On Sunday 18 October 2009 16:11:11 Tom wrote:

Mark Asselstine wrote:

...

The SheevaPlug DevKit is shipped with 4x8 by 1Gb DDR devices in two banks for a total of 512MB of RAM. Based on this configuration the existing values for SDRAM address control register are incorrect and result in random kernel oops as memory is incorrectly accessed (while for example extracting a large tarball such as a rootfs). Based on the hardware configuration along with the supporting documentation from Marvell these are the correct values, as well this change mimics values previously used in Marvell's own u-boot git tree for the SheevaPlug.

Other variants of the hardware such as the PogoPlug and TonidoPlug may have different memory configurations but to properly support those additional board directories should be maintained or a better system to support other kwb*.cfg is needed.

Tested on SheevaPlug DevKit.

Mark and Prafulla If this configuration is different from the what is already in use, then the kwbimage.cfg can not be overwritten.

Reviewing the kwbimage.cfg file shows a lot of magic. What would be a good way to generalize this ?

Let me start with a quick disclaimer that I haven't spent the necessary prerequisite time with the kwb image concept yet to be anything more then a casual observer at this point.

Moving to a more typical header file format would be useful to remove the feeling of "magic", ie. similar to kernel register #defines with BASE and OFFSETs. Groupings of registers should be then captured in structures with a layout that would allow for 'make sheevaplug_devkit_config' to use the include/configs/*.h files to influence the values of particular registers, by name.

If the format of the kwbimage.cfg file is fixed we want to consider generating this file.

I will defer to Prafulla though as he might already have plans and what we see today might only be on the path to the final vision of things.

More versions of the file ?

This would be the easiest route but would not make any strides to making the file less "magic".

Variable support in the file?

Allowing the file to make use of #ifdef, #ifndef would allow for flexibility but again this solves on the issue of supporting variations not in making the file more reader friendly.

The $0.02 of a casual observer.

Mark.

Other ideas ?

Tom

...

Signed-off-by: Mark Asselstine mark.asselstine@windriver.com

board/Marvell/sheevaplug/kwbimage.cfg | 10 +++++----- 1 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/board/Marvell/sheevaplug/kwbimage.cfg b/board/Marvell/sheevaplug/kwbimage.cfg index 6c47d62..61be8c2 100644 --- a/board/Marvell/sheevaplug/kwbimage.cfg +++ b/board/Marvell/sheevaplug/kwbimage.cfg @@ -74,11 +74,11 @@ DATA 0xFFD0140C 0x00000a33 # DDR Timing (High) # bit12-11: TW2W # bit31-13: zero required

-DATA 0xFFD01410 0x00000099 # DDR Address Control -# bit1-0: 01, Cs0width=x16 -# bit3-2: 10, Cs0size=512Mb -# bit5-4: 01, Cs1width=x16 -# bit7-6: 10, Cs1size=512Mb +DATA 0xFFD01410 0x000000cc # DDR Address Control +# bit1-0: 00, Cs0width=reserved +# bit3-2: 11, Cs0size=1Gb +# bit5-4: 00, Cs1width=reserved +# bit7-6: 11, Cs1size=1Gb # bit9-8: 00, Cs2width=nonexistent # bit11-10: 00, Cs2size =nonexistent # bit13-12: 00, Cs3width=nonexistent

The SheevaPlug DevKit is shipped with 4x8 by 1Gb DDR devices in two banks for a total of 512MB of RAM. Based on this configuration the existing values for SDRAM address control register are incorrect and result in random kernel oops as memory is incorrectly accessed (while for example extracting a large tarball such as a rootfs). Based on the hardware configuration along with the supporting documentation from Marvell these are the correct values, as well this change mimics values previously used in Marvell's own u-boot git tree for the SheevaPlug.

Other variants of the hardware such as the PogoPlug and TonidoPlug may have different memory configurations but to properly support those additional board directories should be maintained or a better system to support other kwb*.cfg is needed.

Tested on SheevaPlug DevKit.

Signed-off-by: Mark Asselstine mark.asselstine@windriver.com --- Thanks Simon for the heads up on the documentation change. Changes from V1, fix comment "reserved" -> "x8".

board/Marvell/sheevaplug/kwbimage.cfg | 10 +++++----- 1 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/board/Marvell/sheevaplug/kwbimage.cfg b/board/Marvell/sheevaplug/kwbimage.cfg index 6c47d62..3b9c53f 100644 --- a/board/Marvell/sheevaplug/kwbimage.cfg +++ b/board/Marvell/sheevaplug/kwbimage.cfg @@ -74,11 +74,11 @@ DATA 0xFFD0140C 0x00000a33 # DDR Timing (High) # bit12-11: TW2W # bit31-13: zero required

-DATA 0xFFD01410 0x00000099 # DDR Address Control -# bit1-0: 01, Cs0width=x16 -# bit3-2: 10, Cs0size=512Mb -# bit5-4: 01, Cs1width=x16 -# bit7-6: 10, Cs1size=512Mb +DATA 0xFFD01410 0x000000cc # DDR Address Control +# bit1-0: 00, Cs0width=x8 +# bit3-2: 11, Cs0size=1Gb +# bit5-4: 00, Cs1width=x8 +# bit7-6: 11, Cs1size=1Gb # bit9-8: 00, Cs2width=nonexistent # bit11-10: 00, Cs2size =nonexistent # bit13-12: 00, Cs3width=nonexistent