On 02.10.2014 01:07, Pavel Machek wrote:
On Wed 2014-10-01 21:25:12, Stefan Roese wrote:
On 01.10.2014 21:04, Jagan Teki wrote:
This is needed for the SoCFPGA booting from SPI NOR flash e.g. (N25Q256A). With these changes, the SoCrates can boot and re-boot (reset) from SPI NOR flash without any problems.
Seems like your SPI NOR reset logic is buggy. Does any of [1] apply to your board please?
[1] http://www.rocketboards.org/foswiki/Documentation/SocBoardQspiBoot
Yes. This seems to be that case. But I can't change it right now. So this "solution" with the soft-reset is better than nothing.
If this is some think that must require, any possibility to this resetting prior to u-boot? like preloader or in first stage boot loader or something.
Perhaps I was not clear with the intention of this patch. Its more to show how the problem with SPI flash on this platform / board (SoCrates in this case) can be solved. So that others have a reference. Thats why I marked it as RFC. Its not really meant for inclusion into mainline.
The real solution is a board rework. If not possible, the preloader should be changed. As I don't have access to the preloader code right now, this "solution" (I know, its more a hack) didn't seem too bad.
For the record, I do not think preloader is good place for such workaround. Preloader works with SDRAM, and should load real u-boot as fast as possible. If it does not need to touch SPI (it does not, right?) it should not need to work around bugs there.
In this case, where the board boots from SPI NOR flash, the Preloader (SPL U-Boot version) does use SPI. To load the main U-Boot image from the SPI NOR flash.
My current best guess is that this define in the Preloader (older SPL U-Boot version) causes these problems:
#define CONFIG_SPI_FLASH_QUAD (1)
Once I have full access to the Preloader source (in a few days hopefully) I can verify this.
Thanks, Stefan