RadiSys EPC-5A, Справочное руководство по аппаратному и программному обеспечению

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Chapter 4: BIOS Configuration
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Page 33
Memory Shadow Sub-Menu
The term “shadowing” refers to the technique of copying BIOS extensions from ROM
into DRAM and accessing them from DRAM. This allows the CPU to access the
BIOS extensions much more quickly and generally increases system performance if
many calls to the BIOS extensions are made. The Memory Shadow Sub-menu is
shown below.
The shadow regions should be used only if an EXMbus card is installed in the system
that contains a BIOS extension (ROM) although there is no effect on the system if a
region is shadowed that does not contain a BIOS extension. Note that each shadow
region in the setup menu is 16KB in size. Multiple shadow regions may have to be
enabled if the BIOS extension to be shadowed is larger than 16KB.
System Shadow/Video Shadow
These options are not editable since the System and VGA BIOS are always shadowed.
Shadow Memory Regions
These options enable or disable shadowing for the associated memory region. The
default is “Disabled”.
P ho e n ix B I OS S et u p - Co p y ri g h t 1 98 5 - 96 P ho e n ix Te c h no l o gi e s L t d.
I t e m S p ec i fi c He l p
F1 H e lp S e le c t I t e m - / + C h an g e V a l ue s F 9 S e tu p De f a ul t s
ES C E x it S e le c t M e n u E n te r Se l e ct Su b -M e n u F 1 0 P r ev i o us V al u e s
< T a b> , < S h if t - Ta b > , o r
< E n te r > s e le c t s f i el d .
M e m or y S h a do w
S y st e m S h ad o w : E n ab l e d
V i de o S h a do w : E n ab l e d
Re g io n s w i t h L e ga c y E x pa n s io n RO M s:
C 80 0 - CB F F : [ Di s ab l e d]
D C 00 - D FF F : [ Di s a bl e d ]
D 8 00 - D BF F : [ Di s a bl e d ]
C C0 0 - CF F F : [ Di s ab l e d]
D 40 0 - D7 F F : [ Di s ab l e d]
D 0 00 - D 3F F : [ Di s a bl e d ]
Figure 4-4. Memory Shadow Menu.