[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。
8 [5 r1 P$ D- X9 ~* U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。
(可以访问原512K的ROM 0xFFF8 0000~0xFFFF FFFF)

4 D" V( x) b  s" R, r9 `7 l我的计算机用的是intel的ICH7南桥。
$ r2 i* i3 O( B& [+ ]- w+ H. I在手册上
1 t4 a8 n' X( k: ]/ a* `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.
* M7 ?# e7 O: g* S( q: T, B7 C0 YThe IDSEL programmed in this field addresses the following memory ranges:
FF70 0000h – FF7F FFFFh
FF30 0000h – FF3F FFFFh
7 Z8 C, [$ t: i0 S. F, V+ `在这里 IDSEL 如何理解。
FWH_DEC_EN1—Firmware Hub Decode Enable Register
- }5 Y8 ~5 H2 c: m" L(LPC I/F—D31:F0)
* h8 G& q& v! M; J3 j& E/ QFWH_70_EN — R/W. Enables decoding two 1-M Firmware Hub memory ranges.
+ ?- V6 ^2 h) [, q0 = Disable.
1 l: h5 v, ?7 r8 R1 = Enable the following ranges for the Firmware Hub
2 u5 r1 Q, o" ?4 w* x3 UFF70 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？

4 p# G# [) H* H' W" N% L5 s' ?谢谢大家了！！！

xtdumpling

IDSEL是LPC spec的一个信号(Device Select),
This 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
) \+ \3 x2 s! j5 t9 y6 L+ _; Epins 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.

详见LPC spec:
' Z  B; ~8 l0 l0 s8 Shttp://www.intel.com/design/chipsets/industry/25128901.pdf

+ M) h! l# k& I0 W, [/ x0 l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.