[U-Boot] Can not erase first 2 sectors on flash

[Chen Wen]

Hello

I have a platform modify from powerpc 405EP(Taihu evb).
I try to port u-boot from Taihu evb by using "taihu_config".

There are 4M+4M flash on the board, but I found that I can not erase flash
from ff800000--ff803fff.I had try "protect off all" and "erase all", but
still don't work.

just like this :
=> era ff800000 ff803fff

.. done
Erased 2 sectors
=> md ff800000
ff800000: 27051956 682e4eec 4c070a61 00168502    '..Vh.N.L..a....
ff800010: 00000000 00000000 ad640a83 05070201    .........d......
ff800020: 4c696e75 782d322e 362e3332 2e330000    Linux-2.6.32.3..
ff800030: 00000000 00000000 00000000 00000000    ................
ff800040: 1f8b0808 600a074c 0203766d 6c696e75    ....`..L..vmlinu
ff800050: 782e6269 6e2e3136 39363100 e45b0f70    x.bin.16961..[.p
ff800060: 14559aff 7a7a0213 08cb0881 0d24988e    .U..zz.......$..


"erase" command works every where on flash besides "ff800000--ff803fff"
Thus I can still erase "ff800000--ff803fff" by using a JTAG.
Is there anything wrong in my config(in attachment) ?

This is my flinfo
==================================================================================
Bank # 1: CFI conformant FLASH (16 x 16)  Size: 4 MB in 71 Sectors
  AMD Standard command set, Manufacturer ID: 0xC2, Device ID: 0x22A8
  Erase timeout: 16384 ms, write timeout: 1 ms

  Sector Start Addresses:
  FFC00000        FFC02000        FFC04000        FFC06000        FFC08000
  FFC0A000        FFC0C000        FFC0E000        FFC10000        FFC20000
  FFC30000        FFC40000        FFC50000        FFC60000        FFC70000
  FFC80000        FFC90000        FFCA0000        FFCB0000        FFCC0000
  FFCD0000        FFCE0000        FFCF0000        FFD00000        FFD10000
  FFD20000        FFD30000        FFD40000        FFD50000        FFD60000
  FFD70000        FFD80000        FFD90000        FFDA0000        FFDB0000
  FFDC0000        FFDD0000        FFDE0000        FFDF0000        FFE00000
  FFE10000        FFE20000        FFE30000        FFE40000        FFE50000
  FFE60000        FFE70000        FFE80000        FFE90000        FFEA0000
  FFEB0000        FFEC0000        FFED0000        FFEE0000        FFEF0000
  FFF00000        FFF10000        FFF20000        FFF30000        FFF40000
  FFF50000        FFF60000        FFF70000        FFF80000        FFF90000
  FFFA0000   RO   FFFB0000   RO   FFFC0000   RO   FFFD0000   RO   FFFE0000
RO
  FFFF0000   RO

Bank # 2: CFI conformant FLASH (16 x 16)  Size: 4 MB in 71 Sectors
  AMD Standard command set, Manufacturer ID: 0xC2, Device ID: 0x22A8
  Erase timeout: 16384 ms, write timeout: 1 ms

  Sector Start Addresses:
  FF800000        FF802000        FF804000        FF806000        FF808000
  FF80A000        FF80C000        FF80E000        FF810000        FF820000
  FF830000        FF840000        FF850000        FF860000        FF870000
  FF880000        FF890000        FF8A0000        FF8B0000        FF8C0000
  FF8D0000        FF8E0000        FF8F0000        FF900000        FF910000
  FF920000        FF930000        FF940000        FF950000        FF960000
  FF970000        FF980000        FF990000        FF9A0000        FF9B0000
  FF9C0000        FF9D0000        FF9E0000        FF9F0000        FFA00000
  FFA10000        FFA20000        FFA30000        FFA40000        FFA50000
  FFA60000        FFA70000        FFA80000        FFA90000        FFAA0000
  FFAB0000        FFAC0000        FFAD0000        FFAE0000        FFAF0000
  FFB00000        FFB10000        FFB20000        FFB30000        FFB40000
  FFB50000        FFB60000        FFB70000        FFB80000        FFB90000
  FFBA0000        FFBB0000        FFBC0000        FFBD0000        FFBE0000
  FFBF0000
==================================================================================

This is my config file: http://www.cs.nctu.edu.tw/~chenpc/taihu.h