[U-Boot] fsl_elbc_nand.c and nand_boot_fsl_elbc.c for large page devices
So I have a few quick questions/observations.
1. I don't see anywhere that the AL (address length, or number of address cycles) can be set to anything other than 2. It appears to be hard coded in both files.
2. nand_boot_fsl_elbc.c uses ECCM = 1 for large page devices, but I don't see a place where fsl_elbc_nand.c sets ECCM to 1 for similar devices. The result, I believe, is that if I try to write a new u-boot into the large page flash device it will be written with ECCM = 0. When I try to reset the board it will be read with ECCM = 1 (inside of nand_boot_fsl_elbc.c) resulting in an ecc error in the LTESR.
I would be more than happy to help make these changes (if necessary) but I don't know if there is already a fix in the works, or if perhaps I am wrong in these two assumptions.
Ron
On Tue, Oct 14, 2008 at 01:24:09PM -0700, Ron Madrid wrote:
- I don't see anywhere that the AL (address length, or number of
address cycles) can be set to anything other than 2. It appears to be hard coded in both files.
Correct. AFAICT, setting AL to anything less than 2 is just an optimization for small flashes. Linux will make that optimization, but the way NAND devices are currently probed in u-boot makes that awkward (no opportunity to run code after size is known, but before nand_scan_tail).
- nand_boot_fsl_elbc.c uses ECCM = 1 for large page devices, but I
don't see a place where fsl_elbc_nand.c sets ECCM to 1 for similar devices.
That looks like a bug.
-Scott
So is there a particular convention for which bytes should be used within the OOB area for an ECC? I've looked for information on this but haven't been able to come up with anything.
--- On Thu, 10/16/08, Scott Wood scottwood@freescale.com wrote:
From: Scott Wood scottwood@freescale.com Subject: Re: [U-Boot] fsl_elbc_nand.c and nand_boot_fsl_elbc.c for large page devices To: "Ron Madrid" ron_madrid@sbcglobal.net Cc: u-boot@lists.denx.de Date: Thursday, October 16, 2008, 12:17 PM On Tue, Oct 14, 2008 at 01:24:09PM -0700, Ron Madrid wrote:
- I don't see anywhere that the AL (address
length, or number of
address cycles) can be set to anything other than 2.
It appears to be
hard coded in both files.
Correct. AFAICT, setting AL to anything less than 2 is just an optimization for small flashes. Linux will make that optimization, but the way NAND devices are currently probed in u-boot makes that awkward (no opportunity to run code after size is known, but before nand_scan_tail).
- nand_boot_fsl_elbc.c uses ECCM = 1 for large page
devices, but I
don't see a place where fsl_elbc_nand.c sets ECCM
to 1 for similar
devices.
That looks like a bug.
-Scott
Ron Madrid wrote:
So is there a particular convention for which bytes should be used within the OOB area for an ECC? I've looked for information on this but haven't been able to come up with anything.
The 8313 manual says that when booting from NAND, it expects ECCM 0 on small page and ECCM 1 on large page.
BTW, can you get your e-mail client to wrap long lines?
-Scott
participants (2)
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Ron Madrid -
Scott Wood