/*
 * Copyright (c) 2005-2011 Imperas Software Ltd., www.imperas.com
 *
 * YOUR ACCESS TO THE INFORMATION IN THIS MODEL IS CONDITIONAL
 * UPON YOUR ACCEPTANCE THAT YOU WILL NOT USE OR PERMIT OTHERS
 * TO USE THE INFORMATION FOR THE PURPOSES OF DETERMINING WHETHER
 * IMPLEMENTATIONS OF THE ARM ARCHITECTURE INFRINGE ANY THIRD
 * PARTY PATENTS.
 *
 * THE LICENSE BELOW EXTENDS ONLY TO USE OF THE SOFTWARE FOR
 * MODELING PURPOSES AND SHALL NOT BE CONSTRUED AS GRANTING
 * A LICENSE TO CREATE A HARDWARE IMPLEMENTATION OF THE
 * FUNCTIONALITY OF THE SOFTWARE LICENSED HEREUNDER.
 * YOU MAY USE THE SOFTWARE SUBJECT TO THE LICENSE TERMS BELOW
 * PROVIDED THAT YOU ENSURE THAT THIS NOTICE IS REPLICATED UNMODIFIED
 * AND IN ITS ENTIRETY IN ALL DISTRIBUTIONS OF THE SOFTWARE,
 * MODIFIED OR UNMODIFIED, IN SOURCE CODE OR IN BINARY FORM.
 *
 * Licensed under an Imperas Modfied Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.ovpworld.org/licenses/OVP_MODIFIED_1.0_APACHE_OPEN_SOURCE_LICENSE_2.0.pdf
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied.
 *
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

// VMI header files
#include "vmi/vmiTypes.h"
#include "vmi/vmiMessage.h"
#include "vmi/vmiMt.h"

// model header files
#include "armFunctions.h"
#include "armRegisters.h"
#include "armStructure.h"


//
// Prefix for messages from this module
//
#define CPU_PREFIX "ARM_SEMIHOST"

//
// Return processor endianness
//
inline static memEndian getEndian(armP arm) {
    return armGetEndian((vmiProcessorP)arm, False);
}

//
// Morph return from an opaque intercepted function
//
VMI_INT_RETURN_FN(armIntReturnCB) {
    vmimtUncondJumpReg(0, ARM_REG(ARM_REG_LR), VMI_NOREG, vmi_JH_RETURN);
}

//
// This callback should create code to assign function result to the standard
// return result register
//
VMI_INT_RESULT_FN(armIntResultCB) {
    vmimtMoveRR(32, ARM_REG(0), VMI_FUNCRESULT);
}

//
// This callback should create code to push 32-bit function parameter 'paramNum'
//
static Uns32 push4ByteArg(vmiProcessorP processor, Uns32 paramNum) {

    if(paramNum<=3) {

        // argument in a register
        vmimtArgReg(32, ARM_REG(paramNum));

    } else {

        // argument on the stack
        armP arm = (armP)processor;

        // fetch into a temporary
        vmimtLoadRRO(
            32,                         // destBits
            32,                         // memBits
            (paramNum-4)*4,             // offset
            ARM_TEMP(0),                // destination (rd)
            ARM_REG(ARM_REG_SP),        // stack address (ra)
            getEndian(arm),             // endian
            False,                      // signExtend
            False                       // checkAlign
        );

        // push temporary argument
        vmimtArgReg(32, ARM_TEMP(0));
    }

    return paramNum+1;
}

//
// This callback should create code to push 64-bit function parameter 'paramNum'
//
static Uns32 push8ByteArg(vmiProcessorP processor, Uns32 paramNum) {

    paramNum += push4ByteArg(processor, paramNum);
    paramNum += push4ByteArg(processor, paramNum);

    return paramNum;
}

//
// This callback should create code to push address function parameter 'paramNum'
//
static Uns32 pushAddressArg(vmiProcessorP processor, Uns32 paramNum) {

    if(paramNum<=3) {

        // argument in a register
        vmimtArgRegSimAddress(32, ARM_REG(paramNum));

    } else {

        // argument on the stack
        armP arm = (armP)processor;

        // fetch into a temporary
        vmimtLoadRRO(
            32,                         // destBits
            32,                         // memBits
            (paramNum-4)*4,             // offset
            ARM_TEMP(0),                // destination (rd)
            ARM_REG(ARM_REG_SP),        // stack address (ra)
            getEndian(arm),             // endian
            False,                      // signExtend
            False                       // checkAlign
        );

        // push temporary argument
        vmimtArgRegSimAddress(32, ARM_TEMP(0));
    }

    return paramNum+1;
}

//
// This callback should create code to push function arguments prior to an
// Imperas standard intercept
//
VMI_INT_PAR_FN(armIntParCB) {

    Uns32 paramNum = 0;
    char  ch;

    while((ch=*format++)) {

        switch(ch) {

            case '4':
                paramNum = push4ByteArg(processor, paramNum);
                break;

            case '8':
                paramNum = push8ByteArg(processor, paramNum);
                break;

            case 'a':
                paramNum = pushAddressArg(processor, paramNum);
                break;

            default:
                VMI_ABORT("Unrecognised format character '%c'", ch);
        }
    }
}