On Monday 18 February 2013 05:05 PM, Afzal Mohammed wrote:
(Resending, since it seems, LAKML doesn't accept patches with subject prefix only as "RFC", but requires "PATCH" prefix also) Hi, This series adds minimal support to boot Linux on platforms having AM43 based SoC's. This is being sent as an RFC to seek opinion about modification in twd to register percpu local timer clock event for scheduler tick in the case of one core SMP. AM43 SoC's are based on ARM Cortex-A9. It is an ARM Cortex-A9 SMP configuration with one core (not uniprocessor configuration). AM43 is similar to AM335x in it's peripheral capabilities, with many of the peripheral register mapping's similar like that of uart.
After looking at the specs, you don't need the SMP mode since ACP isn't being used.
AM43 is in pre-silicon stage and currently there are no public documents. This series has been tested on a pre-silicon platform that emulates AM43 SoC, changes proposed here are minimal - to get it booting. Kernel was directly run without the help of bootloader - Images were directly loaded onto a pre-initialized RAM and ARM registers updated as required for booting. Changes have been made over linux-next (next-20130213) with three "OF" related reverts (which otherwise causes problem in other platforms also) and compiled with omap2plus_defconfig. Multiplatform option was enabled, while most of CONFIG options were deselected for a faster boot. Beagle bone boots as earlier with these changes. An interesting observation is that it may be possible to boot this platform to console without any platform specific modification to proper Kernel (by that I mean excluding DT sources) using Arnd's, "[PATCH,RFC] default machine descriptor for multiplatform", along with a "CLOCKSOURCE_OF_DECLARE" for smp twd.
TWD use for AM437x is also limited because these times stops in low power sates and there you will need broad-cast mechanism which again more of SMP machine feature. So I suggest to use the wakeup timer(GPT1) clock-event instead of local timer for the mentioned reason. Regards, Santosh -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
