mirror of
https://github.com/RetroPortingToolKit/psxrecomp
synced 2026-10-28 10:59:16 -04:00
Alex Vanderveen
81 lines
3.3 KiB
C
81 lines
3.3 KiB
C
/*
|
|
* dual_machine.h -- Stage B dual-console driver (serial-link bring-up).
|
|
*
|
|
* Runs TWO complete PSX guest machines in one process by cooperative
|
|
* time-slicing over the existing boot_state snapshot swap: save the live
|
|
* machine at a CPS block boundary, restore the other machine's blob, and
|
|
* psx_scheduler_resume_at() into it. The two machines' SIO1 devices are
|
|
* cross-wired by a psx_link crossover whose rings live in HOST memory and
|
|
* deliberately survive switches (the wire is the channel between machines,
|
|
* so BS_SEC_SIO1 apply is suppressed while dual mode is active).
|
|
*
|
|
* Scheduling invariant: |cycles(A) - cycles(B)| <= slice at every switch
|
|
* decision. While the link is armed (DTR up, shift in flight, or chars
|
|
* queued) the slice is one character time (both consoles see each byte
|
|
* within one char of its true arrival); otherwise a coarse slice keeps the
|
|
* swap tax low during menus/boot.
|
|
*
|
|
* Stage B limitations (documented, by design):
|
|
* - user savestates / rewind / netplay rollback are not dual-aware
|
|
* (rewind is shut down at activation);
|
|
* - host input is pushed to BOTH machines (seat split is Stage D);
|
|
* - only the "local" machine presents video / mixes audio.
|
|
*/
|
|
#ifndef PSX_DUAL_MACHINE_H
|
|
#define PSX_DUAL_MACHINE_H
|
|
|
|
#include <stdint.h>
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
struct CPUState;
|
|
|
|
/* One load+branch gate for the per-edge poll in psx_check_interrupts:
|
|
* nonzero from the moment dual mode is REQUESTED (config/env). */
|
|
extern int g_psx_dual_active;
|
|
|
|
/* Request dual-console mode (config [runtime.link] backend="crossover" or
|
|
* env PSX_DUAL_CONSOLE=1). local_machine selects which machine presents
|
|
* video/audio (0 or 1). Activation itself is lazy: the first poll with a
|
|
* safe resume PC captures the shared boot state and arms the crossover. */
|
|
void psx_dual_machine_request(int local_machine);
|
|
|
|
/* Per-block-edge poll (interrupts.c). On a switch this does NOT return --
|
|
* it longjmps into the other machine via psx_scheduler_resume_at. */
|
|
void psx_dual_machine_poll(struct CPUState *cpu, uint32_t resume_pc);
|
|
|
|
/* Veto a pending config-file dual request before activation
|
|
* (PSX_DUAL_CONSOLE=0). No-op once two machines are running. */
|
|
void psx_dual_machine_cancel(void);
|
|
|
|
/* 1 = present/audio allowed (dual inactive, or the live machine is the
|
|
* local one). Consulted by the vblank present path in main.cpp. */
|
|
int psx_dual_present_gate(void);
|
|
|
|
/* Runtime A/V ownership (F6 focus). Sets the machine psx_dual_present_gate()
|
|
* lets through; the other console runs headless. */
|
|
void psx_dual_set_local_machine(int machine);
|
|
int psx_dual_get_local_machine(void);
|
|
|
|
/* Input routing: which machine(s) receive the host pads. The excluded
|
|
* machine is fed neutral pads. 0 = both (default), 1 = machine 0 only,
|
|
* 2 = machine 1 only. Needed for asymmetric menu navigation (the link
|
|
* master/slave handshake) while Stage B mirrors one set of host pads. */
|
|
void psx_dual_set_input_route(int route);
|
|
int psx_dual_get_input_route(void);
|
|
/* 1 = host pads flow to the LIVE machine under the current route. */
|
|
int psx_dual_input_allowed(void);
|
|
|
|
/* Diagnostics (debug server "dual_state"). */
|
|
int psx_dual_machine_live(void); /* -1 when inactive */
|
|
uint64_t psx_dual_machine_swaps(void);
|
|
void psx_dual_machine_cycles(uint64_t out[2]);
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif /* PSX_DUAL_MACHINE_H */
|