diff options
Diffstat (limited to 'arch/x86_64/src/context_switching/main.cpp')
| -rw-r--r-- | arch/x86_64/src/context_switching/main.cpp | 30 |
1 files changed, 18 insertions, 12 deletions
diff --git a/arch/x86_64/src/context_switching/main.cpp b/arch/x86_64/src/context_switching/main.cpp index a5bd3fb..f449a3a 100644 --- a/arch/x86_64/src/context_switching/main.cpp +++ b/arch/x86_64/src/context_switching/main.cpp @@ -10,24 +10,30 @@ namespace teachos::arch::context_switching { auto initialize_descriptor_tables() -> descriptor_tables { + kernel::cpu::clear_interrupt_flag(); decltype(auto) global_descriptor_table = segment_descriptor_table::initialize_global_descriptor_table(); decltype(auto) interrupt_descriptor_table = interrupt_descriptor_table::initialize_interrupt_descriptor_table(); - kernel::cpu::far_pointer pointer{&boot::reload_segment_register, 1 * sizeof(segment_descriptor_table::segment_descriptor)}; - asm volatile("rex64 lcall *%[far_function_pointer]" : : [far_function_pointer] "m" (pointer)); + kernel::cpu::far_pointer pointer{&boot::reload_segment_register, + 1 * sizeof(segment_descriptor_table::segment_descriptor)}; + asm volatile("rex64 lcall *%[far_function_pointer]" : : [far_function_pointer] "m"(pointer)); - // // Load task state segment descriptor from the last element in the global descriptor table, done by calculating - // // offset in bytes to the start of the segment descriptor (5 * 16) = 80 - // uint16_t const tss_selector = - // (global_descriptor_table.size() - 1) * sizeof(segment_descriptor_table::segment_descriptor); - // kernel::cpu::load_task_register(tss_selector); + // Load task state segment descriptor from the last element in the global descriptor table, done by calculating + // offset in bytes to the start of the segment descriptor (5 * 16) = 80 + uint16_t const tss_selector = + (global_descriptor_table.size() - 1) * sizeof(segment_descriptor_table::segment_descriptor); + kernel::cpu::load_task_register(tss_selector); - // auto const stored_task_register = kernel::cpu::store_task_register(); - // arch::exception_handling::assert(tss_selector == stored_task_register, - // "[Global Descriptor Table] Loaded TR value is not the same as the stored value."); + auto const stored_task_register = kernel::cpu::store_task_register(); + arch::exception_handling::assert(tss_selector == stored_task_register, + "[Global Descriptor Table] Loaded TR value is not the same as the stored value."); - // FIXME: We currently cannot enable interrupts, since for some reason, we will later run into what looks like a GP. Maybe because no IDT is loaded? Maybe our boot code segment is not set up correctly? - // kernel::cpu::set_interrupt_flag(); + // FIXME: We currently cannot enable interrupts, since for some reason, we will later run into what looks like a GP + // and triple fault. + + // @MTO: SOMETIMES i get past a breakpoint here???? seems to happen when i actually pause before (f.e. inside the + // idt). NEVER happened when stepping through quickly. Can you reproduce this? + kernel::cpu::set_interrupt_flag(); descriptor_tables tables = {global_descriptor_table, interrupt_descriptor_table}; return tables; |