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Bochs/bochs/cpu/cpu.cc
Stanislav Shwartsman d7eb001223 small optimization
2009-06-09 15:23:28 +00:00

1032 lines
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/////////////////////////////////////////////////////////////////////////
// $Id: cpu.cc,v 1.292 2009-06-09 15:23:28 sshwarts Exp $
/////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2001 MandrakeSoft S.A.
//
// MandrakeSoft S.A.
// 43, rue d'Aboukir
// 75002 Paris - France
// http://www.linux-mandrake.com/
// http://www.mandrakesoft.com/
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2 of the License, or (at your option) any later version.
//
// This library 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
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA B 02110-1301 USA
/////////////////////////////////////////////////////////////////////////
#define NEED_CPU_REG_SHORTCUTS 1
#include "bochs.h"
#include "cpu.h"
#define LOG_THIS BX_CPU_THIS_PTR
#include "iodev/iodev.h"
// Make code more tidy with a few macros.
#if BX_SUPPORT_X86_64==0
#define RIP EIP
#define RCX ECX
#endif
#define InstrumentICACHE 0
#if InstrumentICACHE
static unsigned iCacheLookups=0;
static unsigned iCacheMisses=0;
#define InstrICache_StatsMask 0xffffff
#define InstrICache_Stats() {\
if ((iCacheLookups & InstrICache_StatsMask) == 0) { \
BX_INFO(("ICACHE lookups: %u, misses: %u, hit rate = %6.2f%% ", \
iCacheLookups, \
iCacheMisses, \
(iCacheLookups-iCacheMisses) * 100.0 / iCacheLookups)); \
iCacheLookups = iCacheMisses = 0; \
} \
}
#define InstrICache_Increment(v) (v)++
#else
#define InstrICache_Stats()
#define InstrICache_Increment(v)
#endif
// The CHECK_MAX_INSTRUCTIONS macro allows cpu_loop to execute a few
// instructions and then return so that the other processors have a chance to
// run. This is used by bochs internal debugger or when simulating
// multiple processors.
//
// If maximum instructions have been executed, return. The zero-count
// means run forever.
#if BX_SUPPORT_SMP || BX_DEBUGGER
#define CHECK_MAX_INSTRUCTIONS(count) \
if ((count) > 0) { \
(count)--; \
if ((count) == 0) return; \
}
#else
#define CHECK_MAX_INSTRUCTIONS(count)
#endif
void BX_CPU_C::cpu_loop(Bit32u max_instr_count)
{
#if BX_DEBUGGER
BX_CPU_THIS_PTR break_point = 0;
BX_CPU_THIS_PTR magic_break = 0;
BX_CPU_THIS_PTR stop_reason = STOP_NO_REASON;
#endif
if (setjmp(BX_CPU_THIS_PTR jmp_buf_env)) {
// only from exception function we can get here ...
BX_INSTR_NEW_INSTRUCTION(BX_CPU_ID);
BX_TICK1_IF_SINGLE_PROCESSOR();
#if BX_DEBUGGER || BX_GDBSTUB
if (dbg_instruction_epilog()) return;
#endif
CHECK_MAX_INSTRUCTIONS(max_instr_count);
#if BX_GDBSTUB
if (bx_dbg.gdbstub_enabled) return;
#endif
}
// If the exception() routine has encountered a nasty fault scenario,
// the debugger may request that control is returned to it so that
// the situation may be examined.
#if BX_DEBUGGER
if (bx_guard.interrupt_requested) return;
#endif
// We get here either by a normal function call, or by a longjmp
// back from an exception() call. In either case, commit the
// new EIP/ESP, and set up other environmental fields. This code
// mirrors similar code below, after the interrupt() call.
BX_CPU_THIS_PTR prev_rip = RIP; // commit new EIP
BX_CPU_THIS_PTR speculative_rsp = 0;
BX_CPU_THIS_PTR EXT = 0;
BX_CPU_THIS_PTR errorno = 0;
while (1) {
// check on events which occurred for previous instructions (traps)
// and ones which are asynchronous to the CPU (hardware interrupts)
if (BX_CPU_THIS_PTR async_event) {
if (handleAsyncEvent()) {
// If request to return to caller ASAP.
return;
}
}
no_async_event:
bx_address eipBiased = RIP + BX_CPU_THIS_PTR eipPageBias;
if (eipBiased >= BX_CPU_THIS_PTR eipPageWindowSize) {
prefetch();
eipBiased = RIP + BX_CPU_THIS_PTR eipPageBias;
}
bx_phy_address pAddr = BX_CPU_THIS_PTR pAddrPage + eipBiased;
bxICacheEntry_c *entry = BX_CPU_THIS_PTR iCache.get_entry(pAddr, BX_CPU_THIS_PTR fetchModeMask);
bxInstruction_c *i = entry->i;
InstrICache_Increment(iCacheLookups);
InstrICache_Stats();
if ((entry->pAddr == pAddr) &&
(entry->writeStamp == *(BX_CPU_THIS_PTR currPageWriteStampPtr)))
{
// iCache hit. An instruction was found in the iCache
}
else {
// iCache miss. No validated instruction with matching fetch parameters
// is in the iCache.
InstrICache_Increment(iCacheMisses);
serveICacheMiss(entry, (Bit32u) eipBiased, pAddr);
i = entry->i;
}
BxExecutePtr_tR execute = i->execute;
#if BX_SUPPORT_TRACE_CACHE
bxInstruction_c *last = i + (entry->ilen);
for(;;) {
#endif
#if BX_INSTRUMENTATION
BX_INSTR_OPCODE(BX_CPU_ID, BX_CPU_THIS_PTR eipFetchPtr + (RIP + BX_CPU_THIS_PTR eipPageBias),
i->ilen(), BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].cache.u.segment.d_b, Is64BitMode());
#endif
#if BX_DISASM
if (BX_CPU_THIS_PTR trace) {
// print the instruction that is about to be executed
debug_disasm_instruction(BX_CPU_THIS_PTR prev_rip);
}
#endif
// decoding instruction compeleted -> continue with execution
BX_INSTR_BEFORE_EXECUTION(BX_CPU_ID, i);
RIP += i->ilen();
BX_CPU_CALL_METHOD(execute, (i)); // might iterate repeat instruction
BX_CPU_THIS_PTR prev_rip = RIP; // commit new RIP
BX_INSTR_AFTER_EXECUTION(BX_CPU_ID, i);
BX_TICK1_IF_SINGLE_PROCESSOR();
// inform instrumentation about new instruction
BX_INSTR_NEW_INSTRUCTION(BX_CPU_ID);
#if BX_SUPPORT_TRACE_CACHE
execute = (++i)->execute;
#endif
// note instructions generating exceptions never reach this point
#if BX_DEBUGGER || BX_GDBSTUB
if (dbg_instruction_epilog()) return;
#endif
CHECK_MAX_INSTRUCTIONS(max_instr_count);
#if BX_SUPPORT_TRACE_CACHE
if (BX_CPU_THIS_PTR async_event) {
// clear stop trace magic indication that probably was set by repeat or branch32/64
BX_CPU_THIS_PTR async_event &= ~BX_ASYNC_EVENT_STOP_TRACE;
break;
}
if (i == last) goto no_async_event;
}
#endif
} // while (1)
}
void BX_CPP_AttrRegparmN(2) BX_CPU_C::repeat(bxInstruction_c *i, BxExecutePtr_tR execute)
{
// non repeated instruction
if (! i->repUsedL()) {
BX_CPU_CALL_METHOD(execute, (i));
return;
}
#if BX_SUPPORT_X86_64
if (i->as64L()) {
while(1) {
if (RCX != 0) {
BX_CPU_CALL_METHOD(execute, (i));
BX_INSTR_REPEAT_ITERATION(BX_CPU_ID, i);
RCX --;
}
if (RCX == 0) return;
#if BX_DEBUGGER == 0
if (BX_CPU_THIS_PTR async_event)
#endif
break; // exit always if debugger enabled
BX_TICK1_IF_SINGLE_PROCESSOR();
}
}
else
#endif
if (i->as32L()) {
while(1) {
if (ECX != 0) {
BX_CPU_CALL_METHOD(execute, (i));
BX_INSTR_REPEAT_ITERATION(BX_CPU_ID, i);
RCX = ECX - 1;
}
if (ECX == 0) return;
#if BX_DEBUGGER == 0
if (BX_CPU_THIS_PTR async_event)
#endif
break; // exit always if debugger enabled
BX_TICK1_IF_SINGLE_PROCESSOR();
}
}
else // 16bit addrsize
{
while(1) {
if (CX != 0) {
BX_CPU_CALL_METHOD(execute, (i));
BX_INSTR_REPEAT_ITERATION(BX_CPU_ID, i);
CX --;
}
if (CX == 0) return;
#if BX_DEBUGGER == 0
if (BX_CPU_THIS_PTR async_event)
#endif
break; // exit always if debugger enabled
BX_TICK1_IF_SINGLE_PROCESSOR();
}
}
RIP = BX_CPU_THIS_PTR prev_rip; // repeat loop not done, restore RIP
#if BX_SUPPORT_TRACE_CACHE
// assert magic async_event to stop trace execution
BX_CPU_THIS_PTR async_event |= BX_ASYNC_EVENT_STOP_TRACE;
#endif
}
void BX_CPP_AttrRegparmN(2) BX_CPU_C::repeat_ZF(bxInstruction_c *i, BxExecutePtr_tR execute)
{
unsigned rep = i->repUsedValue();
// non repeated instruction
if (! rep) {
BX_CPU_CALL_METHOD(execute, (i));
return;
}
if (rep == 3) { /* repeat prefix 0xF3 */
#if BX_SUPPORT_X86_64
if (i->as64L()) {
while(1) {
if (RCX != 0) {
BX_CPU_CALL_METHOD(execute, (i));
BX_INSTR_REPEAT_ITERATION(BX_CPU_ID, i);
RCX --;
}
if (! get_ZF() || RCX == 0) return;
#if BX_DEBUGGER == 0
if (BX_CPU_THIS_PTR async_event)
#endif
break; // exit always if debugger enabled
BX_TICK1_IF_SINGLE_PROCESSOR();
}
}
else
#endif
if (i->as32L()) {
while(1) {
if (ECX != 0) {
BX_CPU_CALL_METHOD(execute, (i));
BX_INSTR_REPEAT_ITERATION(BX_CPU_ID, i);
RCX = ECX - 1;
}
if (! get_ZF() || ECX == 0) return;
#if BX_DEBUGGER == 0
if (BX_CPU_THIS_PTR async_event)
#endif
break; // exit always if debugger enabled
BX_TICK1_IF_SINGLE_PROCESSOR();
}
}
else // 16bit addrsize
{
while(1) {
if (CX != 0) {
BX_CPU_CALL_METHOD(execute, (i));
BX_INSTR_REPEAT_ITERATION(BX_CPU_ID, i);
CX --;
}
if (! get_ZF() || CX == 0) return;
#if BX_DEBUGGER == 0
if (BX_CPU_THIS_PTR async_event)
#endif
break; // exit always if debugger enabled
BX_TICK1_IF_SINGLE_PROCESSOR();
}
}
}
else { /* repeat prefix 0xF2 */
#if BX_SUPPORT_X86_64
if (i->as64L()) {
while(1) {
if (RCX != 0) {
BX_CPU_CALL_METHOD(execute, (i));
BX_INSTR_REPEAT_ITERATION(BX_CPU_ID, i);
RCX --;
}
if (get_ZF() || RCX == 0) return;
#if BX_DEBUGGER == 0
if (BX_CPU_THIS_PTR async_event)
#endif
break; // exit always if debugger enabled
BX_TICK1_IF_SINGLE_PROCESSOR();
}
}
else
#endif
if (i->as32L()) {
while(1) {
if (ECX != 0) {
BX_CPU_CALL_METHOD(execute, (i));
BX_INSTR_REPEAT_ITERATION(BX_CPU_ID, i);
RCX = ECX - 1;
}
if (get_ZF() || ECX == 0) return;
#if BX_DEBUGGER == 0
if (BX_CPU_THIS_PTR async_event)
#endif
break; // exit always if debugger enabled
BX_TICK1_IF_SINGLE_PROCESSOR();
}
}
else // 16bit addrsize
{
while(1) {
if (CX != 0) {
BX_CPU_CALL_METHOD(execute, (i));
BX_INSTR_REPEAT_ITERATION(BX_CPU_ID, i);
CX --;
}
if (get_ZF() || CX == 0) return;
#if BX_DEBUGGER == 0
if (BX_CPU_THIS_PTR async_event)
#endif
break; // exit always if debugger enabled
BX_TICK1_IF_SINGLE_PROCESSOR();
}
}
}
RIP = BX_CPU_THIS_PTR prev_rip; // repeat loop not done, restore RIP
#if BX_SUPPORT_TRACE_CACHE
// assert magic async_event to stop trace execution
BX_CPU_THIS_PTR async_event |= BX_ASYNC_EVENT_STOP_TRACE;
#endif
}
unsigned BX_CPU_C::handleAsyncEvent(void)
{
//
// This area is where we process special conditions and events.
//
if (BX_CPU_THIS_PTR activity_state) {
// For one processor, pass the time as quickly as possible until
// an interrupt wakes up the CPU.
while (1)
{
if ((BX_CPU_INTR && (BX_CPU_THIS_PTR get_IF() ||
(BX_CPU_THIS_PTR activity_state == BX_ACTIVITY_STATE_MWAIT_IF))) ||
BX_CPU_THIS_PTR pending_NMI || BX_CPU_THIS_PTR pending_SMI || BX_CPU_THIS_PTR pending_INIT)
{
// interrupt ends the HALT condition
#if BX_SUPPORT_MONITOR_MWAIT
if (BX_CPU_THIS_PTR activity_state >= BX_ACTIVITY_STATE_MWAIT)
BX_MEM(0)->clear_monitor(BX_CPU_THIS_PTR bx_cpuid);
#endif
BX_CPU_THIS_PTR activity_state = 0;
BX_CPU_THIS_PTR inhibit_mask = 0; // clear inhibits for after resume
break;
}
if (BX_CPU_THIS_PTR activity_state == BX_ACTIVITY_STATE_ACTIVE) {
BX_INFO(("handleAsyncEvent: reset detected in HLT state"));
break;
}
// for multiprocessor simulation, even if this CPU is halted we still
// must give the others a chance to simulate. If an interrupt has
// arrived, then clear the HALT condition; otherwise just return from
// the CPU loop with stop_reason STOP_CPU_HALTED.
#if BX_SUPPORT_SMP
if (BX_SMP_PROCESSORS > 1) {
// HALT condition remains, return so other CPUs have a chance
#if BX_DEBUGGER
BX_CPU_THIS_PTR stop_reason = STOP_CPU_HALTED;
#endif
return 1; // Return to caller of cpu_loop.
}
#endif
#if BX_DEBUGGER
if (bx_guard.interrupt_requested)
return 1; // Return to caller of cpu_loop.
#endif
BX_TICK1();
}
} else if (bx_pc_system.kill_bochs_request) {
// setting kill_bochs_request causes the cpu loop to return ASAP.
return 1; // Return to caller of cpu_loop.
}
// VMLAUNCH/VMRESUME cannot be executed with interrupts inhibited.
// Save inhibit interrupts state into shadow bits after clearing
BX_CPU_THIS_PTR inhibit_mask = (BX_CPU_THIS_PTR inhibit_mask << 2) & 0xF;
// Priority 1: Hardware Reset and Machine Checks
// RESET
// Machine Check
// (bochs doesn't support these)
// Priority 2: Trap on Task Switch
// T flag in TSS is set
if (BX_CPU_THIS_PTR debug_trap & BX_DEBUG_TRAP_TASK_SWITCH_BIT)
exception(BX_DB_EXCEPTION, 0, 0); // no error, not interrupt
// Priority 3: External Hardware Interventions
// FLUSH
// STOPCLK
// SMI
// INIT
if (BX_CPU_THIS_PTR pending_SMI && ! BX_CPU_THIS_PTR smm_mode())
{
// clear SMI pending flag and disable NMI when SMM was accepted
BX_CPU_THIS_PTR pending_SMI = 0;
enter_system_management_mode();
}
if (BX_CPU_THIS_PTR pending_INIT && ! BX_CPU_THIS_PTR disable_INIT) {
#if BX_SUPPORT_VMX
if (BX_CPU_THIS_PTR in_vmx_guest) {
BX_ERROR(("VMEXIT: INIT pin asserted"));
VMexit(0, VMX_VMEXIT_INIT, 0);
}
#endif
// reset will clear pending INIT
BX_CPU_THIS_PTR reset(BX_RESET_SOFTWARE);
}
// Priority 4: Traps on Previous Instruction
// Breakpoints
// Debug Trap Exceptions (TF flag set or data/IO breakpoint)
if (BX_CPU_THIS_PTR debug_trap &&
!(BX_CPU_THIS_PTR inhibit_mask & BX_INHIBIT_DEBUG_SHADOW))
{
// A trap may be inhibited on this boundary due to an instruction
// which loaded SS. If so we clear the inhibit_mask below
// and don't execute this code until the next boundary.
exception(BX_DB_EXCEPTION, 0, 0); // no error, not interrupt
}
// Priority 5: External Interrupts
// NMI Interrupts
// Maskable Hardware Interrupts
if (BX_CPU_THIS_PTR inhibit_mask & BX_INHIBIT_INTERRUPTS_SHADOW) {
// Processing external interrupts is inhibited on this
// boundary because of certain instructions like STI.
// inhibit_mask is cleared below, in which case we will have
// an opportunity to check interrupts on the next instruction
// boundary.
}
#if BX_SUPPORT_VMX
else if (! BX_CPU_THIS_PTR disable_NMI && BX_CPU_THIS_PTR in_vmx_guest &&
VMEXIT(VMX_VM_EXEC_CTRL2_NMI_WINDOW_VMEXIT))
{
// NMI-window exiting
BX_ERROR(("VMEXIT: NMI window exiting"));
VMexit(0, VMX_VMEXIT_NMI_WINDOW, 0);
}
#endif
else if (BX_CPU_THIS_PTR pending_NMI && ! BX_CPU_THIS_PTR disable_NMI) {
BX_CPU_THIS_PTR pending_NMI = 0;
BX_CPU_THIS_PTR disable_NMI = 1;
BX_CPU_THIS_PTR errorno = 0;
BX_CPU_THIS_PTR EXT = 1; /* external event */
#if BX_SUPPORT_VMX
VMexit_Event(0, BX_NMI, 2, 0, 0);
#endif
BX_INSTR_HWINTERRUPT(BX_CPU_ID, 2, BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value, RIP);
interrupt(2, BX_NMI, 0, 0);
}
#if BX_SUPPORT_VMX
else if (BX_CPU_THIS_PTR vmx_interrupt_window && BX_CPU_THIS_PTR get_IF()) {
// interrupt-window exiting
BX_ERROR(("VMEXIT: interrupt window exiting"));
VMexit(0, VMX_VMEXIT_INTERRUPT_WINDOW, 0);
}
#endif
else if (BX_CPU_INTR && BX_CPU_THIS_PTR get_IF() && BX_DBG_ASYNC_INTR)
{
Bit8u vector;
#if BX_SUPPORT_VMX
VMexit_ExtInterrupt();
#endif
// NOTE: similar code in ::take_irq()
#if BX_SUPPORT_APIC
if (BX_CPU_THIS_PTR lapic.INTR)
vector = BX_CPU_THIS_PTR lapic.acknowledge_int();
else
#endif
// if no local APIC, always acknowledge the PIC.
vector = DEV_pic_iac(); // may set INTR with next interrupt
BX_CPU_THIS_PTR errorno = 0;
BX_CPU_THIS_PTR EXT = 1; /* external event */
#if BX_SUPPORT_VMX
VMexit_Event(0, BX_EXTERNAL_INTERRUPT, vector, 0, 0);
#endif
BX_INSTR_HWINTERRUPT(BX_CPU_ID, vector,
BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value, RIP);
interrupt(vector, BX_EXTERNAL_INTERRUPT, 0, 0);
// Set up environment, as would be when this main cpu loop gets
// invoked. At the end of normal instructions, we always commmit
// the new EIP. But here, we call interrupt() much like
// it was a sofware interrupt instruction, and need to effect the
// commit here. This code mirrors similar code above.
BX_CPU_THIS_PTR prev_rip = RIP; // commit new RIP
BX_CPU_THIS_PTR speculative_rsp = 0;
BX_CPU_THIS_PTR EXT = 0;
BX_CPU_THIS_PTR errorno = 0;
}
else if (BX_HRQ && BX_DBG_ASYNC_DMA) {
// NOTE: similar code in ::take_dma()
// assert Hold Acknowledge (HLDA) and go into a bus hold state
DEV_dma_raise_hlda();
}
// Priority 6: Faults from fetching next instruction
// Code breakpoint fault
// Code segment limit violation (priority 7 on 486/Pentium)
// Code page fault (priority 7 on 486/Pentium)
// (handled in main decode loop)
// Priority 7: Faults from decoding next instruction
// Instruction length > 15 bytes
// Illegal opcode
// Coprocessor not available
// (handled in main decode loop etc)
// Priority 8: Faults on executing an instruction
// Floating point execution
// Overflow
// Bound error
// Invalid TSS
// Segment not present
// Stack fault
// General protection
// Data page fault
// Alignment check
// (handled by rest of the code)
if (BX_CPU_THIS_PTR get_TF())
{
// TF is set before execution of next instruction. Schedule
// a debug trap (#DB) after execution. After completion of
// next instruction, the code above will invoke the trap.
BX_CPU_THIS_PTR debug_trap |= BX_DEBUG_SINGLE_STEP_BIT;
}
// Now we can handle things which are synchronous to instruction
// execution.
if (BX_CPU_THIS_PTR get_RF()) {
BX_CPU_THIS_PTR clear_RF();
}
#if BX_X86_DEBUGGER
else {
// only bother comparing if any breakpoints enabled
if (BX_CPU_THIS_PTR dr7 & 0x000000ff) {
bx_address iaddr = get_laddr(BX_SEG_REG_CS, BX_CPU_THIS_PTR prev_rip);
Bit32u dr6_bits = hwdebug_compare(iaddr, 1, BX_HWDebugInstruction, BX_HWDebugInstruction);
if (dr6_bits) {
// Add to the list of debug events thus far.
BX_CPU_THIS_PTR debug_trap |= dr6_bits;
// If debug events are not inhibited on this boundary,
// fire off a debug fault. Otherwise handle it on the next
// boundary. (becomes a trap)
if (! (BX_CPU_THIS_PTR inhibit_mask & BX_INHIBIT_DEBUG_SHADOW)) {
BX_ERROR(("#DB: x86 code breakpoint catched"));
exception(BX_DB_EXCEPTION, 0, 0); // no error, not interrupt
}
}
}
}
#endif
if (!((BX_CPU_INTR && BX_CPU_THIS_PTR get_IF()) ||
BX_CPU_THIS_PTR debug_trap ||
BX_HRQ ||
BX_CPU_THIS_PTR get_TF()
#if BX_SUPPORT_VMX
|| BX_CPU_THIS_PTR vmx_interrupt_window || BX_CPU_THIS_PTR inhibit_mask
#endif
#if BX_X86_DEBUGGER
// any debug code breakpoint is set
|| ((BX_CPU_THIS_PTR dr7 & 0xff) &&
(((BX_CPU_THIS_PTR dr7 >> 16) & 3) == 0 ||
((BX_CPU_THIS_PTR dr7 >> 20) & 3) == 0 ||
((BX_CPU_THIS_PTR dr7 >> 24) & 3) == 0 ||
((BX_CPU_THIS_PTR dr7 >> 28) & 3) == 0))
#endif
))
BX_CPU_THIS_PTR async_event = 0;
return 0; // Continue executing cpu_loop.
}
// boundaries of consideration:
//
// * physical memory boundary: 1024k (1Megabyte) (increments of...)
// * A20 boundary: 1024k (1Megabyte)
// * page boundary: 4k
// * ROM boundary: 2k (dont care since we are only reading)
// * segment boundary: any
void BX_CPU_C::prefetch(void)
{
bx_address laddr;
unsigned pageOffset;
#if BX_SUPPORT_X86_64
if (Is64BitMode()) {
if (! IsCanonical(RIP)) {
BX_ERROR(("prefetch: #GP(0): RIP crossed canonical boundary"));
exception(BX_GP_EXCEPTION, 0, 0);
}
// linear address is equal to RIP in 64-bit long mode
pageOffset = PAGE_OFFSET(EIP);
laddr = RIP;
// Calculate RIP at the beginning of the page.
BX_CPU_THIS_PTR eipPageBias = pageOffset - RIP;
BX_CPU_THIS_PTR eipPageWindowSize = 4096;
}
else
#endif
{
BX_CLEAR_64BIT_HIGH(BX_64BIT_REG_RIP); /* avoid 32-bit EIP wrap */
laddr = BX_CPU_THIS_PTR get_laddr32(BX_SEG_REG_CS, EIP);
pageOffset = PAGE_OFFSET(laddr);
// Calculate RIP at the beginning of the page.
BX_CPU_THIS_PTR eipPageBias = (bx_address) pageOffset - EIP;
Bit32u limit = BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].cache.u.segment.limit_scaled;
if (EIP > limit) {
BX_ERROR(("prefetch: EIP [%08x] > CS.limit [%08x]", EIP, limit));
exception(BX_GP_EXCEPTION, 0, 0);
}
BX_CPU_THIS_PTR eipPageWindowSize = 4096;
if (limit + BX_CPU_THIS_PTR eipPageBias < 4096) {
BX_CPU_THIS_PTR eipPageWindowSize = (Bit32u)(limit + BX_CPU_THIS_PTR eipPageBias + 1);
}
}
bx_address lpf = LPFOf(laddr);
unsigned TLB_index = BX_TLB_INDEX_OF(lpf, 0);
bx_TLB_entry *tlbEntry = &BX_CPU_THIS_PTR TLB.entry[TLB_index];
Bit8u *fetchPtr = 0;
if ((tlbEntry->lpf == lpf) && !(tlbEntry->accessBits & USER_PL)) {
BX_CPU_THIS_PTR pAddrPage = tlbEntry->ppf;
fetchPtr = (Bit8u*) tlbEntry->hostPageAddr;
}
else {
bx_phy_address pAddr;
if (BX_CPU_THIS_PTR cr0.get_PG()) {
pAddr = translate_linear(laddr, CPL, BX_EXECUTE);
}
else {
pAddr = (bx_phy_address) laddr;
}
BX_CPU_THIS_PTR pAddrPage = LPFOf(pAddr);
}
if (fetchPtr) {
BX_CPU_THIS_PTR eipFetchPtr = fetchPtr;
}
else {
BX_CPU_THIS_PTR eipFetchPtr = BX_MEM(0)->getHostMemAddr(BX_CPU_THIS,
BX_CPU_THIS_PTR pAddrPage, BX_EXECUTE);
// Sanity checks
if (! BX_CPU_THIS_PTR eipFetchPtr) {
bx_phy_address pAddr = BX_CPU_THIS_PTR pAddrPage + pageOffset;
if (pAddr >= BX_MEM(0)->get_memory_len()) {
BX_PANIC(("prefetch: running in bogus memory, pAddr=0x" FMT_PHY_ADDRX, pAddr));
}
else {
BX_PANIC(("prefetch: getHostMemAddr vetoed direct read, pAddr=0x" FMT_PHY_ADDRX, pAddr));
}
}
}
BX_CPU_THIS_PTR currPageWriteStampPtr = pageWriteStampTable.getPageWriteStampPtr(BX_CPU_THIS_PTR pAddrPage);
}
void BX_CPU_C::boundaryFetch(const Bit8u *fetchPtr, unsigned remainingInPage, bxInstruction_c *i)
{
unsigned j;
Bit8u fetchBuffer[16]; // Really only need 15
unsigned ret;
if (remainingInPage >= 15) {
BX_ERROR(("boundaryFetch #GP(0): too many instruction prefixes"));
exception(BX_GP_EXCEPTION, 0, 0);
}
// Read all leftover bytes in current page up to boundary.
for (j=0; j<remainingInPage; j++) {
fetchBuffer[j] = *fetchPtr++;
}
// The 2nd chunk of the instruction is on the next page.
// Set RIP to the 0th byte of the 2nd page, and force a
// prefetch so direct access of that physical page is possible, and
// all the associated info is updated.
RIP += remainingInPage;
prefetch();
unsigned fetchBufferLimit = 15;
if (BX_CPU_THIS_PTR eipPageWindowSize < 15) {
BX_DEBUG(("boundaryFetch: small window size after prefetch - %d bytes", BX_CPU_THIS_PTR eipPageWindowSize));
fetchBufferLimit = BX_CPU_THIS_PTR eipPageWindowSize;
}
// We can fetch straight from the 0th byte, which is eipFetchPtr;
fetchPtr = BX_CPU_THIS_PTR eipFetchPtr;
// read leftover bytes in next page
for (; j<fetchBufferLimit; j++) {
fetchBuffer[j] = *fetchPtr++;
}
#if BX_SUPPORT_X86_64
if (BX_CPU_THIS_PTR cpu_mode == BX_MODE_LONG_64)
ret = fetchDecode64(fetchBuffer, i, remainingInPage+fetchBufferLimit);
else
#endif
ret = fetchDecode32(fetchBuffer, i, remainingInPage+fetchBufferLimit);
if (ret==0) {
BX_INFO(("boundaryFetch #GP(0): failed to complete instruction decoding"));
exception(BX_GP_EXCEPTION, 0, 0);
}
// Restore EIP since we fudged it to start at the 2nd page boundary.
RIP = BX_CPU_THIS_PTR prev_rip;
// Since we cross an instruction boundary, note that we need a prefetch()
// again on the next instruction. Perhaps we can optimize this to
// eliminate the extra prefetch() since we do it above, but have to
// think about repeated instructions, etc.
// invalidate_prefetch_q();
BX_INSTR_OPCODE(BX_CPU_ID, fetchBuffer, i->ilen(),
BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].cache.u.segment.d_b, Is64BitMode());
}
void BX_CPU_C::deliver_SIPI(unsigned vector)
{
if (BX_CPU_THIS_PTR activity_state == BX_ACTIVITY_STATE_WAIT_FOR_SIPI) {
BX_CPU_THIS_PTR activity_state = BX_ACTIVITY_STATE_ACTIVE;
RIP = 0;
load_seg_reg(&BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS], vector*0x100);
BX_CPU_THIS_PTR disable_INIT = 0; // enable INIT pin back
BX_INFO(("CPU %d started up at %04X:%08X by APIC",
BX_CPU_THIS_PTR bx_cpuid, vector*0x100, EIP));
} else {
BX_INFO(("CPU %d started up by APIC, but was not halted at the time", BX_CPU_THIS_PTR bx_cpuid));
}
}
void BX_CPU_C::deliver_INIT(void)
{
if (! BX_CPU_THIS_PTR disable_INIT) {
BX_CPU_THIS_PTR pending_INIT = 1;
BX_CPU_THIS_PTR async_event = 1;
}
}
void BX_CPU_C::deliver_NMI(void)
{
BX_CPU_THIS_PTR pending_NMI = 1;
BX_CPU_THIS_PTR async_event = 1;
}
void BX_CPU_C::deliver_SMI(void)
{
BX_CPU_THIS_PTR pending_SMI = 1;
BX_CPU_THIS_PTR async_event = 1;
}
void BX_CPU_C::set_INTR(bx_bool value)
{
BX_CPU_THIS_PTR INTR = value;
BX_CPU_THIS_PTR async_event = 1;
}
#if BX_DEBUGGER || BX_GDBSTUB
bx_bool BX_CPU_C::dbg_instruction_epilog(void)
{
#if BX_DEBUGGER
Bit64u tt = bx_pc_system.time_ticks();
bx_address debug_eip = RIP;
Bit16u cs = BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value;
BX_CPU_THIS_PTR guard_found.icount++;
BX_CPU_THIS_PTR guard_found.cs = cs;
BX_CPU_THIS_PTR guard_found.eip = debug_eip;
BX_CPU_THIS_PTR guard_found.laddr = BX_CPU_THIS_PTR get_laddr(BX_SEG_REG_CS, debug_eip);
BX_CPU_THIS_PTR guard_found.code_32_64 = BX_CPU_THIS_PTR fetchModeMask;
//
// Take care of break point conditions generated during instruction execution
//
// Check if we hit read/write or time breakpoint
if (BX_CPU_THIS_PTR break_point) {
switch (BX_CPU_THIS_PTR break_point) {
case BREAK_POINT_TIME:
BX_INFO(("[" FMT_LL "d] Caught time breakpoint", tt));
BX_CPU_THIS_PTR stop_reason = STOP_TIME_BREAK_POINT;
return(1); // on a breakpoint
case BREAK_POINT_READ:
BX_INFO(("[" FMT_LL "d] Caught read watch point", tt));
BX_CPU_THIS_PTR stop_reason = STOP_READ_WATCH_POINT;
return(1); // on a breakpoint
case BREAK_POINT_WRITE:
BX_INFO(("[" FMT_LL "d] Caught write watch point", tt));
BX_CPU_THIS_PTR stop_reason = STOP_WRITE_WATCH_POINT;
return(1); // on a breakpoint
default:
BX_PANIC(("Weird break point condition"));
}
}
if (BX_CPU_THIS_PTR magic_break) {
BX_INFO(("[" FMT_LL "d] Stopped on MAGIC BREAKPOINT", bx_pc_system.time_ticks()));
BX_CPU_THIS_PTR stop_reason = STOP_MAGIC_BREAK_POINT;
return(1); // on a breakpoint
}
// convenient point to see if user requested debug break or typed Ctrl-C
if (bx_guard.interrupt_requested) {
return(1);
}
// support for 'show' command in debugger
extern unsigned dbg_show_mask;
if(dbg_show_mask) {
int rv = bx_dbg_show_symbolic();
if (rv) return(rv);
}
// Just committed an instruction, before fetching a new one
// see if debugger is looking for iaddr breakpoint of any type
if (bx_guard.guard_for & BX_DBG_GUARD_IADDR_ALL) {
#if (BX_DBG_MAX_VIR_BPOINTS > 0)
if (bx_guard.guard_for & BX_DBG_GUARD_IADDR_VIR) {
for (unsigned n=0; n<bx_guard.iaddr.num_virtual; n++) {
if (bx_guard.iaddr.vir[n].enabled &&
(bx_guard.iaddr.vir[n].cs == cs) &&
(bx_guard.iaddr.vir[n].eip == debug_eip))
{
BX_CPU_THIS_PTR guard_found.guard_found = BX_DBG_GUARD_IADDR_VIR;
BX_CPU_THIS_PTR guard_found.iaddr_index = n;
BX_CPU_THIS_PTR guard_found.time_tick = tt;
return(1); // on a breakpoint
}
}
}
#endif
#if (BX_DBG_MAX_LIN_BPOINTS > 0)
if (bx_guard.guard_for & BX_DBG_GUARD_IADDR_LIN) {
for (unsigned n=0; n<bx_guard.iaddr.num_linear; n++) {
if (bx_guard.iaddr.lin[n].enabled &&
(bx_guard.iaddr.lin[n].addr == BX_CPU_THIS_PTR guard_found.laddr))
{
BX_CPU_THIS_PTR guard_found.guard_found = BX_DBG_GUARD_IADDR_LIN;
BX_CPU_THIS_PTR guard_found.iaddr_index = n;
BX_CPU_THIS_PTR guard_found.time_tick = tt;
return(1); // on a breakpoint
}
}
}
#endif
#if (BX_DBG_MAX_PHY_BPOINTS > 0)
if (bx_guard.guard_for & BX_DBG_GUARD_IADDR_PHY) {
bx_phy_address phy;
bx_bool valid = dbg_xlate_linear2phy(BX_CPU_THIS_PTR guard_found.laddr, &phy);
if (valid) {
for (unsigned n=0; n<bx_guard.iaddr.num_physical; n++) {
if (bx_guard.iaddr.phy[n].enabled && (bx_guard.iaddr.phy[n].addr == phy))
{
BX_CPU_THIS_PTR guard_found.guard_found = BX_DBG_GUARD_IADDR_PHY;
BX_CPU_THIS_PTR guard_found.iaddr_index = n;
BX_CPU_THIS_PTR guard_found.time_tick = tt;
return(1); // on a breakpoint
}
}
}
}
#endif
}
#endif
#if BX_GDBSTUB
if (bx_dbg.gdbstub_enabled) {
unsigned reason = bx_gdbstub_check(EIP);
if (reason != GDBSTUB_STOP_NO_REASON) return(1);
}
#endif
return(0);
}
#endif // BX_DEBUGGER || BX_GDBSTUB
#if BX_DEBUGGER
void BX_CPU_C::dbg_take_irq(void)
{
// NOTE: similar code in ::cpu_loop()
if (BX_CPU_INTR && BX_CPU_THIS_PTR get_IF()) {
if (setjmp(BX_CPU_THIS_PTR jmp_buf_env) == 0) {
// normal return from setjmp setup
unsigned vector = DEV_pic_iac(); // may set INTR with next interrupt
BX_CPU_THIS_PTR errorno = 0;
BX_CPU_THIS_PTR EXT = 1; // external event
BX_CPU_THIS_PTR async_event = 1; // set in case INTR is triggered
interrupt(vector, BX_EXTERNAL_INTERRUPT, 0, 0);
}
}
}
void BX_CPU_C::dbg_force_interrupt(unsigned vector)
{
// Used to force simulator to take an interrupt, without
// regard to IF
if (setjmp(BX_CPU_THIS_PTR jmp_buf_env) == 0) {
// normal return from setjmp setup
BX_CPU_THIS_PTR errorno = 0;
BX_CPU_THIS_PTR EXT = 1; // external event
BX_CPU_THIS_PTR async_event = 1; // probably don't need this
interrupt(vector, BX_EXTERNAL_INTERRUPT, 0, 0);
}
}
void BX_CPU_C::dbg_take_dma(void)
{
// NOTE: similar code in ::cpu_loop()
if (BX_HRQ) {
BX_CPU_THIS_PTR async_event = 1; // set in case INTR is triggered
DEV_dma_raise_hlda();
}
}
#endif // #if BX_DEBUGGER
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