Re: BeagleBone Black , u-boot, and zImage

[Denys Dmytriyenko <denys@ti.com>]

On Thu, Aug 14, 2014 at 10:09:01PM +0200, Carlos Rafael Giani wrote:
> On 08/14/2014 10:04 PM, Denys Dmytriyenko wrote:
> >On Thu, Aug 14, 2014 at 09:53:34PM +0200, Carlos Rafael Giani wrote:
> >>Hello,
> >>
> >>after building a rootfs for the Beaglebone Black, I see the
> >>following files in the deploy folder for the machine:
> >>
> >>MLO
> >>u-boot.img
> >>u-boot-spl.bin
> >>zImage
> >>
> >>as well as other symlinks with "-beaglebone" attached to their filenames.
> >>
> >>What should I copy, the SPL bin, or the .img u-boot binary?
> >>Also, u-boot tries to load a uImage, even though a zImage was built.
> >>There is also no uEnv.txt file.
> >>Do I have to write one to be able to let u-boot load the zImage, or
> >>should it work out-of-the-box?
> >Depends on the rootfs image you are building. Most images that are based on
> >core-image-base will take care of deploying necessary pieces into the rootfs.
> >But core-image-minimal is special and very bare-bone, so extra manual steps
> >are required.
> >
> >Regardless of the rootfs image, you'd need MLO and u-boot.img to be located in
> >the first FAT partition of your SD card or eMMC flash.
> >
> >Then, if your rootfs does not already have zImage and the necessary DTB files
> >in the /boot directory, you have to place them there (i.e. core-image-minimal)
> >and you are ready to boot. All the defaults will work for out-of-the-box in
> >this case. No uEnv.txt is necessary, unless you need to do something extra
> >special...
> >
> 
> Oh, I just built core-image-base .
> 
> So I should use the .img and not the SPL .bin? I was wondering if
> the SPL bin is a newer binary that will eventually replace the .img
> one.
> 
> But when I use the .img file, it turns out that it tries to load a
> uImage, even though a zImage was built. Simply setting the bootfile
> env var to "zImage" won't work, because the u-boot script will try
> to boot with the incorrect command.
> 
> I am trying to rule out that something went wrong in my build, that
> something is wrong in my setup. If I build core-image-base , the
> resulting u-boot.img should automatically load a zImage, not a
> uImage, correct?

u-boot-spl.bin, while named weird, is a special SPL binary (i.e. MLO) for UART 
booting - loading u-boot and the rest over serial. They are similar in sizes 
with MLO...

The real u-boot.img should boot zImage by default - make sure you are building 
the correct one from meta-ti. The one named u-boot-ti-staging is preferred, 
but u-boot_2014.07 should also be fine.

-- 
Denys