main.c

#include <tamtypes.h>
#include <stdio.h>
#include <loadcore.h>
#include <thbase.h>
#include <iop_cop0_defs.h>
#include <ps2_sbus.h>
#include <iopdebug.h>
#include <excepman.h>
#include "sbus_tty.h"
 
IRX_ID("sbusdebug", 1, 0);
 
volatile int _iop_controlled = 0;
volatile int _iop_exception_state = 0;
 
extern void signal_iop_exception(IOP_RegFrame *frame);
 
// this is called by the IOP debug/exception handler
void _iop_ex_handler(IOP_RegFrame *frame)
{
    int excode = M_IOP_GET_CAUSE_EXCODE(frame->cause);
 
    if(excode == IOP_EXCEPTION_HDB)
    {
        _iop_exception_state = 2;
    }
    else
    {
        _iop_exception_state = 1;
    }
 
    _iop_controlled = 1;
 
    // signal to the EE that an IOP exception occured.
    signal_iop_exception(frame);
 
    // wait for EE to send a "IOP control" command and release the IOP.
    while(_iop_controlled)
    {
        // since we're spinning in an interrupt-disabled state, we have to manually
        //  poll for SBUS interrupts from EE, otherwise we'll never get released!
        SBUS_check_intr();
    }
}
 
int tid;
 
extern void soft_break(void);
__asm__
(
    "\t" ".set push" "\n"
    "\t" ".set noreorder" "\n"
    "\t" ".set noat" "\n"
 
    "\t" ".global soft_break" "\n"
    "\t" ".ent soft_break" "\n"
    "\t" "soft_break:" "\n"
    "\t" "\t" "nop" "\n"
    "\t" "\t" "break" "\n"
    "\t" "\t" "nop" "\n"
    "\t" "\t" "jr      $ra" "\n"
    "\t" "\t" "nop" "\n"
    "\t" ".end soft_break" "\n"
 
    "\t" ".set pop" "\n"
);
 
void _controller_thread(void *arg)
{
    (void)arg;
 
    while(1)
    {
//        printf("IOP: Controller thread going to sleep(%d)...\n", _iop_exception_state);
        SleepThread();
//        printf("IOP: Controller thread woke up!\n");
        soft_break();
    }
}
 
void create_th(void)
{
    iop_thread_t param;
 
    param.attr = TH_C;
    param.thread = _controller_thread;
    param.priority = 9; // highest possible priority
    param.stacksize = 512; // tiny stack, not much is needed!
    param.option = 0;
 
    tid = CreateThread(&param);
    StartThread(tid, 0);
}
 
extern void SBUS_dbg_init(void);
 
int _start(int argc, char *argv[])
{
    int i;
 
    (void)argc;
    (void)argv;
 
    for(i = 2; i <= 7; i++)
    {
        iop_dbg_set_handler(i, (IOP_ExceptionHandler *) _iop_ex_handler);
    }
 
    for(i = 9; i <= 15; i++)
    {
        iop_dbg_set_handler(i, (IOP_ExceptionHandler *) _iop_ex_handler);
    }
 
    create_th();
 
    if(sbus_tty_init() != 0)
    {
        printf("Failed initializing SBUS TTY system!\n");
        return MODULE_NO_RESIDENT_END;
    }
 
    SBUS_dbg_init();
 
    FlushIcache();
    FlushDcache();
 
    printf("IOP SBUS Debug installed!\n");
 
    return MODULE_RESIDENT_END;
}