diff options
Diffstat (limited to 'src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-RegCtxConvertToRingX.c')
| -rw-r--r-- | src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-RegCtxConvertToRingX.c | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-RegCtxConvertToRingX.c b/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-RegCtxConvertToRingX.c new file mode 100644 index 00000000..f55c0c78 --- /dev/null +++ b/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-cmn-RegCtxConvertToRingX.c @@ -0,0 +1,182 @@ +/* $Id: bs3-cmn-RegCtxConvertToRingX.c $ */ +/** @file + * BS3Kit - Bs3RegCtxConvertToRingX + */ + +/* + * Copyright (C) 2007-2023 Oracle and/or its affiliates. + * + * This file is part of VirtualBox base platform packages, as + * available from https://www.virtualbox.org. + * + * 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, in version 3 of the + * License. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <https://www.gnu.org/licenses>. + * + * The contents of this file may alternatively be used under the terms + * of the Common Development and Distribution License Version 1.0 + * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included + * in the VirtualBox 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. + * + * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0 + */ + + +/********************************************************************************************************************************* +* Header Files * +*********************************************************************************************************************************/ +#include "bs3kit-template-header.h" + + +/** + * Transforms a real mode segment into a protected mode selector. + * + * @returns Protected mode selector. + * @param uSeg The real mode segment. + * @param bRing The target ring. + */ +static uint16_t bs3RegCtxConvertRealSegToRingX(uint16_t uSeg, uint8_t bRing) +{ + uint16_t uSel; + if ( uSeg == 0 + || uSeg == BS3_SEL_R0_SS16) + uSel = BS3_SEL_R0_SS16 + ((uint16_t)bRing << BS3_SEL_RING_SHIFT); + else if ( uSeg == (BS3_ADDR_BS3TEXT16 >> 4) + || uSeg == BS3_SEL_R0_CS16) + uSel = BS3_SEL_R0_CS16 + ((uint16_t)bRing << BS3_SEL_RING_SHIFT); + else if ( uSeg == (BS3_ADDR_BS3DATA16 >> 4) + || uSeg == BS3_SEL_R0_DS16) + uSel = BS3_SEL_R0_DS16 + ((uint16_t)bRing << BS3_SEL_RING_SHIFT); + else if (uSeg == (BS3_ADDR_BS3SYSTEM16 >> 4)) + uSel = BS3_SEL_SYSTEM16; + else if (!(uSeg & 0xfff)) + uSel = (uSeg >> (12 - X86_SEL_SHIFT)) + BS3_SEL_TILED; + else if (uSeg == BS3_SEL_R0_DS16) + uSel = (uSeg >> (12 - X86_SEL_SHIFT)) + BS3_SEL_TILED; + else + { + Bs3Printf("uSeg=%#x\n", uSeg); + BS3_ASSERT(0); + return 0; + } + uSel |= bRing; + return uSel; +} + + +/** + * Transforms a protected mode selector to a different ring. + * + * @returns Adjusted protected mode selector. + * @param uSel The current selector value. + * @param bRing The target ring. + * @param iReg Register index. + */ +static uint16_t bs3RegCtxConvertProtSelToRingX(uint16_t uSel, uint8_t bRing, uint8_t iReg) +{ + if ( uSel > X86_SEL_RPL + && !(uSel & X86_SEL_LDT) ) + { + if (uSel >= BS3_SEL_R0_FIRST && uSel < BS3_SEL_R0_FIRST + (5 << BS3_SEL_RING_SHIFT)) + { + /* Convert BS3_SEL_R*_XXX to the target ring. */ + uSel &= BS3_SEL_RING_SUB_MASK; + uSel |= bRing; + uSel += BS3_SEL_R0_FIRST; + uSel += (uint16_t)bRing << BS3_SEL_RING_SHIFT; + } + else + { + /* Convert TEXT16 and DATA16 to BS3_SEL_R*_XXX. */ + uint16_t const uSelRaw = uSel & X86_SEL_MASK_OFF_RPL; + if (uSelRaw == BS3_SEL_TEXT16) + uSel = (BS3_SEL_R0_CS16 | bRing) + ((uint16_t)bRing << BS3_SEL_RING_SHIFT); + else if (uSelRaw == BS3_SEL_DATA16) + uSel = (BS3_SEL_R0_DS16 | bRing) + ((uint16_t)bRing << BS3_SEL_RING_SHIFT); + /* CS and SS must have CPL == DPL. So, convert to standard selectors as we're + usually here because Bs3SwitchToRing0 was called to get out of a test situation. */ + else if (iReg == X86_SREG_CS || iReg == X86_SREG_SS) + { + if ( Bs3Gdt[uSel >> X86_SEL_SHIFT].Gen.u1Long + && BS3_MODE_IS_64BIT_SYS(g_bBs3CurrentMode) ) + uSel = iReg == X86_SREG_CS ? BS3_SEL_R0_CS64 : BS3_SEL_R0_DS64; + else + { + uint32_t uFlat = Bs3SelFar32ToFlat32(0, uSel); + bool fDefBig = Bs3Gdt[uSel >> X86_SEL_SHIFT].Gen.u1DefBig; + if (!fDefBig && uFlat == BS3_ADDR_BS3TEXT16 && iReg == X86_SREG_CS) + uSel = BS3_SEL_R0_CS16; + else if (!fDefBig && uFlat == 0 && iReg == X86_SREG_SS) + uSel = BS3_SEL_R0_SS16; + else if (fDefBig && uFlat == 0) + uSel = iReg == X86_SREG_CS ? BS3_SEL_R0_CS32 : BS3_SEL_R0_SS32; + else + { + Bs3Printf("uSel=%#x iReg=%d\n", uSel, iReg); + BS3_ASSERT(0); + return uSel; + } + uSel |= bRing; + uSel += (uint16_t)bRing << BS3_SEL_RING_SHIFT; + } + } + /* Adjust the RPL on tiled and MMIO selectors. */ + else if ( uSelRaw == BS3_SEL_VMMDEV_MMIO16 + || uSelRaw >= BS3_SEL_TILED) + uSel = uSelRaw | bRing; + } + } + return uSel; +} + + +/** + * Transforms a register context to a different ring. + * + * @param pRegCtx The register context. + * @param bRing The target ring (0..3). + * + * @note Do _NOT_ call this for creating real mode or v8086 contexts, because + * it will always output a protected mode context! + */ +#undef Bs3RegCtxConvertToRingX +BS3_CMN_DEF(void, Bs3RegCtxConvertToRingX,(PBS3REGCTX pRegCtx, uint8_t bRing)) +{ + if ( (pRegCtx->rflags.u32 & X86_EFL_VM) + || pRegCtx->bMode == BS3_MODE_RM) + { + pRegCtx->rflags.u32 &= ~X86_EFL_VM; + pRegCtx->bMode &= ~BS3_MODE_CODE_MASK; + pRegCtx->bMode |= BS3_MODE_CODE_16; + pRegCtx->cs = bs3RegCtxConvertRealSegToRingX(pRegCtx->cs, bRing); + pRegCtx->ss = bs3RegCtxConvertRealSegToRingX(pRegCtx->ss, bRing); + pRegCtx->ds = bs3RegCtxConvertRealSegToRingX(pRegCtx->ds, bRing); + pRegCtx->es = bs3RegCtxConvertRealSegToRingX(pRegCtx->es, bRing); + pRegCtx->fs = bs3RegCtxConvertRealSegToRingX(pRegCtx->fs, bRing); + pRegCtx->gs = bs3RegCtxConvertRealSegToRingX(pRegCtx->gs, bRing); + } + else + { + pRegCtx->cs = bs3RegCtxConvertProtSelToRingX(pRegCtx->cs, bRing, X86_SREG_CS); + pRegCtx->ss = bs3RegCtxConvertProtSelToRingX(pRegCtx->ss, bRing, X86_SREG_SS); + pRegCtx->ds = bs3RegCtxConvertProtSelToRingX(pRegCtx->ds, bRing, X86_SREG_DS); + pRegCtx->es = bs3RegCtxConvertProtSelToRingX(pRegCtx->es, bRing, X86_SREG_ES); + pRegCtx->fs = bs3RegCtxConvertProtSelToRingX(pRegCtx->fs, bRing, X86_SREG_FS); + pRegCtx->gs = bs3RegCtxConvertProtSelToRingX(pRegCtx->gs, bRing, X86_SREG_GS); + } + pRegCtx->bCpl = bRing; +} + |