Method and device for booting a CD-ROM from a single disk image having multiple emulations

• US 6,304,965 B1
• Filed: 09/29/1998
• Issued: 10/16/2001
• Est. Priority Date: 09/29/1998
• Status: Expired due to Term

• Current Assignee: Phoenix Technologies Limited (Pharaoh Acquisition LLC)
• Original Assignee: Phoenix Technologies Limited (Pharaoh Acquisition LLC)
• Inventors: Rickey, Albert E.
• Primary Examiner(s): Lee, Thomas
• Assistant Examiner(s): MAI, RIJUE
• Application Number:
  US09/162,512
• Time in Patent Office: 1,113 Days
• Field of Search: 713/1, 713/2, 713/100, 395/700, 714/38, 709/220, 709/221, 709/222
• US Class Current: 713/2
• CPC Class Codes: G06F 9/4406 Loading of operating system

Abstract

A method and computer system including a bootable storage media, preferably a CD-ROM, having a single bootable disk image that allows multiple emulations. A hard disk boot image including an MBR is provided at the beginning of the bootable disk image. A floppy DBR is provided at a predetermined sector boundary in the hard disk image so that the computer system can use either the hard disk or the floppy disk emulation at boot time. A computer article of manufacture embodying a single bootable disk image that allows both a hard disk or a floppy disk emulation is also provided.

Claims

1. A method for producing a bootable storage media comprising:

storing both a hard disk image and a floppy disk DOS Boot Record (“

DBR”

) as a single bootable disk image on the storage media; and

building a boot catalog of the storage media with a first entry and a second entry, the first entry pointing to the hard disk image and the second entry pointing to the floppy disk DBR.

2. The method according to claim 1, wherein the step of storing both a hard disk image and a floppy disk DBR comprises:

storing the hard disk image at the beginning of the bootable disk image; and

storing the floppy disk DBR at a predetermined storage media sector boundary in the bootable disk image.

3. The method according to claim 2, wherein the step of storing the floppy disk DBR includes:

defining a predetermined sector boundary in a reserved area in the hard disk image; and

storing the floppy disk DBR at the predetermined sector boundary.

4. The method according to claim 3, wherein the step of defining a predetermined sector boundary includes providing zero or more alignment sectors in a reserved area of the hard disk image.

5. A method for producing a boutable CD-ROM, the method comprising the steps of:

storing a hard disk image on a bootable disk image of the CD-ROM, the hard disk image including a Master Boot Record (“

MBR”

), a hard disk DOS Boot Record (“

DBR”

) and a first copy of a File Allocation Table (“

FAT”

);

adding at least one sector of reserved area between the hard disk DBR and the FAT;

aligning a boundary in the reserved area, at a predetermined CD-ROM sector boundary in the bootable disk image, by adding zero or more reserved sectors between the hard disk DBR and the FAT;

adding a floppy disk DBR at the aligned boundary at the predetermined CD-ROM sector boundary in the bootable disk image; and

building a boot catalog entry of the CD-ROM to contain at least a first and a second entry, said first entry pointing to the MBR at the bootable disk image and said second entry pointing to said floppy disk DBR at the boundary of the predetermined CD-ROM sector boundary in the bootable disk image.

6. A method according to claim 5, wherein the step of aligning the boundary at the predetermined CD-ROM sector boundary includes adding zero or more reserved sectors between the hard disk DBR and the FAT.

7. A method according to claim 5, wherein said predetermined CD-ROM sector boundary is a 2K boundary.

8. A method according to claim 5, wherein the hard disk DBR includes a hard disk BIOS parameter block (“

BPB”

) having a physical drive number value greater than one.

9. A method according to claim 5, wherein the floppy disk DBR includes a floppy BPB having a hidden sectors count of zero and a physical drive number value of less than two.

10. A computer system including a bootable storage media having multiple emulations in a single bootable disk image, the storage media comprising:

a hard disk image on the bootable disk image of the storage media;

a floppy DOS Boot Record (“

DBR”

) in the hard disk image; and

a boot catalog including a first entry and a second entry, the first entry pointing to the hard disk image and the second entry pointing to the floppy DBR.

11. The computer system according to claim 10, wherein the hard disk image is stored at the beginning of the bootable disk image and the floppy DBR is stored at a predetermined storage media sector boundary in the bootable disk image.

12. The computer system according to claim 11, wherein the predetermined sector boundary is located in a reserved area of the hard disk image.

13. The computer system according to claim 11, wherein the predetermined sector boundary is aligned by adding at least one alignment sector in a reserved area of the hard disk image.

14. The computer system according to claim 11, wherein the predetermined sector boundary is aligned by adding three or less alignment sectors in a reserved sectors area of the hard disk image.

15. A computer system including a CD-ROM having multiple emulations in a single bootable disk image, the CD-ROM comprising:

a hard disk image on the bootable disk image of the CD-ROM, the hard disk image including a Master Boot Record (“

MBR”

), a hard disk DOS Boot Record (“

DBR”

) and a first copy of a File Allocation Table (“

FAT”

);

at least one reserved sector of reserved area between the hard disk DBR and the FAT;

a floppy DBR located a boundary in the reserved area, at a predetermined CD-ROM sector boundary in the bootable disk image, by adding zero or more reserved sectors between the hard disk DBR and the FAT; and

a boot catalog of the CD-ROM that includes at least a first and a second entry, said first entry pointing to the MBR in the bootable disk image and said second entry pointing to the floppy DBR at the predetermined CD-ROM sector boundary in the bootable disk image.

16. The computer system according to claim 15, wherein the at least one reserved sector comprises a number of sectors that allows the location of the floppy DBR at a 2K CD-ROM sector boundary.

17. The computer system according to claim 15, wherein the predetermined CD-ROM sector boundary is a 2K boundary.

18. The computer system according to claim 15 wherein the hard disk DBR includes a BIOS parameter block having a physical drive number value greater than one.

19. The computer system according to claim 15 wherein the floppy disk DBR includes a BIOS parameter block having a hidden sectors count of zero and a physical drive number value of less than two.

20. A computer article of manufacture to be loaded into a drive of a computer having a memory, comprising:

a computer usable medium including computer readable program code and computer readable data structures embodied therein, comprising;

a bootable disk image data structure including a hard disk image data structure embodied therein, the hard disk image including at least one reserved sector; and

a floppy DOS Boot Record (“

DBR”

) located in the reserved sector of the hard disk image,

wherein the computer can boot from the computer usable medium by emulating either a hard disk or a floppy disk.

21. A computer article of manufacture according to claim 20, wherein the computer usable medium includes a boot catalog data structure having a first entry and a second entry, the first entry pointing to a beginning of the hard disk image and the second entry pointing to the floppy DBR, and

wherein the computer article of manufacture can be loaded into a CD-ROM drive of the computer.

22. A computer article of manufacture according to claim 20, wherein the floppy DBR is located in the reserved sector at a predetermined sector boundary in the hard disk image.

23. A computer article of manufacture according to claim 22, wherein the predetermined sector boundary is a 2K boundary.

24. A computer article of manufacture according to claim 22, wherein the hard disk image includes zero or more alignment sectors so that the floppy DBR is aligned at the predetermined sector boundary in the hard disk image.