[aandrejevic] 59782: [SOFT386] Implement instruction fetch functions. Implement CPU exception system.
Author: aandrejevic Date: Mon Aug 19 18:23:39 2013 New Revision: 59782
URL: http://svn.reactos.org/svn/reactos?rev=59782&view=rev Log: [SOFT386] Implement instruction fetch functions. Implement CPU exception system.
Modified: branches/ntvdm/include/reactos/libs/soft386/soft386.h branches/ntvdm/lib/soft386/common.c branches/ntvdm/lib/soft386/common.h
Modified: branches/ntvdm/include/reactos/libs/soft386/soft386.h URL: http://svn.reactos.org/svn/reactos/branches/ntvdm/include/reactos/libs/soft3... ============================================================================== --- branches/ntvdm/include/reactos/libs/soft386/soft386.h [iso-8859-1] (original) +++ branches/ntvdm/include/reactos/libs/soft386/soft386.h [iso-8859-1] Mon Aug 19 18:23:39 2013 @@ -28,6 +28,12 @@ #define SOFT386_CR0_CD (1 << 30) #define SOFT386_CR0_PG (1 << 31)
+#define SOFT386_IDT_TASK_GATE 0x5 +#define SOFT386_IDT_INT_GATE 0x6 +#define SOFT386_IDT_TRAP_GATE 0x7 +#define SOFT386_IDT_INT_GATE_32 0xE +#define SOFT386_IDT_TRAP_GATE_32 0xF + struct _SOFT386_STATE; typedef struct _SOFT386_STATE SOFT386_STATE, *PSOFT386_STATE;
@@ -75,6 +81,26 @@ SOFT386_REG_DR5, SOFT386_REG_DR6, SOFT386_REG_DR7 +}; + +enum _SOFT386_EXCEPTIONS +{ + SOFT386_EXCEPTION_DE = 0x00, + SOFT386_EXCEPTION_DB = 0x01, + SOFT386_EXCEPTION_BP = 0x03, + SOFT386_EXCEPTION_OF = 0x04, + SOFT386_EXCEPTION_BR = 0x05, + SOFT386_EXCEPTION_UD = 0x06, + SOFT386_EXCEPTION_NM = 0x07, + SOFT386_EXCEPTION_DF = 0x08, + SOFT386_EXCEPTION_TS = 0x0A, + SOFT386_EXCEPTION_NP = 0x0B, + SOFT386_EXCEPTION_SS = 0x0C, + SOFT386_EXCEPTION_GP = 0x0D, + SOFT386_EXCEPTION_PF = 0x0E, + SOFT386_EXCEPTION_MF = 0x10, + SOFT386_EXCEPTION_AC = 0x11, + SOFT386_EXCEPTION_MC = 0x12 };
typedef @@ -162,7 +188,7 @@ ULONG Size : 1; ULONG Granularity : 1; ULONG BaseHigh : 8; -} SOFT386_GDT_ENTRY; +} SOFT386_GDT_ENTRY, *PSOFT386_GDT_ENTRY;
typedef struct { @@ -174,12 +200,12 @@ ULONG Dpl : 2; ULONG Present : 1; ULONG OffsetHigh : 16; -} SOFT386_IDT_ENTRY; +} SOFT386_IDT_ENTRY, *PSOFT386_IDT_ENTRY;
typedef struct _SOFT386_TABLE_REG { USHORT Size; - ULONG Address; + ULONG Address; } SOFT386_TABLE_REG, *PSOFT386_TABLE_REG;
typedef union _SOFT386_FLAGS_REG @@ -255,6 +281,7 @@ ULONGLONG TimeStampCounter; ULONG ControlRegisters[SOFT386_NUM_CTRL_REGS]; ULONG DebugRegisters[SOFT386_NUM_DBG_REGS]; + ULONG ExceptionCount; };
/* FUNCTIONS ******************************************************************/
Modified: branches/ntvdm/lib/soft386/common.c URL: http://svn.reactos.org/svn/reactos/branches/ntvdm/lib/soft386/common.c?rev=5... ============================================================================== --- branches/ntvdm/lib/soft386/common.c [iso-8859-1] (original) +++ branches/ntvdm/lib/soft386/common.c [iso-8859-1] Mon Aug 19 18:23:39 2013 @@ -50,7 +50,7 @@ if ((Offset + Size) >= CachedDescriptor->Limit) { /* Read beyond limit */ - // TODO: Generate exception #GP + Soft386Exception(State, SOFT386_EXCEPTION_GP);
return FALSE; } @@ -62,13 +62,13 @@
if (!CachedDescriptor->Present) { - // TODO: Generate exception #NP + Soft386Exception(State, SOFT386_EXCEPTION_NP); return FALSE; }
if (GET_SEGMENT_RPL(CachedDescriptor->Selector) > CachedDescriptor->Dpl) { - // TODO: Generate exception #GP + Soft386Exception(State, SOFT386_EXCEPTION_GP); return FALSE; }
@@ -78,7 +78,7 @@ { /* Data segment not executable */
- // TODO: Generate exception #GP + Soft386Exception(State, SOFT386_EXCEPTION_GP); return FALSE; } } @@ -88,7 +88,7 @@ { /* Code segment not readable */
- // TODO: Generate exception #GP + Soft386Exception(State, SOFT386_EXCEPTION_GP); return FALSE; } } @@ -133,7 +133,7 @@ if ((Offset + Size) >= CachedDescriptor->Limit) { /* Write beyond limit */ - // TODO: Generate exception #GP + Soft386Exception(State, SOFT386_EXCEPTION_GP);
return FALSE; } @@ -145,13 +145,13 @@
if (!CachedDescriptor->Present) { - // TODO: Generate exception #NP + Soft386Exception(State, SOFT386_EXCEPTION_NP); return FALSE; }
if (GET_SEGMENT_RPL(CachedDescriptor->Selector) > CachedDescriptor->Dpl) { - // TODO: Generate exception #GP + Soft386Exception(State, SOFT386_EXCEPTION_GP); return FALSE; }
@@ -159,14 +159,14 @@ { /* Code segment not writable */
- // TODO: Generate exception #GP + Soft386Exception(State, SOFT386_EXCEPTION_GP); return FALSE; } else if (!CachedDescriptor->ReadWrite) { /* Data segment not writeable */
- // TODO: Generate exception #GP + Soft386Exception(State, SOFT386_EXCEPTION_GP); return FALSE; } } @@ -207,7 +207,7 @@ if (State->GeneralRegs[SOFT386_REG_ESP].Long >= 1 && State->GeneralRegs[SOFT386_REG_ESP].Long <= 3) { - // TODO: Exception #SS + Soft386Exception(State, SOFT386_EXCEPTION_SS); return FALSE; }
@@ -229,7 +229,7 @@ /* Check if SP is 1 */ if (State->GeneralRegs[SOFT386_REG_ESP].Long == 1) { - // TODO: Exception #SS + Soft386Exception(State, SOFT386_EXCEPTION_SS); return FALSE; }
@@ -262,7 +262,7 @@ /* Check if ESP is 0xFFFFFFFF */ if (State->GeneralRegs[SOFT386_REG_ESP].Long == 0xFFFFFFFF) { - // TODO: Exception #SS + Soft386Exception(State, SOFT386_EXCEPTION_SS); return FALSE; }
@@ -291,7 +291,7 @@ /* Check if SP is 0xFFFF */ if (State->GeneralRegs[SOFT386_REG_ESP].LowWord == 0xFFFF) { - // TODO: Exception #SS + Soft386Exception(State, SOFT386_EXCEPTION_SS); return FALSE; }
@@ -319,7 +319,7 @@
inline BOOLEAN -Soft386LoadSegment(PSOFT386_STATE State, INT Segment, WORD Selector) +Soft386LoadSegment(PSOFT386_STATE State, INT Segment, USHORT Selector) { PSOFT386_SEG_REG CachedDescriptor; SOFT386_GDT_ENTRY GdtEntry; @@ -335,7 +335,7 @@ /* Make sure the GDT contains the entry */ if (GET_SEGMENT_INDEX(Selector) >= (State->Gdtr.Size + 1)) { - // TODO: Exception #GP + Soft386Exception(State, SOFT386_EXCEPTION_GP); return FALSE; }
@@ -362,26 +362,26 @@ { if (GET_SEGMENT_INDEX(Selector) == 0) { - // TODO: Exception #GP + Soft386Exception(State, SOFT386_EXCEPTION_GP); return FALSE; }
if (GdtEntry.Executable || !GdtEntry.ReadWrite) { - // TODO: Exception #GP + Soft386Exception(State, SOFT386_EXCEPTION_GP); return FALSE; }
if ((GET_SEGMENT_RPL(Selector) != Soft386GetCurrentPrivLevel(State)) || (GET_SEGMENT_RPL(Selector) != GdtEntry.Dpl)) { - // TODO: Exception #GP + Soft386Exception(State, SOFT386_EXCEPTION_GP); return FALSE; }
if (!GdtEntry.Present) { - // TODO: Exception #SS + Soft386Exception(State, SOFT386_EXCEPTION_SS); return FALSE; } } @@ -390,13 +390,13 @@ if ((GET_SEGMENT_RPL(Selector) > GdtEntry.Dpl) && (Soft386GetCurrentPrivLevel(State) > GdtEntry.Dpl)) { - // TODO: Exception #GP + Soft386Exception(State, SOFT386_EXCEPTION_GP); return FALSE; }
if (!GdtEntry.Present) { - // TODO: Exception #NP + Soft386Exception(State, SOFT386_EXCEPTION_NP); return FALSE; } } @@ -427,4 +427,329 @@ return TRUE; }
+inline +BOOLEAN +Soft386FetchByte(PSOFT386_STATE State, PUCHAR Data) +{ + PSOFT386_SEG_REG CachedDescriptor; + + /* Get the cached descriptor of CS */ + CachedDescriptor = &State->SegmentRegs[SOFT386_REG_CS]; + + /* Read from memory */ + if (!Soft386ReadMemory(State, + SOFT386_REG_CS, + (CachedDescriptor->Size) ? State->InstPtr.Long + : State->InstPtr.LowWord, + TRUE, + Data, + sizeof(UCHAR))) + { + /* Exception occurred during instruction fetch */ + return FALSE; + } + + /* Advance the instruction pointer */ + if (CachedDescriptor->Size) State->InstPtr.Long++; + else State->InstPtr.LowWord++; + + return TRUE; +} + +inline +BOOLEAN +Soft386FetchWord(PSOFT386_STATE State, PUSHORT Data) +{ + PSOFT386_SEG_REG CachedDescriptor; + + /* Get the cached descriptor of CS */ + CachedDescriptor = &State->SegmentRegs[SOFT386_REG_CS]; + + /* Read from memory */ + // FIXME: Fix byte order on big-endian machines + if (!Soft386ReadMemory(State, + SOFT386_REG_CS, + (CachedDescriptor->Size) ? State->InstPtr.Long + : State->InstPtr.LowWord, + TRUE, + Data, + sizeof(USHORT))) + { + /* Exception occurred during instruction fetch */ + return FALSE; + } + + /* Advance the instruction pointer */ + if (CachedDescriptor->Size) State->InstPtr.Long += sizeof(USHORT); + else State->InstPtr.LowWord += sizeof(USHORT); + + return TRUE; +} + +inline +BOOLEAN +Soft386FetchDword(PSOFT386_STATE State, PULONG Data) +{ + PSOFT386_SEG_REG CachedDescriptor; + + /* Get the cached descriptor of CS */ + CachedDescriptor = &State->SegmentRegs[SOFT386_REG_CS]; + + /* Read from memory */ + // FIXME: Fix byte order on big-endian machines + if (!Soft386ReadMemory(State, + SOFT386_REG_CS, + (CachedDescriptor->Size) ? State->InstPtr.Long + : State->InstPtr.LowWord, + TRUE, + Data, + sizeof(ULONG))) + { + /* Exception occurred during instruction fetch */ + return FALSE; + } + + /* Advance the instruction pointer */ + if (CachedDescriptor->Size) State->InstPtr.Long += sizeof(ULONG); + else State->InstPtr.LowWord += sizeof(ULONG); + + return TRUE; +} + +inline +BOOLEAN +Soft386InterruptInternal(PSOFT386_STATE State, + USHORT SegmentSelector, + ULONG Offset, + BOOLEAN InterruptGate) +{ + /* Check for protected mode */ + if (State->ControlRegisters[SOFT386_REG_CR0] & SOFT386_CR0_PE) + { + SOFT386_TSS Tss; + USHORT OldSs = State->SegmentRegs[SOFT386_REG_SS].Selector; + ULONG OldEsp = State->GeneralRegs[SOFT386_REG_ESP].Long; + + /* Check if the interrupt handler is more privileged */ + if (Soft386GetCurrentPrivLevel(State) > GET_SEGMENT_RPL(SegmentSelector)) + { + /* Read the TSS */ + // FIXME: This code is only correct when paging is disabled!!! + if (State->MemReadCallback) + { + State->MemReadCallback(State, + State->Tss.Address, + &Tss, + sizeof(Tss)); + } + else + { + RtlMoveMemory(&Tss, (PVOID)State->Tss.Address, sizeof(Tss)); + } + + /* Check the new (higher) privilege level */ + switch (GET_SEGMENT_RPL(SegmentSelector)) + { + case 0: + { + if (!Soft386LoadSegment(State, SOFT386_REG_SS, Tss.Ss0)) + { + /* Exception occurred */ + return FALSE; + } + State->GeneralRegs[SOFT386_REG_ESP].Long = Tss.Esp0; + + break; + } + + case 1: + { + if (!Soft386LoadSegment(State, SOFT386_REG_SS, Tss.Ss1)) + { + /* Exception occurred */ + return FALSE; + } + State->GeneralRegs[SOFT386_REG_ESP].Long = Tss.Esp1; + + break; + } + + case 2: + { + if (!Soft386LoadSegment(State, SOFT386_REG_SS, Tss.Ss2)) + { + /* Exception occurred */ + return FALSE; + } + State->GeneralRegs[SOFT386_REG_ESP].Long = Tss.Esp2; + + break; + } + + default: + { + /* Should never reach here! */ + ASSERT(FALSE); + } + } + + /* Push SS selector */ + if (!Soft386StackPush(State, OldSs)) return FALSE; + + /* Push stack pointer */ + if (Soft386StackPush(State, OldEsp)) return FALSE; + } + } + + /* Push EFLAGS */ + if (!Soft386StackPush(State, State->Flags.Long)) return FALSE; + + /* Push CS selector */ + if (!Soft386StackPush(State, State->SegmentRegs[SOFT386_REG_CS].Selector)) return FALSE; + + /* Push the instruction pointer */ + if (!Soft386StackPush(State, State->InstPtr.Long)) return FALSE; + + if (InterruptGate) + { + /* Disable interrupts after a jump to an interrupt gate handler */ + State->Flags.If = FALSE; + } + + /* Load new CS */ + if (!Soft386LoadSegment(State, SOFT386_REG_CS, SegmentSelector)) + { + /* An exception occurred during the jump */ + return FALSE; + } + + if (State->SegmentRegs[SOFT386_REG_CS].Size) + { + /* 32-bit code segment, use EIP */ + State->InstPtr.Long = Offset; + } + else + { + /* 16-bit code segment, use IP */ + State->InstPtr.LowWord = LOWORD(Offset); + } + + return TRUE; +} + +inline +BOOLEAN +Soft386GetIntVector(PSOFT386_STATE State, + UCHAR Number, + PSOFT386_IDT_ENTRY IdtEntry) +{ + ULONG FarPointer; + + /* Check for protected mode */ + if (State->ControlRegisters[SOFT386_REG_CR0] & SOFT386_CR0_PE) + { + /* Read from the IDT */ + // FIXME: This code is only correct when paging is disabled!!! + if (State->MemReadCallback) + { + State->MemReadCallback(State, + State->Idtr.Address + + Number * sizeof(*IdtEntry), + IdtEntry, + sizeof(*IdtEntry)); + } + else + { + RtlMoveMemory(IdtEntry, + (PVOID)(State->Idtr.Address + + Number * sizeof(*IdtEntry)), + sizeof(*IdtEntry)); + } + } + else + { + /* Read from the real-mode IVT */ + + /* Paging is always disabled in real mode */ + if (State->MemReadCallback) + { + State->MemReadCallback(State, + State->Idtr.Address + + Number * sizeof(FarPointer), + &FarPointer, + sizeof(FarPointer)); + } + else + { + RtlMoveMemory(IdtEntry, + (PVOID)(State->Idtr.Address + + Number * sizeof(FarPointer)), + sizeof(FarPointer)); + } + + /* Fill a fake IDT entry */ + IdtEntry->Offset = LOWORD(FarPointer); + IdtEntry->Selector = HIWORD(FarPointer); + IdtEntry->Zero = 0; + IdtEntry->Type = SOFT386_IDT_INT_GATE; + IdtEntry->Storage = FALSE; + IdtEntry->Dpl = 0; + IdtEntry->Present = TRUE; + IdtEntry->OffsetHigh = 0; + } + + /* + * Once paging support is implemented this function + * will not always return true + */ + return TRUE; +} + +VOID +__fastcall +Soft386Exception(PSOFT386_STATE State, INT ExceptionCode) +{ + SOFT386_IDT_ENTRY IdtEntry; + + /* Increment the exception count */ + State->ExceptionCount++; + + /* Check if the exception occurred more than once */ + if (State->ExceptionCount > 1) + { + /* Then this is a double fault */ + ExceptionCode = SOFT386_EXCEPTION_DF; + } + + /* Check if this is a triple fault */ + if (State->ExceptionCount == 3) + { + /* Reset the CPU */ + Soft386Reset(State); + return; + } + + if (!Soft386GetIntVector(State, ExceptionCode, &IdtEntry)) + { + /* + * If this function failed, that means Soft386Exception + * was called again, so just return in this case. + */ + return; + } + + /* Perform the interrupt */ + if (!Soft386InterruptInternal(State, + IdtEntry.Selector, + MAKELONG(IdtEntry.Offset, IdtEntry.OffsetHigh), + IdtEntry.Type)) + { + /* + * If this function failed, that means Soft386Exception + * was called again, so just return in this case. + */ + return; + } +} + /* EOF */
Modified: branches/ntvdm/lib/soft386/common.h URL: http://svn.reactos.org/svn/reactos/branches/ntvdm/lib/soft386/common.h?rev=5... ============================================================================== --- branches/ntvdm/lib/soft386/common.h [iso-8859-1] (original) +++ branches/ntvdm/lib/soft386/common.h [iso-8859-1] Mon Aug 19 18:23:39 2013 @@ -61,7 +61,58 @@ ( PSOFT386_STATE State, INT Segment, - WORD Selector + USHORT Selector +); + +inline +BOOLEAN +Soft386FetchByte +( + PSOFT386_STATE State, + PUCHAR Data +); + +inline +BOOLEAN +Soft386FetchWord +( + PSOFT386_STATE State, + PUSHORT Data +); + +inline +BOOLEAN +Soft386FetchDword +( + PSOFT386_STATE State, + PULONG Data +); + +inline +BOOLEAN +Soft386InterruptInternal +( + PSOFT386_STATE State, + USHORT SegmentSelector, + ULONG Offset, + BOOLEAN InterruptGate +); + +inline +BOOLEAN +Soft386GetIntVector +( + PSOFT386_STATE State, + UCHAR Number, + PSOFT386_IDT_ENTRY IdtEntry +); + +VOID +__fastcall +Soft386Exception +( + PSOFT386_STATE State, + INT ExceptionCode );
#endif // _COMMON_H_
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