Emulating disk drives of a first system on a second system
First Claim
1. An emulator for emulating a disk drive of a first data processing system on a second data processing system, the first data processing system including a user level, an executive level, an input/output level and a hardware platform, the user level including at least one user program and at least one executive program for managing operations of the first data processing system and the hardware platform including a plurality of first system input/output devices, including the disk drive, the executive level including at least one user task performing user level program operations and at least one executive task performing executive program operations, the user and executive tasks generating requests for disk drive input/output operations by the disk drive, the input/output level including input/output tasks, at least one input/output task corresponding to the disk drive and performing disk drive input/output operations in response to the input/output requests directed to the disk drive and the disk drive performing input/output operations in response to the corresponding disk drive input/output task, the disk drive emulator executing on the second data processing system and comprising:
- a second system user level process executing in a user level of the second data processing system, the second system user level process includingthe first system user level program,the first system executive program, andthe first system user and executive tasks,an emulator level interposed between the second system user level process and a kernel level, the emulator level includinga pseudo device driver corresponding to the first system disk drive, the kernel level, includinga kernel process corresponding to the pseudo device driver and emulating the disk drive, whereinthe pseudo device driver and the kernel process execute in a second system process to emulate the operations of the disk drive, and whereinthe kernel process emulating the disk drive is a file input/output process, so that the disk drive is emulated by a second system file.
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Accused Products
Abstract
The emulation of a first system disk drive on a second processing system including a second system user level process including first system user and executive tasks issuing disk input/output requests. An emulator level is interposed between the second system user level process and a kernel level and includes a pseudo device driver corresponding to the first system disk drive and the kernel level includes a kernel process corresponding to the pseudo device driver and emulating the disk drive. The pseudo device driver and the kernel process execute in a second system process to emulate the operations of the disk drive and the kernel process emulating the disk drive is a file input/output process. The pseudo device driver includes a pseudo device queue, a return queue and a queue manager responsive to first system disk input/output instructions and to completed disk operations. The second system includes a resource control table containing a disk drive type identification as a SCSI type drive and the kernel process reads the file capacity of the second system file emulating the first system disk drive and provides the file capacity to the requesting task as the disk drive capacity.
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Citations
12 Claims
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1. An emulator for emulating a disk drive of a first data processing system on a second data processing system, the first data processing system including a user level, an executive level, an input/output level and a hardware platform, the user level including at least one user program and at least one executive program for managing operations of the first data processing system and the hardware platform including a plurality of first system input/output devices, including the disk drive, the executive level including at least one user task performing user level program operations and at least one executive task performing executive program operations, the user and executive tasks generating requests for disk drive input/output operations by the disk drive, the input/output level including input/output tasks, at least one input/output task corresponding to the disk drive and performing disk drive input/output operations in response to the input/output requests directed to the disk drive and the disk drive performing input/output operations in response to the corresponding disk drive input/output task, the disk drive emulator executing on the second data processing system and comprising:
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a second system user level process executing in a user level of the second data processing system, the second system user level process including the first system user level program, the first system executive program, and the first system user and executive tasks, an emulator level interposed between the second system user level process and a kernel level, the emulator level including a pseudo device driver corresponding to the first system disk drive, the kernel level, including a kernel process corresponding to the pseudo device driver and emulating the disk drive, wherein the pseudo device driver and the kernel process execute in a second system process to emulate the operations of the disk drive, and wherein the kernel process emulating the disk drive is a file input/output process, so that the disk drive is emulated by a second system file. - View Dependent Claims (2, 3, 4, 5, 6, 11, 12)
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7. An method for emulating a disk drive of a first data processing system on a second data processing system, the first data processing system including a user level, an executive level, an input/output level and a hardware platform, the user level including at least one user program and at least one executive program for managing operations of the first data processing system and the hardware platform including a plurality of first system input/output devices, including the disk drive, the executive level including at least one user task performing user level program operations and at least one executive task performing executive program operations, the user and executive tasks generating requests for disk drive input/output operations by the disk drive, the input/output level including input/output tasks, at least one input/output task corresponding to the disk drive and performing disk drive input/output operations in response to the input/output requests directed to the disk drive and the disk drive performing input/output operations in response to the corresponding disk drive input/output task, the method for emulating the disk drive emulator executing on the second data processing system and comprising the steps of:
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executing a second system user level process, the second system user level process including the first system user level program, the first system executive program, and the first system user and executive tasks, interposing an emulator level between the second system user level process and a kernel level, and, in the emulator level, constructing a pseudo device driver corresponding to the first system disk drive, executing a kernel process corresponding to the pseudo device driver and emulating the disk drive, wherein the pseudo device driver and the kernel process execute in a second system process to emulate the operations of the disk drive, and wherein the kernel process emulating the disk drive is a file input/output process, so that the disk drive is emulated by a second system file. - View Dependent Claims (8, 9, 10)
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Specification