6 files changed, 0 insertions, 360 deletions
diff --git a/arch/x86_64/pre/src/context_switching/main.cpp b/arch/x86_64/pre/src/context_switching/main.cpp
deleted file mode 100644
index 0961499..0000000
--- a/arch/x86_64/pre/src/context_switching/main.cpp
+++ /dev/null
@@ -1,66 +0,0 @@
-#include <arch/context_switching/main.hpp>
-
-#include <arch/boot/pointers.hpp>
-#include <arch/context_switching/syscall/syscall_enable.hpp>
-#include <arch/kernel/cpu/call.hpp>
-#include <arch/kernel/cpu/if.hpp>
-#include <arch/kernel/cpu/segment_register.hpp>
-#include <arch/kernel/cpu/tr.hpp>
-#include <arch/user/main.hpp>
-
-namespace teachos::arch::context_switching
-{
-  namespace
-  {
-    constexpr interrupt_descriptor_table::segment_selector KERNEL_CODE_SEGMENT_SELECTOR{
-      1U, interrupt_descriptor_table::segment_selector::REQUEST_LEVEL_KERNEL};
-    constexpr kernel::cpu::far_pointer KERNEL_CODE_POINTER{&kernel::cpu::reload_data_segment_registers,
-                                                           KERNEL_CODE_SEGMENT_SELECTOR};
-    constexpr context_switching::interrupt_descriptor_table::segment_selector USER_CODE_SEGMENT_SELECTOR{
-      3U, context_switching::interrupt_descriptor_table::segment_selector::REQUEST_LEVEL_USER};
-    constexpr context_switching::interrupt_descriptor_table::segment_selector USER_DATA_SEGMENT_SELECTOR{
-      4U, context_switching::interrupt_descriptor_table::segment_selector::REQUEST_LEVEL_USER};
-
-    auto reload_gdtr() -> void
-    {
-      kernel::cpu::call(KERNEL_CODE_POINTER);
-    }
-  }  // namespace
-
-  auto initialize_descriptor_tables() -> descriptor_tables
-  {
-    bool static initalized = false;
-
-    if (!initalized)
-    {
-      kernel::cpu::clear_interrupt_flag();
-
-      segment_descriptor_table::update_gdtr();
-      interrupt_descriptor_table::update_interrupt_descriptor_table_register();
-
-      reload_gdtr();
-      segment_descriptor_table::update_tss_register();
-
-      kernel::cpu::set_interrupt_flag();
-      initalized = true;
-    }
-
-    descriptor_tables tables = {segment_descriptor_table::get_or_create_gdt(),
-                                interrupt_descriptor_table::get_or_create_interrupt_descriptor_table()};
-    return tables;
-  }
-
-  auto switch_to_user_mode() -> void
-  {
-    syscall::enable_syscall();
-    switch_context(USER_DATA_SEGMENT_SELECTOR, USER_CODE_SEGMENT_SELECTOR, user::main);
-  }
-
-  auto switch_context(interrupt_descriptor_table::segment_selector data_segment,
-                      interrupt_descriptor_table::segment_selector code_segment, void (*return_function)()) -> void
-  {
-    (void)initialize_descriptor_tables();
-    kernel::cpu::set_data_segment_registers(data_segment);
-    kernel::cpu::set_code_segment_register(data_segment, code_segment, reinterpret_cast<uint64_t>(return_function));
-  }
-}  // namespace teachos::arch::context_switching
diff --git a/arch/x86_64/pre/src/context_switching/syscall/main.cpp b/arch/x86_64/pre/src/context_switching/syscall/main.cpp
deleted file mode 100644
index 10bd087..0000000
--- a/arch/x86_64/pre/src/context_switching/syscall/main.cpp
+++ /dev/null
@@ -1,35 +0,0 @@
-#include <arch/context_switching/syscall/main.hpp>
-
-namespace teachos::arch::context_switching::syscall
-{
-  auto syscall(type syscall_number, arguments args) -> response
-  {
-    asm volatile("mov %[input], %%rax"
-                 : /* no output from call */
-                 : [input] "m"(syscall_number)
-                 : "memory");
-
-    asm volatile("mov %[input], %%rdi " : /* no output from call */ : [input] "m"(args.arg_0) : "memory");
-    asm volatile("mov %[input], %%rsi" : /* no output from call */ : [input] "m"(args.arg_1) : "memory");
-    asm volatile("mov %[input], %%rdx" : /* no output from call */ : [input] "m"(args.arg_2) : "memory");
-    asm volatile("mov %[input], %%r10" : /* no output from call */ : [input] "m"(args.arg_3) : "memory");
-    asm volatile("mov %[input], %%r8" : /* no output from call */ : [input] "m"(args.arg_4) : "memory");
-    asm volatile("mov %[input], %%r9" : /* no output from call */ : [input] "m"(args.arg_5) : "memory");
-
-    asm volatile("syscall");
-
-    arguments values{};
-    asm volatile("mov %%rdi, %[output]" : [output] "=m"(values.arg_0));
-    asm volatile("mov %%rsi, %[output]" : [output] "=m"(values.arg_1));
-    asm volatile("mov %%rdx, %[output]" : [output] "=m"(values.arg_2));
-    asm volatile("mov %%r10, %[output]" : [output] "=m"(values.arg_3));
-    asm volatile("mov %%r8, %[output]" : [output] "=m"(values.arg_4));
-    asm volatile("mov %%r9, %[output]" : [output] "=m"(values.arg_5));
-
-    error error_code{};
-    asm volatile("mov %%al, %[output]" : [output] "=m"(error_code));
-
-    return {error_code, values};
-  }
-
-}  // namespace teachos::arch::context_switching::syscall
diff --git a/arch/x86_64/pre/src/context_switching/syscall/syscall_enable.cpp b/arch/x86_64/pre/src/context_switching/syscall/syscall_enable.cpp
deleted file mode 100644
index f9f070a..0000000
--- a/arch/x86_64/pre/src/context_switching/syscall/syscall_enable.cpp
+++ /dev/null
@@ -1,32 +0,0 @@
-#include <arch/context_switching/syscall/syscall_enable.hpp>
-
-#include <arch/context_switching/interrupt_descriptor_table/segment_selector.hpp>
-#include <arch/context_switching/syscall/syscall_handler.hpp>
-#include <arch/kernel/cpu/msr.hpp>
-
-namespace teachos::arch::context_switching::syscall
-{
-  namespace
-  {
-    constexpr interrupt_descriptor_table::segment_selector KERNEL_CODE_SEGMENT_SELECTOR{
-      1U, interrupt_descriptor_table::segment_selector::REQUEST_LEVEL_KERNEL};
-
-    constexpr auto IA32_STAR_ADDRESS = 0xC000'0081;
-    constexpr auto IA32_LSTAR_ADDRESS = 0xC000'0082;
-    constexpr auto IA32_FMASK_ADDRESS = 0xC000'0084;
-
-  }  // namespace
-
-  auto enable_syscall() -> void
-  {
-    uint64_t const syscall_function = reinterpret_cast<uint64_t>(syscall_handler);
-    kernel::cpu::write_msr(IA32_LSTAR_ADDRESS, syscall_function);
-    kernel::cpu::write_msr(IA32_FMASK_ADDRESS, 0U);
-
-    uint64_t const kernel_cs = KERNEL_CODE_SEGMENT_SELECTOR;
-    uint64_t const star_value = (kernel_cs << 32) | (kernel_cs << 48);
-    kernel::cpu::write_msr(IA32_STAR_ADDRESS, star_value);
-
-    kernel::cpu::set_efer_bit(kernel::cpu::efer_flags::SCE);
-  }
-}  // namespace teachos::arch::context_switching::syscall
diff --git a/arch/x86_64/pre/src/context_switching/syscall/syscall_handler.cpp b/arch/x86_64/pre/src/context_switching/syscall/syscall_handler.cpp
deleted file mode 100644
index 430d65c..0000000
--- a/arch/x86_64/pre/src/context_switching/syscall/syscall_handler.cpp
+++ /dev/null
@@ -1,121 +0,0 @@
-#include <arch/context_switching/syscall/syscall_handler.hpp>
-
-#include <arch/context_switching/syscall/main.hpp>
-#include <arch/exception_handling/assert.hpp>
-#include <arch/exception_handling/panic.hpp>
-#include <arch/memory/heap/global_heap_allocator.hpp>
-#include <arch/memory/main.hpp>
-#include <arch/video/vga/text.hpp>
-
-namespace teachos::arch::context_switching::syscall
-{
-
-  namespace
-  {
-    auto write_to_vga_buffer(uint64_t buffer) -> response
-    {
-      video::vga::text::write(reinterpret_cast<char const *>(buffer),
-                              video::vga::text::common_attributes::green_on_black);
-      video::vga::text::newline();
-      return {error::OK};
-    }
-
-    auto expand_user_heap() -> response
-    {
-      auto static current_heap_end = memory::heap::USER_HEAP_START;
-      uint64_t const heap_start = current_heap_end;
-      memory::remap_heap(heap_start, memory::heap::USER_HEAP_SIZE, memory::paging::entry::USER_ACCESSIBLE);
-      current_heap_end += memory::heap::USER_HEAP_SIZE;
-      return {
-        error::OK,
-        {heap_start, memory::heap::USER_HEAP_SIZE}
-      };
-    }
-  }  // namespace
-
-  auto syscall_handler() -> void
-  {
-    // Saving state of rcx and r11 because it is required by sysretq to function.
-    // Calls to other functions potentially overwrite these registers, because of
-    // callee saved calling convention.
-    uint64_t return_instruction_pointer, rflags = {};
-    asm volatile("mov %%rcx, %[output]" : [output] "=m"(return_instruction_pointer));
-    asm volatile("mov %%r11, %[output]" : [output] "=m"(rflags));
-
-    uint64_t syscall_number, arg_0, arg_1, arg_2, arg_3, arg_4, arg_5 = {};
-    asm volatile("mov %%rdi, %[output]" : [output] "=m"(arg_0));
-    asm volatile("mov %%rsi, %[output]" : [output] "=m"(arg_1));
-    asm volatile("mov %%rdx, %[output]" : [output] "=m"(arg_2));
-    asm volatile("mov %%r10, %[output]" : [output] "=m"(arg_3));
-    asm volatile("mov %%r8, %[output]" : [output] "=m"(arg_4));
-    asm volatile("mov %%r9, %[output]" : [output] "=m"(arg_5));
-
-    // RAX is read last, because paired with our type enum, we can use it to check
-    // if the register has been written by the compiled code between executing the syscall
-    // and now.
-    asm volatile("mov %%rax, %[output]" : [output] "=m"(syscall_number));
-
-    response result;
-    switch (static_cast<type>(syscall_number))
-    {
-      case type::WRITE:
-        result = write_to_vga_buffer(arg_0);
-        break;
-      case type::EXPAND_HEAP:
-        result = expand_user_heap();
-        break;
-      case type::ASSERT:
-        teachos::arch::exception_handling::assert(arg_0, reinterpret_cast<char const *>(arg_1));
-        break;
-      default:
-        teachos::arch::exception_handling::panic("[Syscall Handler] Invalid syscall number");
-        break;
-    }
-
-    asm volatile("mov %[input], %%rax"
-                 : /* no output from call */
-                 : [input] "m"(result.error_code)
-                 : "memory");
-
-    asm volatile("mov %[input], %%rdi"
-                 : /* no output from call */
-                 : [input] "m"(result.values.arg_0)
-                 : "memory");
-    asm volatile("mov %[input], %%rsi"
-                 : /* no output from call */
-                 : [input] "m"(result.values.arg_1)
-                 : "memory");
-    asm volatile("mov %[input], %%rdx"
-                 : /* no output from call */
-                 : [input] "m"(result.values.arg_2)
-                 : "memory");
-    asm volatile("mov %[input], %%r10"
-                 : /* no output from call */
-                 : [input] "m"(result.values.arg_3)
-                 : "memory");
-    asm volatile("mov %[input], %%r8"
-                 : /* no output from call */
-                 : [input] "m"(result.values.arg_4)
-                 : "memory");
-    asm volatile("mov %[input], %%r9"
-                 : /* no output from call */
-                 : [input] "m"(result.values.arg_5)
-                 : "memory");
-
-    asm volatile("mov %[input], %%rcx"
-                 : /* no output from call */
-                 : [input] "m"(return_instruction_pointer)
-                 : "memory");
-    asm volatile("mov %[input], %%r11"
-                 : /* no output from call */
-                 : [input] "m"(rflags)
-                 : "memory");
-
-    // Additionally call leave, because x86 allocates stack space for the internal variables. If we do not clean up this
-    // newly created stack frame the syscall instruction that landed in this syscall_handler, will never return to the
-    // method that originally called it, because the RIP has not been restored from the previous stack frame.
-    asm volatile("leave\n"
-                 "sysretq");
-  }
-
-}  // namespace teachos::arch::context_switching::syscall
diff --git a/arch/x86_64/pre/src/kernel/main.cpp b/arch/x86_64/pre/src/kernel/main.cpp
deleted file mode 100644
index 2658678..0000000
--- a/arch/x86_64/pre/src/kernel/main.cpp
+++ /dev/null
@@ -1,71 +0,0 @@
-#include <arch/kernel/main.hpp>
-
-#include <arch/boot/pointers.hpp>
-#include <arch/context_switching/interrupt_descriptor_table/segment_selector.hpp>
-#include <arch/context_switching/main.hpp>
-#include <arch/kernel/cpu/if.hpp>
-#include <arch/kernel/cpu/segment_register.hpp>
-#include <arch/memory/heap/bump_allocator.hpp>
-#include <arch/memory/heap/global_heap_allocator.hpp>
-#include <arch/memory/main.hpp>
-#include <arch/memory/multiboot/reader.hpp>
-#include <arch/stl/vector.hpp>
-#include <arch/video/vga/text.hpp>
-
-namespace teachos::arch::kernel
-{
-  auto stack_overflow_test(int count) -> int
-  {
-    int test[5000] = {};
-    if (test[0] == 0xFFFF)
-    {
-      return count;
-    }
-    count = stack_overflow_test(count);
-    return count++;
-  }
-
-  auto heap_test() -> void
-  {
-    auto test2 = new memory::multiboot::memory_information{};
-    auto test3 = new memory::multiboot::memory_information{};
-    auto test4 = *test2;
-    auto test5 = *test3;
-    test4.kernel_end = 5000;
-    test5.kernel_end = 3000;
-    auto test6 = test4.kernel_end;
-    auto test7 = test5.kernel_end;
-    auto test8 = memory::multiboot::read_multiboot2();
-    if (test6 && test7 && test8.kernel_end)
-    {
-      video::vga::text::write("Heap test successful", video::vga::text::common_attributes::green_on_black);
-    }
-    test2->kernel_end = 2000;
-    test2->kernel_start = 1000;
-    test2->multiboot_start = 2000;
-    delete test2;
-    delete test3;
-
-    auto test9 = new int(50);
-    delete test9;
-  }
-
-  auto main() -> void
-  {
-    video::vga::text::clear();
-    video::vga::text::cursor(false);
-    video::vga::text::write("TeachOS is starting up...", video::vga::text::common_attributes::green_on_black);
-    video::vga::text::newline();
-
-    memory::initialize_memory_management();
-    // stack_overflow_test(0);
-
-    memory::heap::global_heap_allocator::register_heap_allocator(memory::heap::heap_allocator_type::LINKED_LIST);
-    // heap_test();
-
-    auto address = memory::heap::global_heap_allocator::kmalloc(8U);
-    (void)address;
-
-    context_switching::switch_to_user_mode();
-  }
-}  // namespace teachos::arch::kernel
diff --git a/arch/x86_64/pre/src/user/main.cpp b/arch/x86_64/pre/src/user/main.cpp
deleted file mode 100644
index 10a17db..0000000
--- a/arch/x86_64/pre/src/user/main.cpp
+++ /dev/null
@@ -1,35 +0,0 @@
-#include <arch/user/main.hpp>
-
-#include <arch/context_switching/syscall/main.hpp>
-#include <arch/memory/heap/global_heap_allocator.hpp>
-
-#include <algorithm>
-#include <array>
-#include <atomic>
-#include <ranges>
-
-namespace teachos::arch::user
-{
-  auto main() -> void
-  {
-    constexpr char syscall_message[] = "Successfully entered user mode and wrote to VGA buffer via syscall!";
-    context_switching::syscall::syscall(context_switching::syscall::type::WRITE,
-                                        {reinterpret_cast<uint64_t>(&syscall_message)});
-
-    // Test C++ standard library
-    std::array<std::atomic<uint8_t>, 4> array_test = {std::atomic<uint8_t>{5}, std::atomic<uint8_t>{10},
-                                                      std::atomic<uint8_t>{15}, std::atomic<uint8_t>{20}};
-    std::ranges::for_each(array_test, [](auto & item) {
-      auto value = item.load();
-      uint8_t max_value = std::max(value, uint8_t{10});
-      item.exchange(max_value + 2);
-    });
-
-    auto address = new uint64_t{10U};
-    (void)address;
-
-    for (;;)
-    {
-    }
-  }
-}  // namespace teachos::arch::user