Date: Thu, 18 Oct 2012 21:13:29 -0400 From: Justin Hibbits <chmeeedalf@gmail.com> To: Rob Ballantyne <robballantyne3@gmail.com> Cc: freebsd-ppc@freebsd.org Subject: Re: Open Firmware available after kernel is running? Message-ID: <20121018211329.6bf8f5df@narn.knownspace> In-Reply-To: <CAKLrb5e9JiH8=VZfXuWmqSH4V_Nggk3A_Yx1=2kGcN5n4TPsAg@mail.gmail.com> References: <CAKLrb5e9JiH8=VZfXuWmqSH4V_Nggk3A_Yx1=2kGcN5n4TPsAg@mail.gmail.com>
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On Thu, 18 Oct 2012 12:27:51 -0700 Rob Ballantyne <robballantyne3@gmail.com> wrote: > Hi All, > > I was wondering if the Open Firmware client interface is available > after the kernel is booted. > > For example, could I write a kernel module that accessed Open > Firmware via the client interface? I'm supposing that there is likely > a static variable that points to the client interface that is stashed > there in early startup -- I understand open firmware passes it's own > address to the client program on the stack. However, I'm also > guessing that the kernel may have taken completely over the machine in > a way that doesn't permit access to the OF client interface. > > It appears that ~/sys/powerpc/aim/locore64.S stashes the entry point > for OF in openfirmware_entry - is this still usable after the system > is up and running? > > Thanks, > > Rob Hi Rob, Yes, Open Firmware is available after bootup. sys/dev/openfirm provides a device interface for Open Firmware that you can look at as a reference. I'm hoping to eventually be able to quiesce Open Firmware on PowerPC, as it may be necessary for certain features (speed change on PowerBooks and sleep) to work. This is still a ways off though. - Justin
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