Remy Bohmer wrote:
> Create a default fallback routine that can be used if there is no
> strong implementation:
> -------------------------------------------------------------------------------------------
> __attribute__((weak)) unsigned long long printk_clock(void)
> {
> return sched_clock();
> }
> -------------------------------------------------------------------------------------------
> and here is an example of the strong implementation (from the ARM
> architecture):
> -------------------------------------------------------------------------------------------
> unsigned long long printk_clock(void)
> {
> return (unsigned long long)(jiffies - INITIAL_JIFFIES) *
> (1000000000 / HZ);
> }
> -------------------------------------------------------------------------------------------
>
> If the strong implementation is available, the weak is simply
> discarded during linking, if the strong is omitted, the weak is used
> as fallback. This is a clean, lean and mean example without
> complex/superfluous aliases or checks for NULL pointers.
> It should not get any harder than this...
+1. I like this one, and U-Boot/MIPS _machine_restart() is implemented
in the same manner.
--
Shinya Kuribayashi
NEC Electronics
_______________________________________________
U-Boot mailing list
U-Boot@lists.denx.de
http://lists.denx.de/mailman/listinfo/u-boot
