[U-Boot] [PATCH] armv8/ls1043a: Add the OCRAM initialization

[Mingkai Hu]

> -----Original Message-----
> From: york sun
> Sent: Tuesday, October 25, 2016 12:15 AM
> To: Prabhakar Kushwaha <prabhakar.kushwaha at nxp.com>; Pratiyush
> Srivastava <pratiyush.srivastava at nxp.com>; u-boot at lists.denx.de; Mingkai
> Hu <mingkai.hu at nxp.com>
> Cc: Hou Zhiqiang <Zhiqiang.Hou at freescale.com>
> Subject: Re: [PATCH] armv8/ls1043a: Add the OCRAM initialization
> 
> On 10/23/2016 06:59 AM, Prabhakar Kushwaha wrote:
> > Hi York,
> >
> >
> >> -----Original Message-----
> >> From: york sun
> >> Sent: Saturday, October 22, 2016 1:39 AM
> >> To: Prabhakar Kushwaha <prabhakar.kushwaha at nxp.com>; Pratiyush
> >> Srivastava <pratiyush.srivastava at nxp.com>; u-boot at lists.denx.de;
> >> Mingkai Hu <mingkai.hu at nxp.com>
> >> Cc: Hou Zhiqiang <Zhiqiang.Hou at freescale.com>
> >> Subject: Re: [PATCH] armv8/ls1043a: Add the OCRAM initialization
> >>
> >> On 10/16/2016 10:35 PM, Prabhakar Kushwaha wrote:
> >>> Hi Mingkai,
> >>>
> >>>> -----Original Message-----
> >>>> From: Pratiyush Srivastava [mailto:pratiyush.srivastava at nxp.com]
> >>>> Sent: Wednesday, October 12, 2016 5:46 PM
> >>>> To: u-boot at lists.denx.de
> >>>> Cc: york sun <york.sun at nxp.com>; Prabhakar Kushwaha
> >>>> <prabhakar.kushwaha at nxp.com>; Pratiyush Srivastava
> >>>> <pratiyush.srivastava at nxp.com>; Hou Zhiqiang
> >> <Zhiqiang.Hou at freescale.com>
> >>>> Subject: [PATCH] armv8/ls1043a: Add the OCRAM initialization
> >>>>
> >>>> Clear the content to zero and the ECC error bit of OCRAM1/2.
> >>>>
> >>>> The OCRAM must be initialized to ZERO by the unit of 8-Byte before
> >>>> accessing it, or else it will generate ECC error. And the IBR has
> >>>> accessed the OCRAM before this initialization, so the ECC error
> >>>> status bit should to be cleared.
> >>>>
> >>>> Signed-off-by: Pratiyush Srivastava <pratiyush.srivastava at nxp.com>
> >>>> Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou at freescale.com>
> >>>> Signed-off-by: Prabhakar Kushwaha <prabhakar.kushwaha at nxp.com>
> >>>> ---
> >>>
> >>> This requirement is for both ls1043 and ls1088a.  was this patch
> >>> taken care
> >> during ls1043a upstreaming
> >>> If not, how it is being taken care for ls1043a.  Same approach can
> >>> be used for
> >> ls1088a
> >>>
> >>
> >> I wonder why we don't see ECC errors before this patch. We have
> >> LS1043A boots on NAND, SD.
> >>
> >
> > OCRAM has a requirement of initializing before first time "read".
> > If user reads OCRAM before **initializing**; ECC error will come.  (u-boot is
> not handling this error for now).
> >
> > I can only guess the reason of not seeing this error as OCRAM never read
> before any write.
> > Even in case of Stack, data is first written and then read.
> >
> 
> Is there a case you want to read from OCRAM before writing anything to it?
> Why don't we need to do so for SPL or LSCH3?
> 

Hi York,

For secure boot case, the bootrom uses the OCRAM as workspace but does not
Cleare the after the using, which will trigger this issue.

Thanks,
Mingkai