Method, apparatus, and computer-readable medium for utilizing an alternate video buffer for console redirection in a headless computer system
First Claim
1. A non-transitory computer storage medium having computer-executable instructions stored thereon which, when executed by a computer, will cause the computer to:
- create a buffer in a memory of the computer, the buffer configured to store character and attribute information for a display screen and having an address distinct from that of any memory provided by a display adapter;
register a handler within an interrupt vector table provided by the computer for handling video services software interrupts;
trap an occurrence of the video services software interrupt;
in response to trapping the occurrence of the video services software interrupt, determine whether a function associated with the interrupt is for writing to a video display memory;
in response to determining that the function associated with the interrupt is for writing to a video display memory, detect the presence of a display adapter in the computer;
in response to detecting the presence of the display adapter, update the contents of the buffer with character or attribute information specified by the function and call an interrupt handler provided by the display adapter to write the character or attribute information to the display memory provided by the display adapter;
in response to not detecting the presence of the display adapter, update the contents of the buffer with character or attribute information specified by the function; and
encode and transmit the character or attribute information written to the buffer to a remote computing device.
3 Assignments
0 Petitions
Accused Products
Abstract
Methods, systems, apparatus, and computer-readable media are provided for utilizing an alternate video buffer for console redirection in a headless computer system. According to the method, a buffer is created in the main memory of the computer that is configured to store character and attribute data for a display of the computer. When a video services software interrupt is detected, the interrupt is trapped. A determination is then made as to whether a function associated with the interrupt is for writing to a video display memory. If the function is for writing, the contents of the buffer are updated with the character or attribute information specified by the function. Data representing the updated character or attribute is then redirected to the remote computing device. If a read function is encountered, character or attribute information is retrieved from the buffer at a specified location and is returned in response to the function call.
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Citations
14 Claims
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1. A non-transitory computer storage medium having computer-executable instructions stored thereon which, when executed by a computer, will cause the computer to:
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create a buffer in a memory of the computer, the buffer configured to store character and attribute information for a display screen and having an address distinct from that of any memory provided by a display adapter; register a handler within an interrupt vector table provided by the computer for handling video services software interrupts; trap an occurrence of the video services software interrupt; in response to trapping the occurrence of the video services software interrupt, determine whether a function associated with the interrupt is for writing to a video display memory; in response to determining that the function associated with the interrupt is for writing to a video display memory, detect the presence of a display adapter in the computer; in response to detecting the presence of the display adapter, update the contents of the buffer with character or attribute information specified by the function and call an interrupt handler provided by the display adapter to write the character or attribute information to the display memory provided by the display adapter; in response to not detecting the presence of the display adapter, update the contents of the buffer with character or attribute information specified by the function; and encode and transmit the character or attribute information written to the buffer to a remote computing device. - View Dependent Claims (2, 3, 4, 5)
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6. A computer-implemented method for redirecting a display of a computer system, the method comprising:
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creating a buffer in a memory of the computer system, the buffer configured to store character and attribute information for the display and having an address distinct from that of any memory provided by a display adapter; registering a handler within an interrupt vector table of the computer system for handling video services software interrupts; trapping an occurrence of the video services software interrupt in the computer system; in response to trapping the occurrence of the video services software interrupt, determining whether a function associated with the interrupt is for writing to a video display memory; in response to determining that the function associated with the interrupt is for writing to a video display memory, detecting the presence of a display adapter in the computer system; in response to detecting the presence of the display adapter, updating the contents of the buffer with character or attribute information specified by the function and calling an interrupt handler provided by the display adapter to write the character or attribute information to the display memory provided by the display adapter; in response to not detecting the presence of the display adapter, updating the contents of the buffer with character or attribute information specified by the function; and converting the data representing the character or attribute information written to the buffer to an escape sequence appropriate for display by a terminal emulation program and transmitting the escape sequence to a remote computing device. - View Dependent Claims (7, 8, 9)
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10. A computer system operable to redirect a display to a remote computing device, the system comprising:
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a first memory operable to store a buffer representing character and attribute information for the display on the remote computing device, the first memory having an address distinct from that of memory provided by a display adapter;
a second memory provided by a display adapter present in the computer system operable to store a display memory representing character and attribute information for the display on the computer system; anda third memory storing a BIOS program operative to; create the buffer, trap a video services software interrupt, determine whether a function associated with the interrupt is for writing to a video display memory, in response to determining that the function associated with the interrupt is for writing to a video display memory, detect the presence of the display adapter in the computer system, in response to detecting the presence of the display adapter, update the contents of the buffer with character or attribute information specified by the function and call an interrupt handler provided by the display adapter to write the character or attribute information to the display memory, and convert the data representing the character or attribute information written to the buffer to an escape sequence appropriate for display by a terminal emulation program and transmit the escape sequence to the remote computing device. - View Dependent Claims (11, 12, 13, 14)
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Specification