BIOS ROM

8.6 PnP Support

The BIOS includes Plug 'n Play (PnP) support for PnP version 1.0A. Table 8-6 lists the PnP functions supported.

 

Table 8-6.

 

PnP BIOS Functions

 

 

Function

Register

 

 

00h

Get number of system device nodes

 

 

01h

Get system device node

 

 

02h

Set system device node

 

 

03h

Get event

 

 

04h

Send message

 

 

50h

Get SMBIOS Structure Information

 

 

51h

Get Specific SMBIOS Structure

The BIOS call INT 15, AX=E841h, BH=01h can be used by an application to retrieve the default settings of PnP devices for the user. The application should use the following steps for the display function:

1.Call PnP function 01(get System Device Node) for each devnode with bit 1 of the control flag set (get static configuration) and save the results.

2.Call INT 15, AX=E841h, BH=01h.

3.Call PnP “Get Static Configuration” for each devnode and display the defaults.

4.If the user chooses to save the configuration, no further action is required. The system board devices will be configured at the next boot. If the user wants to abandon the changes, then the application must call PnP function 02 (Set System Device Node) for each devnode (with bit 1 of the control flag set for static configuration) with the results from the calls made prior to invoking this function.

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Technical Reference Guide