[U-Boot] u-boot preventing access to NAND chip on imx28evk board

[U-Boot] u-boot preventing access to NAND chip on imx28evk board

[Bill]

All,

     I'm needing to access the NAND chip on the imx28evk board with the 
Linux (Freescale Kernel - FSL).  I've compiled a recent version of the 
mainstream u-boot with the NAND switches and U-boot works fine.  The 
U-boot also allows me access to the NAND chip and also boots the FSL 
kernel just fine.  However, once the kernel is running, it can not "see" 
the /dev/mtdX devices.

     However, if I boot the *same* kernel directly (no U-boot - and 
attach boot-stream to kernel) the FSL kernel works fine and can gets the 
/dev/mtdX etc devices.  I tracked this down to a couple of differences 
that are output during the kernel booting process.  I also can replicate 
this problem with no NAND chip in the socket. I can do this by using the 
script that comes with the imx28evk that is used for formatting the 
SDCard for booting.  The mk_mx28_sd script writes the uboot, kernel, and 
rootfs to an SDcard depending on the parameters.  So if I write the 
uboot to the card and boot the imx28 from uboot and network boot uImage 
I get the error.  If I write the kernel to the card and boot the imx28 
with it I get no error (Using the same kernel).  Here are the steps

1.  Setup card for kernel boot
- run mk_mx28_sd  -b /dev/sdb  (only writes kernel with bootstream on card)
- place card in imx28 and boot it
- the kernel (while booting) outputs these lines:
...
...
i.MX GPMI NFC
NFC: Version 1, 8-chip GPMI and BCH
Boot ROM: Version 1, Single-chip boot area, block mark swapping 
supported Scanning for NAND Flash chips...
No NAND device found.
gpmi-nfc gpmi-nfc.0: Chip scan failed
...
...


2.  Setup card for uboot
-setup your host ubuntu so uboot can tftp your kernel -use *same* kernel 
from #1 (but use uImage) -run mk_mx28_sd -u -b /dev/sdb (only writes 
uboot with bootstream on card) -place card in imx28 and boot it -you may 
have to edit uboot parms to get your uImage from your host -Allow kernel 
to boot, it will output these lines:

...
i.MX GPMI NFC
NFC: Version 1, 8-chip GPMI and BCH
gpmi-nfc: probe of gpmi-nfc.0 failed with error 1 ...
...



So maybe U-boot does some things that prevents kernel from working or 
the kernel with the boot stream added on does the right things ?

Thanks,
Bill

[U-Boot] u-boot preventing access to NAND chip on imx28evk board

[Fabio Estevam]

On Mon, Aug 13, 2012 at 5:18 PM, Bill <bsousan@techsi.com> wrote:
> All,
>
>     I'm needing to access the NAND chip on the imx28evk board with the Linux
> (Freescale Kernel - FSL).  I've compiled a recent version of the mainstream
> u-boot with the NAND switches and U-boot works fine.  The U-boot also allows
> me access to the NAND chip and also boots the FSL kernel just fine.
> However, once the kernel is running, it can not "see" the /dev/mtdX devices.
>
>     However, if I boot the *same* kernel directly (no U-boot - and attach
> boot-stream to kernel) the FSL kernel works fine and can gets the /dev/mtdX
> etc devices.  I tracked this down to a couple of differences that are output
> during the kernel booting process.  I also can replicate this problem with
> no NAND chip in the socket. I can do this by using the script that comes
> with the imx28evk that is used for formatting the SDCard for booting.  The
> mk_mx28_sd script writes the uboot, kernel, and rootfs to an SDcard
> depending on the parameters.  So if I write the uboot to the card and boot
> the imx28 from uboot and network boot uImage I get the error.  If I write
> the kernel to the card and boot the imx28 with it I get no error (Using the
> same kernel).  Here are the steps

Last week I tried accessing NAND using U-boot mainline + kernel
mainline and it worked fine.

Can you try it?

Haven't tested with FSL 2.6.35 kernel though.

Regards,

Fabio Estevam

[U-Boot] Configure U-boot to output to LCD on imx28evk board

[Bill]

All,

     Is it possible to configure u-boot output (console) to the LCD on 
the imx28evk board?  I see in the u-boot configuration options switches 
for LCD support: CONFIG_LCD.  However, I don't see an LCD display that 
matches the one on the imx28evk?

Thanks,
Bill

[U-Boot] Configure U-boot to output to LCD on imx28evk board

[Fabio Estevam]

Hi Bill,

On Tue, Aug 21, 2012 at 11:20 AM, Bill <bsousan@techsi.com> wrote:
> All,
>
>     Is it possible to configure u-boot output (console) to the LCD on the
> imx28evk board?  I see in the u-boot configuration options switches for LCD
> support: CONFIG_LCD.  However, I don't see an LCD display that matches the
> one on the imx28evk?

Yes, this is possible, but currently there is no mxs framebuffer
support in U-boot.

Regards,

Fabio Estevam

[U-Boot] Configure U-boot to output to LCD on imx28evk board

[Bill]

Thanks.  I'm a bit fuzzy on Linux graphics.  So you mention that this is 
possible - but what criteria?
Does this mean all I need to do is configure U-boot?  Or you mention 
that there is no mxs framebuffer support.  Is there a way around this in 
u-boot?  Or can I add a patch for mxs framebuffer support in U-boot?

On 8/21/2012 9:25 AM, Fabio Estevam wrote:
> Hi Bill,
>
> On Tue, Aug 21, 2012 at 11:20 AM, Bill<bsousan@techsi.com>  wrote:
>> All,
>>
>>      Is it possible to configure u-boot output (console) to the LCD on the
>> imx28evk board?  I see in the u-boot configuration options switches for LCD
>> support: CONFIG_LCD.  However, I don't see an LCD display that matches the
>> one on the imx28evk?
> Yes, this is possible, but currently there is no mxs framebuffer
> support in U-boot.
>
> Regards,
>
> Fabio Estevam

-- 
William (Bill) L. Sousan, Ph.D.
(w) 402.331.4977 ext. 4002
bsousan at techsi.com
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[U-Boot] Configure U-boot to output to LCD on imx28evk board

[Fabio Estevam]

On Tue, Aug 21, 2012 at 11:35 AM, Bill <bsousan@techsi.com> wrote:
> Thanks.  I'm a bit fuzzy on Linux graphics.  So you mention that this is
> possible - but what criteria?
> Does this mean all I need to do is configure U-boot?  Or you mention that
> there is no mxs framebuffer support.  Is there a way around this in u-boot?
> Or can I add a patch for mxs framebuffer support in U-boot?

Yes, you need to create a patch to add mxs framebuffer support in
U-boot. You can look at the linux kernel as a reference
(drivers/video/mxsfb.c) and port it into U-boot.

There are other i.mx processors (mx31, mx51, mx53)  that do support
framebuffer in U-boot. You can look at drivers/video/mxc_ipuv3_fb.c in
U-boot for a reference for mx51/mx53 implementation.

The LCD controller on mxs is different so that is why you will need to
create a new driver for it.

Regards,

Fabio Estevam