Hooks for the System BIOS

The video BIOS performs several system BIOS interrupt function calls (interrupt 15h hooks). Each function provides the system BIOS with the opportunity to gain control at specific times to perform any custom processing that may be required. After each interrupt hook, the system BIOS must return control to the video BIOS. INT 10h calls could be made within the INT 15h hook calls provided that it is not recursive and thus cause a deadlock.

See the following topics for details on these function calls:

• 5F31h – POST Completion Notification Hook

• 5F33h – Hook After Mode Set

• 5F35h – Boot Display Device Hook

• 5F36h – Boot TV Format Hook

• 5F38h – Hook Before Set Mode

• 5F40h – Config ID Hook