Method and apparatus for extending BIOS control of screen display beyond operating system boot process
First Claim
1. A method of controlling a video controller, comprising:
- configuring a video controller to write data to an unused area of a video memory;
configuring the video controller to display the data in the unused area of video memory on a display screen;
a configuring the video controller so that additional data is written to a second area in video memory;
starting an operating system;
intercepting an access to the video controller; and
determining if said operating system is attempting to set said video controller to a runtime video mode by interrogating one or more parameters of said access, and if so, configuring the video controller to display the additional data written in the second area of video memory.
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Accused Products
Abstract
A method and apparatus for extending basic input output system (BIOS) control of the display screen beyond the loading of the operating system is described. In one embodiment, the BIOS, during power-on self test (POST), writes content to the display screen, redirects a video controller interrupt vector to a new handler, and traps I/O accesses to the video controller. During the time the operating system is starting, accesses to the video controller, through the interrupt vector or directly, is intercepted and/or redirected. Once the operating is loaded, the original interrupt vector is restored, and trapping of I/O accesses to the video controller is disabled, allowing the operating system to take control of the video controller and hence the display screen.
110 Citations
19 Claims
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1. A method of controlling a video controller, comprising:
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configuring a video controller to write data to an unused area of a video memory;
configuring the video controller to display the data in the unused area of video memory on a display screen;
a configuring the video controller so that additional data is written to a second area in video memory;
starting an operating system;
intercepting an access to the video controller; and
determining if said operating system is attempting to set said video controller to a runtime video mode by interrogating one or more parameters of said access, and if so, configuring the video controller to display the additional data written in the second area of video memory. - View Dependent Claims (2, 3, 4, 8, 9, 10, 11, 12, 13)
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5. A computer program product, comprising:
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a computer usable medium having computer program code embodied therein to configure a video controller to write data to an unused area of a video memory;
computer readable program code to configure the video controller to display the data in the unused area of video memory on a display screen;
computer readable program code to configure the video controller so that additional data is written to a second area in video memory;
computer readable program code to start an operating system;
computer readable program code to intercept an access to the video controller; and
computer readable program code to determine if said operating system is attempting to set said video controller to a runtime video mode by interrogating one or more parameters of said access, and if so, to configure the video controller to display the additional data written in the second area of video memory. - View Dependent Claims (6)
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7. A computer system, comprising:
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a memory element having one or more instructions; and
a processor coupled to the memory element, the processor, in response to the one or more instructions, to, configure a video controller to write data to an unused area of a video memory, configure the video controller to display the data in the unused area of video memory on a display screen, configure the video controller so that additional data is written to a second area in video memory, start an operating system, intercept an access to the video controller, and determine if said operating system is attempting to set said video controller to a runtime video mode by interrogating one or more parameters of said access, and if so configure the video controller to display the additional data written in the second area of video memory. - View Dependent Claims (14, 15, 16, 17, 18, 19)
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Specification