/*
 * Copyright 2008-2010, François Revol, revol@free.fr. All rights reserved.
 * Distributed under the terms of the MIT License.
*/


#include "cpu.h"
#include "toscalls.h"

#include <OS.h>
#include <boot/platform.h>
#include <boot/stdio.h>
#include <boot/kernel_args.h>
#include <boot/stage2.h>
#include <arch/cpu.h>
#include <arch_kernel.h>
#include <arch_platform.h>
#include <arch_system_info.h>

#include <string.h>


//#define TRACE_CPU
#ifdef TRACE_CPU
#       define TRACE(x) dprintf x
#else
#       define TRACE(x) ;
#endif

#warning M68K: add set_vbr()


static status_t
check_cpu_features()
{
#warning M68K: TODO: probe ourselves, we shouldnt trust the TOS!

        const tos_cookie *c;
        uint16 cpu_type, fpu_type, fpu_emul;
        uint16 machine_type;
        int fpu = 0;

        c = tos_find_cookie('_CPU');
        if (!c) {
                panic("can't get a cookie (_CPU)!");
                return EINVAL;
        }
        cpu_type = (uint16) c->ivalue;

        dump_tos_cookies();

#warning M68K: check for 020 + mmu
        if (cpu_type < 30/*20*/)
                return EINVAL;
        
#warning M68K: check cpu type passed to kern args
        gKernelArgs.arch_args.cpu_type = 68000 + cpu_type;
        gKernelArgs.arch_args.mmu_type = 68000 + cpu_type;
        gKernelArgs.arch_args.has_lpstop = (cpu_type >= 60)?true:false;

        c = tos_find_cookie('_FPU');
        if (!c) {
                panic("can't get a cookie (_FPU)!");
                return EINVAL;
        }
        fpu_type = (uint16)(c->ivalue >> 16);
        fpu_emul = (uint16)(c->ivalue);

        // http://toshyp.atari.org/003007.htm#Cookie_2C_20_FPU
        if (fpu_type & 0x10)
                fpu = 68060;
        else if (fpu_type & 0x8)
                fpu = 68040;
        else if ((fpu_type & 0x6) == 0x6)
                fpu = 68882;
        else if ((fpu_type & 0x6) == 0x4)
                fpu = 68881;
        else if ((fpu_type & 0x6) == 0x2)
                fpu = 68881; // not certain
        else if (fpu_type & 0x4) {
                panic("bad fpu");
                return EINVAL;
        }
        gKernelArgs.arch_args.fpu_type = fpu;

        gKernelArgs.arch_args.platform = M68K_PLATFORM_ATARI;

        c = tos_find_cookie('_MCH');
        if (!c) {
                panic("can't get a cookie (_MCH)!");
                return EINVAL;
        }
        machine_type = (uint16)(c->ivalue >> 16);
        gKernelArgs.arch_args.machine = machine_type;

        return B_OK;
}

#warning M68K: move and implement system_time()
static bigtime_t gSystemTimeCounter = 0; //HACK
extern "C" bigtime_t
system_time(void)
{
        // _hz_200
        //return (*TOSVAR_hz_200) * 1000000LL / 200;
        return gSystemTimeCounter++;
}


//      #pragma mark -


extern "C" void
spin(bigtime_t microseconds)
{
        bigtime_t time = system_time();
        while ((system_time() - time) < microseconds)
                asm volatile ("nop;");
}


extern "C" void
cpu_init()
{
        if (check_cpu_features() != B_OK)
                panic("You need a 68020 or higher in order to boot!\n");

        gKernelArgs.num_cpus = 1;
                // this will eventually be corrected later on
                // ...or not!
}


void
platform_load_ucode(BootVolume& volume)
{
}