[U-Boot-Users] Where does U-Boot's CFI driver check for top/bottom boot?

[Tolunay Orkun <listmember@orkun.us>]

Tolunay Orkun wrote:

> I will look at some AMD part datasheets. If this is generally available
> on all AMD and AMD like parts, we can add it as a patch for AMD only.

I have found the AMD CFI specification at the following URL:

http://www.amd.com/us-en/assets/content_type/DownloadableAssets/cfi_r20.pdf

For completeness, Intel CFI specification is here:

http://www.intel.com/design/flcomp/applnots/292204.htm

Intel does not have top/bottom boot field. It is trivial to limit any 
code to AMD command set only. For AMD command sets, I see the Top/Bottom 
field is in Vendor Specific Tables for those flash parts that implement 
CFI Specification 1.1 or later. CFI Specification 1.0 does not support 
this.

However, the note from 1.1 table says if this field contains 0 for such 
devices and check device ID codes for Am29LV160 and Am29LV116 to 
determine top/bottom boot determination. I do not know if these are the 
only 2 devices that are CFI 1.0 compliant or there are more to handle 
differently.

Tolunay