JPS60175259A - Disk control system - Google Patents

Abstract

PURPOSE:To omit the hardware such as a set switch for storage of control information, a ROM, etc. by setting the protection information to protect an area of a disk where the control information is stored and using a command set separately from that set in an access mode to other areas to give an access to an area on the disk. CONSTITUTION:A disk name needed for control and the information on a control program, etc. are written previously to a protection area 20b of a disk main body 20 under the control of a disk control channel 1. A protection table 11a contains the address of the area 20b; while a command table 11b contains the general commands and key commands. The channel 1 receives a command for access to a disk 2, and a processing part 10 decides whether an address belongs to the area 20b. Then the part 10 decides whether the address is equal to a key command or not if said address exists within the area 20b. Then no access is allowed if no key command is decided. Thus an error is processed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a disk control method in which disk control information is stored in an information storage disk such as a magnetic disk.

[Technology background]

Information storage disks such as ceramic disks, floppy disks, and optical disks are widely used to store various types of information. Compared to other storage methods, these storage devices are compact and have a large capacity, and are non-volatile.
It is widely used.

On the other hand, controlling these disks requires control information such as disk names and control programs, and these also need to be stored.

[Prior art and problems]

Conventionally, to store such control information, the disk name is stored using a setting switch, and the control program is stored in read-only memory (ROM), both of which are stored in a disk control channel (control device) other than the disk. It was stored.

For this reason, conventional disk control methods require a setting switcher, ROM, etc. in terms of hardware, making the configuration complicated and expensive.
For expansion, these hardware must be replaced.
The problem was that it was not easy.

[Purpose of the invention]

An object of the present invention is to provide a disk control method that does not require any special configuration (hardware) for storing and setting such control information.

C Structure of the Invention] To achieve the above object, the present invention includes a disk on which information can be written and read, and a disk control device that controls access to the disk, and the disk control device controls access to the disk. An area for storing control information necessary for control is provided on the disk, and protect information is set to protect the area where the control information is stored, and an area on the disk where the protect information is set is provided. It is characterized in that access to is performed by a command provided separately from commands for accessing other areas.

[Embodiments of the invention] Hereinafter, one embodiment of the present invention will be explained in detail.

FIG. 1 is a configuration diagram of an embodiment of the present invention. In the figure, 1 is a magnetic disk control channel, which controls a magnetic disk, which will be described later, and 10 is a processing section, which is configured by a processor and has a control channel. 11 is a memory that stores information necessary for the processing of the processing section 10, and stores a protect table lla and a command table llb, which will be described later. . 2 is a magnetic disk, 20 is the magnetic disk body, 21 is a read/write head for writing to or reading from the disk body 20;
22 is a head access mechanism that moves the head 21 in the radial direction of the disk body 20; 23 is a write/read circuit that allows the head 21 to write/read from the disk body 20; be.

FIG. 2 is an explanatory diagram of the contents of the table in the configuration of FIG. 1, and as shown in FIG.
The protected area 20a is divided into a protected area (area) 20a and a protected area (area) 20b in which control information is stored.
Suppose that b is set to atlus "xOOO" to "XFFF" and the others are set to the general area 20a, then the addresses "xooo" to "XFFF" of the protected area 20b are set in the protect table lla. On the other hand, access to the private area 20b is prohibited by general commands, and key commands are prepared for accessing this area. Therefore, when a command arrives, the processing unit IO
to identify this, the general command is glued/
Write command, i.e. READ D'ATASWRI
In addition to TEDATA, there is also a read/write command as a key command, that is, READ CONT ROL.
AREA, WRITE C0NTR0LA RE A
is stored in command table llb.

Next, the operation of the embodiment configuration shown in FIG. 1 will be explained using the process flow diagram shown in FIG.

Here, in advance, in the protected area 20b of the disc main body 20, ;1□
'11 information is written under the control of disk control channel 1, the address of the protect area 20b is written in the protect table lla, and the general commands and key commands are written in the command table llb. Assume that it is stored.

■ First, when the disk control channel l receives a command to access the disk 2 (including the address to be accessed) from an external cPU (central processing unit), etc., the processing unit 10 reads the address included in the command and the protect table. Compare the contents of lla and find out that? It is determined whether the address is in the protected area 20b.

(2) If the command is within the protected area 20b, the processing unit IO compares the contents of the command table llb with the command F' in order to determine whether the command is a key command or not. If the processing unit 1o determines that the command does not correspond to a key command based on the comparison a, the command is a general command other than a key command, and access to the protected area 20b is prohibited for this command, so access is permitted. Instead, handle the error. That is, the CPU etc. are notified of the error.

■On the other hand, if it is determined in step ■ that the area is other than the protected area 20b, or in step ■
20b and if the command is determined to be a key command, the command (read or write 1-) is executed for the address included in the command. That is, the processing section 10 controls the write/read circuit 23 and the head access mechanism 22 to cause the head 21 to write or read the record specified by the address on the disk body 20.

In this way, before actually accessing the disk, the incoming command is analyzed and access is permitted/disallowed.

Next, a second embodiment of the present invention will be described with reference to the explanatory diagram in FIG. 4 and the processing flow diagram in FIG. 5.

In the first embodiment described above, the address to be accessed was used to identify whether the access was to a protected area.
In the second embodiment, access to the ID section of the protected area is performed, but access to the DATA section is
It is permitted/disapproved depending on the contents of the section.

That is, as shown in No. 4 and 1, each record (RE CORD) on the disk body 20 is composed of an ID section and a DATA section (in which data is stored), and the ID section contains the record that is stored on the disk. In addition to storing a cylinder address indicating which concentric circle position on the main body 20, a trunk address indicating the front or back side of the disk body 20, and a record address indicating which position on the concentric circle, data (DATA) is stored.
) has a flag section that stores a replacement address when the section is damaged. In the second embodiment of the present invention, in the record of the protected area 20b, a protect flag indicating that it is a protected area is written in the flag part of the ID part, and control information is written as data in the DATA part. Keep it packed. The protect table lla in the configuration of FIG. 1 is omitted.

Next, a second embodiment will be explained with reference to FIGS. 1, 4, and 5.

(2) First, when the disk control channel 1 receives a command (including an address) for accessing the disk 2 from an external CPU or the like, the processing section 10 accesses the disk 2.

That is, the head 21 is moved to the record position corresponding to the address of the command by controlling the access mechanism 22, the head 21 reads the ID part of the record, the position is confirmed by the address included in the ID part, and the ID part is read. Read the section flag.

(2) The processing unit 10 of the disk control channel 1 receives the read flag and determines whether or not there is a protect flag.

■If there is a protect flag, the accessed record is in the protect area, so the processing unit 10 checks the contents of the command table 11b and the command in order to determine whether the received command is a key command. compare. If the processing unit 10 determines that the command does not correspond to a key command based on this comparison, the command is a general command other than a key command, and access to the protected area 20b is prohibited for this command, so access is not permitted. First, handle the error. In other words,
Notify the CPU etc. of the error.

■On the other hand, if there is no protect flag (not a protected area) in step ■, or if the command is determined to be within the protect area and the command is a key command in step ■,
The head 21 allows access to the DATA section (data area) of the accessed record, controls the write/read circuit 23 to read or write to the DATA section.
I will make you do it.

In this way, after accessing the ID part of the record with a command, it is determined whether or not it is a protected area based on the flag in the ID part, and the incoming command is analyzed to permit/disallow access to the DATA part of the record. .

In the above description, a magnetic disk was used as an example of the disk, but the present invention can also be applied to well-known information storage type disks such as floppy disks and optical disks.

Further, the control information in the protected area is read out by a key command when the power is turned on or when the system is reset, and is also read out by a command (key command) from the CPU as necessary.

Although the present invention has been described above using examples, the present invention can be modified in various ways according to the gist of the present invention, and these are not excluded from the present invention.

〔Effect of the invention〕

As explained above, according to the present invention, there is provided a disk on which information can be written and read, and a disk control device that controls access to the disk, and the disk control device is required to control the disk. Provide an area on the disk to store control information, set protect information to protect the area where the control information is stored, and create an area on the disk where the protect information is set. Access is performed using a command that is separate from the commands used when accessing other areas, and since the control information can be stored on the disk, there is no need for hardware such as setting switches or ROM to store the control information. This has the effect of not having to use the device, making it possible to have a simple and inexpensive device configuration. In addition, since the control information on the disk can be rewritten and the area expanded using key commands, it is easy to change and expand the control information.
:1. --Functions can be easily changed to meet the user's requirements, and disk control can be expanded. Furthermore, the area where control information is stored is the key frame.

Since the control information is protected from commands other than commands, there is no risk of destruction of the control information, and the reliability of disk control is guaranteed even if control information is stored on the disk.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention, FIG. 2 is an explanatory diagram of table contents in the configuration of FIG. 1, FIG. 3 is a processing flow diagram of an embodiment of the present invention, and FIG. FIG. 5 is a process flow diagram of another embodiment of the present invention. In the figure, 1-disk control channel, 1o-processing unit, 11
---Memory, 2--Disk, 20--Disk body, 21-Head. Patent applicant Fujitsu Ltd. Representative Patent Attorney Akira Yamatani Eisai +I! 1 2 2 Figure

Claims (1)

[Claims] It has a disk on which information can be written and read, and a disk control device that controls access to the disk, and an area on the disk that stores control information necessary for the disk control device to control the disk. In addition to providing
Protect information is set to protect the area where the control information is stored, and the area on the disk where the protect information is set is accessed by a command provided separately from commands used when accessing other areas. A disk control method characterized by: