x86/state.cc

/*
 * Copyright (c) 2008-2014, Pedigree Developers
 *
 * Please see the CONTRIB file in the root of the source tree for a full
 * list of contributors.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "pedigree/kernel/processor/state.h"

const char *X86InterruptStateRegisterName[11] = {
    "eax", "ebx", "ecx", "edx", "edi", "esi", "ebp", "esp", "eip", "eflags"};

size_t X86InterruptState::getRegisterCount() const
{
    return 10;
}
processor_register_t X86InterruptState::getRegister(size_t index) const
{
    if (index == 0)
        return m_Eax;
    if (index == 1)
        return m_Ebx;
    if (index == 2)
        return m_Ecx;
    if (index == 3)
        return m_Edx;
    if (index == 4)
        return m_Edi;
    if (index == 5)
        return m_Esi;
    if (index == 6)
        return m_Ebp;
    if (index == 7)
        return getStackPointer();
    if (index == 8)
        return m_Eip;
    if (index == 9)
        return m_Eflags;
    return 0;
}
const char *X86InterruptState::getRegisterName(size_t index) const
{
    return X86InterruptStateRegisterName[index];
}

X86InterruptState *
X86InterruptState::construct(X86ProcessorState &state, bool userMode)
{
    // Obtain the stack pointer.
    uintptr_t *pStack = reinterpret_cast<uintptr_t *>(state.getStackPointer());

    if (userMode)
    {
        *--pStack = (userMode) ? 0x23 : 0x10;  // SS
        *--pStack = state.esp;                 // ESP
    }
    *--pStack = 0x200;                     // EFLAGS - IF enabled.
    *--pStack = (userMode) ? 0x1b : 0x08;  // CS
    *--pStack = state.eip;                 // EIP
    *--pStack = 0;                         // Error code
    *--pStack = 0;                         // Interrupt number
    *--pStack = state.eax;                 // EAX
    *--pStack = state.ecx;                 // ECX
    *--pStack = state.edx;                 // EDX
    *--pStack = state.ebx;                 // EBX
    *--pStack = 0;                         // Reserved/unused
    *--pStack = state.ebp;                 // EBP
    *--pStack = state.esi;                 // ESI
    *--pStack = state.edi;                 // EDI
    *--pStack = (userMode) ? 0x23 : 0x10;  // DS.

    X86InterruptState *toRet = reinterpret_cast<X86InterruptState *>(pStack);

    return toRet;
}