>From further tinkering, I discovered that my Pi was only recognizing 128 MB of RAM until I switched to using the DTB and fixup.dat files from Raspbian. Seems that those /boot/ files should be kept in sync.
Thanks for all your work on this new platform! On March 5, 2017 3:36:16 AM EST, Jonathan Gray <j...@jsg.id.au> wrote: >On Sun, Mar 05, 2017 at 09:23:13AM +0100, Otto Moerbeek wrote: >> On Sun, Mar 05, 2017 at 07:00:46PM +1100, Jonathan Gray wrote: >> >> > On Sun, Mar 05, 2017 at 08:37:30AM +0100, Otto Moerbeek wrote: >> > > On Sat, Mar 04, 2017 at 06:40:57PM -0500, Joe Gidi wrote: >> > > >> > > > After jsg@ mentioned that booting a Raspberry Pi 3 from a USB >device >> > > > might be >> > > > possible, I decided to find out how deep the rabbit hole is. >> > > > As it turns out, >> > > > it's currently a bit convoluted, but it can be made >> > > > to work with OpenBSD. >> > > > First off, USB boot support is just now getting fully ironed >out. >> > > > You'll need >> > > > to update the firmware on your Pi to make it work. I >> > > > installed the latest >> > > > (2017-03-02) Raspbian image to an SD card and >> > > > booted the Pi from that. While >> > > > booted in Raspbian, update the >> > > > firmware: >> > > > >> > > > sudo apt-get update >> > > > sudo apt-get >> > > > install rpi-update >> > > > sudo rpi-update >> > > > >> > > > It's then necessary to actually enable USB >> > > > boot support. Add the >> > > > following 2 lines to /boot/config.txt to enable USB boot >> > > > mode and set >> > > > a 5-second timeout to allow time for USB device initialization: >> > > > program_usb_boot_mode=1 >> > > > program_usb_boot_timeout=1 >> > > > >> > > > NOTE: Apparently these >> > > > variables are set in the Pi's OTP memory, which >> > > > means once they're set, they >> > > > can't ever be unset. >> > > > >> > > > Reboot for the changes to take effect. At this point the >> > > > Pi should be >> > > > ready to support USB booting. >> > > > >> > > > While you still have a working >> > > > Raspbian install, grab a copy of the >> > > > /boot/bootcode.bin and /boot/start.elf >> > > > files for later use; apparently >> > > > we need these special versions of those two >> > > > files for USB boot >> > > > support. At this point we're done with Raspbian and can >> > > > shut it down >> > > > to install OpenBSD. >> > > > >> > > > Next, write the OpenBSD miniroot60.fs to an >> > > > SD card, plug in your USB >> > > > drive, and boot the Pi. You should be greeted with >> > > > the usual OpenBSD >> > > > installer, and you should be able to install to your USB >> > > > drive >> > > > (probably sd0). Once the installer is done, run 'halt', unplug >the Pi, >> > > > and remove the SD card and USB drive. >> > > > >> > > > To make your USB drive bootable, you'll >> > > > need to plug it into another >> > > > system and mount its 'i' partition (the FAT32 >> > > > boot partition) to make >> > > > a few changes. Replace the bootcode.bin and start.elf >> > > > files with the >> > > > ones from Raspbian, and add the u-boot.bin file from the 'i' >> > > > partition >> > > > of your miniroot60.fs SD card. >> > > > >> > > > With those changes made, your Pi >> > > > should be able to boot OpenBSD >> > > > directly from a USB drive with no SD card >> > > > needed. Note that it seems >> > > > to take around 10 seconds for the Pi to reach the >> > > > OpenBSD bootloader >> > > > and fire up the kernel. >> > > > >> > > > Hope this information is helpful >> > > > to someone... >> > > > >> > > > -- >> > > > Joe Gidi >> > > > j...@entropicblur.com >> > > > >> > > > "You cannot buy skill." >> > > > -- Ross Seyfried >> > > >> > > Thanks, I'll try this out soon, >> > > >> > > Some notes of things I saw when trying to boot from a sd-card >using >> > > various a USB devices to install to: >> > > >> > > Some USB devices do seem to hang the rpi3 sometimes while u-boot >is >> > > scanning the usb bus, in my case an old USB flash stick. >> > > >> > > With a disk enclosure (2.5" usb bus powered with spinning disk), >the >> > > hangs did not occur. But I saw another problem that looked to be >> > > caused by the reset of the usb bus while the kernel was booting >(from >> > > sd-card). The disk enclosure did not get recognized in time when >the >> > > kernel reached the ask root device questions, making it imposible >to >> > > select the usb drive as boot device. >> > > >> > > I manged to boot the machine using an externally powered >enclosure >> > > with a 3.5 disk. I'll be buying a SSD today to see how that goes. >> > > >> > > -Otto >> > > >> > >> > You don't need to bother with linux, the files are in the >> > raspberrypi-firmware package with version 1.20170215. And the next >> > snapshot will include the newer firmware. >> > >> > Though that will take a few days, due to -current moving to 6.1 a >> > xenocara build will have to be done as well and that tends to >trigger >> > problems with stuck and segfaulting processes. >> >> Will the fidding with >> >> > > program_usb_boot_mode=1 >> > > program_usb_boot_timeout=1 >> >> still be neccesary? >> >> -Otto >> > >Unless the parts of the miniroot/ramdisk which create config.txt are >changed to do so yes. > >I'm not clear on the downsides of irreversibly setting these otp bits. >Not being able to use older firmware versions? > >From what I've read the boot rom will still try to load from the >sd slot first before trying to probe usb when it is set. -- Sent from my Android device with K-9 Mail. Please excuse my brevity.
