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