/*
* Handles the emulator's side of a 68k call (from an extended trap)
*/
static uae_u32 REGPARAM3 m68k_call_handler (TrapContext *dummy_ctx)
{
TrapContext *context = current_context;
uae_u32 sp;
sp = m68k_areg (regs, 7);
/* Push address of trap context on 68k stack. This is
* so the return trap can find this context. */
sp -= sizeof (void *);
put_pointer (sp, context);
/* Push addr to return handler trap on 68k stack.
* When the called m68k function does an RTS, the CPU will pull this
* address off the stack and so call the return handler. */
sp -= 4;
put_long (sp, m68k_return_trapaddr);
m68k_areg (regs, 7) = sp;
/* Set PC to address of 68k function to call. */
m68k_setpc (context->call68k_func_addr);
fill_prefetch ();
/* End critical section: allow other traps run. */
uae_sem_post (&trap_mutex);
/* Restore interrupts. */
regs.intmask = context->saved_regs.intmask;
/* Dummy return value. */
return 0;
}
/*
* This function is called by the 68k interpreter to handle an emulator trap.
*
* trap_num = number of trap to invoke
* regs = current 68k state
*/
void REGPARAM2 m68k_handle_trap (unsigned int trap_num)
{
struct Trap *trap = &traps[trap_num];
uae_u32 retval = 0;
int has_retval = (trap->flags & TRAPFLAG_NO_RETVAL) == 0;
int implicit_rts = (trap->flags & TRAPFLAG_DORET) != 0;
if (trap->name && trap->name[0] != 0 && trace_traps)
write_log (_T("TRAP: %s\n"), trap->name);
if (trap_num < trap_count) {
if (trap->flags & TRAPFLAG_EXTRA_STACK) {
/* Handle an extended trap.
* Note: the return value of this trap is passed back to 68k
* space via a separate, dedicated simple trap which the trap
* handler causes to be invoked when it is done.
*/
trap_HandleExtendedTrap (trap->handler, has_retval);
} else {
/* Handle simple trap */
retval = (trap->handler) (NULL);
if (has_retval)
m68k_dreg (regs, 0) = retval;
if (implicit_rts) {
m68k_do_rts ();
fill_prefetch ();
}
}
} else
write_log (_T("Illegal emulator trap %d\n"), trap_num);
}
/*
* Call m68k function from an extended trap handler
*
* This function is to be called from the trap context.
*/
static uae_u32 trap_Call68k (TrapContext *context, uaecptr func_addr)
{
/* Enter critical section - only one trap at a time, please! */
uae_sem_wait (&trap_mutex);
current_context = context;
/* Don't allow an interrupt and thus potentially another
* trap to be invoked while we hold the above mutex.
* This is probably just being paranoid. */
regs.intmask = 7;
/* Set up function call address. */
context->call68k_func_addr = func_addr;
/* Set PC to address of 68k call trap, so that it will be
* executed when emulator context resumes. */
m68k_setpc (m68k_call_trapaddr);
fill_prefetch ();
/* Switch to emulator context. */
uae_sem_post (&context->switch_to_emu_sem);
/* Wait for 68k call return handler to switch back to us. */
uae_sem_wait (&context->switch_to_trap_sem);
/* End critical section. */
uae_sem_post (&trap_mutex);
/* Get return value from 68k function called. */
return context->call68k_retval;
}
static void ersatz_init (void)
{
int32_t f;
uaecptr request;
uaecptr a;
already_failed = 0;
write_log (_T("initializing kickstart replacement\n"));
if (disk_empty (0)) {
already_failed = 1;
notify_user (NUMSG_KICKREP);
uae_quit ();
//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 (_T("Loading Kickstart rom image from Kickstart disk\n"));
/* print some notes... */
write_log (_T("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 (0xFC0002);
fill_prefetch ();
uae_reset (0);
ersatzkickfile = 0;
return;
}
m68k_setpc (0x400C);
fill_prefetch ();
/* 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);
}