Date: Thu, 19 Mar 2015 11:19:32 -0400 From: Paul Mather <paul@gromit.dlib.vt.edu> To: Ian Lepore <ian@FreeBSD.org> Cc: freebsd-arm <freebsd-arm@freebsd.org> Subject: Re: How to use u-boot-beaglebone port? Message-ID: <33BDB9B4-2226-4B51-A7CF-BA6D0277E92A@gromit.dlib.vt.edu> In-Reply-To: <1426623518.62241.11.camel@freebsd.org> References: <17B779D7-2962-4455-9062-51411F316648@gromit.dlib.vt.edu> <986F5E5D-C784-4BEF-81E3-49A9F27C0E8F@kientzle.com> <1426534773.95554.15.camel@freebsd.org> <F016BFCC-8CAA-4AE6-8142-40A9B69BD707@gromit.dlib.vt.edu> <1426607993.25614.9.camel@freebsd.org> <F7EAB879-E70D-4ED5-8C5B-3B21FBED123A@gromit.dlib.vt.edu> <1426617259.62241.3.camel@freebsd.org> <C9CD0919-10D4-4F7A-B90B-157762189DAD@gromit.dlib.vt.edu> <1426623518.62241.11.camel@freebsd.org>
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On Mar 17, 2015, at 4:18 PM, Ian Lepore <ian@FreeBSD.org> wrote: > On Tue, 2015-03-17 at 15:30 -0400, Paul Mather wrote: >> On Mar 17, 2015, at 2:34 PM, Ian Lepore <ian@freebsd.org> wrote: >> >>> On Tue, 2015-03-17 at 14:21 -0400, Paul Mather wrote: >>>> On Mar 17, 2015, at 11:59 AM, Ian Lepore <ian@freebsd.org> wrote: >>>> >>>>> On Tue, 2015-03-17 at 09:55 -0400, Paul Mather wrote: >>>>>> On Mar 16, 2015, at 3:39 PM, Ian Lepore <ian@FreeBSD.org> wrote: >>>>>> >>>>>>> On Sun, 2015-03-15 at 19:57 -0700, Tim Kientzle wrote: >>>>>>>>> On Mar 12, 2015, at 5:59 PM, Paul Mather <paul@gromit.dlib.vt.edu> wrote: >>>>>>>>> >>>>>>>>> Has anyone successfully used the sysutils/u-boot-beaglebone port? >>>>>>>>> >>>>>>>>> I managed to build [1] and install it today. I tried to install it to the SD card FAT partition, as per the README, and the result was an unbootable system. >>>>>>>>> >>>>>>>>> When I copied the u-boot.img file as u-boot.img (rather than the bb-uboot.img as suggested in the README), I got it to start up to the "U-Boot#" prompt. >>>>>>>> >>>>>>>> >>>>>>>> Apparently, no one ever patched the port to use bb-uboot.img and bb-ubldr >>>>>>>> as the name. >>>>>>>> >>>>>>>> I did this in Crochet when I was experimenting with having multiple >>>>>>>> U-Boots on a single SD card image. That experiment was to try >>>>>>>> to see what would be required to build single images that booted on >>>>>>>> multiple different devices. >>>>>>>> >>>>>>> >>>>>>> When I created the u-boot-beaglebone port I specifically removed that >>>>>>> bb- prefix stuff, because there will never be a unified image that runs >>>>>>> on both rpi and beaglebone [*]. I had hoped someone would update >>>>>>> crochet to use the new ports and this is one of the minor changes that >>>>>>> would be needed on the crochet side. >>>>>>> >>>>>>> -- Ian >>>>>>> >>>>>>> [*] Because armv6 != armv7 in this case. While armv6 is synonymous with >>>>>>> armv7 for most purposes in freebsd, the rpi is the exception to that in >>>>>>> that it really IS armv6, and that leads to the kernel being built with >>>>>>> different cache maintenance routines that don't work on armv7. >>>>>> >>>>>> >>>>>> Does the sysutils/u-boot-beaglebone boot the BeagleBone Black for you? As I reported earlier in the start to this thread, I can't get it to boot the system for me. >>>>>> >>>>>> I've copied MLO, u-boot.img, and /boot/ubldr to the FAT partition, but I just get to where U-Boot loads ubldr and then pauses before starting over again in a loop. >>>>>> >>>>>> Are there some other files that need to be copied to the FAT partition, or are those three files, plus the defaults compiled into u-boot.img sufficient to boot the BeagleBone Black from SD card? >>>>>> >>>>>> Cheers, >>>>>> >>>>>> Paul. >>>>> >>>>> Yep, it works for me on BBW and BBB. The only time I've seen a totally >>>>> silent lockup like that is when the loadaddr variable in the uboot env >>>>> didn't match the UBLDR_LOADADDR value when ubldr was compiled. For BB, >>>>> those values are usually 0x88000000, iirc. If you do a "readelf -a >>>>> ubldr" on your build system you should see a line like >>>>> >>>>> Entry point address: 0x88000074 >>>>> >>>>> and whatever it is should be your uboot loadaddr + 0x74. >>>> >>>> My current /boot/ubldr entry point address appears to be 0x1000074, which seems to be derived from the default set in /usr/src/sys/boot/arm/uboot/Makefile. >>>> >>>> What would I need to put in uEnv.txt to get such a ubldr to boot via the sysutils/u-boot-beaglebone port files? Would I just need to have the single line "loadaddr=1000000" in uEnv.txt, or would I have to reproduce the whole environment embedded into u-boot.img? (Do the settings in uEnv.txt replace entirely those in u-boot.img?) >>>> >>>>> You should only need MLO, u-boot.img, and ubldr on the fat partition. >>>>> (There is an optional uEnv.txt that can be there, but it's not required >>>>> to boot.) >>>> >>>> It looks like your supposition above is correct and a mis-matching loadaddr variable is likely to blame. >>>> >>>> Is a loadaddr of 0x1000000 correct for a BBB? >>>> >>>> Cheers, >>>> >>>> Paul. >>> >>> The address is a physical ram address, so you can't just make up any >>> number -- there has to be actual ram at that address on the board, and >>> the address must not conflict with where u-boot itself is loaded and >>> where the kernel will be loaded. >>> >>> I think the BB ram starts at 0x80000000, so 0x10000000 won't work. The >>> right fix would be to recompile ubldr with UBLDR_LOADADDR set to >>> 0x88000000. >> >> What is the best place to set this? >> >> My current /boot/ubldr is the product of a native build. I looked through the source code and it seems the only place that sets this is /usr/src/sys/boot/arm/uboot/Makefile, where we have this: >> >> # Address at which ubldr will be loaded. >> # This varies for different boards and SOCs. >> UBLDR_LOADADDR?= 0x1000000 >> >> >> The "?=" makes me think this is just a fallback default to stop the build from breaking and that UBLDR_LOADADDR needs to be set accordingly for each different ARM system. If that is so, and we know what the UBLDR_LOADADDR should be for the BBB (or at least that the default won't work because there's no RAM there on the BBB), then why doesn't -CURRENT set a value such that a working ubldr is built? (I'd prefer ubldr not to be built at all than a non-working version be built.) >> >> I presume I could set this in /etc/make.conf on my BBB. Could I put it in my BBB kernel config file (which seems a good place for it)? >> >> Many thanks for the help and information. I plan to rebuild /boot/ubldr with a UBLDR_LOADADDR of 0x88000000. >> >> Cheers, >> >> Paul. > > The value needs to be different for every system/board, so the value in > the makefile is just a placeholder to let test builds finish. It can't > go into the kernel config because ubldr is built with world, not kernel. Maybe the value should be changed to 0xdeadbeef to make it more obvious it is just a placeholder? :-) > If you only build for BBB on your build host, you could just put the > value in /etc/make.conf because it doesn't mean anything for an x86 > build. I think you can also set it as an env var. If you build for > more than one arm board then you probably need a wrapper script that > supplies such per-board values to the build. > > The crochet script is one such wrapper, appropriate for people who want > to occasionally build a complete image. If you're doing development > work where you need to repeatedly rebuild, another type of wrapper > script (and other developer info) can be found here: > > https://wiki.freebsd.org/FreeBSD/arm/crossbuild Thanks for the info and the crossbuild link (which documents the UBLDR_LOADADDR issue under "Pesky details":). The crossbuild Wiki page looks very good. Now I have an installed BBB and RPi, I usually try to do native build updates. I have a script for rebuilding world and kernel, and I'll add an appropriate "-DUBLDR_LOADADDR=..." to the make invocation in that. Cheers, Paul.home | help
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