; $Id: bs3-mode-BiosInt15hE820.asm 92256 2021-11-08 08:33:27Z vboxsync $ ;; @file ; BS3Kit - Bs3BiosInt15hE820 ; ; ; Copyright (C) 2021 Oracle Corporation ; ; This file is part of VirtualBox Open Source Edition (OSE), as ; available from http://www.virtualbox.org. This file is free software; ; you can redistribute it and/or modify it under the terms of the GNU ; General Public License (GPL) as published by the Free Software ; Foundation, in version 2 as it comes in the "COPYING" file of the ; VirtualBox OSE distribution. VirtualBox OSE is distributed in the ; hope that it will be useful, but WITHOUT ANY WARRANTY of any kind. ; ; The contents of this file may alternatively be used under the terms ; of the Common Development and Distribution License Version 1.0 ; (CDDL) only, as it comes in the "COPYING.CDDL" file of the ; VirtualBox OSE distribution, in which case the provisions of the ; CDDL are applicable instead of those of the GPL. ; ; You may elect to license modified versions of this file under the ; terms and conditions of either the GPL or the CDDL or both. ; ;********************************************************************************************************************************* ;* Header Files * ;********************************************************************************************************************************* %include "bs3kit-template-header.mac" ;********************************************************************************************************************************* ;* Defined Constants And Macros * ;********************************************************************************************************************************* ;; Signature: 'SMAP' %define INT15_E820_SIGNATURE 0534d4150h ;********************************************************************************************************************************* ;* External symbols * ;********************************************************************************************************************************* TMPL_BEGIN_TEXT extern TMPL_NM(Bs3SwitchToRM) BS3_BEGIN_TEXT16 extern RT_CONCAT3(_Bs3SwitchTo,TMPL_MODE_UNAME,_Safe_rm) ;; ; Performs a int 15h function 0xe820 call. ; ; @cproto BS3_MODE_PROTO_STUB(bool, Bs3BiosInt15hE820,(INT15E820ENTRY BS3_FAR *pEntry, uint32_t BS3_FAR *pcbEntry, ; uint32_t BS3_FAR *puContinuationValue)); ; ; @returns Success indicator. ; @param pEntry The return buffer. ; @param pcbEntry Input: The size of the buffer (min 20 bytes); ; Output: The size of the returned data. ; @param puContinuationValue Where to get and return the continuation value (EBX) ; Set to zero the for the first call. Returned as zero ; after the last entry. ; ; @remarks ASSUMES we're in ring-0 when not in some kind of real mode. ; @remarks ASSUMES we're on a 16-bit suitable stack. ; ; @uses rax ; TMPL_BEGIN_TEXT BS3_PROC_BEGIN_MODE Bs3BiosInt15hE820, BS3_PBC_HYBRID push xBP mov xBP, xSP sPUSHF cli push sBX push sCX push sDX push sSI push sDI %ifdef TMPL_16BIT push ds push es %endif ; Load/Save parameters. %define a_pEntry [xBP + xCB + cbCurRetAddr + sCB*0] %define a_pcbEntry [xBP + xCB + cbCurRetAddr + sCB*1] %define a_puContinuationValue [xBP + xCB + cbCurRetAddr + sCB*2] %ifdef TMPL_64BIT mov a_pEntry, rcx ; save pEntry mov a_pcbEntry, rdx ; save pcbEntry mov a_puContinuationValue, r8 ; save a_puContinuationValue mov ebx, [r8] ; uContinuationValue for int15 mov ecx, [rdx] ; Buffer size for int15. %elifdef TMPL_16BIT les bx, a_pcbEntry mov ecx, [es:bx] ; Buffer size for int15. les bx, a_puContinuationValue mov ebx, [es:bx] ; Buffer size for int15. %else mov ecx, a_pcbEntry mov ecx, [ecx] ; Buffer size for int15. mov ebx, a_puContinuationValue mov ebx, [ebx] ; uContinuationValue for int15 %endif ; ; Check that the cbEntry isn't too big or too small before doing ; the stack allocation. (Our BIOS doesn't check if too small.) ; cmp ecx, 100h jae .failed cmp cl, 14h jb .failed %if TMPL_MODE != BS3_MODE_RM sub xSP, xCX ; allocate a temporary buffer on the stack. and xSP, ~0fh %endif ; ; Switch to real mode, first we just ot the 16-bit text segment. ; This preserve all 32-bit register values. ; %if TMPL_MODE != BS3_MODE_RM %ifndef TMPL_16BIT jmp .to_text16 BS3_BEGIN_TEXT16 .to_text16: BS3_SET_BITS TMPL_BITS %endif call TMPL_NM(Bs3SwitchToRM) BS3_SET_BITS 16 %endif ; ; Make the call. ; %if TMPL_MODE == BS3_MODE_RM les di, a_pEntry %else push ss ; es:di -> ss:sp pop es mov di, sp %endif mov edx, INT15_E820_SIGNATURE mov eax, 0e820h ; BIOS function number int 15h ; ; Switch back. ; %if TMPL_MODE != BS3_MODE_RM call RT_CONCAT3(_Bs3SwitchTo,TMPL_MODE_UNAME,_Safe_rm) BS3_SET_BITS TMPL_BITS %ifndef TMPL_16BIT jmp .from_text16 TMPL_BEGIN_TEXT .from_text16: %endif %endif ; ; Check that we didn't failed. ; jc .failed cmp eax, INT15_E820_SIGNATURE jc .failed cmp ecx, 20 jb .failed ; ; Save the continuation value. ; %ifdef TMPL_16BIT mov eax, ebx lds bx, a_puContinuationValue mov [bx], eax %else mov xAX, a_puContinuationValue mov [xAX], ebx %endif ; ; Save the entry size. ; %ifdef TMPL_16BIT lds bx, a_pcbEntry %else mov xBX, a_pcbEntry %endif mov [xBX], ecx %if TMPL_MODE != BS3_MODE_RM ; ; Copy the returned stuff into the caller's buffer. ; mov xSI, xSP %ifdef TMPL_16BIT push ss pop es lds di, a_pEntry %else mov xDI, a_pEntry %endif cld rep movsb %endif ; ; Return success ; mov al, 1 .return: %ifdef TMPL_16BIT lea xSP, [xBP - sCB * 6 - xCB*2] pop es pop ds %else lea xSP, [xBP - sCB * 6] %endif pop sDI pop sSI pop sDX pop sCX pop sBX sPOPF leave BS3_HYBRID_RET ; ; Failed. ; .failed: xor al, al jmp .return BS3_PROC_END_MODE Bs3BiosInt15hE820