On Monday 13 February 2017 03:23 PM, Maxime Ripard wrote:
Hi Jagan, Scott,
On Mon, Jan 23, 2017 at 02:46:42PM +0100, Maxime Ripard wrote:
The CHIP Pro is a SoM made by NextThing Co, and that embeds a GR8 SIP, an
AXP209 PMIC, a WiFi BT chip and a 512MB SLC NAND.
Since the first Allwinner device coming whit an SLC NAND that doesn't have
the shortcomings (and breakages) the MLC NAND has, we can finally enable
the NAND support on a board by default.
This is the occasion to introduce a bunch of additions needed imo to be
able to come up with a sane NAND support for our users.
The biggest pain point is that the BROM uses a different ECC and randomizer
configuration than for the rest of the NAND. In order to lessen the number
of bitflips, you also need to pad with random data the SPL image.
Since it's quite tedious to do right (and most users won't be able to
figure it out) and since if it is not done right, it will eventually turn
into an unusable system (which is bad UX), we think that the best solution
is to generate an SPL image that already embeds all this. We'll possible
have to do the same thing for the U-Boot image (at least for the random
padding) on MLC NANDs.
The only drawback from that is that you need to flash it raw, instead of
using the usual nand write, but it's just a different command, nothing
major anyway.
In order to flash it, from a device switched in FEL, on your host:
sunxi-fel spl spl/sunxi-spl.bin
sunxi-fel write 0x4a000000 u-boot-dtb.bin
sunxi-fel write 0x43000000 spl/sunxi-spl-with-ecc.bin
sunxi-fel exe 0x4a000000
And on the board, once u-boot is running (assuming the NAND is already
erased):
nand write.raw.noverify 0x43000000 0 40
nand write.raw.noverify 0x43000000 0x400000 40
nand write 0x4a000000 0x800000 0xc0000
Any objections to merging that?
I've few comments, and answered then as well. Let me comeback with those
rest look OK to me.
thanks!
--
Jagan Teki
Free Software Engineer | www.openedev.com
U-Boot, Linux | Upstream Maintainer
Hyderabad, India.
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