ladybird/Kernel/Memory/MappedROM.h

40 lines
1.1 KiB
C++

/*
* Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/OwnPtr.h>
#include <Kernel/Memory/PhysicalAddress.h>
#include <Kernel/Memory/Region.h>
namespace Kernel::Memory {
class MappedROM {
public:
u8 const* base() const { return region->vaddr().offset(offset).as_ptr(); }
u8 const* end() const { return base() + size; }
OwnPtr<Region> region;
size_t size { 0 };
size_t offset { 0 };
PhysicalAddress paddr;
Optional<PhysicalAddress> find_chunk_starting_with(StringView prefix, size_t chunk_size) const
{
auto prefix_length = prefix.length();
if (size < prefix_length)
return {};
for (auto* candidate = base(); candidate <= end() - prefix_length; candidate += chunk_size) {
if (!__builtin_memcmp(prefix.characters_without_null_termination(), candidate, prefix.length()))
return paddr_of(candidate);
}
return {};
}
PhysicalAddress paddr_of(u8 const* ptr) const { return paddr.offset(ptr - this->base()); }
};
}