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/*
* Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
* Copyright (c) 2022, Liav A. <liavalb@hotmail.co.il>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/Firmware/BIOS.h>
#include <Kernel/Memory/MemoryManager.h>
#include <Kernel/Memory/TypedMapping.h>
namespace Kernel {
ErrorOr<Memory::MappedROM> map_bios()
{
Memory::MappedROM mapping;
mapping.size = 128 * KiB;
mapping.paddr = PhysicalAddress(0xe0000);
auto region_size = TRY(Memory::page_round_up(mapping.size));
mapping.region = TRY(MM.allocate_kernel_region(mapping.paddr, region_size, {}, Memory::Region::Access::Read));
return mapping;
}
ErrorOr<Memory::MappedROM> map_ebda()
{
auto ebda_segment_ptr = TRY(Memory::map_typed<u16>(PhysicalAddress(0x40e)));
PhysicalAddress ebda_paddr(PhysicalAddress(*ebda_segment_ptr).get() << 4);
// The EBDA size is stored in the first byte of the EBDA in 1K units
size_t ebda_size = *TRY(Memory::map_typed<u8>(ebda_paddr));
ebda_size *= 1024;
Memory::MappedROM mapping;
auto region_size = TRY(Memory::page_round_up(ebda_size));
mapping.region = TRY(MM.allocate_kernel_region(ebda_paddr.page_base(), region_size, {}, Memory::Region::Access::Read));
mapping.offset = ebda_paddr.offset_in_page();
mapping.size = ebda_size;
mapping.paddr = ebda_paddr;
return mapping;
}
}
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