On 19.04.2009 04:23, Kevin O'Connor wrote:
On Sat, Apr 18, 2009 at 09:40:56PM -0400, Kevin O'Connor wrote:
On Sat, Apr 18, 2009 at 09:14:06PM -0400, Kevin O'Connor wrote:
On my epia-cn machine, it takes coreboot-v2 8.7 seconds to launch SeaBIOS. It looks like about 4 seconds is lost due to a reboot half-way through the startup - I'm guessing a watchdog timer is kicking in. As to why it takes so long to boot - maybe rom caching is off?
Nope - looks like calibrate_tsc is taking 2.9 seconds to calibrate:
00.608: Jumping to coreboot. 00.609: coreboot-2.0.0-epiacn Sat Apr 18 21:34:47 EDT 2009 booting... 00.612: Calibrating delay loop...
If I add the following to Config.lb:
option CONFIG_TSC_X86RDTSC_CALIBRATE_WITH_TIMER2=1
then the problem goes away - coreboot takes only 1.8 seconds.
Still, 1.8 seconds can surely be trimmed down further. Our early startup code has some variants performing totally nonsensical operations which easily account for 200 ms or more. (One variant does nothing except switch CAR on, fill the cache slowly, switch CAR off again and hope that CAR works although it is switched off.) The big problem here is that early startup is considered magic and the accumulated cruft is legendary.
Regards, Carl-Daniel