| 662 | } |
| 663 | |
| 664 | void CPU::iret(U32 big, U32 oldeip) { |
| 665 | CPU* cpu = this; |
| 666 | |
| 667 | if (this->flags & VM) { |
| 668 | if ((this->flags & IOPL)!=IOPL) { |
| 669 | this->prepareException(EXCEPTION_GP, 0); |
| 670 | return; |
| 671 | } else { |
| 672 | if (big) { |
| 673 | U32 new_eip = this->peek32(0); |
| 674 | U32 new_cs = this->peek32(1); |
| 675 | U32 new_flags = this->peek32(2); |
| 676 | |
| 677 | ESP = (ESP & this->stackNotMask) | ((ESP + 12) & this->stackMask); |
| 678 | |
| 679 | this->eip.u32 = new_eip; |
| 680 | this->setSegment(CS, new_cs & 0xFFFF); |
| 681 | |
| 682 | /* IOPL can not be modified in v86 mode by IRET */ |
| 683 | this->setFlags(new_flags, FMASK_NORMAL | NT); |
| 684 | } else { |
| 685 | U32 new_eip = this->peek16(0); |
| 686 | U32 new_cs = this->peek16(1); |
| 687 | U32 new_flags = this->peek16(2); |
| 688 | |
| 689 | ESP = (ESP & this->stackNotMask) | ((ESP + 6) & this->stackMask); |
| 690 | |
| 691 | cpu->eip.u32 = new_eip; |
| 692 | this->setSegment(CS, new_cs); |
| 693 | /* IOPL can not be modified in v86 mode by IRET */ |
| 694 | cpu->setFlags(new_flags, FMASK_NORMAL | NT); |
| 695 | } |
| 696 | this->setIsBig(0); |
| 697 | this->lazyFlagType = FLAGS_NONE; |
| 698 | return; |
| 699 | } |
| 700 | } |
| 701 | /* Check if this is task IRET */ |
| 702 | if (this->flags & NT) { |
| 703 | kpanic("cpu tasks not implemented"); |
| 704 | return; |
| 705 | } else { |
| 706 | U32 n_cs_sel = 0; |
| 707 | U32 n_flags = 0; |
| 708 | U32 n_eip = 0; |
| 709 | |
| 710 | if (big) { |
| 711 | n_eip = this->peek32(0); |
| 712 | n_cs_sel = this->peek32(1) & 0xffff; |
| 713 | n_flags = this->peek32(2); |
| 714 | |
| 715 | if ((n_flags & VM) && (this->cpl==0)) { |
| 716 | // commit point |
| 717 | ESP = (ESP & this->stackNotMask) | ((ESP + 12) & this->stackMask); |
| 718 | this->eip.u32 = n_eip & 0xffff; |
| 719 | U32 n_esp=this->pop32(); |
| 720 | U32 n_ss=this->pop32() & 0xffff; |
| 721 | U32 n_es=this->pop32() & 0xffff; |
no test coverage detected