7ff6c06814
Here we depend on the signal instruction that is patched by exeflat to indicate whether we were compressed. This replaces the prior check that detected the UPX help data solely by checking the CONFIG signature at 05E2h.
1210 lines
42 KiB
NASM
1210 lines
42 KiB
NASM
;
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; File:
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; kernel.asm
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; Description:
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; kernel start-up code
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;
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; Copyright (c) 1995, 1996
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; Pasquale J. Villani
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; All Rights Reserved
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;
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; This file is part of DOS-C.
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;
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; DOS-C is free software; you can redistribute it and/or
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; modify it under the terms of the GNU General Public License
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; as published by the Free Software Foundation; either version
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; 2, or (at your option) any later version.
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;
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; DOS-C is distributed in the hope that it will be useful, but
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; WITHOUT ANY WARRANTY; without even the implied warranty of
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; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
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; the GNU General Public License for more details.
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;
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; You should have received a copy of the GNU General Public
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; License along with DOS-C; see the file COPYING. If not,
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; write to the Free Software Foundation, 675 Mass Ave,
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; Cambridge, MA 02139, USA.
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;
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; $Id: kernel.asm 1705 2012-02-07 08:10:33Z perditionc $
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;
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%include "segs.inc"
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%include "stacks.inc"
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%include "ludivmul.inc"
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segment PSP
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extern _ReqPktPtr
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STACK_SIZE equ 384/2 ; stack allocated in words
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;************************************************************
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; KERNEL BEGINS HERE, i.e. this is byte 0 of KERNEL.SYS
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;************************************************************
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%ifidn __OUTPUT_FORMAT__, obj
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..start:
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%endif
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entry:
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jmp short realentry
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;************************************************************
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; KERNEL CONFIGURATION AREA
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; this is copied up on the very beginning
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; it's a good idea to keep this in sync with KConfig.h
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;************************************************************
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global _LowKernelConfig
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_LowKernelConfig:
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config_signature:
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db 'CONFIG' ; constant
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dw configend-configstart; size of config area
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; to be checked !!!
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configstart:
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DLASortByDriveNo db 0 ; sort disks by drive order
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InitDiskShowDriveAssignment db 1 ;
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SkipConfigSeconds db 2 ;
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ForceLBA db 0 ;
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GlobalEnableLBAsupport db 1 ;
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BootHarddiskSeconds db 0 ;
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; The following VERSION resource must be keep in sync with VERSION.H
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Version_OemID db 0xFD ; OEM_ID
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Version_Major db 2
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Version_Revision dw 41 ; REVISION_SEQ
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Version_Release dw 1 ; 0=release build, >0=svn#
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configend:
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kernel_config_size: equ configend - config_signature
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; must be below-or-equal the size of struct _KernelConfig
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; in the file kconfig.h !
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;************************************************************
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; KERNEL CONFIGURATION AREA END
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;************************************************************
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;************************************************************
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; KERNEL real entry (at ~60:20)
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;
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; moves the INIT part of kernel.sys to high memory (~9000:0)
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; then jumps there
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; to aid debugging, some '123' messages are output
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; this area is discardable and used as temporary PSP for the
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; init sequence
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;************************************************************
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cpu 8086 ; (keep initial entry compatible)
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global realentry
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realentry: ; execution continues here
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clc ; this is patched to stc by exeflat
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adc byte [cs:use_upx_config], 0
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push ax
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push bx
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pushf
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mov ax, 0e31h ; '1' Tracecode - kernel entered
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mov bx, 00f0h
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int 010h
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popf
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pop bx
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pop ax
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jmp IGROUP:kernel_start
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use_upx_config: db 0
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beyond_entry: times 256-(beyond_entry-entry) db 0
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; scratch area for data (DOS_PSP)
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segment INIT_TEXT
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extern _FreeDOSmain
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extern _query_cpu
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;
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; kernel start-up
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;
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kernel_start:
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push bx
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pushf
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mov ax, 0e32h ; '2' Tracecode - kernel entered
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mov bx, 00f0h
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int 010h
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popf
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pop bx
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mov ax,I_GROUP
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cli
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mov ss,ax
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mov sp,init_tos
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int 12h ; move init text+data to higher memory
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mov cl,6
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shl ax,cl ; convert kb to para
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mov dx,15 + INITSIZE
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mov cl,4
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shr dx,cl
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sub ax,dx
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mov es,ax
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mov dx,INITTEXTSIZE ; para aligned
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shr dx,cl
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add ax,dx
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mov ss,ax ; set SS to init data segment
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sti ; now enable them
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mov ax,cs
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mov dx,__HMATextEnd ; para aligned
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shr dx,cl
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%ifdef WATCOM
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add ax,dx
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%endif
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mov ds,ax
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mov si,-2 + INITSIZE; word aligned
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lea cx,[si+2]
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mov di,si
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shr cx,1
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std ; if there's overlap only std is safe
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rep movsw
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; move HMA_TEXT to higher memory
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sub ax,dx
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mov ds,ax ; ds = HMA_TEXT
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mov ax,es
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sub ax,dx
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mov es,ax ; es = new HMA_TEXT
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mov si,-2 + __HMATextEnd
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lea cx,[si+2]
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mov di,si
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shr cx,1
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rep movsw
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cld
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%ifndef WATCOM ; for WATCOM: CS equal for HMA and INIT
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add ax,dx
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mov es,ax ; otherwise CS -> init_text
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%endif
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push es
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mov ax,cont
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push ax
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retf
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cont: ; Now set up call frame
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mov ds,[cs:_INIT_DGROUP]
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mov bp,sp ; and set up stack frame for c
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push bx
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pushf
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mov ax, 0e33h ; '3' Tracecode - kernel entered
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mov bx, 00f0h
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int 010h
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popf
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pop bx
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mov byte [_BootDrive],bl ; tell where we came from
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;!! int 11h
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;!! mov cl,6
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;!! shr al,cl
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;!! inc al
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;!! mov byte [_NumFloppies],al ; and how many
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call _query_cpu
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%if XCPU != 86
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%if XCPU < 186 || (XCPU % 100) != 86 || (XCPU / 100) > 9
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%fatal Unknown CPU level defined
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%endif
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cmp al, (XCPU / 100)
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jb cpu_abort ; if CPU not supported -->
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cpu XCPU
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%endif
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mov [_CPULevel], al
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initialise_kernel_config:
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extern _InitKernelConfig
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push ds
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pop es ; => DOS data segment (for _BootDrive)
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mov ax, ss ; => init data segment
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mov si, 60h
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mov ds, si ; => entry section
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mov si, _LowKernelConfig ; -> our own CONFIG block
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; This block is part of what got decompressed if
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; the kernel is UPX-compressed. And if UPX was
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; used in .SYS mode then the first several words
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; are overwritten with pseudo device header fields.
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cmp byte [use_upx_config], 0 ; from UPX ?
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je .notupx ; no, use own CONFIG block -->
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mov si, 5Eh
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mov ds, si
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mov si, 2 ; -> CONFIG block of compressed entry
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mov bl, [0] ; 05E0h has the boot load unit
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mov byte [es:_BootDrive], bl ; overwrite the value in DOS data segment
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.notupx:
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mov es, ax ; => init data segment
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mov di, _InitKernelConfig ; -> init's CONFIG block buffer
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mov cx, kernel_config_size / 2 ; size that we support
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rep movsw ; copy it over
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%if kernel_config_size & 1
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movsb ; allow odd size
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%endif
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mov ds, ax ; => init data segment
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jmp _FreeDOSmain
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%if XCPU != 86
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cpu 8086
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cpu_abort:
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mov ah, 0Fh
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int 10h ; get video mode, bh = active page
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call .first ; print string that follows (address pushed by call)
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%define LOADNAME "FreeDOS"
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db 13,10 ; (to emit a blank line after the tracecodes)
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db 13,10
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db LOADNAME, " load error: An 80", '0'+(XCPU / 100)
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db "86 processor or higher is required by this build.",13,10
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db "To use ", LOADNAME, " on this processor please"
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db " obtain a compatible build.",13,10
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db 13,10
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db "Press any key to reboot.",13,10
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db 0
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.display:
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mov ah, 0Eh
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mov bl, 07h ; page in bh, bl = colour for some modes
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int 10h ; write character (may change bp!)
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db 0A8h ; [test al,imm8] skip "pop si" [=imm8] after the first iteration
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.first:
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pop si ; (first iteration only) get message address from stack
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cs lodsb ; get character
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test al, al ; zero ?
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jnz .display ; no, display and get next character -->
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xor ax, ax
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xor dx, dx
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int 13h ; reset floppy disks
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xor ax, ax
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mov dl, 80h
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int 13h ; reset hard disks
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; this "test ax, imm16" opcode is used to
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db 0A9h ; skip "sti" \ "hlt" [=imm16] during first iteration
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.wait:
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sti
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hlt ; idle while waiting for keystroke
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mov ah, 01h
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int 16h ; get keystroke
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jz .wait ; none available, loop -->
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mov ah, 00h
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int 16h ; remove keystroke from buffer
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int 19h ; reboot
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jmp short $ ; (in case it returns, which it shouldn't)
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cpu XCPU
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%endif ; XCPU != 86
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segment INIT_TEXT_END
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;************************************************************
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; KERNEL CODE AREA END
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; the NUL device
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;************************************************************
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segment CONST
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;
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; NUL device strategy
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;
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global _nul_strtgy
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extern GenStrategy
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_nul_strtgy:
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jmp LGROUP:GenStrategy
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;
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; NUL device interrupt
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;
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global _nul_intr
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_nul_intr:
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push es
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push bx
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mov bx,LGROUP
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mov es,bx
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les bx,[es:_ReqPktPtr] ;es:bx--> rqheadr
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cmp byte [es:bx+2],4 ;if read, set 0 read
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jne no_nul_read
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mov word [es:bx+12h],0
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no_nul_read:
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or word [es:bx+3],100h ;set "done" flag
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pop bx
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pop es
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retf
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segment _LOWTEXT
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; low interrupt vectors 10h,13h,15h,19h,1Bh
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; these need to be at 0070:0100 (see RBIL memory.lst)
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global _intvec_table
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_intvec_table: db 10h
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dd 0
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; used by int13 handler and get/set via int 2f/13h
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global _BIOSInt13 ; BIOS provided disk handler
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global _UserInt13 ; actual disk handler used by kernel
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db 13h
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_BIOSInt13: dd 0
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db 15h
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dd 0
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; used for cleanup on reboot
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global _BIOSInt19
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db 19h
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_BIOSInt19: dd 0
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db 1Bh
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dd 0
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; default to using BIOS provided disk handler
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db 13h
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_UserInt13: dd 0
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; floppy parameter table
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global _int1e_table
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_int1e_table: times 0eh db 0
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;************************************************************
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; KERNEL FIXED DATA AREA
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;************************************************************
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segment _FIXED_DATA
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; Because of the following bytes of data, THIS MODULE MUST BE THE FIRST
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; IN THE LINK SEQUENCE. THE BYTE AT DS:0004 determines the SDA format in
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; use. A 0 indicates MS-DOS 3.X style, a 1 indicates MS-DOS 4.0-6.X style.
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global DATASTART
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DATASTART:
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global _DATASTART
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_DATASTART:
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dos_data db 0
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dw kernel_start
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db 0 ; padding
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dw 1 ; Hardcoded MS-DOS 4.0+ style
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times (0eh - ($ - DATASTART)) db 0
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global _NetBios
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_NetBios dw 0 ; NetBios Number
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times (26h - 0ch - ($ - DATASTART)) db 0
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; Globally referenced variables - WARNING: DO NOT CHANGE ORDER
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; BECAUSE THEY ARE DOCUMENTED AS UNDOCUMENTED (?) AND HAVE
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; MANY MULTIPLEX PROGRAMS AND TSRs ACCESSING THEM
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global _NetRetry
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_NetRetry dw 3 ;-000c network retry count
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global _NetDelay
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_NetDelay dw 1 ;-000a network delay count
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global _DskBuffer
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_DskBuffer dd -1 ;-0008 current dos disk buffer
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global _inputptr
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_inputptr dw 0 ;-0004 Unread con input
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global _first_mcb
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_first_mcb dw 0 ;-0002 Start of user memory
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global _DPBp
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global MARK0026H
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; A reference seems to indicate that this should start at offset 26h.
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MARK0026H equ $
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_DPBp dd 0 ; 0000 First drive Parameter Block
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global _sfthead
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_sfthead dd 0 ; 0004 System File Table head
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global _clock
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_clock dd 0 ; 0008 CLOCK$ device
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global _syscon
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_syscon dw _con_dev,LGROUP ; 000c console device
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global _maxsecsize
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_maxsecsize dw 512 ; 0010 maximum bytes/sector of any block device
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dd 0 ; 0012 pointer to buffers info structure
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global _CDSp
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_CDSp dd 0 ; 0016 Current Directory Structure
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global _FCBp
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_FCBp dd 0 ; 001a FCB table pointer
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global _nprotfcb
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_nprotfcb dw 0 ; 001e number of protected fcbs
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global _nblkdev
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_nblkdev db 0 ; 0020 number of block devices
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global _lastdrive
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_lastdrive db 0 ; 0021 value of last drive
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global _nul_dev
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_nul_dev: ; 0022 device chain root
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extern _con_dev
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dw _con_dev, LGROUP
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; next is con_dev at init time.
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dw 8004h ; attributes = char device, NUL bit set
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dw _nul_strtgy
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dw _nul_intr
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db 'NUL '
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global _njoined
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_njoined db 0 ; 0034 number of joined devices
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dw 0 ; 0035 DOS 4 pointer to special names (always zero in DOS 5)
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global _setverPtr
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_setverPtr dw 0,0 ; 0037 setver list
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dw 0 ; 003B cs offset for fix a20
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dw 0 ; 003D psp of last umb exec
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global _LoL_nbuffers
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_LoL_nbuffers dw 1 ; 003F number of buffers
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dw 1 ; 0041 size of pre-read buffer
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global _BootDrive
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_BootDrive db 1 ; 0043 drive we booted from
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global _CPULevel
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_CPULevel db 0 ; 0044 cpu type (MSDOS >0 indicates dword moves ok, ie 386+)
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; unless compatibility issues arise FD uses
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; 0=808x, 1=18x, 2=286, 3=386+
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; see cpu.asm, use >= as may add checks for 486 ...
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dw 0 ; 0045 Extended memory in KBytes
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buf_info:
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global _firstbuf
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_firstbuf dd 0 ; 0047 disk buffer chain
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dw 0 ; 004B Number of dirty buffers
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dd 0 ; 004D pre-read buffer
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dw 0 ; 0051 number of look-ahead buffers
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global _bufloc
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_bufloc db 0 ; 0053 00=conv 01=HMA
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global _deblock_buf
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_deblock_buf dd 0 ; 0054 deblock buffer
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times 3 db 0 ; 0058 unknown
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dw 0 ; 005B unknown
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db 0, 0FFh, 0 ; 005D unknown
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global _VgaSet
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_VgaSet db 0 ; 0060 unknown
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dw 0 ; 0061 unknown
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global _uppermem_link
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_uppermem_link db 0 ; 0063 upper memory link flag
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_min_pars dw 0 ; 0064 minimum paragraphs of memory
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; required by program being EXECed
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global _uppermem_root
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_uppermem_root dw 0ffffh ; 0066 dmd_upper_root (usually 9fff)
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_last_para dw 0 ; 0068 para of last mem search
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SysVarEnd:
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;; FreeDOS specific entries
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;; all variables below this point are subject to relocation.
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;; programs should not rely on any values below this point!!!
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global _os_setver_minor
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_os_setver_minor db 0
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global _os_setver_major
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_os_setver_major db 5
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global _os_minor
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_os_minor db 0
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global _os_major
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_os_major db 5
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_rev_number db 0
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global _version_flags
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_version_flags db 0
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global os_release
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extern _os_release
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os_release dw _os_release
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%IFDEF WIN31SUPPORT
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global _winStartupInfo, _winInstanced
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_winInstanced dw 0 ; set to 1 on WinInit broadcast, 0 on WinExit broadcast
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_winStartupInfo:
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dw 0 ; structure version (same as windows version)
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dd 0 ; next startup info structure, 0:0h marks end
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dd 0 ; far pointer to name virtual device file or 0:0h
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dd 0 ; far pointer, reference data for virtual device driver
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dw instance_table,seg instance_table ; array of instance data
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instance_table: ; should include stacks, Win may auto determine SDA region
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; we simply include whole DOS data segment
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dw seg _DATASTART, 0 ; [SEG:OFF] address of region's base
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dw markEndInstanceData wrt seg _DATASTART ; size in bytes
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dd 0 ; 0 marks end of table
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dw 0 ; and 0 length for end of instance_table entry
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global _winPatchTable
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_winPatchTable: ; returns offsets to various internal variables
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dw 0x0006 ; DOS version, major# in low byte, eg. 6.00
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dw save_DS ; where DS stored during int21h dispatch
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dw save_BX ; where BX stored during int21h dispatch
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dw _InDOS ; offset of InDOS flag
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dw _MachineId ; offset to variable containing MachineID
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dw _CritPatch ; offset of to array of offsets to patch
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; NOTE: this points to a null terminated
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; array of offsets of critical section bytes
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; to patch, for now we can just point this
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; to an empty table
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; ie we just point to a 0 word to mark end
|
|
dw _uppermem_root ; seg of last arena header in conv memory
|
|
; this matches MS DOS's location, but
|
|
; do we have the same meaning?
|
|
%ENDIF ; WIN31SUPPORT
|
|
|
|
;; The first 5 sft entries appear to have to be at DS:00cc
|
|
times (0cch - ($ - DATASTART)) db 0
|
|
global _firstsftt
|
|
_firstsftt:
|
|
dd -1 ; link to next
|
|
dw 5 ; count
|
|
times 5*59 db 0 ; reserve space for the 5 sft entries
|
|
db 0 ; pad byte so next value on even boundary
|
|
|
|
; Some references seem to indicate that this data should start at 01fbh in
|
|
; order to maintain 100% MS-DOS compatibility.
|
|
times (01fbh - ($ - DATASTART)) db 0
|
|
|
|
global MARK01FBH
|
|
MARK01FBH equ $
|
|
global _local_buffer ; local_buffer is 256 bytes long
|
|
; so it overflows into kb_buf!!
|
|
; only when kb_buf is used, local_buffer is limited to 128 bytes.
|
|
_local_buffer: times 128 db 0
|
|
global _kb_buf
|
|
_kb_buf db 128,0 ; initialise buffer to empty
|
|
times 128+1 db 0 ; room for 128 byte readline + LF
|
|
;
|
|
; Variables that follow are documented as part of the DOS 4.0-6.X swappable
|
|
; data area in Ralf Browns Interrupt List #56
|
|
;
|
|
; this byte is used for ^P support
|
|
global _PrinterEcho
|
|
_PrinterEcho db 0 ;-34 - 0 = no printer echo, ~0 echo
|
|
global _verify_ena
|
|
_verify_ena db 0 ; ~0, write with verify
|
|
|
|
; this byte is used for TABs (shared by all char device writes??)
|
|
global _scr_pos
|
|
_scr_pos db 0 ; Current Cursor Column
|
|
global _switchar
|
|
_switchar db '/' ;-31 - switch char
|
|
global _mem_access_mode
|
|
_mem_access_mode db 0 ;-30 - memory allocation strategy
|
|
global sharing_flag
|
|
sharing_flag db 0 ; 00 = sharing module not loaded
|
|
; 01 = sharing module loaded, but
|
|
; open/close for block devices
|
|
; disabled
|
|
; FF = sharing module loaded,
|
|
; open/close for block devices
|
|
; enabled (not implemented)
|
|
global _net_set_count
|
|
_net_set_count db 1 ;-28 - count the name below was set
|
|
global _net_name
|
|
_net_name db ' ' ;-27 - 15 Character Network Name
|
|
db 00 ; Terminating 0 byte
|
|
|
|
|
|
;
|
|
; Variables contained the the "STATE_DATA" segment contain
|
|
; information about the STATE of the current DOS Process. These
|
|
; variables must be preserved regardless of the state of the INDOS
|
|
; flag.
|
|
;
|
|
; All variables that appear in "STATE_DATA" **MUST** be declared
|
|
; in this file as the offsets from the INTERNAL_DATA variable are
|
|
; critical to the DOS applications that modify this data area.
|
|
;
|
|
;
|
|
global _ErrorMode, _InDOS
|
|
global _CritErrLocus, _CritErrCode
|
|
global _CritErrAction, _CritErrClass
|
|
global _CritErrDev, _CritErrDrive
|
|
global _dta
|
|
global _cu_psp, _default_drive
|
|
global _break_ena
|
|
global _return_code
|
|
global _internal_data
|
|
|
|
; ensure offset of critical patch table remains fixed, some programs hard code offset
|
|
times (0315h - ($ - DATASTART)) db 0
|
|
global _CritPatch
|
|
_CritPatch dw 0 ;-11 zero list of patched critical
|
|
dw 0 ; section variables
|
|
dw 0 ; DOS puts 0d0ch here but some
|
|
dw 0 ; progs really write to that addr.
|
|
dw 0 ;-03 - critical patch list terminator
|
|
db 90h ;-01 - unused, NOP pad byte
|
|
_internal_data: ; <-- Address returned by INT21/5D06
|
|
_ErrorMode db 0 ; 00 - Critical Error Flag
|
|
_InDOS db 0 ; 01 - Indos Flag
|
|
_CritErrDrive db 0 ; 02 - Drive on write protect error
|
|
_CritErrLocus db 0 ; 03 - Error Locus
|
|
_CritErrCode dw 0 ; 04 - DOS format error Code
|
|
_CritErrAction db 0 ; 06 - Error Action Code
|
|
_CritErrClass db 0 ; 07 - Error Class
|
|
_CritErrDev dd 0 ; 08 - Failing Device Address
|
|
_dta dd 0 ; 0C - current DTA
|
|
_cu_psp dw 0 ; 10 - Current PSP
|
|
break_sp dw 0 ; 12 - used in int 23
|
|
_return_code dw 0 ; 14 - return code from process
|
|
_default_drive db 0 ; 16 - Current Drive
|
|
_break_ena db 1 ; 17 - Break Flag (default TRUE)
|
|
db 0 ; 18 - flag, code page switching
|
|
db 0 ; 19 - flag, copy of 18 on int 24h abort
|
|
|
|
global _swap_always, _swap_indos
|
|
_swap_always:
|
|
|
|
global _Int21AX
|
|
_Int21AX dw 0 ; 1A - AX from last Int 21
|
|
|
|
global owning_psp, _MachineId
|
|
owning_psp dw 0 ; 1C - owning psp
|
|
_MachineId dw 0 ; 1E - remote machine ID
|
|
dw 0 ; 20 - First usable mcb
|
|
dw 0 ; 22 - Best usable mcb
|
|
dw 0 ; 24 - Last usable mcb
|
|
dw 0 ; 26 - memory size in paragraphs
|
|
dw 0 ; 28 - unknown
|
|
db 0 ; 2A - unknown
|
|
db 0 ; 2B - unknown
|
|
db 0 ; 2C - unknown
|
|
global _break_flg
|
|
_break_flg db 0 ; 2D - Program aborted by ^C
|
|
db 0 ; 2E - unknown
|
|
db 0 ; 2F - not referenced
|
|
global _DayOfMonth
|
|
_DayOfMonth db 1 ; 30 - day of month
|
|
global _Month
|
|
_Month db 1 ; 31 - month
|
|
global _YearsSince1980
|
|
_YearsSince1980 dw 0 ; 32 - year since 1980
|
|
daysSince1980 dw 0FFFFh ; 34 - number of days since epoch
|
|
; force rebuild on first clock read
|
|
global _DayOfWeek
|
|
_DayOfWeek db 2 ; 36 - day of week
|
|
_console_swap db 0 ; 37 console swapped during read from dev
|
|
global _dosidle_flag
|
|
_dosidle_flag db 1 ; 38 - safe to call int28 if nonzero
|
|
_abort_progress db 0 ; 39 - abort in progress
|
|
global _CharReqHdr
|
|
_CharReqHdr:
|
|
global _ClkReqHdr
|
|
_ClkReqHdr times 30 db 0 ; 3A - Device driver request header
|
|
dd 0 ; 58 - pointer to driver entry
|
|
global _MediaReqHdr
|
|
_MediaReqHdr times 22 db 0 ; 5C - Device driver request header
|
|
global _IoReqHdr
|
|
_IoReqHdr times 30 db 0 ; 72 - Device driver request header
|
|
times 6 db 0 ; 90 - unknown
|
|
global _ClkRecord
|
|
_ClkRecord times 6 db 0 ; 96 - CLOCK$ transfer record
|
|
dw 0 ; 9C - unknown
|
|
global __PriPathBuffer
|
|
__PriPathBuffer times 80h db 0 ; 9E - buffer for file name
|
|
global __SecPathBuffer
|
|
__SecPathBuffer times 80h db 0 ;11E - buffer for file name
|
|
global _sda_tmp_dm
|
|
_sda_tmp_dm times 21 db 0 ;19E - 21 byte srch state
|
|
global _SearchDir
|
|
_SearchDir times 32 db 0 ;1B3 - 32 byte dir entry
|
|
global _TempCDS
|
|
_TempCDS times 88 db 0 ;1D3 - TemporaryCDS buffer
|
|
global _DirEntBuffer
|
|
_DirEntBuffer times 32 db 0 ;22B - space enough for 1 dir entry
|
|
global _wAttr
|
|
_wAttr dw 0 ;24B - extended FCB file attribute
|
|
|
|
|
|
global _SAttr
|
|
_SAttr db 0 ;24D - Attribute Mask for Dir Search
|
|
global _OpenMode
|
|
_OpenMode db 0 ;24E - File Open Attribute
|
|
|
|
times 3 db 0
|
|
global _Server_Call
|
|
_Server_Call db 0 ;252 - Server call Func 5D sub 0
|
|
db 0
|
|
; Pad to 05CCh
|
|
times (25ch - ($ - _internal_data)) db 0
|
|
|
|
global _tsr ; used by break and critical error
|
|
_tsr db 0 ;25C - handlers during termination
|
|
db 0 ;25D - padding
|
|
global term_psp
|
|
term_psp dw 0 ;25E - 0??
|
|
global int24_esbp
|
|
int24_esbp times 2 dw 0 ;260 - pointer to criticalerr DPB
|
|
global _user_r, int21regs_off, int21regs_seg
|
|
_user_r:
|
|
int21regs_off dw 0 ;264 - pointer to int21h stack frame
|
|
int21regs_seg dw 0
|
|
global critical_sp
|
|
critical_sp dw 0 ;268 - critical error internal stack
|
|
global current_ddsc
|
|
current_ddsc times 2 dw 0
|
|
|
|
; Pad to 059ah
|
|
times (27ah - ($ - _internal_data)) db 0
|
|
global current_device
|
|
current_device times 2 dw 0 ;27A - 0??
|
|
global _lpCurSft
|
|
_lpCurSft times 2 dw 0 ;27e - Current SFT
|
|
global _current_ldt
|
|
_current_ldt times 2 dw 0 ;282 - Current CDS
|
|
global _sda_lpFcb
|
|
_sda_lpFcb times 2 dw 0 ;286 - pointer to callers FCB
|
|
global _current_sft_idx
|
|
_current_sft_idx dw 0 ;28A - SFT index for next open
|
|
; used by MS NET
|
|
|
|
; Pad to 05b2h
|
|
times (292h - ($ - _internal_data)) db 0
|
|
dw __PriPathBuffer ; 292 - "sda_WFP_START" offset in DOS DS of first filename argument
|
|
dw __SecPathBuffer ; 294 - "sda_REN_WFP" offset in DOS DS of second filename argument
|
|
|
|
; Pad to 05ceh
|
|
times (2aeh - ($ - _internal_data)) db 0
|
|
global _current_filepos
|
|
_current_filepos times 2 dw 0 ;2AE - current offset in file
|
|
|
|
; Pad to 05eah
|
|
times (2cah - ($ - _internal_data)) db 0
|
|
;global _save_BX
|
|
;global _save_DS
|
|
save_BX dw 0 ;2CA - unused by FreeDOS, for Win3.x
|
|
save_DS dw 0 ; compatibility, match MS's positions
|
|
dw 0
|
|
global _prev_user_r
|
|
global prev_int21regs_off
|
|
global prev_int21regs_seg
|
|
_prev_user_r:
|
|
prev_int21regs_off dw 0 ;2D0 - pointer to prev int 21 frame
|
|
prev_int21regs_seg dw 0
|
|
|
|
; Pad to 05fdh
|
|
times (2ddh - ($ - _internal_data)) db 0
|
|
global _ext_open_action
|
|
global _ext_open_attrib
|
|
global _ext_open_mode
|
|
_ext_open_action dw 0 ;2DD - extended open action
|
|
_ext_open_attrib dw 0 ;2DF - extended open attrib
|
|
_ext_open_mode dw 0 ;2E1 - extended open mode
|
|
|
|
; Pad to 0620h
|
|
times (300h - ($ - _internal_data)) db 0
|
|
|
|
global apistk_bottom
|
|
apistk_bottom:
|
|
; use bottom of error stack as scratch buffer
|
|
; - only used during int 21 call
|
|
global _sda_tmp_dm_ren
|
|
_sda_tmp_dm_ren:times 21 db 0x90 ;300 - 21 byte srch state for rename
|
|
global _SearchDir_ren
|
|
_SearchDir_ren: times 32 db 0x90 ;315 - 32 byte dir entry for rename
|
|
|
|
; stacks are made to initialize to no-ops so that high-water
|
|
; testing can be performed
|
|
times STACK_SIZE*2-($-apistk_bottom) db 0x90
|
|
;300 - Error Processing Stack
|
|
global _error_tos
|
|
_error_tos:
|
|
times STACK_SIZE dw 0x9090 ;480 - Disk Function Stack
|
|
global _disk_api_tos
|
|
_disk_api_tos:
|
|
times STACK_SIZE dw 0x9090 ;600 - Char Function Stack
|
|
global _char_api_tos
|
|
_char_api_tos:
|
|
apistk_top:
|
|
db 0 ; 780 ???
|
|
_VolChange db 0 ;781 - volume change
|
|
_VirtOpen db 0 ;782 - virtual open flag
|
|
|
|
; controlled variables end at offset 78Ch so pad to end
|
|
times (78ch - ($ - _internal_data)) db 0
|
|
|
|
;
|
|
; end of controlled variables
|
|
;
|
|
|
|
segment _BSS
|
|
;!! global _NumFloppies
|
|
;!!_NumFloppies resw 1
|
|
;!!intr_dos_stk resw 1
|
|
;!!intr_dos_seg resw 1
|
|
|
|
|
|
; mark front and end of bss area to clear
|
|
segment IB_B
|
|
global __ib_start
|
|
__ib_start:
|
|
segment IB_E
|
|
global __ib_end
|
|
__ib_end:
|
|
;; do not clear the other init BSS variables + STACK: too late.
|
|
|
|
; kernel startup stack
|
|
global init_tos
|
|
resw 512
|
|
init_tos:
|
|
; the last paragraph of conventional memory might become an MCB
|
|
resb 16
|
|
global __init_end
|
|
__init_end:
|
|
init_end:
|
|
|
|
segment _DATA
|
|
; blockdev private stack
|
|
global blk_stk_top
|
|
times 256 dw 0
|
|
blk_stk_top:
|
|
|
|
; clockdev private stack
|
|
global clk_stk_top
|
|
times 128 dw 0
|
|
clk_stk_top:
|
|
|
|
; int2fh private stack
|
|
global int2f_stk_top
|
|
times 128 dw 0
|
|
int2f_stk_top:
|
|
|
|
; Dynamic data:
|
|
; member of the DOS DATA GROUP
|
|
; and marks definitive end of all used data in kernel data segment
|
|
;
|
|
|
|
segment _DATAEND
|
|
|
|
_swap_indos:
|
|
; we don't know precisely what needs to be swapped before this, so set it here.
|
|
; this is just after FIXED_DATA+BSS+DATA and before (D)CONST+BSS
|
|
; probably, the clock and block stacks and disktransferbuffer should go past
|
|
; _swap_indos but only if int2a ah=80/81 (critical section start/end)
|
|
; are called upon entry and exit of the device drivers
|
|
|
|
times 96 dw 0x9090 ; Process 0 Stack
|
|
global _p_0_tos
|
|
_p_0_tos:
|
|
|
|
segment DYN_DATA
|
|
|
|
global _Dyn
|
|
_Dyn:
|
|
DynAllocated dw 0
|
|
|
|
markEndInstanceData: ; mark end of DOS data seg we say needs instancing
|
|
|
|
|
|
segment ID_B
|
|
global __INIT_DATA_START
|
|
__INIT_DATA_START:
|
|
segment ID_E
|
|
global __INIT_DATA_END
|
|
__INIT_DATA_END:
|
|
|
|
|
|
segment INIT_TEXT_START
|
|
global __InitTextStart
|
|
__InitTextStart: ; and c version
|
|
|
|
segment INIT_TEXT_END
|
|
global __InitTextEnd
|
|
__InitTextEnd: ; and c version
|
|
|
|
;
|
|
; start end end of HMA area
|
|
|
|
segment HMA_TEXT_START
|
|
global __HMATextAvailable
|
|
__HMATextAvailable:
|
|
global __HMATextStart
|
|
__HMATextStart:
|
|
|
|
;
|
|
; the HMA area is filled with 1eh+3(=sizeof VDISK) = 33 byte dummy data,
|
|
; so nothing will ever be below 0xffff:0031
|
|
;
|
|
segment HMA_TEXT
|
|
begin_hma:
|
|
times 10h db 0 ; filler [ffff:0..ffff:10]
|
|
times 20h db 0
|
|
db 0
|
|
|
|
; to minimize relocations
|
|
global _DGROUP_
|
|
_DGROUP_ dw DGROUP
|
|
|
|
%ifdef WATCOM
|
|
; 32 bit multiplication + division
|
|
global __U4M
|
|
__U4M:
|
|
LMULU
|
|
global __U4D
|
|
__U4D:
|
|
LDIVMODU
|
|
%endif
|
|
|
|
%ifdef gcc
|
|
%macro ULONG_HELPERS 1
|
|
global %1udivsi3
|
|
%1udivsi3: call %1ldivmodu
|
|
ret 8
|
|
|
|
global %1umodsi3
|
|
%1umodsi3: call %1ldivmodu
|
|
mov dx, cx
|
|
mov ax, bx
|
|
ret 8
|
|
|
|
%1ldivmodu: LDIVMODU
|
|
|
|
global %1ashlsi3
|
|
%1ashlsi3: LSHLU
|
|
|
|
global %1lshrsi3
|
|
%1lshrsi3: LSHRU
|
|
%endmacro
|
|
ULONG_HELPERS ___
|
|
%endif
|
|
|
|
times 0xd0 - ($-begin_hma) db 0
|
|
; reserve space for far jump to cp/m routine
|
|
times 5 db 0
|
|
|
|
;End of HMA segment
|
|
segment HMA_TEXT_END
|
|
global __HMATextEnd
|
|
__HMATextEnd: ; and c version
|
|
|
|
|
|
|
|
; The default stack (_TEXT:0) will overwrite the data area, so I create a dummy
|
|
; stack here to ease debugging. -- ror4
|
|
|
|
segment _STACK class(STACK) nobits stack
|
|
|
|
|
|
|
|
|
|
|
|
segment CONST
|
|
; dummy interrupt return handlers
|
|
|
|
global _int22_handler
|
|
global _int28_handler
|
|
global _int2a_handler
|
|
global _empty_handler
|
|
_int22_handler:
|
|
_int28_handler:
|
|
_int2a_handler:
|
|
_empty_handler:
|
|
iret
|
|
|
|
|
|
global _initforceEnableA20
|
|
initforceEnableA20:
|
|
call near forceEnableA20
|
|
retf
|
|
|
|
global __HMARelocationTableStart
|
|
__HMARelocationTableStart:
|
|
|
|
global _int2f_handler
|
|
extern reloc_call_int2f_handler
|
|
_int2f_handler: jmp 0:reloc_call_int2f_handler
|
|
call near forceEnableA20
|
|
|
|
global _int20_handler
|
|
extern reloc_call_int20_handler
|
|
_int20_handler: jmp 0:reloc_call_int20_handler
|
|
call near forceEnableA20
|
|
|
|
global _int21_handler
|
|
extern reloc_call_int21_handler
|
|
_int21_handler: jmp 0:reloc_call_int21_handler
|
|
call near forceEnableA20
|
|
|
|
|
|
global _low_int25_handler
|
|
extern reloc_call_low_int25_handler
|
|
_low_int25_handler: jmp 0:reloc_call_low_int25_handler
|
|
call near forceEnableA20
|
|
|
|
global _low_int26_handler
|
|
extern reloc_call_low_int26_handler
|
|
_low_int26_handler: jmp 0:reloc_call_low_int26_handler
|
|
call near forceEnableA20
|
|
|
|
global _int27_handler
|
|
extern reloc_call_int27_handler
|
|
_int27_handler: jmp 0:reloc_call_int27_handler
|
|
call near forceEnableA20
|
|
|
|
global _int0_handler
|
|
extern reloc_call_int0_handler
|
|
_int0_handler: jmp 0:reloc_call_int0_handler
|
|
call near forceEnableA20
|
|
|
|
global _int6_handler
|
|
extern reloc_call_int6_handler
|
|
_int6_handler: jmp 0:reloc_call_int6_handler
|
|
call near forceEnableA20
|
|
|
|
global _int19_handler
|
|
extern reloc_call_int19_handler
|
|
_int19_handler: jmp 0:reloc_call_int19_handler
|
|
call near forceEnableA20
|
|
|
|
global _cpm_entry
|
|
extern reloc_call_cpm_entry
|
|
_cpm_entry: jmp 0:reloc_call_cpm_entry
|
|
call near forceEnableA20
|
|
|
|
global _reloc_call_blk_driver
|
|
extern _blk_driver
|
|
_reloc_call_blk_driver:
|
|
jmp 0:_blk_driver
|
|
call near forceEnableA20
|
|
|
|
global _reloc_call_clk_driver
|
|
extern _clk_driver
|
|
_reloc_call_clk_driver:
|
|
jmp 0:_clk_driver
|
|
call near forceEnableA20
|
|
|
|
global _CharMapSrvc ; in _DATA (see AARD)
|
|
extern _reloc_call_CharMapSrvc
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_CharMapSrvc: jmp 0:_reloc_call_CharMapSrvc
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call near forceEnableA20
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global _init_call_p_0
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extern reloc_call_p_0
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_init_call_p_0: jmp 0:reloc_call_p_0
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call near forceEnableA20
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global __HMARelocationTableEnd
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__HMARelocationTableEnd:
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;
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; if we were lucky, we found all entries from the outside to the kernel.
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; if not, BUMS
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;
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;
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; this routine makes the HMA area available. PERIOD.
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; must conserve ALL registers
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; will be only ever called, if HMA (DOS=HIGH) is enabled.
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; for obvious reasons it should be located at the relocation table
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;
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global _XMSDriverAddress
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_XMSDriverAddress:
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dw 0 ; XMS driver, if detected
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dw 0
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global _ENABLEA20
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_ENABLEA20:
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mov ah,5
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UsingXMSdriver:
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push bx
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call far [cs:_XMSDriverAddress]
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pop bx
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retf
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global _DISABLEA20
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_DISABLEA20:
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mov ah,6
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jmp short UsingXMSdriver
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dslowmem dw 0
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eshighmem dw 0ffffh
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global forceEnableA20
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forceEnableA20:
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push ds
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push es
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push ax
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forceEnableA20retry:
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mov ds, [cs:dslowmem]
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mov es, [cs:eshighmem]
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|
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mov ax, [ds:00000h]
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cmp ax, [es:00010h]
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jne forceEnableA20success
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mov ax, [ds:00002h]
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cmp ax, [es:00012h]
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jne forceEnableA20success
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mov ax, [ds:00004h]
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cmp ax, [es:00014h]
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jne forceEnableA20success
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|
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mov ax, [ds:00006h]
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cmp ax, [es:00016h]
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jne forceEnableA20success
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;
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; ok, we have to enable A20 )at least seems so
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;
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call DGROUP:_ENABLEA20
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jmp short forceEnableA20retry
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|
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forceEnableA20success:
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pop ax
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pop es
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pop ds
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ret
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;
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; global f*cking compatibility issues:
|
|
;
|
|
; very old brain dead software (PKLITE, copyright 1990)
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; forces us to execute with A20 disabled
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;
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global _ExecUserDisableA20
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_ExecUserDisableA20:
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|
|
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cmp word [cs:_XMSDriverAddress], byte 0
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jne NeedToDisable
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cmp word [cs:_XMSDriverAddress+2], byte 0
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je noNeedToDisable
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NeedToDisable:
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push ax
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|
call DGROUP:_DISABLEA20
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|
pop ax
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noNeedToDisable:
|
|
iret
|
|
|
|
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|
;
|
|
; Default Int 24h handler -- always returns fail
|
|
; so we have not to relocate it (now)
|
|
;
|
|
FAIL equ 03h
|
|
|
|
global _int24_handler
|
|
_int24_handler: mov al,FAIL
|
|
iret
|
|
|
|
;
|
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; this makes some things easier
|
|
;
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|
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segment _LOWTEXT
|
|
global _TEXT_DGROUP
|
|
_TEXT_DGROUP dw DGROUP
|
|
|
|
segment INIT_TEXT
|
|
global _INIT_DGROUP
|
|
_INIT_DGROUP dw DGROUP
|
|
|
|
%ifdef gcc
|
|
ULONG_HELPERS _init_
|
|
%endif
|