From: hpa Date: Thu, 19 Apr 2001 04:57:57 +0000 (+0000) Subject: TSR for virtual INT 13h disk in high memory (under development.) X-Git-Tag: syslinux-3.11~833 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=23d61d559b41a241c9844bcbe69340e282339a88;p=profile%2Fivi%2Fsyslinux.git TSR for virtual INT 13h disk in high memory (under development.) --- diff --git a/memdisk.asm b/memdisk.asm new file mode 100644 index 0000000..aa95f9e --- /dev/null +++ b/memdisk.asm @@ -0,0 +1,167 @@ +; -*- fundamental -*- (asm-mode sucks) +; $Id$ +; **************************************************************************** +; +; memdisk.asm +; +; A program to emulate an INT 13h disk BIOS from a "disk" in extended +; memory. +; +; Copyright (C) 2001 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., 675 Mass Ave, Cambridge MA 02139, +; USA; either version 2 of the License, or (at your option) any later +; version; incorporated herein by reference. +; +; **************************************************************************** + + org 0h + +MyStack equ 1024 + + ; Parameter registers definition; this is the definition + ; of the stack frame. +%define P_EAX dword [bp+28] +%define P_AX word [bp+28] +%define P_AL byte [bp+28] +%define P_AH byte [bp+29] +%define P_ECX dword [bp+24] +%define P_CX word [bp+24] +%define P_CL byte [bp+24] +%define P_CH byte [bp+25] +%define P_EDX dword [bp+20] +%define P_DX word [bp+20] +%define P_DL byte [bp+20] +%define P_DH byte [bp+21] +%define P_EBX dword [bp+16] +%define P_BX word [bp+16] +%define P_BL byte [bp+16] +%define P_BH byte [bp+17] +%define P_EBP dword [bp+8] +%define P_BP word [bp+8] +%define P_ESI dword [bp+4] +%define P_SI word [bp+4] +%define P_EDI dword [bp] +%define P_DI word [bp] + + section .text +Int13Start: + ; See if DL points to our class of device (FD, HD) + push dx + xor dl,[cs:DriveNo] + pop dx + js .nomatch ; If SF=0, we have a match here + cmp dl,[cs:DriveNo] + je .our_drive + jb .nomatch ; Drive < Our drive + dec dl ; Drive > Our drive, adjust drive # +.nomatch: + jmp far [OldInt13] + +.our_drive: + mov [cs:Stack],sp + mov [cs:SavedAX],ax + mov ax,ss + mov [cs:Stack+2],ax + mov ax,cs + mov ss,ax + mov sp,MyStack + push ds + push es + mov ds,ax + mov es,ax + mov ax,[SavedAX] + pushad + mov bp,sp + cmp ah,Int13FuncsMax + jae Invalid + xor al,al ; AL = 0 is standard entry condition + mov di,ax + shr di,7 + call [Int13Funcs+di] + +Done: ; Standard routine for return + mov [LastStatus],ah + mov P_AX,ax + cmp ah,1 + setnb al ; AL <- (AH > 0) ? 1 : 0 (CF) + lds bx,[Stack] ; DS:BX <- Old stack pointer + mov [bx+4],al ; Low byte of old FLAGS -> arithmetric flags + popad + pop es + pop ds + lss sp,[cs:Stack] + iret + +Reset: + ; Reset affects multiple drives, so we need to pass it on + pop ax ; Drop return address + mov [LastStatus], byte 0 + popad + pop es + pop ds + lss sp,[cs:Stack] + and dl,80h ; Clear all but the type bit + jmp far [OldInt13] + +GetStatus: + mov ah,[LastStatus] ; Copy last status + ret + +CheckIfReady: +Recalibrate: + xor ah,ah ; Always successful + ret + +Read: +Write: +Verify: +Format: +GetParms: +InitWithParms: +Seek: +GetDriveType: +DetectChange: + +Invalid: + mov ah,01h ; Unsupported function + ret + + section .data +Int13Funcs dw Reset ; 00h - RESET + dw GetStatus ; 01h - GET STATUS + dw Read ; 02h - READ + dw Write ; 03h - WRITE + dw Verify ; 04h - VERIFY + dw Format ; 05h - FORMAT TRACK + dw Format ; 06h - FORMAT TRACK AND SET BAD FLAGS + dw Format ; 07h - FORMAT DRIVE AT TRACK + dw GetParms ; 08h - GET PARAMETERS + dw InitWithParms ; 09h - INITIALIZE CONTROLLER WITH DRIVE PARAMETERS + dw Invalid ; 0Ah + dw Invalid ; 0Bh + dw Seek ; 0Ch - SEEK TO CYLINDER + dw Reset ; 0Dh - RESET HARD DISKS + dw Invalid ; 0Eh + dw Invalid ; 0Fh + dw CheckIfReady ; 10h - CHECK IF READY + dw Recalibrate ; 11h - RECALIBRATE + dw Invalid ; 12h + dw Invalid ; 13h + dw Invalid ; 14h + dw GetDriveType ; 15h - GET DRIVE TYPE + dw DetectChange ; 16h - DETECT DRIVE CHANGE +Int13FuncsEnd equ $ +Int13FuncsMax equ (Int13FuncsEnd-Int13Funcs) >> 1 + +DriveNo db 0 ; Our drive number +LastStatus db 0 ; Last return status + + section .bss +OldInt13 resd 1 ; INT 13h in chain +Stack resd 1 ; Saved SS:SP on invocation +SavedAX resw 1 ; AX saved during initialization + + diff --git a/memdisk/memdisk.asm b/memdisk/memdisk.asm new file mode 100644 index 0000000..aa95f9e --- /dev/null +++ b/memdisk/memdisk.asm @@ -0,0 +1,167 @@ +; -*- fundamental -*- (asm-mode sucks) +; $Id$ +; **************************************************************************** +; +; memdisk.asm +; +; A program to emulate an INT 13h disk BIOS from a "disk" in extended +; memory. +; +; Copyright (C) 2001 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., 675 Mass Ave, Cambridge MA 02139, +; USA; either version 2 of the License, or (at your option) any later +; version; incorporated herein by reference. +; +; **************************************************************************** + + org 0h + +MyStack equ 1024 + + ; Parameter registers definition; this is the definition + ; of the stack frame. +%define P_EAX dword [bp+28] +%define P_AX word [bp+28] +%define P_AL byte [bp+28] +%define P_AH byte [bp+29] +%define P_ECX dword [bp+24] +%define P_CX word [bp+24] +%define P_CL byte [bp+24] +%define P_CH byte [bp+25] +%define P_EDX dword [bp+20] +%define P_DX word [bp+20] +%define P_DL byte [bp+20] +%define P_DH byte [bp+21] +%define P_EBX dword [bp+16] +%define P_BX word [bp+16] +%define P_BL byte [bp+16] +%define P_BH byte [bp+17] +%define P_EBP dword [bp+8] +%define P_BP word [bp+8] +%define P_ESI dword [bp+4] +%define P_SI word [bp+4] +%define P_EDI dword [bp] +%define P_DI word [bp] + + section .text +Int13Start: + ; See if DL points to our class of device (FD, HD) + push dx + xor dl,[cs:DriveNo] + pop dx + js .nomatch ; If SF=0, we have a match here + cmp dl,[cs:DriveNo] + je .our_drive + jb .nomatch ; Drive < Our drive + dec dl ; Drive > Our drive, adjust drive # +.nomatch: + jmp far [OldInt13] + +.our_drive: + mov [cs:Stack],sp + mov [cs:SavedAX],ax + mov ax,ss + mov [cs:Stack+2],ax + mov ax,cs + mov ss,ax + mov sp,MyStack + push ds + push es + mov ds,ax + mov es,ax + mov ax,[SavedAX] + pushad + mov bp,sp + cmp ah,Int13FuncsMax + jae Invalid + xor al,al ; AL = 0 is standard entry condition + mov di,ax + shr di,7 + call [Int13Funcs+di] + +Done: ; Standard routine for return + mov [LastStatus],ah + mov P_AX,ax + cmp ah,1 + setnb al ; AL <- (AH > 0) ? 1 : 0 (CF) + lds bx,[Stack] ; DS:BX <- Old stack pointer + mov [bx+4],al ; Low byte of old FLAGS -> arithmetric flags + popad + pop es + pop ds + lss sp,[cs:Stack] + iret + +Reset: + ; Reset affects multiple drives, so we need to pass it on + pop ax ; Drop return address + mov [LastStatus], byte 0 + popad + pop es + pop ds + lss sp,[cs:Stack] + and dl,80h ; Clear all but the type bit + jmp far [OldInt13] + +GetStatus: + mov ah,[LastStatus] ; Copy last status + ret + +CheckIfReady: +Recalibrate: + xor ah,ah ; Always successful + ret + +Read: +Write: +Verify: +Format: +GetParms: +InitWithParms: +Seek: +GetDriveType: +DetectChange: + +Invalid: + mov ah,01h ; Unsupported function + ret + + section .data +Int13Funcs dw Reset ; 00h - RESET + dw GetStatus ; 01h - GET STATUS + dw Read ; 02h - READ + dw Write ; 03h - WRITE + dw Verify ; 04h - VERIFY + dw Format ; 05h - FORMAT TRACK + dw Format ; 06h - FORMAT TRACK AND SET BAD FLAGS + dw Format ; 07h - FORMAT DRIVE AT TRACK + dw GetParms ; 08h - GET PARAMETERS + dw InitWithParms ; 09h - INITIALIZE CONTROLLER WITH DRIVE PARAMETERS + dw Invalid ; 0Ah + dw Invalid ; 0Bh + dw Seek ; 0Ch - SEEK TO CYLINDER + dw Reset ; 0Dh - RESET HARD DISKS + dw Invalid ; 0Eh + dw Invalid ; 0Fh + dw CheckIfReady ; 10h - CHECK IF READY + dw Recalibrate ; 11h - RECALIBRATE + dw Invalid ; 12h + dw Invalid ; 13h + dw Invalid ; 14h + dw GetDriveType ; 15h - GET DRIVE TYPE + dw DetectChange ; 16h - DETECT DRIVE CHANGE +Int13FuncsEnd equ $ +Int13FuncsMax equ (Int13FuncsEnd-Int13Funcs) >> 1 + +DriveNo db 0 ; Our drive number +LastStatus db 0 ; Last return status + + section .bss +OldInt13 resd 1 ; INT 13h in chain +Stack resd 1 ; Saved SS:SP on invocation +SavedAX resw 1 ; AX saved during initialization + +