196 lines
3.7 KiB
C
196 lines
3.7 KiB
C
/*
|
|
* 86Box A hypervisor and IBM PC system emulator that specializes in
|
|
* running old operating systems and software designed for IBM
|
|
* PC systems and compatibles from 1981 through fairly recent
|
|
* system designs based on the PCI bus.
|
|
*
|
|
* This file is part of the 86Box distribution.
|
|
*
|
|
* 808x CPU emulation, mostly ported from reenigne's XTCE, which
|
|
* is cycle-accurate.
|
|
*
|
|
* Authors: gloriouscow, <https://github.com/dbalsom>
|
|
* Miran Grca, <mgrca8@gmail.com>
|
|
*
|
|
* Copyright 2023 gloriouscow.
|
|
* Copyright 2023 Miran Grca.
|
|
*/
|
|
#include <inttypes.h>
|
|
#include <math.h>
|
|
#include <stdarg.h>
|
|
#include <stdint.h>
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <wchar.h>
|
|
|
|
#define HAVE_STDARG_H
|
|
#include <86box/86box.h>
|
|
#include "cpu.h"
|
|
#include "x86.h"
|
|
#include <86box/machine.h>
|
|
#include <86box/io.h>
|
|
#include <86box/mem.h>
|
|
#include <86box/rom.h>
|
|
#include <86box/nmi.h>
|
|
#include <86box/pic.h>
|
|
#include <86box/ppi.h>
|
|
#include <86box/timer.h>
|
|
#include <86box/gdbstub.h>
|
|
// #include "808x.h"
|
|
#include "queue.h"
|
|
|
|
/* TODO: Move to cpu.h so this can eventually be reused for 286+ as well. */
|
|
#define QUEUE_MAX 6
|
|
|
|
typedef struct queue_t
|
|
{
|
|
size_t size;
|
|
size_t len;
|
|
size_t back;
|
|
size_t front;
|
|
uint8_t q[QUEUE_MAX];
|
|
uint16_t preload;
|
|
queue_delay_t delay;
|
|
} queue_t;
|
|
|
|
static queue_t queue;
|
|
|
|
#ifdef ENABLE_QUEUE_LOG
|
|
int queue_do_log = ENABLE_QUEUE_LOG;
|
|
|
|
static void
|
|
queue_log(const char *fmt, ...)
|
|
{
|
|
va_list ap;
|
|
|
|
if (queue_do_log) {
|
|
va_start(ap, fmt);
|
|
pclog_ex(fmt, ap);
|
|
va_end(ap);
|
|
}
|
|
}
|
|
#else
|
|
# define queue_log(fmt, ...)
|
|
#endif
|
|
|
|
void
|
|
queue_set_size(size_t size)
|
|
{
|
|
if (size > QUEUE_MAX)
|
|
#if (defined __amd64__ || defined _M_X64 || defined __aarch64__ || defined _M_ARM64)
|
|
fatal("Requested prefetch queue of %" PRIi64 " bytes is too big\n", size);
|
|
#else
|
|
fatal("Requested prefetch queue of %i bytes is too big\n", size);
|
|
#endif
|
|
|
|
queue.size = size;
|
|
}
|
|
|
|
size_t
|
|
queue_get_len(void)
|
|
{
|
|
return queue.len;
|
|
}
|
|
|
|
int
|
|
queue_is_full(void)
|
|
{
|
|
return (queue.len != queue.size);
|
|
}
|
|
|
|
uint16_t
|
|
queue_get_preload(void)
|
|
{
|
|
uint16_t ret = queue.preload;
|
|
queue.preload = 0x0000;
|
|
|
|
return ret;
|
|
}
|
|
|
|
int
|
|
queue_has_preload(void)
|
|
{
|
|
return (queue.preload & FLAG_PRELOADED) ? 1 : 0;
|
|
}
|
|
|
|
void
|
|
queue_set_preload(void)
|
|
{
|
|
uint8_t byte;
|
|
|
|
if (queue.len > 0) {
|
|
byte = queue_pop();
|
|
queue.preload = ((uint16_t) byte) | FLAG_PRELOADED;
|
|
} else
|
|
fatal("Tried to preload with empty queue\n");
|
|
}
|
|
|
|
void
|
|
queue_push8(uint8_t byte)
|
|
{
|
|
if (queue.len < queue.size) {
|
|
queue.q[queue.front] = byte;
|
|
queue.front = (queue.front + 1) % queue.size;
|
|
queue.len++;
|
|
|
|
if (queue.len == 3)
|
|
queue.delay = DELAY_WRITE;
|
|
else
|
|
queue.delay = DELAY_NONE;
|
|
} else
|
|
fatal("Queue overrun\n");
|
|
}
|
|
|
|
void
|
|
queue_push16(uint16_t word)
|
|
{
|
|
queue_push8((uint8_t) (word & 0xff));
|
|
queue_push8((uint8_t) ((word >> 8) & 0xff));
|
|
}
|
|
|
|
uint8_t
|
|
queue_pop(void)
|
|
{
|
|
uint8_t byte = 0xff;
|
|
|
|
if (queue.len > 0) {
|
|
byte = queue.q[queue.back];
|
|
|
|
queue.back = (queue.back + 1) % queue.size;
|
|
queue.len--;
|
|
|
|
if (queue.len >= 3)
|
|
queue.delay = DELAY_READ;
|
|
else
|
|
queue.delay = DELAY_NONE;
|
|
} else
|
|
fatal("Queue underrun\n");
|
|
|
|
return byte;
|
|
}
|
|
|
|
queue_delay_t
|
|
queue_get_delay(void)
|
|
{
|
|
return queue.delay;
|
|
}
|
|
|
|
void
|
|
queue_flush(void)
|
|
{
|
|
memset(&queue, 0x00, sizeof(queue_t));
|
|
|
|
queue.delay = DELAY_NONE;
|
|
}
|
|
|
|
void
|
|
queue_init(void)
|
|
{
|
|
queue_flush();
|
|
|
|
if (is8086)
|
|
queue_set_size(6);
|
|
else
|
|
queue_set_size(4);
|
|
}
|