[U-Boot] U-Boot SPL 2016.09-rc1 on NTC C.H.I.P.

[Boris Brezillon]

Hi,

On Sun, 21 Aug 2016 12:03:19 +0200
Hans de Goede <hdegoede at redhat.com> wrote:

> Hi,
> 
> On 21-08-16 11:01, Marcus Glocker wrote:
> > On Sat, Aug 20, 2016 at 03:05:38PM -0400, Tom Rini wrote:
> >  
> >> On Sat, Aug 20, 2016 at 07:26:19AM +0200, Marcus Glocker wrote:  
> >>> Hello,
> >>>
> >>> While U-Boot SPL 2015.10 works fine on my allwinner,sun5i-r8 board I
> >>> face following issue with U-Boot SPL 2016.09-rc1 on it:
> >>>
> >>> 	bash-4.3# cu -l /dev/cuaU0 -s 115200
> >>> 	Connected to /dev/cuaU0 (speed 115200)
> >>>
> >>> 	U-Boot SPL 2016.09-rc1 (Jul 31 2016 - 16:37:00)
> >>> 	DRAM: 512 MiB
> >>> 	CPU: 1008000000Hz, AXI/AHB/APB: 3/2/2
> >>> 	Trying to boot from NAND
> >>> 	### ERROR ### Please RESET the board ###
> >>>
> >>> Any ideas what change did cause this or where to start looking after?  

Markus, can you share your .config?
I tested the different bits while submitting the NAND driver and the
SPL NAND driver improvements and it was working fine.
I'll try to test 2016.09-rc1 tomorrow.

> >>
> >> You're not talking about mainline when you say v2015.10, are you?  IIRC
> >> the current state of CHIP support in mainline is that we don't have NAND
> >> support so it's not useful just yet.  

That's not the case anymore (the sunxi_nand driver has been merged
recently and is part of 2016.09-rc1). Or at least, you should now be
able to boot uboot from NAND (SPL
+ uboot loaded from NAND).
For the rest (loading a kernel from NAND within u-boot), it's another
story. It should work, but as you might already know, MLC NANDs are
unreliable. We're working on UBI to make those NANDs usable in a
reliable way, but those bits haven't been mainlined in Linux yet
(actually it's not even ready for submission). This is why I want to
keep NAND support disabled on all setup embedding an MLC NAND. AFAIK,
there's not sunxi board with MLC NANDs, so this means disabling NAND on
all sunxi configs.

> >
> > You sure?

The SPL driver was present in 2015.10, but I still doubt you were using
a mainline version of u-boot. It's probably flashed with [1].

> 
> Yes, for one mainline u-boot configs/CHIP_defconfig does not
> select SPL nand support...

That's what I was talking about. Not sure I want to enable booting from
NAND by default until the whole chain (SPL -> UBOOT -> Linux) is really
reliable.

> 
> We have some code in mainline u-boot but the nand code is not complete
> so it never got enabled. Boris Brezillon is working on this and he
> is making good progress.
> 
> Boris what is the status on this ?

Well, the NAND part is ready (the sunxi_nand driver is there and has
been tested, and the SPL driver has been recently improved to
auto-detect the ECC config). The real problem is MLC support in general,
and this is not only impacting sunxi platforms, but all platforms
booting from and MLC NAND.
We're working on this aspect with Richard, and will hopefully have
something to share/submit by the end of the year.

Regards,

Boris

[1]https://github.com/NextThingCo/CHIP-u-boot/tree/nextthing/2015.10/next