[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。
  l+ Q2 P' a3 U1 D! [; {( {6 }0 i3 d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 Z, _4 d+ o/ K6 J/ h; J# v(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。
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.
* u3 a# a6 L  _6 _The IDSEL programmed in this field addresses the following memory ranges:
' A; m* R8 H% {$ k; d6 }FF70 0000h – FF7F FFFFh
FF30 0000h – FF3F FFFFh
$ @  D* j$ x5 U; U在这里 IDSEL 如何理解。
7 {& P6 {" D0 l, XFWH_DEC_EN1—Firmware Hub Decode Enable Register
, _  r6 x/ P1 Z4 f; o(LPC I/F—D31:F0)
( U0 O( F$ w( a5 D2 }& Q4 O* f; tFWH_70_EN — R/W. Enables decoding two 1-M Firmware Hub memory ranges.
5 _) G" k- |. F: n1 R- C0 = Disable.
: x- O7 }. U5 }& L: q& U# _1 = Enable the following ranges for the Firmware Hub
0 e8 J9 z( s4 D1 w& J* KFF70 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？

谢谢大家了！！！

xtdumpling

IDSEL是LPC spec的一个信号(Device Select),
' i) F! X) c) y8 ?, d  F8 UThis one clock field is used to indicate which of multiple Firmware components is being selected.
The four bits transmitted over AD[3:0] during this clock are compared with values strapped onto
* W/ j) H9 b, z- \3 ?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.
9 c/ {, L1 ]2 n: C5 o
详见LPC spec:
http://www.intel.com/design/chipsets/industry/25128901.pdf

/ ?4 }! z4 K" O7 A. _% U5 V' a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.