Date: Fri, 27 Jun 2014 17:22:02 -0400 From: Lowell Gilbert <freebsd-questions-local@be-well.ilk.org> To: paul beard <paulbeard@gmail.com> Cc: "questions@freebsd.org" <questions@freebsd.org> Subject: Re: what should uname -v be telling me here? Message-ID: <44y4wi3v5x.fsf@be-well.ilk.org> In-Reply-To: <CAMtcK2rh3tSF6brU_JxA1%2Btzzuv8SsEoHf_oxAhcW95NRRpKjQ@mail.gmail.com> (paul beard's message of "Fri, 27 Jun 2014 13:57:06 -0700") References: <CAMtcK2rBDWwu1=4DbKGB_4kDdi5Fz9Mq3%2Bzf_Ph9jTmrCLZpSg@mail.gmail.com> <44lhsi5ugm.fsf@be-well.ilk.org> <CAMtcK2rZzJPaWBnuZ6s2iZyg4_XjE62JBFTo=iUd%2BT_r4_zoew@mail.gmail.com> <20140627223650.25210a53.freebsd@edvax.de> <CAMtcK2rh3tSF6brU_JxA1%2Btzzuv8SsEoHf_oxAhcW95NRRpKjQ@mail.gmail.com>
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paul beard <paulbeard@gmail.com> writes: > On Fri, Jun 27, 2014 at 1:36 PM, Polytropon <freebsd@edvax.de> wrote: >> You need to find out where /boot resides (in my case, >> it's on ad4s1a, which is mounted at /) to identify the boot >> device (or to be precise, the device the kernel has been read >> from). > > > I keep thinking this should be something you ought to be able to > discover without being on console. I realize the BIOS can't be > interrogated but if I knew that the active kernel was ad3:/boot/kernel > or ad2:/boot/kernel, it would be useful. Kind of surprised that > doesn't appear anywhere in dmesg or that it can't be read out of > somewhere. The boot procedure has to load and boot the kernel without having the kernel available to create the device nomenclature. [Kind of obvious, if you think about it.] So interrogating the firmware is the only way the kernel *could* know where it was booted from. That's impossible in the BIOS world, and even if there were a table indicating it in an ACPI table, that would only tell you which disk the bootloader came from, which isn't necessarily where the kernel came from.
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