Hi, On 11/17/2014 03:52 PM, Tom Rini wrote: > On Thu, Nov 13, 2014 at 07:38:50PM +0100, Hans de Goede wrote: >> Hi, >> >> On 11/13/2014 07:34 PM, Tom Rini wrote: >>> On Thu, Nov 13, 2014 at 07:08:59PM +0100, Hans de Goede wrote: >>>> Hi all, >>>> >>>> So as you know I've been working on getting mainline u-boot to boot the >>>> older android derived linux-sunxi kernels, as some people need features >>>> not yet in mainline, and I would like there to be only one u-boot for both. >>>> >>>> I had this working a while ago, but recently it broke, this is caused by >>>> config_distro_defaults.h setting CONFIG_OF_LIBFDT, if I undef that >>>> after including config_distro_defaults.h things work again. >>>> >>>> I do not know if CONFIG_OF_LIBFDT is a recent addition to >>>> config_distro_defaults.h, >>>> or if something else broke things. But if I do not undef it, boot fails >>>> with: >>>> >>>> sun7i# bootm start 0x48000000 >>>> ## Booting kernel from Legacy Image at 48000000 ... >>>> Image Name: Linux-3.4.75.sun7i+ >>>> Image Type: ARM Linux Kernel Image (uncompressed) >>>> Data Size: 3966672 Bytes = 3.8 MiB >>>> Load Address: 40008000 >>>> Entry Point: 40008000 >>>> Verifying Checksum ... OK >>>> Could not find a valid device tree >>> >>> My hunch is that we've got more fall-out from Simon's re-org of the >>> bootm code ages ago. It should be valid to try and boot a kernel >>> without a device tree and other parts of the code base (for example >>> arch/arm/lib/bootm.c) still do a FDT-or-ATAGS dance for example. >> >> That is good news, because ideally upstream u-boot build with >> OLD_SUNXI_KERNEL_COMPAT should be able to boot old disk images without >> needing them to modify their boot.scr, which requiring bootm 0xfoo - - >> would do. >> >> So maybe check if there is a third argument to bootm, and if there >> is not still try the dance for finding one appended in various ways, >> and if that fails continue normally (where as with the third >> argument present this of course needs to stay an error) ? > > So first, I have to take it back. This isn't a behavior change > introduced by Simon's re-org (Sorry Simon!). This is a real long > standing "feature". I am agreeable to doing whatever the lowest impact > change would be to allow a non-DT tree to boot with CONFIG_OF_LIBFDT > set. I'm thinking we turn the error into a warning (so that it's still > clear to the user that they booted without a DT, for when they didn't > mean to do that)
I was thinking along the same lines, except that when a third argument is explicitly given to u-boot, and then we do not find a dt, that should be treated as an error IMHO. I've put whipping up a patch for this on my todo list. > and instead of a hang we just don't do the follow-up > steps. Actually not doing the follow-up steps (as in bootm execution steps) is what we currently do. What we want to do is skip further dt processing / prepping, but otherwise still continue with trying to boot the kernel. > That should let all the existing scripts work, yes? With the amendments done above, I think so, yes. But the proof is in the pudding, iow I'll find out when I go work on that patch. Regards, Hans _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
