Date: Wed, 13 Apr 2016 17:36:41 +0200 From: Bernd Walter <ticso@cicely7.cicely.de> To: Ian Lepore <ian@freebsd.org> Cc: Tim Kientzle <tim@kientzle.com>, Hal Murray <hmurray@megapathdsl.net>, freebsd-arm <freebsd-arm@freebsd.org> Subject: Re: Booting FreeBSD on BeagleBone Black from microSD by default Message-ID: <20160413153641.GB31903@cicely7.cicely.de> In-Reply-To: <1460470770.52955.14.camel@freebsd.org> References: <20160411040655.632D3406076@ip-64-139-1-69.sjc.megapath.net> <3BC5A04D-79DD-4820-A44F-B0A921D2FAA9@kientzle.com> <1460470770.52955.14.camel@freebsd.org>
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On Tue, Apr 12, 2016 at 08:19:30AM -0600, Ian Lepore wrote: > On Mon, 2016-04-11 at 06:33 -0700, Tim Kientzle wrote: > > > On Apr 10, 2016, at 9:06 PM, Hal Murray <hmurray@megapathdsl.net> > > > wrote: > > > > > > > > > Does anybody have the recipe for setting things up so that power on > > > boots > > > from the microSD card without holding down the button? > > > > If the ROM cannot boot from eMMC, it will try to boot from microSD. > > > > The easiest way to make the eMMC not bootable is to zero out the > > boot sectors using dd: > > > > dd if=/dev/zero of=<eMMC device> count=100 > > > > Of course, this makes the eMMC entirely unusable. I think you > > can then reformat the eMMC (make sure it does not have a FAT > > partition and does not have boot blocks) so it can be used without > > the ROM trying to boot from it. > > > > This way, the ROM will load U-Boot from microSD. > > > > > > > > I'm pretty sure it will be simple after I know how to do it. > > > Google found info on the idea, but I couldn't find the file that > > > needs editing. It's off in uBoot land. > > > > Even if the ROM loads U-Boot from eMMC, the default Linux > > U-Boot setup on the eMMC can be configured to then load > > the Linux kernel from microSD. > > > > If you install the FreeBSD version of U-Boot to eMMC, you might be > > able to > > do the same thing. Personally, I find the recipe above much > > simpler. > > > > Cheers, > > > > Tim > > No need to zero out the onboard emmc or mess with its too-complicated > linux-centric env vars... The AM335x ROM boot code loads u-boot from > the first FAT partition it finds with the active/bootable flag set. > Normally that's the emmc, but you can turn it off and then it'll look > for a partition on the external sdcard. Once you've booted to freebsd > normally, do > > gpart unset -a active -i 1 mmcsd1 > > And now it will boot from the sdcard unless you turn the active flag > back on on the emmc. Good to know - that's so much better than erasing the old content, -- B.Walter <bernd@bwct.de> http://www.bwct.de Modbus/TCP Ethernet I/O Baugruppen, ARM basierte FreeBSD Rechner uvm.
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