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428afca32b
Most of the ACPI static parsing methods (methods that can be called without initializing a full AML parser) are not tied to any specific platform or CPU architecture. The only method that is platform-specific is the one that finds the RSDP structure. Thus, each CPU architecture/platform needs to implement it. This means that now aarch64 can implement its own method to find the ACPI RSDP structure, which would be hooked into the rest of the ACPI code elegantly, but for now I just added a FIXME and that method returns empty value of Optional<PhysicalAddress>.
57 lines
2.2 KiB
C++
57 lines
2.2 KiB
C++
/*
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* Copyright (c) 2023, Liav A. <liavalb@hotmail.co.il>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#include <Kernel/Firmware/ACPI/StaticParsing.h>
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#include <Kernel/Firmware/BIOS.h>
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#include <Kernel/Memory/MemoryManager.h>
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namespace Kernel::ACPI::StaticParsing {
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// https://uefi.org/specs/ACPI/6.4/05_ACPI_Software_Programming_Model/ACPI_Software_Programming_Model.html#finding-the-rsdp-on-ia-pc-systems
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ErrorOr<Optional<PhysicalAddress>> find_rsdp_in_platform_specific_memory_locations()
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{
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constexpr auto signature = "RSD PTR "sv;
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auto ebda_or_error = map_ebda();
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if (!ebda_or_error.is_error()) {
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auto rsdp = ebda_or_error.value().find_chunk_starting_with(signature, 16);
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if (rsdp.has_value())
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return rsdp;
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}
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auto bios_or_error = map_bios();
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if (!bios_or_error.is_error()) {
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auto rsdp = bios_or_error.value().find_chunk_starting_with(signature, 16);
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if (rsdp.has_value())
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return rsdp;
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}
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// On some systems the RSDP may be located in ACPI NVS or reclaimable memory regions
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Optional<PhysicalAddress> rsdp;
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MM.for_each_physical_memory_range([&](auto& memory_range) {
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if (!(memory_range.type == Memory::PhysicalMemoryRangeType::ACPI_NVS || memory_range.type == Memory::PhysicalMemoryRangeType::ACPI_Reclaimable))
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return IterationDecision::Continue;
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Memory::MappedROM mapping;
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auto region_size_or_error = Memory::page_round_up(memory_range.length);
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if (region_size_or_error.is_error())
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return IterationDecision::Continue;
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auto region_or_error = MM.allocate_kernel_region(memory_range.start, region_size_or_error.value(), {}, Memory::Region::Access::Read);
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if (region_or_error.is_error())
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return IterationDecision::Continue;
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mapping.region = region_or_error.release_value();
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mapping.offset = memory_range.start.offset_in_page();
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mapping.size = memory_range.length;
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mapping.paddr = memory_range.start;
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rsdp = mapping.find_chunk_starting_with(signature, 16);
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if (rsdp.has_value())
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return IterationDecision::Break;
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return IterationDecision::Continue;
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});
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return rsdp;
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}
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}
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