Bochs/bochs/pc_system.h
2021-01-30 18:50:09 +00:00

208 lines
7.4 KiB
C++

/////////////////////////////////////////////////////////////////////////
// $Id$
/////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2001-2017 The Bochs Project
//
// 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 02110-1301 USA
//
/////////////////////////////////////////////////////////////////////////
#ifndef BX_PCSYS_H
#define BX_PCSYS_H
#define BX_MAX_TIMERS 64
#define BX_NULL_TIMER_HANDLE 10000
typedef void (*bx_timer_handler_t)(void *);
BOCHSAPI extern class bx_pc_system_c bx_pc_system;
#ifdef PROVIDE_M_IPS
extern double m_ips;
#endif
class BOCHSAPI bx_pc_system_c : private logfunctions {
private:
// ===============================
// Timer oriented private features
// ===============================
struct {
bool inUse; // Timer slot is in-use (currently registered).
Bit64u period; // Timer periodocity in cpu ticks.
Bit64u timeToFire; // Time to fire next (in absolute ticks).
bool active; // 0=inactive, 1=active.
bool continuous; // 0=one-shot timer, 1=continuous periodicity.
bx_timer_handler_t funct; // A callback function for when the
// timer fires.
void *this_ptr; // The this-> pointer for C++ callbacks
// has to be stored as well.
#define BxMaxTimerIDLen 32
char id[BxMaxTimerIDLen]; // String ID of timer.
Bit32u param; // Device-specific value assigned to timer (optional)
} timer[BX_MAX_TIMERS];
unsigned numTimers; // Number of currently allocated timers.
unsigned triggeredTimer; // ID of the actually triggered timer.
Bit32u currCountdown; // Current countdown ticks value (decrements to 0).
Bit32u currCountdownPeriod; // Length of current countdown period.
Bit64u ticksTotal; // Num ticks total since start of emulator execution.
Bit64u lastTimeUsec; // Last sequentially read time in usec.
Bit64u usecSinceLast; // Number of useconds claimed since then.
// A special null timer is always inserted in the timer[0] slot. This
// make sure that at least one timer is always active, and that the
// duration is always less than a maximum 32-bit integer, so a 32-bit
// counter can be used for the current countdown.
static const Bit64u NullTimerInterval;
static void nullTimer(void* this_ptr);
#if !defined(PROVIDE_M_IPS)
// This is the emulator speed, as measured in millions of
// x86 instructions per second that it can emulate on some hypothetically
// nomimal workload.
double m_ips; // Millions of Instructions Per Second
#endif
// This handler is called when the function which decrements the clock
// ticks finds that an event has occurred.
void countdownEvent(void);
public:
// ==============================
// Timer oriented public features
// ==============================
void initialize(Bit32u ips);
int register_timer(void *this_ptr, bx_timer_handler_t, Bit32u useconds,
bool continuous, bool active, const char *id);
bool unregisterTimer(unsigned timerID);
void setTimerParam(unsigned timerID, Bit32u param);
void start_timers(void);
void activate_timer(unsigned timer_index, Bit32u useconds, bool continuous);
void activate_timer_nsec(unsigned timer_index, Bit64u nseconds, bool continuous);
void deactivate_timer(unsigned timer_index);
unsigned triggeredTimerID(void) {
return triggeredTimer;
}
Bit32u triggeredTimerParam(void) {
return timer[triggeredTimer].param;
}
static BX_CPP_INLINE void tick1(void) {
if (--bx_pc_system.currCountdown == 0) {
bx_pc_system.countdownEvent();
}
}
static BX_CPP_INLINE void tickn(Bit32u n) {
while (n >= bx_pc_system.currCountdown) {
n -= bx_pc_system.currCountdown;
bx_pc_system.currCountdown = 0;
bx_pc_system.countdownEvent();
// bx_pc_system.currCountdown is adjusted to new value by countdownevent().
}
// 'n' is not (or no longer) >= the countdown size. We can just decrement
// the remaining requested ticks and continue.
bx_pc_system.currCountdown -= n;
}
int register_timer_ticks(void* this_ptr, bx_timer_handler_t, Bit64u ticks,
bool continuous, bool active, const char *id);
void activate_timer_ticks(unsigned index, Bit64u instructions,
bool continuous);
Bit64u time_usec();
Bit64u time_nsec();
Bit64u time_usec_sequential();
static BX_CPP_INLINE Bit64u time_ticks() {
return bx_pc_system.ticksTotal +
Bit64u(bx_pc_system.currCountdownPeriod - bx_pc_system.currCountdown);
}
static BX_CPP_INLINE Bit32u getNumCpuTicksLeftNextEvent(void) {
return bx_pc_system.currCountdown;
}
#if BX_DEBUGGER
static void timebp_handler(void* this_ptr);
#endif
static void benchmarkTimer(void* this_ptr);
#if BX_ENABLE_STATISTICS
static void dumpStatsTimer(void* this_ptr);
#endif
void isa_bus_delay(void);
// ===========================
// Non-timer oriented features
// ===========================
bool HRQ; // Hold Request
// Address line 20 control:
// 1 = enabled: extended memory is accessible
// 0 = disabled: A20 address line is forced low to simulate
// an 8088 address map
bool enable_a20;
// start out masking physical memory addresses to:
// 8086: 20 bits
// 286: 24 bits
// 386: 32 bits
// when A20 line is disabled, mask physical memory addresses to:
// 286: 20 bits
// 386: 20 bits
bx_phy_address a20_mask;
volatile bool kill_bochs_request;
void set_HRQ(bool val); // set the Hold ReQuest line
void raise_INTR(void);
void clear_INTR(void);
// Cpu and System Reset
int Reset(unsigned type);
Bit8u IAC(void);
bx_pc_system_c();
Bit32u inp(Bit16u addr, unsigned io_len) BX_CPP_AttrRegparmN(2);
void outp(Bit16u addr, Bit32u value, unsigned io_len) BX_CPP_AttrRegparmN(3);
void set_enable_a20(bool value);
bool get_enable_a20(void);
void MemoryMappingChanged(void); // flush TLB in all CPUs
void invlpg(bx_address addr); // flush TLB page in all CPUs
void exit(void);
void register_state(void);
};
#define BX_TICK1() bx_pc_system.tick1()
#define BX_TICKN(n) bx_pc_system.tickn(n)
#define BX_INTR bx_pc_system.INTR
#define BX_RAISE_INTR() bx_pc_system.raise_INTR()
#define BX_CLEAR_INTR() bx_pc_system.clear_INTR()
#define BX_HRQ bx_pc_system.HRQ
#define BX_SET_ENABLE_A20(enabled) bx_pc_system.set_enable_a20(enabled)
#define BX_GET_ENABLE_A20() bx_pc_system.get_enable_a20()
#if BX_SUPPORT_A20
# define A20ADDR(x) ((bx_phy_address)(x) & bx_pc_system.a20_mask)
#else
# define A20ADDR(x) ((bx_phy_address)(x))
#endif
#endif