Messages in this thread | | | Subject | Re: [linux-sunxi] Re: [RFC PATCH 0/9] mtd: nand: add sunxi NAND Flash Controller support | From | Henrik Nordström <> | Date | Tue, 21 Jan 2014 19:13:31 +0100 |
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lör 2014-01-18 klockan 05:46 -0800 skrev Boris BREZILLON:
> Do you know which mode are used (X ECC strength / 512 or 1024 bytes ?) > and > when they are are selected (does it depend on the connected NAND > chip ?) ?
It seems to blindly try some modes until something usable is found. Varying both chip address size and ECC layout.
Sorry I do not have the exact details on the ECC modes used. Only analyzed nand controller command traces of A13 BROM trying to load boot0. The trace can be found at https://github.com/hno/Allwinner-Info/blob/master/NAND/boot0/A13-brom
> > > > - boot0 code is stored only on the first ECC block of each > page (1024 > > bytes + ecc bytes) > > No, it reads a whole page at a time in sequental mode > (data,ecc,data,ecc,data,ecc,data,ecc...). > > > Are you sure ? > This thread says that only the first 1024 bytes of data (+ 96 bytes of > ECC) of each page are used:
yes I am sure. There was no page access commands between the sectors, only linear read of data,ecc,data,ecc.
> I'm not a big fan of this approach, because the real media is an MTD > (NAND) device, > not a block device.
Hit implementation acks this by not providing a block device.
> iirc there is an interface for dynamically selecting ECC mode > and other > parameers. Or maybe that's only u-boot mtd? > > > Haven't found anything authorizing per partiton ECC config, though > this could be an > enhancement of the MTD framework.
u-boot have user selectable ecc scheme for some boards. I.e. omap3 based ones.
other boards select based on NAND size etc.
Regards Henrik
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