Subversion Repositories s80186

// Copyright Jamie Iles, 2017

//

// This file is part of s80x86.

//

// s80x86 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, either version 3 of the License, or

// (at your option) any later version.

//

// s80x86 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 s80x86.  If not, see <http://www.gnu.org/licenses/>.

void EmulatorPimpl::bound62()

{

    modrm_decoder->decode();

    if (modrm_decoder->rm_type() == OP_REG) {

        invalid_opcode();

        return;

    }

    auto p32 = get_phys_addr(registers->get(get_segment(false)),

                             modrm_decoder->effective_address());

    auto lower = static_cast<int16_t>(mem->read<uint16_t>(p32));

    auto upper = static_cast<int16_t>(mem->read<uint16_t>(p32 + 2));

    auto v = static_cast<int16_t>(registers->get(modrm_decoder->reg()));

    if (v >= lower && v <= upper)

        return;

    auto flags = registers->get_flags();

    push_word(flags);

    push_word(registers->get(CS));

    push_word(registers->get(IP) + instr_length);

    flags &= ~(IF | TF);

    registers->set_flags(flags, IF | TF);

    // int 3

    auto new_cs = mem->read<uint16_t>(VEC_BOUND + 2);

    auto new_ip = mem->read<uint16_t>(VEC_BOUND + 0);

    registers->set(CS, new_cs);

    registers->set(IP, new_ip);

    jump_taken = true;

}