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#include "arch/memory/main.hpp"
#include "arch/exception_handling/assert.hpp"
#include "arch/kernel/cpu/control_register.hpp"
#include "arch/kernel/cpu/msr.hpp"
#include "arch/memory/allocator/area_frame_allocator.hpp"
#include "arch/memory/allocator/concept.hpp"
#include "arch/memory/heap/global_heap_allocator.hpp"
#include "arch/memory/paging/active_page_table.hpp"
#include "arch/memory/paging/kernel_mapper.hpp"
#include <optional>
namespace teachos::arch::memory
{
namespace
{
static std::optional<allocator::area_frame_allocator> frame_allocator;
auto create_frame_allocator(multiboot::memory_information const & memory_information)
-> allocator::area_frame_allocator
{
frame_allocator.emplace(memory_information);
return frame_allocator.value();
}
auto get_frame_allocator() -> allocator::area_frame_allocator
{
exception_handling::assert(frame_allocator.has_value(), "[Memory main] Frame allocator has not been created yet");
return frame_allocator.value();
}
} // namespace
auto remap_heap(std::size_t heap_start, std::size_t heap_size, paging::entry::bitset additional_flags = {}) -> void
{
auto allocator = get_frame_allocator();
decltype(auto) active_table = paging::active_page_table::create_or_get();
auto const start_page = paging::virtual_page::containing_address(heap_start);
auto const end_page = ++(paging::virtual_page::containing_address(heap_start + heap_size - 1));
paging::page_container::iterator const begin{start_page};
paging::page_container::iterator const end{end_page};
paging::page_container const pages{begin, end};
constexpr auto base_flags = paging::entry::WRITABLE;
auto const flags = base_flags | additional_flags;
for (auto const & page : pages)
{
active_table.map_page_to_next_free_frame(allocator, page, flags);
}
}
auto initialize_memory_management() -> void
{
static bool has_been_called = false;
arch::exception_handling::assert(!has_been_called,
"[Initialization] Memory management has already been initialized");
has_been_called = true;
auto const memory_information = multiboot::read_multiboot2();
auto allocator = create_frame_allocator(memory_information);
kernel::cpu::set_cr0_bit(kernel::cpu::cr0_flags::WRITE_PROTECT);
kernel::cpu::set_efer_bit(kernel::cpu::efer_flags::NXE);
paging::kernel_mapper kernel(allocator, memory_information);
kernel.remap_kernel();
video::vga::text::write("Kernel remapping successful", video::vga::text::common_attributes::green_on_black);
video::vga::text::newline();
// Remap kernel heap
remap_heap(heap::KERNEL_HEAP_START, heap::KERNEL_HEAP_SIZE);
// Remap user heap
remap_heap(heap::USER_HEAP_SIZE, heap::USER_HEAP_SIZE, paging::entry::USER_ACCESSIBLE);
video::vga::text::write("Heap remapping successful", video::vga::text::common_attributes::green_on_black);
video::vga::text::newline();
}
} // namespace teachos::arch::memory
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