/*
 * Copyright (c) 2023 Ian Marco Moffett and the VegaOS team.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of VegaOS nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <machine/gdt.h>

struct gdt_entry g_gdt[256] = {
    /* Null */
    {0},

    /* Kernel code (0x8) */
    {
            .limit          = 0x0000,
            .base_low       = 0x0000,
            .base_mid       = 0x00,
            .access         = 0x9A,
            .granularity    = 0x20,
            .base_hi        = 0x00
    },

    /* Kernel data (0x10) */
    {
            .limit          = 0x0000,
            .base_low       = 0x0000,
            .base_mid       = 0x00,
            .access         = 0x92,
            .granularity    = 0x00,
            .base_hi        = 0x00
    },

    /* User code (0x18) */
    {
            .limit       = 0x0000,
            .base_low    = 0x0000,
            .base_mid    = 0x00,
            .access      = 0xFA,
            .granularity = 0xAF,
            .base_hi     = 0x00
    },

    /* User data (0x20) */
    {
            .limit       = 0x0000,
            .base_low    = 0x0000,
            .base_mid    = 0x00,
            .access      = 0xF2,
            .granularity = 0x00,
            .base_hi     = 0x00
    },
};

struct gdtr g_gdtr = {
    .limit = sizeof(struct gdt_entry) * 256 - 1,
    .offset = (uintptr_t)&g_gdt[0]
};