For u-boot-v2 from:

git clone git://www.denx.de/git/u-boot-v2.git

2.0.0 rc3 ran all ST and Spansion CFI NOR flash from the i.mx27 using /arch/arm and /board ads27 or pcm038. (or any other board built on pattern.)

2.0.0 rc7 no longer supports the SPANSION S29GL512/256/128N programing ST is still supported as pulled from the above repository.

Freescale and Lufkin may look into this issue.