Add some comments to entry.S And remove some old obsolete ones. Signed-off-by: Andi Kleen --- arch/x86_64/kernel/entry.S | 18 +++++++++++++++--- 1 files changed, 15 insertions(+), 3 deletions(-) Index: linux/arch/x86_64/kernel/entry.S =================================================================== --- linux.orig/arch/x86_64/kernel/entry.S +++ linux/arch/x86_64/kernel/entry.S @@ -22,9 +22,21 @@ * at the top of the kernel process stack. * - partial stack frame: partially saved registers upto R11. * - full stack frame: Like partial stack frame, but all register saved. - * - * TODO: - * - schedule it carefully for the final hardware. + * + * Some macro usage: + * - CFI macros are used to generate dwarf2 unwind information for better + * backtraces. They don't change any code. + * - SAVE_ALL/RESTORE_ALL - Save/restore all registers + * - SAVE_ARGS/RESTORE_ARGS - Save/restore registers that C functions modify. + * There are unfortunately lots of special cases where some registers + * not touched. The macro is a big mess that should be cleaned up. + * - SAVE_REST/RESTORE_REST - Handle the registers not saved by SAVE_ARGS. + * Gives a full stack frame. + * - ENTRY/END Define functions in the symbol table. + * - FIXUP_TOP_OF_STACK/RESTORE_TOP_OF_STACK - Fix up the hardware stack + * frame that is otherwise undefined after a SYSCALL + * - TRACE_IRQ_* - Trace hard interrupt state for lock debugging. + * - errorentry/paranoidentry/zeroentry - Define exception entry points. */ #include