cog/Frameworks/lazyusf/lazyusf/pif.c

100 lines
2.7 KiB
C

/*
* Project 64 - A Nintendo 64 emulator.
*
* (c) Copyright 2001 zilmar (zilmar@emulation64.com) and
* Jabo (jabo@emulation64.com).
*
* pj64 homepage: www.pj64.net
*
* Permission to use, copy, modify and distribute Project64 in both binary and
* source form, for non-commercial purposes, is hereby granted without fee,
* providing that this license information and copyright notice appear with
* all copies and any derived work.
*
* This software is provided 'as-is', without any express or implied
* warranty. In no event shall the authors be held liable for any damages
* arising from the use of this software.
*
* Project64 is freeware for PERSONAL USE only. Commercial users should
* seek permission of the copyright holders first. Commercial use includes
* charging money for Project64 or software derived from Project64.
*
* The copyright holders request that bug fixes and improvements to the code
* should be forwarded to them so if they want them.
*
*/
#include "usf.h"
#include "main.h"
#include "cpu.h"
#include "usf_internal.h"
// Skeletal support so USFs that read the controller won't fail (bad practice, though)
void ProcessControllerCommand ( usf_state_t * state, int32_t Control, uint8_t * Command);
void PifRamRead (usf_state_t * state) {
int32_t Channel, CurPos;
Channel = 0;
CurPos = 0;
do {
switch(state->PIF_Ram[CurPos]) {
case 0x00:
Channel += 1;
if (Channel > 6) { CurPos = 0x40; }
break;
case 0xFE: CurPos = 0x40; break;
case 0xFF: break;
case 0xB4: case 0x56: case 0xB8: break; /* ??? */
default:
if ((state->PIF_Ram[CurPos] & 0xC0) == 0) {
CurPos += state->PIF_Ram[CurPos] + (state->PIF_Ram[CurPos + 1] & 0x3F) + 1;
Channel += 1;
} else {
CurPos = 0x40;
}
break;
}
CurPos += 1;
} while( CurPos < 0x40 );
}
void PifRamWrite (usf_state_t * state) {
int Channel, CurPos;
Channel = 0;
for (CurPos = 0; CurPos < 0x40; CurPos++){
switch(state->PIF_Ram[CurPos]) {
case 0x00:
Channel += 1;
if (Channel > 6) { CurPos = 0x40; }
break;
case 0xFE: CurPos = 0x40; break;
case 0xFF: break;
case 0xB4: case 0x56: case 0xB8: break; /* ??? */
default:
if ((state->PIF_Ram[CurPos] & 0xC0) == 0) {
if (Channel < 4) {
ProcessControllerCommand(state,Channel,&state->PIF_Ram[CurPos]);
}
CurPos += state->PIF_Ram[CurPos] + (state->PIF_Ram[CurPos + 1] & 0x3F) + 1;
Channel += 1;
} else
CurPos = 0x40;
break;
}
}
state->PIF_Ram[0x3F] = 0;
}
// always return failure
void ProcessControllerCommand ( usf_state_t * state, int32_t Control, uint8_t * Command) {
(void)state;
(void)Control;
Command[1] |= 0x80;
}