/*
 * Copyright 2008-2010, François Revol, revol@free.fr. All rights reserved.
 * Copyright 2003-2010, Axel Dörfler, axeld@pinc-software.de.
 * Distributed under the terms of the MIT License.
 */


#include <KernelExport.h>
#include <boot/platform.h>
#include <boot/heap.h>
#include <boot/stage2.h>
#include <arch/cpu.h>

#include <string.h>

#include "console.h"
#include "cpu.h"
#include "mmu.h"
#include "keyboard.h"
#include "toscalls.h"


// GCC defined globals
extern void (*__ctor_list)(void);
extern void (*__ctor_end)(void);
extern uint8 __bss_start;
extern uint8 _end;

extern "C" int main(stage2_args *args);
extern "C" void _start(void);


static uint32 sBootOptions;


static void
clear_bss(void)
{
        memset(&__bss_start, 0, &_end - &__bss_start);
}


static void
call_ctors(void)
{
        void (**f)(void);

        for (f = &__ctor_list; f < &__ctor_end; f++) {          
                (**f)();
        }
}


extern "C" uint32
platform_boot_options(void)
{
#if 0
        if (!gKernelArgs.fb.enabled)
                sBootOptions |= check_for_boot_keys();
#endif
        return sBootOptions;
}


extern "C" void
platform_start_kernel(void)
{
        static struct kernel_args *args = &gKernelArgs;
                // something goes wrong when we pass &gKernelArgs directly
                // to the assembler inline below - might be a bug in GCC
                // or I don't see something important...
        addr_t stackTop
                = gKernelArgs.cpu_kstack[0].start + gKernelArgs.cpu_kstack[0].size;

        preloaded_elf32_image *image = static_cast<preloaded_elf32_image *>(
                gKernelArgs.kernel_image.Pointer());

        //smp_init_other_cpus();
        //serial_cleanup();
        mmu_init_for_kernel();
        //smp_boot_other_cpus();

#warning M68K: stop ints
        
        dprintf("kernel entry at %lx\n", image->elf_header.e_entry);

        asm volatile (
                "move.l %0,%%sp;        "                       // move stack out of way
                : : "m" (stackTop));

        asm volatile (
                "or     #0x0700,%%sr; " : : );          // disable interrupts

        asm volatile (
                "move.l  #0x0,-(%%sp); "                // we're the BSP cpu (0)
                "move.l         %0,-(%%sp);     "               // kernel args
                "move.l         #0x0,-(%%sp);"          // dummy retval for call to main
                "move.l         %1,-(%%sp);     "               // this is the start address
                "rts;           "                                       // jump.
                : : "g" (args), "g" (image->elf_header.e_entry));

        // Huston, we have a problem!

        asm volatile (
                "and    #0xf8ff,%%sr; " : : );          // reenable interrupts

        panic("kernel returned!\n");

}


extern "C" void
platform_exit(void)
{
        // Terminate if running under ARAnyM
        int32 nfShutdownId = nat_feat_getid("NF_SHUTDOWN");
        if (nfShutdownId)
                nat_feat_call(nfShutdownId, 0);

        // This crashes...
        // TODO: Puntaes() instead ?
        Pterm0();
}


extern "C" void
_start(void)
{
        stage2_args args;
        Bconout(DEV_CON, 'H');

        //asm("cld");                   // Ain't nothing but a GCC thang.
        //asm("fninit");                // initialize floating point unit

        clear_bss();
        Bconout(DEV_CON, 'A');
        call_ctors();
                // call C++ constructors before doing anything else
        Bconout(DEV_CON, 'I');

        args.heap_size = 0;
        args.arguments = NULL;
        
        // so we can dprintf
        init_nat_features();

        //serial_init();
        Bconout(DEV_CON, 'K');
        console_init();
        Bconout(DEV_CON, 'U');
        Bconout(DEV_CON, '\n');
        dprintf("membot   = %p\n", (void*)*TOSVAR_membot);
        dprintf("memtop   = %p\n", (void*)*TOSVAR_memtop);
        dprintf("v_bas_ad = %p\n", *TOSVAR_v_bas_ad);
        dprintf("phystop  = %p\n", (void*)*TOSVARphystop);
        dprintf("ramtop   = %p\n", (void*)*TOSVARramtop);
        cpu_init();
        mmu_init();

        // wait a bit to give the user the opportunity to press a key
        spin(750000);

        // reading the keyboard doesn't seem to work in graphics mode (maybe a bochs problem)
        sBootOptions = check_for_boot_keys();
        //if (sBootOptions & BOOT_OPTION_DEBUG_OUTPUT)
                //serial_enable();

        //apm_init();
        //smp_init();
        main(&args);
}