-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Tue, 6 Aug 2013 17:31:04 -0500 Rob Herring <[email protected]> wrote:
> On Tue, Aug 6, 2013 at 8:51 AM, Dennis Gilmore <[email protected]> > wrote: > > -----BEGIN PGP SIGNED MESSAGE----- > > Hash: SHA1 > > > > On Tue, 06 Aug 2013 07:53:14 -0500 > > Rob Herring <[email protected]> wrote: > > > >> On 08/05/2013 10:53 PM, Andy Green wrote: > >> > On 6 August 2013 11:05, Rob Herring <[email protected]> > >> > wrote: > >> >> -----BEGIN PGP SIGNED MESSAGE----- > >> >> Hash: SHA1 > >> >> > >> >> On 08/05/2013 04:41 PM, Dennis Gilmore wrote: > >> >>> Hi all, > >> >>> > >> >>> As part of the unified features in u-boot thread I said that I > >> >>> would work to get distros to agree to a common location that > >> >>> u-boot will be able to assume exists for it to transparently > >> >>> load dtbs from for us. > >> >>> > >> >>> I would like to propose /boot/dtb/ > >> >>> > >> >>> I think it needs to be in /boot/ to allow for booting from > >> >>> systems with / and /boot on separate partitions. I believe > >> >>> Ubuntu and hence Debian put them in /lib somewhere today. > >> >>> Fedora puts them in /boot/dtb-<kernel version>. im not sure > >> >>> where the other distros put them. > >> >> > >> >> A DTB should not be tied to a kernel version. I realize that is > >> >> a reality for some boards, but lets not encourage that. There > >> >> are also plans to remove dts files from the kernel. > >> >> > >> >>> > >> >>> I think that until they are decoupled from the kernel Fedora > >> >>> would have /boot/dtb be a symlink to the latest installed > >> >>> kernel. once its decoupled it would be the location where the > >> >>> dtbs are installed. > >> >> > >> >> If /boot/dtb is THE dtb to use, does more than that need to be > >> >> specified (at least from a bootloader perspective). > >> > > >> > If I understood you correctly, that'd be needlessly limiting one > >> > image to one board. > >> > > >> > Consider an SD Card + CONFIG_ARCH_MULTIPLATFORM kernel you can > >> > pull out and plug in to use on a variety of different boards, the > >> > bootloader would need to identify the correct dtb and pass it to > >> > the kernel. > >> > >> Ah, right. I misread this. > >> > >> So do we assume the dtb file names are known by the bootloader for > >> a board or standardized in some way? > > > > Yes, u-boot today on omap had a find_fdt function that provides the > > name for the expected dtb for the board that its running on. as > > part of the unified u-boot platform ive proposed, u-boot would > > transparently load the dtb for us and pass it to the kernel. just > > like highbank does today. > > How would you provide a dtb to override the firmware version of the > dtb? Of course the firmware version is perfect and will never have to > updated, but suppose it does need to be overridden? We really want to > load the dtb if present somewhere on disk, otherwise use the firmware > version. if using sysboot or pxe you would add a fdt line to your config then the dtb would be loaded from filesystem or network and used. if you use boot.scr or uEnv.txt ou would need to load the new dtb to ${fdt_addr} Dennis -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) iEYEARECAAYFAlIBg9AACgkQkSxm47BaWfd/AgCfV4fOD1FRKKNoxGvqEWaKQKyd ICQAoLKFcDTmLsm2QvrT4f6xe7JnppCJ =kxiq -----END PGP SIGNATURE----- _______________________________________________ cross-distro mailing list [email protected] http://lists.linaro.org/mailman/listinfo/cross-distro
