.img using primary loader)
call parse_number
jc .nothing
cmp al, 1
jb .nothing
cmp al, 2
ja .nothing
mov [es:preboot_device], al
.nothing:
ret
parse_char:
; skip spaces and return the next character or CF if EOF.
cmp si, dx
jae .eof
lodsb
cmp al, ' '
jbe parse_char
ret
.eof:
stc
ret
parse_number:
; initialize high part of ax to zero
xor ax, ax
; skip spaces
call parse_char
jc .bad
; al should be a digit
sub al, '0'
cmp al, 9
ja .bad
; accumulate the value in cx
xchg cx, ax
@@:
cmp si, dx
jae .eof
lodsb
sub al, '0'
cmp al, 9
ja .end
imul cx, 10
add cx, ax
jmp @b
; if the end is caused by non-digit, unwind the last character
.end:
dec si
.eof:
xchg cx, ax
clc
ret
.bad:
stc
ret
parse_bool:
; skip spaces
call parse_char
jc .bad
; Boolean false can be represented as 0=no=off,
; boolean true can be represented as 1=yes=on.
cmp al, '0'
jz .false
cmp al, '1'
jz .true
mov ah, al
cmp si, dx
jae .bad
lodsb
cmp ax, 'n'*256 + 'o'
jz .false
cmp ax, 'o'*256 + 'f'
jz .false
cmp ax, 'y'*256 + 'e'
jz .true
cmp ax, 'o'*256 + 'n'
jz .true
.bad:
stc
ret
.true:
xor ax, ax
inc ax
ret
.false:
xor ax, ax
ret