[请教]BIOS地址映射?

暴雪

原512K的ROM，现换了一个1M的ROM，windows下在 0xFFF0 0000~0xFFF7 FFFF 可以看到追加的512K的内容。
但在启动计算机时(BIOS没有初始化计算机），无法访问追加的512K的ROM。
5 c  f3 V* j3 V* |! L0 ?' z(可以访问原512K的ROM 0xFFF8 0000~0xFFFF FFFF)

我的计算机用的是intel的ICH7南桥。
: L. s; f& v) S# d( [在手册上
. x2 G5 `( \( W$ ?! }" y+ g1 mFWH_SEL2—Firmware Hub Select 2 Register (LPC I/F—D31:F0)
" W8 Y3 L' V9 o' n+ T' ^5 cFWH_70_IDSEL — R/W. IDSEL for two, 1-M Firmware Hub memory ranges.
7 C  g- S0 O$ y  a8 n+ ^The IDSEL programmed in this field addresses the following memory ranges:
  ^* O) ^- ^9 X  z3 iFF70 0000h – FF7F FFFFh
FF30 0000h – FF3F FFFFh
, _, U! Z5 W, f在这里 IDSEL 如何理解。
FWH_DEC_EN1—Firmware Hub Decode Enable Register
(LPC I/F—D31:F0)
FWH_70_EN — R/W. Enables decoding two 1-M Firmware Hub memory ranges.
0 = Disable.
1 = Enable the following ranges for the Firmware Hub
FF70 0000h – FF7F FFFFh
FF30 0000h – FF3F FFFFh
除了上面的数据区域，还有其它的数据区域控制ROM到内存地址的映射吗？

  @$ d7 ~" o! \1 ?$ G谢谢大家了！！！

xtdumpling

IDSEL是LPC spec的一个信号(Device Select),
; {( f5 a7 H4 {5 fThis one clock field is used to indicate which of multiple Firmware components is being selected.
. I! p3 h+ t/ M7 |$ ~" r1 }The four bits transmitted over AD[3:0] during this clock are compared with values strapped onto
! S, Q5 c* h8 ^9 w2 X1 X( wpins on the Firmware component. If there is a match, the Firmware component will continue to
decode the cycle to determine which bytes are requested on a read or which bytes to update on a
0 N6 g/ u1 e# {9 [; K0 `! Ywrite. If there isn’t a match, the Firmware component may discard the rest of the cycle and go into
* O4 I7 z0 V. e/ V5 a5 T; o; wa standby power state.
, M$ T5 ^( M/ K8 K+ F; r
- X& J1 d" O  M% H2 x详见LPC spec:
http://www.intel.com/design/chipsets/industry/25128901.pdf

/ D. a% L0 _' |1 Z6 s在ICH 7 中似乎就这几个吧(FWH_SEL1,FWH_SEL2,FWH_DEC_EN1,BIOS_CNTL),据我现在知道的.