macemu/BasiliskII/src/scsi.cpp
2005-01-30 21:42:16 +00:00

349 lines
7.2 KiB
C++

/*
* scsi.cpp - SCSI Manager
*
* Basilisk II (C) 1997-2005 Christian Bauer
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* SEE ALSO
* Inside Macintosh: Devices, chapter 3 "SCSI Manager"
* Technote DV 24: "Fear No SCSI"
*/
#include <stdio.h>
#include <string.h>
#include "sysdeps.h"
#include "cpu_emulation.h"
#include "main.h"
#include "user_strings.h"
#include "scsi.h"
#define DEBUG 0
#include "debug.h"
// Error codes
enum {
scCommErr = 2,
scArbNBErr,
scBadParmsErr,
scPhaseErr,
scCompareErr,
scMgrBusyErr,
scSequenceErr,
scBusTOErr,
scComplPhaseErr
};
// TIB opcodes
enum {
scInc = 1,
scNoInc,
scAdd,
scMove,
scLoop,
scNop,
scStop,
scComp
};
// Logical SCSI phases
enum {
PH_FREE, // Bus free
PH_ARBITRATED, // Bus arbitrated (after SCSIGet())
PH_SELECTED, // Target selected (after SCSISelect())
PH_TRANSFER // Command sent (after SCSICmd())
};
// Global variables
static int target_id; // ID of active target
static int phase; // Logical SCSI phase
static uint16 fake_status; // Faked 5830 status word
static bool reading; // Flag: reading from device
const int SG_TABLE_SIZE = 1024;
static int sg_index; // Index of first unused entry in S/G table
static uint8 *sg_ptr[SG_TABLE_SIZE]; // Scatter/gather table data pointer (host address space)
static uint32 sg_len[SG_TABLE_SIZE]; // Scatter/gather table data length
static uint32 sg_total_length; // Total data length
/*
* Execute TIB, constructing S/G table
*/
static int16 exec_tib(uint32 tib)
{
for (;;) {
// Read next opcode and parameters
uint16 cmd = ReadMacInt16(tib); tib += 2;
uint32 ptr = ReadMacInt32(tib); tib += 4;
uint32 len = ReadMacInt32(tib); tib += 4;
#if DEBUG
const char *cmd_str;
switch (cmd) {
case scInc: cmd_str = "INC "; break;
case scNoInc: cmd_str = "NOINC"; break;
case scAdd: cmd_str = "ADD "; break;
case scMove: cmd_str = "MOVE "; break;
case scLoop: cmd_str = "LOOP "; break;
case scNop: cmd_str = "NOP "; break;
case scStop: cmd_str = "STOP "; break;
case scComp: cmd_str = "COMP "; break;
default: cmd_str = "??? "; break;
}
D(bug(" %s(%d) %08x %d\n", cmd_str, cmd, ptr, len));
#endif
switch (cmd) {
case scInc:
WriteMacInt32(tib - 8, ptr + len);
case scNoInc:
if ((sg_index > 0) && (Mac2HostAddr(ptr) == sg_ptr[sg_index-1] + sg_len[sg_index-1]))
sg_len[sg_index-1] += len; // Merge to previous entry
else {
if (sg_index == SG_TABLE_SIZE) {
ErrorAlert(GetString(STR_SCSI_SG_FULL_ERR));
return -108;
}
sg_ptr[sg_index] = Mac2HostAddr(ptr); // Create new entry
sg_len[sg_index] = len;
sg_index++;
}
sg_total_length += len;
break;
case scAdd:
WriteMacInt32(ptr, ReadMacInt32(ptr) + len);
break;
case scMove:
WriteMacInt32(len, ReadMacInt32(ptr));
break;
case scLoop:
WriteMacInt32(tib - 4, len - 1);
if (len - 1 > 0)
tib += (int32)ptr - 10;
break;
case scNop:
break;
case scStop:
return 0;
case scComp:
printf("WARNING: Unimplemented scComp opcode\n");
return scCompareErr;
default:
printf("FATAL: Unrecognized TIB opcode %d\n", cmd);
return scBadParmsErr;
}
}
}
/*
* Reset SCSI bus
*/
int16 SCSIReset(void)
{
D(bug("SCSIReset\n"));
phase = PH_FREE;
fake_status = 0x0000; // Bus free
sg_index = 0;
target_id = 8;
return 0;
}
/*
* Arbitrate bus
*/
int16 SCSIGet(void)
{
D(bug("SCSIGet\n"));
if (phase != PH_FREE)
return scMgrBusyErr;
phase = PH_ARBITRATED;
fake_status = 0x0040; // Bus busy
reading = false;
sg_index = 0; // Flush S/G table
sg_total_length = 0;
return 0;
}
/*
* Select SCSI device
*/
int16 SCSISelect(int id)
{
D(bug("SCSISelect %d\n", id));
if (phase != PH_ARBITRATED)
return scSequenceErr;
// ID valid?
if (id >= 0 && id <= 7) {
target_id = id;
// Target present?
if (scsi_is_target_present(target_id)) {
phase = PH_SELECTED;
fake_status = 0x006a; // Target selected, command phase
return 0;
}
}
// Error
phase = PH_FREE;
fake_status = 0x0000; // Bus free
return scCommErr;
}
/*
* Send SCSI command
*/
int16 SCSICmd(int cmd_length, uint8 *cmd)
{
#if DEBUG
switch (cmd_length) {
case 6:
D(bug("SCSICmd len 6, cmd %02x %02x %02x %02x %02x %02x\n", cmd[0], cmd[1], cmd[2], cmd[3], cmd[4], cmd[5]));
break;
case 10:
D(bug("SCSICmd len 10, cmd %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x\n", cmd[0], cmd[1], cmd[2], cmd[3], cmd[4], cmd[5], cmd[6], cmd[7], cmd[8], cmd[9]));
break;
case 12:
D(bug("SCSICmd len 12, cmd %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x\n", cmd[0], cmd[1], cmd[2], cmd[3], cmd[4], cmd[5], cmd[6], cmd[7], cmd[8], cmd[9], cmd[10], cmd[11]));
break;
default:
D(bug("SCSICmd bogus length %d\n", cmd_length));
break;
}
#endif
if (phase != PH_SELECTED)
return scPhaseErr;
// Commdn length valid?
if (cmd_length != 6 && cmd_length != 10 && cmd_length != 12)
return scBadParmsErr;
// Set command, extract LUN
scsi_set_cmd(cmd_length, cmd);
// Extract LUN, set target
if (!scsi_set_target(target_id, (cmd[1] >> 5) & 7)) {
phase = PH_FREE;
fake_status = 0x0000; // Bus free
return scCommErr;
}
phase = PH_TRANSFER;
fake_status = 0x006e; // Target selected, data phase
return 0;
}
/*
* Read data
*/
int16 SCSIRead(uint32 tib)
{
D(bug("SCSIRead TIB %08lx\n", tib));
if (phase != PH_TRANSFER)
return scPhaseErr;
// Execute TIB, fill S/G table
reading = true;
return exec_tib(tib);
}
/*
* Write data
*/
int16 SCSIWrite(uint32 tib)
{
D(bug("SCSIWrite TIB %08lx\n", tib));
if (phase != PH_TRANSFER)
return scPhaseErr;
// Execute TIB, fill S/G table
return exec_tib(tib);
}
/*
* Wait for command completion (we're actually doing everything in here...)
*/
int16 SCSIComplete(uint32 timeout, uint32 message, uint32 stat)
{
D(bug("SCSIComplete wait %d, msg %08lx, stat %08lx\n", timeout, message, stat));
WriteMacInt16(message, 0);
if (phase != PH_TRANSFER)
return scPhaseErr;
// Send command, process S/G table
uint16 scsi_stat = 0;
bool success = scsi_send_cmd(sg_total_length, reading, sg_index, sg_ptr, sg_len, &scsi_stat, timeout);
WriteMacInt16(stat, scsi_stat);
// Complete command
phase = PH_FREE;
fake_status = 0x0000; // Bus free
return success ? 0 : scCommErr;
}
/*
* Get bus status
*/
uint16 SCSIStat(void)
{
D(bug("SCSIStat returns %04x\n", fake_status));
return fake_status;
}
/*
* SCSI Manager busy?
*/
int16 SCSIMgrBusy(void)
{
// D(bug("SCSIMgrBusy\n"));
return phase != PH_FREE;
}