diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86_64/include/arch/memory/multiboot.hpp | 46 | ||||
| -rw-r--r-- | arch/x86_64/src/kernel/main.cpp | 19 |
2 files changed, 49 insertions, 16 deletions
diff --git a/arch/x86_64/include/arch/memory/multiboot.hpp b/arch/x86_64/include/arch/memory/multiboot.hpp index 37b10f0..f6ff480 100644 --- a/arch/x86_64/include/arch/memory/multiboot.hpp +++ b/arch/x86_64/include/arch/memory/multiboot.hpp @@ -124,40 +124,43 @@ namespace teachos::arch::memory // Nothing to do } - auto writeable() -> bool { return is_bit_set(0); } + auto writeable() const -> bool { return is_bit_set(0); } - auto occupies_memory() -> bool { return is_bit_set(1); } + auto occupies_memory() const -> bool { return is_bit_set(1); } - auto is_executable() -> bool { return is_bit_set(2); } + auto is_executable() const -> bool { return is_bit_set(2); } - auto contains_duplicate_data() -> bool { return is_bit_set(4); } + auto contains_duplicate_data() const -> bool { return is_bit_set(4); } - auto contains_strings() -> bool { return is_bit_set(5); } + auto contains_strings() const -> bool { return is_bit_set(5); } - auto section_header_info_is_section_header_table_index() -> bool { return is_bit_set(6); } + auto section_header_info_is_section_header_table_index() const -> bool { return is_bit_set(6); } - auto preserve_ordering_after_combination() -> bool { return is_bit_set(7); } + auto preserve_ordering_after_combination() const -> bool { return is_bit_set(7); } - auto requires_special_os_processing() -> bool { return is_bit_set(8); } + auto requires_special_os_processing() const -> bool { return is_bit_set(8); } - auto is_section_group_member() -> bool { return is_bit_set(9); } + auto is_section_group_member() const -> bool { return is_bit_set(9); } - auto holds_thread_local_data() -> bool { return is_bit_set(10); } + auto holds_thread_local_data() const -> bool { return is_bit_set(10); } - auto is_compressed() -> bool { return is_bit_set(11); } + auto is_compressed() const -> bool { return is_bit_set(11); } - auto has_special_ordering_requirements() -> bool { return is_bit_set(30); } + auto has_special_ordering_requirements() const -> bool { return is_bit_set(30); } - auto is_excluded_unless_referenced_or_allocated() -> bool { return is_bit_set(31); } + auto is_excluded_unless_referenced_or_allocated() const -> bool { return is_bit_set(31); } + + auto operator==(elf_section_flags const & other) const -> bool { return flags == other.flags; } private: - auto is_bit_set(uint8_t index) -> bool { return flags[index] == 1; } + auto is_bit_set(uint8_t index) const -> bool { return flags[index] == 1; } std::bitset<64U> flags; }; /** - * https://docs.oracle.com/cd/E19455-01/806-3773/elf-2/index.html + * @brief Defines the data included in a section header, where each section has exactly one section header. + * See https://refspecs.linuxbase.org/elf/gabi4+/ch4.sheader.html for more information */ struct elf_section_header { @@ -171,6 +174,19 @@ namespace teachos::arch::memory uint32_t additional_information; uint64_t address_alignment; uint64_t fixed_table_entry_size; + + /** + * @brief Detect whether e section header is inactive or not, should always be the case for the first entry in the + * sections table + * @return Whether the current section header is actually null or not, requires all fields besides section_size and + * other_section to actually contain 0 + */ + auto is_null() const -> bool + { + return name_table_index == 0U && type == elf_section_type::UNSPECIFIED && flags == 0U && virtual_address == 0U && + file_offset == 0U && additional_information == 0U && address_alignment == 0U && + fixed_table_entry_size == 0U; + } }; /** diff --git a/arch/x86_64/src/kernel/main.cpp b/arch/x86_64/src/kernel/main.cpp index 636ddf2..2ba4fe2 100644 --- a/arch/x86_64/src/kernel/main.cpp +++ b/arch/x86_64/src/kernel/main.cpp @@ -11,7 +11,12 @@ namespace teachos::arch::kernel video::vga::text::write("Assert failed", video::vga::text::common_attributes::green_on_black); while (!condition) { - ; + // Trick the compiler into thinking the variable is changes at run time, + // to prevent the while loop being optimized away + // See + // https://stackoverflow.com/questions/9495856/how-to-prevent-g-from-optimizing-out-a-loop-controlled-by-a-variable-that-can + // for mroe information. + asm volatile("" : "+g"(condition)); } } @@ -44,8 +49,20 @@ namespace teachos::arch::kernel constexpr auto actual_entry_size = sizeof(arch::memory::elf_section_header); assert(expected_entry_size == actual_entry_size); + auto expected_total_size = symbol->tag.size; + auto actual_total_entry_size = actual_entry_size * symbol->number_of_sections; + constexpr auto actual_total_section_size = + sizeof(arch::memory::elf_symbols_section) - actual_entry_size - sizeof(uint32_t); + auto actual_total_size = actual_total_entry_size + actual_total_section_size; + assert(expected_total_size == actual_total_size); + auto begin = &symbol->sections; auto end = begin + symbol->number_of_sections; + // TODO: Last value is completly wrong, should show 0 but shows huge value for size of entries in the table of the + // SHT_NULL elf section entry. Memory around value also make no sense and look even worse? But according to api + // value should be zero :( + // assert(begin->is_null()); + for (auto section = begin; section != end; ++section) { video::vga::text::write("Looping Code section", video::vga::text::common_attributes::green_on_black); |