Merge branch 'develop-BA-FS26' into 'develop'HEADdevelop

Merge of BA-FS26 branch into develop

See merge request teachos/kernel!49

10 files changed, 0 insertions, 398 deletions

diff --git a/arch/x86_64/pre/src/context_switching/interrupt_descriptor_table/gate_descriptor.cpp b/arch/x86_64/pre/src/context_switching/interrupt_descriptor_table/gate_descriptor.cpp
deleted file mode 100644
index 28f289c..0000000
--- a/arch/x86_64/pre/src/context_switching/interrupt_descriptor_table/gate_descriptor.cpp
+++ /dev/null
@@ -1,24 +0,0 @@
-#include "arch/context_switching/interrupt_descriptor_table/gate_descriptor.hpp"
-
-namespace teachos::arch::context_switching::interrupt_descriptor_table
-{
-  gate_descriptor::gate_descriptor(uint128_t flags)
-      : _offset_1(flags)
-      , _selector(flags >> 19U, flags >> 16U)
-      , _ist(flags >> 32U)
-      , _flags(flags >> 40U)
-      , _offset_2(flags >> 48U)
-  {
-    // Nothing to do.
-  }
-
-  gate_descriptor::gate_descriptor(segment_selector selector, ist_offset ist, idt_flags flags, uint64_t offset)
-      : _offset_1(offset)
-      , _selector(selector)
-      , _ist(ist)
-      , _flags(flags)
-      , _offset_2(offset >> 16U)
-  {
-    // Nothing to do.
-  }
-}  // namespace teachos::arch::context_switching::interrupt_descriptor_table
diff --git a/arch/x86_64/pre/src/context_switching/interrupt_descriptor_table/idt_flags.cpp b/arch/x86_64/pre/src/context_switching/interrupt_descriptor_table/idt_flags.cpp
deleted file mode 100644
index f3b9d5e..0000000
--- a/arch/x86_64/pre/src/context_switching/interrupt_descriptor_table/idt_flags.cpp
+++ /dev/null
@@ -1,20 +0,0 @@
-#include "arch/context_switching/interrupt_descriptor_table/idt_flags.hpp"
-
-namespace teachos::arch::context_switching::interrupt_descriptor_table
-{
-  idt_flags::idt_flags(uint8_t flags)
-      : _flags(flags)
-  {
-    // Nothing to do.
-  }
-
-  auto idt_flags::contains_flags(std::bitset<8U> other) const -> bool
-  {
-    return (std::bitset<8U>{_flags} & other) == other;
-  }
-
-  auto idt_flags::operator|=(std::bitset<8U> other) -> void
-  {
-    _flags |= other.to_ulong();
-  }
-}  // namespace teachos::arch::context_switching::interrupt_descriptor_table
diff --git a/arch/x86_64/pre/src/context_switching/interrupt_descriptor_table/interrupt_descriptor_table.cpp b/arch/x86_64/pre/src/context_switching/interrupt_descriptor_table/interrupt_descriptor_table.cpp
deleted file mode 100644
index 8640385..0000000
--- a/arch/x86_64/pre/src/context_switching/interrupt_descriptor_table/interrupt_descriptor_table.cpp
+++ /dev/null
@@ -1,53 +0,0 @@
-#include "arch/context_switching/interrupt_descriptor_table/interrupt_descriptor_table.hpp"
-
-#include "arch/exception_handling/assert.hpp"
-#include "arch/interrupt_handling/generic_interrupt_handler.hpp"
-#include "arch/kernel/cpu/idtr.hpp"
-
-namespace teachos::arch::context_switching::interrupt_descriptor_table
-{
-  namespace
-  {
-    /// @brief Amount of currently reserved interrupt indicies.
-    /// See https://wiki.osdev.org/Interrupt_Descriptor_Table#IDT_items for more information.
-    constexpr uint16_t RESERVED_INTERRUPT_COUNT = 256U;
-
-    auto create_interrupt_descriptor_table() -> interrupt_descriptor_table
-    {
-      interrupt_descriptor_table interrupt_descriptor_table{RESERVED_INTERRUPT_COUNT};
-
-      uint64_t offset = reinterpret_cast<uint64_t>(interrupt_handling::generic_interrupt_handler);
-      segment_selector selector{1U, segment_selector::REQUEST_LEVEL_KERNEL};
-      ist_offset ist{0U};
-      idt_flags flags{idt_flags::DESCRIPTOR_LEVEL_KERNEL | idt_flags::INTERRUPT_GATE | idt_flags::PRESENT};
-
-      for (std::size_t i = 0; i < interrupt_descriptor_table.size(); i++)
-      {
-        interrupt_descriptor_table.at(i) = {selector, ist, flags, offset};
-      }
-
-      return interrupt_descriptor_table;
-    }
-  }  // namespace
-
-  auto get_or_create_interrupt_descriptor_table() -> interrupt_descriptor_table &
-  {
-    // Interrupt Descriptor Table needs to be kept alive
-    interrupt_descriptor_table static idt = create_interrupt_descriptor_table();
-    return idt;
-  }
-
-  auto update_interrupt_descriptor_table_register() -> void
-  {
-    decltype(auto) idt = get_or_create_interrupt_descriptor_table();
-
-    interrupt_descriptor_table_pointer idt_pointer{static_cast<uint16_t>((idt.size() * sizeof(gate_descriptor)) - 1),
-                                                   idt.data()};
-    kernel::cpu::load_interrupt_descriptor_table(idt_pointer);
-
-    auto const stored_gdt_pointer = kernel::cpu::store_interrupt_descriptor_table();
-    arch::exception_handling::assert(
-        idt_pointer == stored_gdt_pointer,
-        "[Interrupt Descriptor Table] Loaded IDTR value is not the same as the stored value.");
-  }
-}  // namespace teachos::arch::context_switching::interrupt_descriptor_table
diff --git a/arch/x86_64/pre/src/context_switching/interrupt_descriptor_table/interrupt_descriptor_table_pointer.cpp b/arch/x86_64/pre/src/context_switching/interrupt_descriptor_table/interrupt_descriptor_table_pointer.cpp
deleted file mode 100644
index 7bcbae6..0000000
--- a/arch/x86_64/pre/src/context_switching/interrupt_descriptor_table/interrupt_descriptor_table_pointer.cpp
+++ /dev/null
@@ -1,13 +0,0 @@
-#include "arch/context_switching/interrupt_descriptor_table/interrupt_descriptor_table_pointer.hpp"
-
-namespace teachos::arch::context_switching::interrupt_descriptor_table
-{
-  interrupt_descriptor_table_pointer::interrupt_descriptor_table_pointer(uint16_t table_length,
-                                                                         gate_descriptor * address)
-      : table_length(table_length)
-      , address(address)
-  {
-    // Nothing to do.
-  }
-
-}  // namespace teachos::arch::context_switching::interrupt_descriptor_table
diff --git a/arch/x86_64/pre/src/context_switching/interrupt_descriptor_table/ist_offset.cpp b/arch/x86_64/pre/src/context_switching/interrupt_descriptor_table/ist_offset.cpp
deleted file mode 100644
index a70e75d..0000000
--- a/arch/x86_64/pre/src/context_switching/interrupt_descriptor_table/ist_offset.cpp
+++ /dev/null
@@ -1,10 +0,0 @@
-#include "arch/context_switching/interrupt_descriptor_table/ist_offset.hpp"
-
-namespace teachos::arch::context_switching::interrupt_descriptor_table
-{
-  ist_offset::ist_offset(uint8_t index)
-      : _ist(index)
-  {
-    // Nothing to do.
-  }
-}  // namespace teachos::arch::context_switching::interrupt_descriptor_table
diff --git a/arch/x86_64/pre/src/context_switching/interrupt_descriptor_table/segment_selector.cpp b/arch/x86_64/pre/src/context_switching/interrupt_descriptor_table/segment_selector.cpp
deleted file mode 100644
index 25ba859..0000000
--- a/arch/x86_64/pre/src/context_switching/interrupt_descriptor_table/segment_selector.cpp
+++ /dev/null
@@ -1,24 +0,0 @@
-#include "arch/context_switching/interrupt_descriptor_table/segment_selector.hpp"
-
-namespace teachos::arch::context_switching::interrupt_descriptor_table
-{
-  auto segment_selector::contains_flags(std::bitset<3U> other) const -> bool
-  {
-    return (std::bitset<3U>{_flags} & other) == other;
-  }
-
-  auto segment_selector::get_index() const -> uint16_t
-  {
-    return _index;
-  }
-
-  auto segment_selector::operator|=(std::bitset<3U> other) -> void
-  {
-    _flags |= other.to_ulong();
-  }
-
-  segment_selector::operator uint16_t() const
-  {
-    return *reinterpret_cast<uint16_t const *>(this);
-  }
-}  // namespace teachos::arch::context_switching::interrupt_descriptor_table
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 3eb6dae..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 b4ab468..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 dbb3ed9..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 c120f77..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