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#include "kapi/system.hpp"
#include "arch/cpu/global_descriptor_table.hpp"
#include "arch/cpu/segment_descriptor.hpp"
#include "arch/cpu/task_state_segment.hpp"
#include <kstd/print>
#include <bit>
#include <cstdint>
namespace kapi::system
{
namespace
{
constexpr auto gdt_null_descriptor = arch::cpu::segment_descriptor{};
constexpr auto gdt_kernel_code_descriptor = arch::cpu::segment_descriptor{
.limit_low = 0xffff,
.base_low = 0,
.accessed = false,
.read_write = false,
.direction_or_conforming = false,
.executable = true,
.type = arch::cpu::segment_type::code_or_data,
.privilege_level = 0,
.present = true,
.limit_high = 0xf,
.long_mode = true,
.protected_mode = false,
.granularity = arch::cpu::segment_granularity::page,
.base_high = 0,
};
constexpr auto gdt_kernel_data_descriptor = arch::cpu::segment_descriptor{
.limit_low = 0xffff,
.base_low = 0,
.accessed = false,
.read_write = true,
.direction_or_conforming = false,
.executable = false,
.type = arch::cpu::segment_type::code_or_data,
.privilege_level = 0,
.present = true,
.limit_high = 0xf,
.long_mode = false,
.protected_mode = true,
.granularity = arch::cpu::segment_granularity::page,
.base_high = 0,
};
constexpr auto gdt_user_code_descriptor = arch::cpu::segment_descriptor{
.limit_low = 0xffff,
.base_low = 0,
.accessed = false,
.read_write = false,
.direction_or_conforming = false,
.executable = true,
.type = arch::cpu::segment_type::code_or_data,
.privilege_level = 3,
.present = true,
.limit_high = 0xf,
.long_mode = true,
.protected_mode = false,
.granularity = arch::cpu::segment_granularity::page,
.base_high = 0,
};
constexpr auto gdt_user_data_descriptor = arch::cpu::segment_descriptor{
.limit_low = 0xffff,
.base_low = 0,
.accessed = false,
.read_write = true,
.direction_or_conforming = false,
.executable = false,
.type = arch::cpu::segment_type::code_or_data,
.privilege_level = 3,
.present = true,
.limit_high = 0xf,
.long_mode = false,
.protected_mode = false,
.granularity = arch::cpu::segment_granularity::page,
.base_high = 0,
};
} // namespace
auto memory_initialized() -> void
{
auto static tss = arch::cpu::task_state_segment{};
auto static tss_descriptor = arch::cpu::system_segment_descriptor{
{
.limit_low = (sizeof(tss) - 1) & 0xffff, // NOLINT(readability-magic-numbers)
.base_low = std::bit_cast<std::uintptr_t>(&tss) & 0xffffff, // NOLINT(readability-magic-numbers)
.accessed = false,
.read_write = false,
.direction_or_conforming = false,
.executable = false,
.type = arch::cpu::segment_type::system,
.privilege_level = 0,
.present = true,
.limit_high = ((sizeof(tss) - 1) >> 16) & 0xf, // NOLINT(readability-magic-numbers)
.long_mode = false,
.protected_mode = false,
.granularity = arch::cpu::segment_granularity::byte,
.base_high = (std::bit_cast<std::uintptr_t>(&tss) >> 24) & 0xff, // NOLINT(readability-magic-numbers)
},
(std::bit_cast<std::uintptr_t>(&tss) >> 32) & 0xffff'ffff, // NOLINT(readability-magic-numbers)
};
auto static gdt = arch::cpu::global_descriptor_table{
gdt_null_descriptor, gdt_kernel_code_descriptor, gdt_kernel_data_descriptor,
gdt_user_code_descriptor, gdt_user_data_descriptor, tss_descriptor,
};
kstd::println("[x86_64:SYS] Reloading Global Descriptor Table.");
gdt.load(1, 2);
kstd::println("[x86_64:SYS] TODO: initialize Interrupt Descriptor Table.");
}
} // namespace kapi::system
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