[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。
+ C3 e2 P7 ?/ w1 f( l(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。
8 N' q3 X$ G" W" ?在手册上
FWH_SEL2—Firmware Hub Select 2 Register (LPC I/F—D31:F0)
FWH_70_IDSEL — R/W. IDSEL for two, 1-M Firmware Hub memory ranges.
9 `- e  S0 c& E# OThe IDSEL programmed in this field addresses the following memory ranges:
' V% k' E7 V* v4 Q1 EFF70 0000h – FF7F FFFFh
6 t3 J) |+ p6 s* U; s$ T; J1 \FF30 0000h – FF3F FFFFh
* m# f/ v) n3 d在这里 IDSEL 如何理解。
; w, {# F( T" x, ]( OFWH_DEC_EN1—Firmware Hub Decode Enable Register
(LPC I/F—D31:F0)
8 k' D/ w- S/ D2 g0 I* [FWH_70_EN — R/W. Enables decoding two 1-M Firmware Hub memory ranges.
" c# p/ ?: _" S. s0 = Disable.
* \8 M1 \, |. f* }' H1 = Enable the following ranges for the Firmware Hub
FF70 0000h – FF7F FFFFh
2 N& ?  O" T4 nFF30 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？

谢谢大家了！！！

xtdumpling

IDSEL是LPC spec的一个信号(Device Select),
% n$ J7 M1 M% Z6 k7 v7 ~+ fThis one clock field is used to indicate which of multiple Firmware components is being selected.
4 S' U3 P  \+ g* q$ o( V; O# N5 dThe four bits transmitted over AD[3:0] during this clock are compared with values strapped onto
pins 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
write. If there isn’t a match, the Firmware component may discard the rest of the cycle and go into
a standby power state.
; G6 M; H7 B" s3 N1 k/ A
9 `8 Z& y; {1 K* c详见LPC spec:
http://www.intel.com/design/chipsets/industry/25128901.pdf

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.