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/* $Id: bs3-cmn-Trap16Init.c $ */
/** @file
* BS3Kit - Bs3Trap16Init
*/
/*
* 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"
/*********************************************************************************************************************************
* 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 Bs3Trap16DoubleFaultHandler80386(void);
extern BS3_DECL(void) BS3_FAR_CODE Bs3Trap16DoubleFaultHandler80286(void);
extern BS3_DECL(void) BS3_FAR_CODE Bs3Trap16GenericEntries(void);
/* These two are ugly. Need data access for patching purposes. */
extern uint8_t BS3_FAR_DATA bs3Trap16GenericTrapOrInt[];
#undef Bs3Trap16InitEx
BS3_CMN_DEF(void, Bs3Trap16InitEx,(bool f386Plus))
{
X86TSS16 BS3_FAR *pTss;
unsigned iIdt;
/*
* 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 = &bs3Trap16GenericTrapOrInt[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;
}
/*
* IDT entries, except the system call gate.
*/
for (iIdt = 0; iIdt < 256; iIdt++)
if (iIdt != BS3_TRAP_SYSCALL)
Bs3Trap16SetGate(iIdt, X86_SEL_TYPE_SYS_286_INT_GATE, 0 /*bDpl*/,
BS3_SEL_R0_CS16, (uint16_t)(uintptr_t)Bs3Trap16GenericEntries + iIdt * 8, 0 /*cParams*/);
/*
* Initialize the normal TSS so we can do ring transitions via the IDT.
*/
pTss = &Bs3Tss16;
Bs3MemZero(pTss, sizeof(*pTss));
pTss->sp0 = BS3_ADDR_STACK_R0;
pTss->ss0 = BS3_SEL_R0_SS16;
pTss->sp1 = BS3_ADDR_STACK_R1;
pTss->ss1 = BS3_SEL_R1_SS16 | 1;
pTss->sp2 = BS3_ADDR_STACK_R2;
pTss->ss2 = BS3_SEL_R2_SS16 | 2;
/*
* Initialize the double fault TSS.
* cr3 is filled in by switcher code, when needed.
*/
pTss = &Bs3Tss16DoubleFault;
Bs3MemZero(pTss, sizeof(*pTss));
pTss->sp0 = BS3_ADDR_STACK_R0;
pTss->ss0 = BS3_SEL_R0_SS16;
pTss->sp1 = BS3_ADDR_STACK_R1;
pTss->ss1 = BS3_SEL_R1_SS16 | 1;
pTss->sp2 = BS3_ADDR_STACK_R2;
pTss->ss2 = BS3_SEL_R2_SS16 | 2;
pTss->ip = (uint16_t)(uintptr_t)(f386Plus ? &Bs3Trap16DoubleFaultHandler80386 : &Bs3Trap16DoubleFaultHandler80286);
pTss->flags = X86_EFL_1;
pTss->sp = BS3_ADDR_STACK_R0_IST1;
pTss->es = BS3_SEL_R0_DS16;
pTss->ds = BS3_SEL_R0_DS16;
pTss->cs = BS3_SEL_R0_CS16;
pTss->ss = BS3_SEL_R0_SS16;
pTss->dx = f386Plus;
Bs3Trap16SetGate(X86_XCPT_DF, X86_SEL_TYPE_SYS_TASK_GATE, 0 /*bDpl*/, BS3_SEL_TSS16_DF, 0, 0 /*cParams*/);
}
#undef Bs3Trap16Init
BS3_CMN_DEF(void, Bs3Trap16Init,(void))
{
BS3_CMN_NM(Bs3Trap16InitEx)((g_uBs3CpuDetected & BS3CPU_TYPE_MASK) >= BS3CPU_80386);
}
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