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) and instead of a hang we just don't do the follow-up steps. That should let all the existing scripts work, yes?