diff options
6 files changed, 53 insertions, 12 deletions
diff --git a/arch/x86_64/include/arch/context_switching/syscall/main.hpp b/arch/x86_64/include/arch/context_switching/syscall/main.hpp index ae4c2db..48fa195 100644 --- a/arch/x86_64/include/arch/context_switching/syscall/main.hpp +++ b/arch/x86_64/include/arch/context_switching/syscall/main.hpp @@ -5,28 +5,61 @@ namespace teachos::arch::context_switching::syscall { + /** + * @brief Possible syscall implementation that should actually be called. + * + * @note Attempts to reflect the Linux interface partially. See https://filippo.io/linux-syscall-table/ for more + * information. + */ enum class type : uint64_t { - WRITE = 1U + WRITE = 1U, ///< Loads the arg_0 parameter as an address pointing to a const char array, which will then be printed + ///< onto the VGA buffer screen. }; + /** + * @brief Possible error codes that can be returned by the different syscall methods called depending on the type + * enum. + */ enum class error { OK = 0U, }; + /** + * @brief Allows to convert the error enum type into a boolean directly. Where any code besides 0 being no error, will + * return true. The remaining errors return true. + * + * @param e Error code that was returned by the syscall. + * @return Return true if there was no error and false otherwise. + */ constexpr bool operator!(error e) { return e == error::OK; } + /** + * @brief Maximum amount of arguments that can be passed to a syscall. Default value is 0 and arguments are only ever + * used depending on the actual enum type and if the method requires thoose parameters. + */ struct arguments { - uint64_t arg_0{}; - uint64_t arg_1{}; - uint64_t arg_2{}; - uint64_t arg_3{}; - uint64_t arg_4{}; - uint64_t arg_5{}; + uint64_t arg_0{}; ///< First optional paramter to the syscall representing the RDI register. + uint64_t arg_1{}; ///< Second optional paramter to the syscall representing the RSI register. + uint64_t arg_2{}; ///< Third optional paramter to the syscall representing the RDX register. + uint64_t arg_3{}; ///< Fourth optional paramter to the syscall representing the R10 register. + uint64_t arg_4{}; ///< Fifth optional paramter to the syscall representing the R8 register. + uint64_t arg_5{}; ///< Sixth optional paramter to the syscall representing the R9 register. }; + /** + * @brief Calls the method associated with the given syscall number and passes the given optional arguments to it, + * over the RDI, RSI, RDX, R10, R8 and R9 register. + * + * @param syscall_number Syscall method that should be called. See enum values in type for possible implemented + * methods. + * @param args Optional arguments passable to the different syscall methods, called depending on the syscall_number. + * Not passing the required parameters to the method, will result in passing 0 instead, which might make the fail or + * not function correctly. + * @return Bool-convertable error code converting to true if the syscall failed or false if it didn't. + */ auto syscall(type syscall_number, arguments args = {}) -> error; } // namespace teachos::arch::context_switching::syscall diff --git a/arch/x86_64/include/arch/context_switching/syscall/syscall_enable.hpp b/arch/x86_64/include/arch/context_switching/syscall/syscall_enable.hpp index 59b97b2..8cb468a 100644 --- a/arch/x86_64/include/arch/context_switching/syscall/syscall_enable.hpp +++ b/arch/x86_64/include/arch/context_switching/syscall/syscall_enable.hpp @@ -3,6 +3,14 @@ namespace teachos::arch::context_switching::syscall { + /** + * @brief Enables and sets up internal CPU registers to allow for syscall to function correctly and switch context + * temporarily back to the kernel level. + * + * @note Configures the Model Specific Register required by syscall (LSTAR, FMASK, STAR) with the correct values so + * that the syscall_handler is called and sets the System Call Extension bit on the EFER flags to allow for syscall + * to be used. + */ auto enable_syscall() -> void; } // namespace teachos::arch::context_switching::syscall diff --git a/arch/x86_64/src/context_switching/syscall/main.cpp b/arch/x86_64/src/context_switching/syscall/main.cpp index a226e23..93fc613 100644 --- a/arch/x86_64/src/context_switching/syscall/main.cpp +++ b/arch/x86_64/src/context_switching/syscall/main.cpp @@ -23,4 +23,4 @@ namespace teachos::arch::context_switching::syscall return error; } -} // namespace teachos::arch::context_switching::syscall
\ No newline at end of file +} // namespace teachos::arch::context_switching::syscall diff --git a/arch/x86_64/src/context_switching/syscall/syscall_enable.cpp b/arch/x86_64/src/context_switching/syscall/syscall_enable.cpp index e6265d3..3c43336 100644 --- a/arch/x86_64/src/context_switching/syscall/syscall_enable.cpp +++ b/arch/x86_64/src/context_switching/syscall/syscall_enable.cpp @@ -8,7 +8,7 @@ namespace teachos::arch::context_switching::syscall { namespace { - constexpr interrupt_descriptor_table::segment_selector KERNEL_CODE_SEGMENT_SELECTOR{ + interrupt_descriptor_table::segment_selector constexpr KERNEL_CODE_SEGMENT_SELECTOR{ 1U, interrupt_descriptor_table::segment_selector::REQUEST_LEVEL_KERNEL}; auto constexpr IA32_STAR_ADDRESS = 0xC0000081; @@ -29,4 +29,4 @@ namespace teachos::arch::context_switching::syscall kernel::cpu::set_efer_bit(kernel::cpu::efer_flags::SCE); } -} // namespace teachos::arch::context_switching::syscall
\ No newline at end of file +} // namespace teachos::arch::context_switching::syscall diff --git a/arch/x86_64/src/context_switching/syscall/syscall_handler.cpp b/arch/x86_64/src/context_switching/syscall/syscall_handler.cpp index fbfecc0..da9eb1b 100644 --- a/arch/x86_64/src/context_switching/syscall/syscall_handler.cpp +++ b/arch/x86_64/src/context_switching/syscall/syscall_handler.cpp @@ -72,4 +72,4 @@ namespace teachos::arch::context_switching::syscall "sysretq"); } -} // namespace teachos::arch::context_switching::syscall
\ No newline at end of file +} // namespace teachos::arch::context_switching::syscall diff --git a/arch/x86_64/src/user/main.cpp b/arch/x86_64/src/user/main.cpp index 8ce21ba..1d56d2e 100644 --- a/arch/x86_64/src/user/main.cpp +++ b/arch/x86_64/src/user/main.cpp @@ -32,4 +32,4 @@ namespace teachos::arch::user video::vga::text::common_attributes::green_on_black); } } -} // namespace teachos::arch::user
\ No newline at end of file +} // namespace teachos::arch::user |