uae-wii/src/ersatz.c
2009-05-05 15:36:48 +00:00

256 lines
6.2 KiB
C

/*
* UAE - The Un*x Amiga Emulator
*
* A "replacement" for a missing Kickstart
* Warning! Q&D
*
* (c) 1995 Bernd Schmidt
*/
#include "sysconfig.h"
#include "sysdeps.h"
#include "options.h"
#include "uae.h"
#include "memory.h"
#include "custom.h"
#include "newcpu.h"
#include "cpu_prefetch.h"
#include "cia.h"
#include "disk.h"
#include "ersatz.h"
#include "gui.h"
#define EOP_INIT 0
#define EOP_NIMP 1
#define EOP_SERVEINT 2
#define EOP_DOIO 3
#define EOP_OPENLIB 4
#define EOP_AVAILMEM 5
#define EOP_ALLOCMEM 6
#define EOP_ALLOCABS 7
#define EOP_LOOP 8
static int already_failed = 0;
void init_ersatz_rom (uae_u8 *data)
{
*data++ = 0x00; *data++ = 0x08; /* initial SP */
*data++ = 0x00; *data++ = 0x00;
*data++ = 0x00; *data++ = 0xF8; /* initial PC */
*data++ = 0x00; *data++ = 0x08;
*data++ = 0xFF; *data++ = 0x0D;
*data++ = 0x00; *data++ = EOP_INIT;
*data++ = 0xFF; *data++ = 0x0D;
*data++ = 0x00; *data++ = EOP_NIMP;
*data++ = 0xFF; *data++ = 0x0D;
*data++ = 0x00; *data++ = EOP_LOOP;
*data++ = 0xFF; *data++ = 0x0D;
*data++ = 0x00; *data++ = EOP_DOIO;
*data++ = 0x4E; *data++ = 0x75;
*data++ = 0xFF; *data++ = 0x0D;
*data++ = 0x00; *data++ = EOP_SERVEINT;
*data++ = 0x4E; *data++ = 0x73;
*data++ = 0xFF; *data++ = 0x0D;
*data++ = 0x00; *data++ = EOP_AVAILMEM;
*data++ = 0x4E; *data++ = 0x75;
*data++ = 0xFF; *data++ = 0x0D;
*data++ = 0x00; *data++ = EOP_ALLOCMEM;
*data++ = 0x4E; *data++ = 0x75;
*data++ = 0xFF; *data++ = 0x0D;
*data++ = 0x00; *data++ = EOP_ALLOCABS;
*data++ = 0x4E; *data++ = 0x75;
}
static void ersatz_failed (void)
{
if (already_failed)
return;
already_failed = 1;
// notify_user (NUMSG_KICKREPNO);
gui_message ("Diskfile in DF0: is not compatible with Kickstart replacement.\n");
uae_restart (-1, NULL);
}
static void ersatz_doio (void)
{
uaecptr request = m68k_areg (&regs, 1);
switch (get_word (request + 0x1C)) {
case 9: /* TD_MOTOR is harmless */
case 2: case 0x8002: /* READ commands */
break;
default:
write_log ("Only CMD_READ supported in DoIO()\n");
ersatz_failed ();
}
{
uaecptr dest = get_long (request + 0x28);
int start = get_long (request + 0x2C) / 512;
int nsecs = get_long (request + 0x24) / 512;
int tr = start / 11;
int sec = start % 11;
while (nsecs--) {
DISK_ersatz_read (tr, sec, dest);
dest += 512;
if (++sec == 11)
sec = 0, tr++;
}
}
}
static void ersatz_init (void)
{
int f;
uaecptr request;
uaecptr a;
already_failed = 0;
write_log ("initializing kickstart replacement\n");
if (disk_empty (0)) {
already_failed = 1;
// notify_user (NUMSG_KICKREP);
gui_message ("You need to have a diskfile in DF0 to use the Kickstart replacement!\n");
uae_restart (-1, NULL);
return;
}
regs.s = 0;
/* Set some interrupt vectors */
for (a = 8; a < 0xC0; a += 4) {
put_long (a, 0xF8001A);
}
regs.isp = regs.msp = regs.usp = 0x800;
m68k_areg (&regs, 7) = 0x80000;
regs.intmask = 0;
/* Build a dummy execbase */
put_long (4, m68k_areg (&regs, 6) = 0x676);
put_byte (0x676 + 0x129, 0);
for (f = 1; f < 105; f++) {
put_word (0x676 - 6*f, 0x4EF9);
put_long (0x676 - 6*f + 2, 0xF8000C);
}
/* Some "supported" functions */
put_long (0x676 - 456 + 2, 0xF80014);
put_long (0x676 - 216 + 2, 0xF80020);
put_long (0x676 - 198 + 2, 0xF80026);
put_long (0x676 - 204 + 2, 0xF8002c);
put_long (0x676 - 210 + 2, 0xF8002a);
/* Build an IORequest */
request = 0x800;
put_word (request + 0x1C, 2);
put_long (request + 0x28, 0x4000);
put_long (request + 0x2C, 0);
put_long (request + 0x24, 0x200 * 4);
m68k_areg (&regs, 1) = request;
ersatz_doio ();
/* kickstart disk loader */
if (get_long(0x4000) == 0x4b49434b) {
/* a kickstart disk was found in drive 0! */
write_log ("Loading Kickstart rom image from Kickstart disk\n");
/* print some notes... */
write_log ("NOTE: if UAE crashes set CPU to 68000 and/or chipmem size to 512KB!\n");
/* read rom image from kickstart disk */
put_word (request + 0x1C, 2);
put_long (request + 0x28, 0xF80000);
put_long (request + 0x2C, 0x200);
put_long (request + 0x24, 0x200 * 512);
m68k_areg (&regs, 1) = request;
ersatz_doio ();
/* read rom image once again to mirror address space.
not elegant, but it works... */
put_word (request + 0x1C, 2);
put_long (request + 0x28, 0xFC0000);
put_long (request + 0x2C, 0x200);
put_long (request + 0x24, 0x200 * 512);
m68k_areg (&regs, 1) = request;
ersatz_doio ();
disk_eject (0);
m68k_setpc (&regs, 0xFC0002);
fill_prefetch_slow (&regs);
uae_reset (0);
ersatzkickfile = 0;
return;
}
m68k_setpc (&regs, 0x400C);
fill_prefetch_slow (&regs);
/* Init the hardware */
put_long (0x3000, 0xFFFFFFFEul);
put_long (0xDFF080, 0x3000);
put_word (0xDFF088, 0);
put_word (0xDFF096, 0xE390);
put_word (0xDFF09A, 0xE02C);
put_word (0xDFF09E, 0x0000);
put_word (0xDFF092, 0x0038);
put_word (0xDFF094, 0x00D0);
put_word (0xDFF08E, 0x2C81);
put_word (0xDFF090, 0xF4C1);
put_word (0xDFF02A, 0x8000);
put_byte (0xBFD100, 0xF7);
put_byte (0xBFEE01, 0);
put_byte (0xBFEF01, 0x08);
put_byte (0xBFDE00, 0x04);
put_byte (0xBFDF00, 0x84);
put_byte (0xBFDD00, 0x9F);
put_byte (0xBFED01, 0x9F);
}
void ersatz_perform (uae_u16 what)
{
switch (what) {
case EOP_INIT:
ersatz_init ();
break;
case EOP_SERVEINT:
/* Just reset all the interrupt request bits */
put_word (0xDFF09C, get_word (0xDFF01E) & 0x3FFF);
break;
case EOP_DOIO:
ersatz_doio ();
break;
case EOP_AVAILMEM:
m68k_dreg (&regs, 0) = m68k_dreg (&regs, 1) & 4 ? 0 : 0x70000;
break;
case EOP_ALLOCMEM:
m68k_dreg (&regs, 0) = m68k_dreg (&regs, 1) & 4 ? 0 : 0x0F000;
break;
case EOP_ALLOCABS:
m68k_dreg (&regs, 0) = m68k_areg (&regs, 1);
break;
case EOP_NIMP:
write_log ("Unimplemented Kickstart function called\n");
ersatz_failed ();
/* fall through */
case EOP_LOOP:
m68k_setpc (&regs, 0xF80010);
break;
case EOP_OPENLIB:
default:
write_log ("Internal error. Giving up.\n");
ersatz_failed ();
}
}