/*
 * Copyright (c) 2024, Sönke Holz <sholz8530@gmail.com>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#include <Kernel/Arch/x86_64/Firmware/PCBIOS/DMI/Definitions.h>
#include <Kernel/EFIPrekernel/ConfigurationTable.h>
#include <Kernel/EFIPrekernel/Globals.h>

#include <LibDeviceTree/FlattenedDeviceTree.h>

namespace Kernel {

static void* search_efi_configuration_table(EFI::GUID guid)
{
    for (FlatPtr i = 0; i < g_efi_system_table->number_of_table_entries; i++) {
        if (g_efi_system_table->configuration_table[i].vendor_guid == guid)
            return g_efi_system_table->configuration_table[i].vendor_table;
    }

    return nullptr;
}

void populate_firmware_boot_info(BootInfo* boot_info)
{
    boot_info->flattened_devicetree_paddr = PhysicalAddress { bit_cast<PhysicalPtr>(search_efi_configuration_table(EFI::DTB_TABLE_GUID)) };
    if (!boot_info->flattened_devicetree_paddr.is_null()) {
        DeviceTree::FlattenedDeviceTreeHeader* fdt_header = reinterpret_cast<DeviceTree::FlattenedDeviceTreeHeader*>(boot_info->flattened_devicetree_paddr.as_ptr());
        boot_info->flattened_devicetree_size = fdt_header->totalsize;
    }

    // Prefer ACPI 2.0 or newer.
    boot_info->acpi_rsdp_paddr = PhysicalAddress { bit_cast<PhysicalPtr>(search_efi_configuration_table(EFI::ACPI_2_0_TABLE_GUID)) };
    if (boot_info->acpi_rsdp_paddr.is_null())
        boot_info->acpi_rsdp_paddr = PhysicalAddress { bit_cast<PhysicalPtr>(search_efi_configuration_table(EFI::ACPI_TABLE_GUID)) };

    // Prefer SMBIOS 3.x.
    boot_info->smbios.entry_point_paddr = PhysicalAddress { bit_cast<PhysicalPtr>(search_efi_configuration_table(EFI::SMBIOS3_TABLE_GUID)) };
    if (!boot_info->smbios.entry_point_paddr.is_null()) {
        boot_info->smbios.entry_point_is_64_bit = true;

        auto* entry_point = reinterpret_cast<SMBIOS::EntryPoint64bit*>(boot_info->smbios.entry_point_paddr.as_ptr());
        boot_info->smbios.entry_point_length = entry_point->length;
        boot_info->smbios.structure_table_paddr = PhysicalAddress { entry_point->table_ptr };
        boot_info->smbios.maximum_structure_table_length = entry_point->table_maximum_size;
    } else {
        boot_info->smbios.entry_point_paddr = PhysicalAddress { bit_cast<PhysicalPtr>(search_efi_configuration_table(EFI::SMBIOS_TABLE_GUID)) };
        boot_info->smbios.entry_point_is_64_bit = false;

        auto* entry_point = reinterpret_cast<SMBIOS::EntryPoint32bit*>(boot_info->smbios.entry_point_paddr.as_ptr());
        boot_info->smbios.entry_point_length = entry_point->length;
        boot_info->smbios.structure_table_paddr = PhysicalAddress { entry_point->legacy_structure.smbios_table_ptr };
        boot_info->smbios.maximum_structure_table_length = entry_point->legacy_structure.smbios_table_length;
    }
}

}