diff options
Diffstat (limited to 'src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-TrapRmV86Init.c')
| -rw-r--r-- | src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-TrapRmV86Init.c | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-TrapRmV86Init.c b/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-TrapRmV86Init.c new file mode 100644 index 00000000..ec341e94 --- /dev/null +++ b/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-TrapRmV86Init.c @@ -0,0 +1,110 @@ +/* $Id: bs3-cmn-TrapRmV86Init.c $ */ +/** @file + * BS3Kit - Bs3TrapRmV86Init + */ + +/* + * Copyright (C) 2007-2019 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.h" + + +/********************************************************************************************************************************* +* Global Variables * +*********************************************************************************************************************************/ +/* We ASSUME that BS3CLASS16CODE is 64KB aligned, so the low 16-bit of the + flat address matches. Also, these symbols are defined both with + and without underscore prefixes. */ +extern BS3_DECL(void) BS3_FAR_CODE Bs3TrapRmV86GenericEntries(void); + +/* These two are ugly. Need data access for patching purposes. */ +extern uint8_t BS3_FAR_DATA bs3TrapRmV86GenericTrapOrInt[]; + +/* bs3-cmn-TrapRmV86Data.c: */ +#define g_fBs3RmIvtCopied BS3_DATA_NM(g_fBs3RmIvtCopied) +extern bool g_fBs3RmIvtCopied; + + +#undef Bs3TrapRmV86InitEx +BS3_CMN_DEF(void, Bs3TrapRmV86InitEx,(bool f386Plus)) +{ + RTFAR16 BS3_FAR *paIvt = Bs3XptrFlatToCurrent(0); + unsigned iIvt; + + /* + * Copy the real mode IVT the first time we are here. + */ + if (!g_fBs3RmIvtCopied) + { + Bs3MemCpy(g_aBs3RmIvtOriginal, paIvt, sizeof(g_aBs3RmIvtOriginal)); + g_fBs3RmIvtCopied = true; + } + /* + * The rest of the times, we copy back the original and modify it. + */ + else + Bs3MemCpy(paIvt, g_aBs3RmIvtOriginal, sizeof(g_aBs3RmIvtOriginal)); + + + /* + * If 386 or later, patch the trap handler code to not jump to the 80286 + * code but continue with the next instruction (the 386+ code). + */ + if (f386Plus) + { + uint8_t BS3_FAR_DATA *pbFunction = &bs3TrapRmV86GenericTrapOrInt[0]; +#if ARCH_BITS == 16 + if (g_bBs3CurrentMode != BS3_MODE_RM) + pbFunction = (uint8_t BS3_FAR_DATA *)BS3_FP_MAKE(BS3_SEL_TILED + 1, BS3_FP_OFF(pbFunction)); +#endif + pbFunction[1] = 0; + pbFunction[2] = 0; + } + + /* + * Since we want to play with V86 mode as well as 8086 and 186 CPUs, we + * cannot move the IVT from its default location. So, modify it in place. + * + * Note! We must keep INT 10h working, which is easy since the CPU does + * use it (well, it's been reserved for 30+ years). + * Turns out we must not hook INT 6Dh either then, as some real VGA + * BIOS installs their INT 10h handler there as well, and seemingly + * must be using it internally or something. + */ + for (iIvt = 0; iIvt < 256; iIvt++) + if (iIvt != 0x10 && iIvt != 0x6d && iIvt != BS3_TRAP_SYSCALL) + { + paIvt[iIvt].off = (uint16_t)(uintptr_t)Bs3TrapRmV86GenericEntries + iIvt * 8; + paIvt[iIvt].sel = BS3_SEL_TEXT16; + } +} + + +#undef Bs3TrapRmV86Init +BS3_CMN_DEF(void, Bs3TrapRmV86Init,(void)) +{ + BS3_CMN_NM(Bs3TrapRmV86InitEx)((g_uBs3CpuDetected & BS3CPU_TYPE_MASK) >= BS3CPU_80386); +} + |