//----------------------------------------------------------------------------//
//                           GNU GPL OS/K                                     //
//                                                                            //
//  Desc:       Kernel entry point                                            //
//                                                                            //
//                                                                            //
//  Copyright © 2018-2019 The OS/K Team                                       //
//                                                                            //
//  This file is part of OS/K.                                                //
//                                                                            //
//  OS/K is free software: you can redistribute it and/or modify              //
//  it under the terms of the GNU General Public License as published by      //
//  the Free Software Foundation, either version 3 of the License, or         //
//  any later version.                                                        //
//                                                                            //
//  OS/K is distributed in the hope that it will be useful,                   //
//  but WITHOUT ANY WARRANTY//without even the implied warranty of            //
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the             //
//  GNU General Public License for more details.                              //
//                                                                            //
//  You should have received a copy of the GNU General Public License         //
//  along with OS/K.  If not, see <https://www.gnu.org/licenses/>.            //
//----------------------------------------------------------------------------//

#include <kernel/multiboot.h>
#include <kernel/term.h>
#include <kernel/panic.h>
#include <kernel/mm.h>

//
// BootInfo_t initialization. It is necessary because grub will potentially be
//  wiped since it is below 1MB.... And we must reorganize all that stuff.
//
void InitBootInfo(multiboot_info_t *mbi)
{
    extern uint MB_header;
    char okStr[] = "available";
    char noStr[] = "unavailable";

    // We need the multiboot structure
    KalAlwaysAssert(mbi);

    //Retrieves the bootloader flags to ensure infos are valid
    GetBootInfo(btldr).grubFlags            = mbi->flags;

    if (GetBootInfo(btldr).grubFlags & MULTIBOOT_INFO_BOOT_LOADER_NAME) {
        GetBootInfo(btldr).grubName         = (char*)(ullong)(mbi->boot_loader_name);
        GetBootInfo(btldr).mbHeaderAddr     = (void*)(ullong)&MB_header;
        GetBootInfo(btldr).valid            = 1;
    }
    if (GetBootInfo(btldr).grubFlags & MULTIBOOT_INFO_MODS) {
        GetBootInfo(btldr).modulesCount     = mbi->mods_count;
        GetBootInfo(btldr).modulesAddr      = (void*)(ullong)mbi->mods_addr;
    }
    //Retrieves the drives informations
    if (GetBootInfo(btldr).grubFlags & MULTIBOOT_INFO_DRIVE_INFO) {
        GetBootInfo(drives).bufferLength    = mbi->drives_length;
        GetBootInfo(drives).bufferAddr      = (void*)(ullong)mbi->drives_addr;
        GetBootInfo(drives).bufferValid     = 1;
    }
    if (GetBootInfo(btldr).grubFlags & MULTIBOOT_INFO_BOOTDEV) {
        GetBootInfo(drives).bootDrv         = mbi->boot_device;
        GetBootInfo(drives).drvValid        = 1;
    }

    //Retrieves the memory informations
    if (GetBootInfo(btldr).grubFlags & MULTIBOOT_INFO_MEMORY) {
        GetBootInfo(memory).lowMemory       = mbi->mem_lower;
        GetBootInfo(memory).upMemory        = mbi->mem_upper;
        GetBootInfo(memory).memValid        = 1;
    }
    if (GetBootInfo(btldr).grubFlags & MULTIBOOT_INFO_MEM_MAP) {
        GetBootInfo(memory).mapAddr         = (void*)(ullong)mbi->mmap_addr;
        GetBootInfo(memory).mapLength       = mbi->mmap_length;
        GetBootInfo(memory).mapValid        = 1;
    }

    // XXX assign video infos, but unused at this time

    // Retrieves the firmware infos
    if (GetBootInfo(btldr).grubFlags & MULTIBOOT_INFO_CONFIG_TABLE) {
        GetBootInfo(firmware).romTable      = mbi->config_table;
        GetBootInfo(firmware).romValid      = 1;
    }
    if (GetBootInfo(btldr).grubFlags & MULTIBOOT_INFO_APM_TABLE) {
        GetBootInfo(firmware).apmTable      = mbi->apm_table;
        GetBootInfo(firmware).apmValid      = 1;
    }

    //Now we check (debug)
    DebugLog("\n[InitBootInfo] Flags :      %b",
             GetBootInfo(btldr).grubFlags);
    DebugLog("\n[InitBootInfo] Boot loader  %s",
             GetBootInfo(btldr).valid ? &okStr : &noStr);
    DebugLog("\n[InitBootInfo] Boot drive   %s",
             GetBootInfo(drives).drvValid ? &okStr : &noStr);
    DebugLog("\n[InitBootInfo] Disk buffer  %s",
             GetBootInfo(drives).bufferValid ? &okStr : &noStr);
    DebugLog("\n[InitBootInfo] Basic mem    %s",
             GetBootInfo(memory).memValid ? &okStr : &noStr);
    DebugLog("\n[InitBootInfo] Memory map   %s",
             GetBootInfo(memory).mapValid ? &okStr : &noStr);
    DebugLog("\n[InitBootInfo] ROM table    %s",
             GetBootInfo(firmware).romValid ? &okStr : &noStr);
    DebugLog("\n[InitBootInfo] APM table    %s",
             GetBootInfo(firmware).apmValid ? &okStr : &noStr);
    DebugLog("\n");
}


//
// Entry point of the Kaleid kernel
//
noreturn void StartKern(multiboot_info_t *mbInfo, int mbMagic)
{
    // We're not ready to deal with interrupts
    DisableIRQs();

    // Kernel terminals
    InitTerms();

    //Hello world because why not
    KernLog("%c%c%c OS/K\n\n", 219, 219, 219);

    KalAlwaysAssert(mbMagic == MULTIBOOT_BOOTLOADER_MAGIC);
    KernLog("[Init] We have magic : %x\n", mbMagic);

    //Initialize the BootInfo_t structure
    InitBootInfo(mbInfo);

    //Memory mapping
    error_t mapBad = InitMemoryMap();
    if (mapBad)
        StartPanic("[Init] The memory map failed to initialize. Error : %d", mapBad);

    // We're out
    KernLog("\n[Init] Evil never dies !");
    CrashSystem(); //yay
}