Messages in this thread | | | Date | Tue, 20 Mar 2012 09:43:18 -0700 | From | "H. Peter Anvin" <> | Subject | Re: EFI Boot Stub Early Console |
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On 03/20/2012 08:45 AM, Maarten Lankhorst wrote: > Hey Matt, > > Op 19-03-12 17:03, Matt Fleming schreef: >> On Mon, 2012-03-19 at 15:56 +0000, Alan Cox wrote: >>>>> any bootloader (including the bootstub) will call ExitBootServices() >>>>> before any printk'ing actually happens?? Or am I misunderstanding the >>>>> spec somehow? I suppose I could just try it and see what happens... >>>> Oops. Good point, that isn't going to work. >>> Surely it works fine if you are using bootstub directly from EFI ? >> Yeah, up until the point you call ExitBootServices(), which is very >> early in the boot process. After that you can't rely on the validity of >> the console pointers in the system table. >> > I think my system spontaneously rebooted when I tried to > do some output right after ExitBootServices when debugging > the efi stub, so not only is this unreliable, it will fail to boot for > at least some systems out there. >
I would expect it to fail for just about any system.
-hpa
-- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.
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