Messages in this thread | | | Subject | Re: EFI Boot Stub Early Console | From | Matt Fleming <> | Date | Mon, 19 Mar 2012 08:47:14 +0000 |
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On Sun, 2012-03-18 at 08:10 -0400, Shea Levy wrote: > Hi Matt, > > On 3/18/12 7:21 AM, Matt Fleming wrote: > > I don't think you'll need to use the graphics protocols, you should > > just be able to put something together using the 'output_string' > > function from the EFI simple text output protocol, e.g. something like > > this, https://lkml.org/lkml/2012/3/16/193 > > From the UEFI 2.3.1 spec: > > > Prior to a call to ExitBootServices(), all of the fields of the EFI > > System Table are valid. After an operating system has taken control of > > the platform with a call to ExitBootServices(), only the Hdr, > > FirmwareVendor, FirmwareRevision, RuntimeServices, > > NumberOfTableEntries, and ConfigurationTable fields are valid. > > Doesn't this mean that ConOut can't be used for the earlyprintk, since > 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.
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