diff options
Diffstat (limited to 'arch/x86_64/src/kernel/cpu')
| -rw-r--r-- | arch/x86_64/src/kernel/cpu/lgdt.cpp | 13 | ||||
| -rw-r--r-- | arch/x86_64/src/kernel/cpu/ss.cpp | 8 |
2 files changed, 12 insertions, 9 deletions
diff --git a/arch/x86_64/src/kernel/cpu/lgdt.cpp b/arch/x86_64/src/kernel/cpu/lgdt.cpp index 70a48dd..386914f 100644 --- a/arch/x86_64/src/kernel/cpu/lgdt.cpp +++ b/arch/x86_64/src/kernel/cpu/lgdt.cpp @@ -4,14 +4,17 @@ namespace teachos::arch::kernel::cpu { + auto store_global_descriptor_table() -> context_switching::descriptor_table::global_descriptor_table_pointer + { + context_switching::descriptor_table::global_descriptor_table_pointer current_value{}; + asm("sgdt %[output]" : [output] "=m"(current_value)); + return current_value; + } + auto load_global_descriptor_table(context_switching::descriptor_table::global_descriptor_table_pointer const & gdt_pointer) -> void { - // TODO: build lgdt argument from global_descriptor_table_pointer (don't know how yet) - // asm volatile("lgdt (%0)" : : "r"(gdt_pointer)); - if (gdt_pointer.table_length) - { - } + asm volatile("lgdt %[input]" : /* no output from call */ : [input] "m"(gdt_pointer)); } } // namespace teachos::arch::kernel::cpu diff --git a/arch/x86_64/src/kernel/cpu/ss.cpp b/arch/x86_64/src/kernel/cpu/ss.cpp index 9c8dd61..1f28e7f 100644 --- a/arch/x86_64/src/kernel/cpu/ss.cpp +++ b/arch/x86_64/src/kernel/cpu/ss.cpp @@ -19,15 +19,15 @@ namespace teachos::arch::kernel::cpu auto read_ss() -> uint16_t { - uint16_t ss; - asm volatile("mov %%ss, %0" : "=r"(ss)); - return ss; + uint16_t segment_selector; + asm volatile("mov %%ss, %[output]" : [output] "=r"(segment_selector)); + return segment_selector; } auto write_ss(segment_selector selector) -> void { uint16_t ss = selector.to_uint16(); - asm volatile("mov %0, %%ss" ::"r"(ss)); + asm volatile("mov %[input], %%ss" : /* no output from call */ : [input] "r"(ss)); } } // namespace teachos::arch::kernel::cpu
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