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|
; -----------------------------------------------------------------------
;
; Copyright 2010-2015 Gene Cumm
;
; Portions from diskstart.inc:
; Copyright 1994-2009 H. Peter Anvin - All Rights Reserved
; Copyright 2009-2010 Intel Corporation; author: H. Peter Anvin
;
; This program is free software; you can redistribute it and/or modify
; it under the terms of the GNU General Public License as published by
; the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
; Boston MA 02110-1301, USA; either version 2 of the License, or
; (at your option) any later version; incorporated herein by reference.
;
; -----------------------------------------------------------------------
;
; geodspms.asm
;
; Display geometry translation info for diagnosing misconceptions
; multi-sector variant
;
; nasm -Ox -f bin -o geodsp.bin -l geodsp.lst geodsp.asm
;
; nasm -Ox -f elf -o geodsp.o -l geodsp.lst geodsp.asm
; ld -m elf_i386 -T syslinux.ld -M -o geodsp.elf geodsp.o > geodsp.map
; objcopy -O binary geodsp.elf geodsp.raw
;
; # OF=/dev/sdb
; # dd if=core/geodsp.bin of=$OF
; # dd skip=1 seek=1 if=../dbg/lba-img/lba-img.bin of=$OF
; # eject $OF
; # dd count=$() if=/dev/zero of=$OF
;
; # OF=geo-2.255.63.i
; # (dd if=core/geodsp.bin; dd skip=1 if=../dbg/lba-img/lba-img.bin; dd count=$((2*255*63 - 256*63 - 1)) if=/dev/zero )|dd of=$OF
; # OF=geo-20.16.63.i
; # (dd if=core/geodsp.bin; dd skip=1 if=../dbg/lba-img/lba-img.bin; dd count=$((40*16*63 - 256*63 - 1)) if=/dev/zero )|dd of=$OF
;
; Just to define it to look like SYSLINUX
%define IS_SYSLINUX 1
%include "macros.inc"
; %include "layout.inc"
m_CHS0 equ 00534843h ;'CHS',0
m_EDD0 equ 00444445h ;'EDD',0
m_EDD_SP equ 20444445h ;'EDD '
retry_count equ 16
dbuf equ 8000h
; int13_ret equ 7e00h
LDLINUX_MAGIC equ 0x3eb202fe ; A random number to identify ourselves with
Sect1Ptr0_VAL equ 1
Sect1Ptr1_VAL equ 0
; Uncomment to test EDD
%define TEST_EDD 1
; Uncomment to show errors (while it still continues)
%define SHOW_ERR 1
; global STACK_LEN, STACK_TOP, STACK_BASE
; STACK_LEN equ 4096
STACK_TOP equ 7c00h
; STACK_BASE equ STACK_TOP - STACK_LEN
section .init
org STACK_TOP
geodsp_start:
%include "diskboot.inc"
HEXDATE equ 1
section .init
sector_1:
ldlinux_sys:
alignz 8
ldlinux_magic dd LDLINUX_MAGIC
dd LDLINUX_MAGIC^HEXDATE
ldlinux_ent:
get_geo: ; DL and ES ready
mov ah,08h
mov di,0
call xint13
write_geo:
jc .bad_geo
mov si,s_chs
call writestr_early
call write_chs
mov si,s_crlf
call writestr_early
jmp short .done
.bad_geo:
.done:
mov bx,dbuf
get_h1c: ; 0,1,1
mov cx,0001h
mov dh,01h
call getonesec_chs
call write_chs_lba
get_c1c: ; 1,0,1
mov cx,0101h
mov dh,00h
call getonesec_chs
call write_chs_lba
; Do we have EBIOS (EDD)?
;
edd:
.check:
mov bx,55AAh
mov ah,41h ; EDD existence query
call xint13
jc .noedd
cmp bx,0AA55h
jne .noedd
test cl,1 ; Extended disk access functionality set
jz .noedd
;
; We have EDD support...
;
mov bx,dbuf ; ES should still be safe.
xor edx,edx
mov dword [s_chs],m_EDD_SP
.get_lba63:
mov eax,63 ; Same length as mov al,64; movzx eax,al
call getonesec_ebios
jc .bad_edd ;read error
call write_edd_lba
.get_lba16065:
mov eax,16065
call getonesec_ebios
jc .bad_edd ;read error
call write_edd_lba
.good_edd:
mov dword [s_type],m_EDD0
.bad_edd:
.noedd:
.end:
write_final_type:
mov si,s_typespec
call writestr_early
jmp kaboom
;
; getonesec_chs:
;
; CX,DH specifies CHS address
;
getonesec_chs: ; We could use an xchg and get a loop
; mov cx,retry_count
.retry:
pushad
mov ax,0201h ; Read one sector
call xint13
popad
jc .error
ret
.error:
; loop .retry
; Fall through to disk_error
jmp disk_error
%include "geodsplib.inc"
SuperInfo: zd 32 ; The first 16 bytes expanded 8 times
; This fails if the sector overflows
zb 400h-($-$$)
end:
absolute 4*1Eh
fdctab equ $
fdctab1 resw 1
fdctab2 resw 1
|
