JP2005189907A - Disk device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a disk device for suppressing the increase of a use RAM region and the frequency of a reading operation from the disk medium of a necessary module, and for executing a command without rotating a spindle motor(SPM) according to the type of a command in response to a request from a host system. <P>SOLUTION: This disk device is provided with a CPU, a CPU bus, a RAM, a flash ROM and a disk medium, and when a program module corresponding to execution contents of a program does not exist in the RAM, and the program module exists in the flash ROM, the program module is read from the flash ROM, and when any program module does not exist, it is read from the disk medium, and developed to the RAM. Then, this disk device is configured by a means which calculates the priority order of the existence of the program module in the flash ROM based on its use frequency to successively replace the program module whose priority order is lower among program modules stored in the flash ROM by the program module whose priority order is higher. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to storage and deployment of embedded software, and more particularly to a disk device characterized by storage and deployment of firmware.

  Conventionally, in a magnetic disk such as a hard disk device, firmware for device control is generally stored in a flash ROM or a magnetic disk medium. Of these, it is indispensable to place the minimum required modules such as device startup, servo control and data read / write (R / W) modules on ROM. It was possible to arrange in the area on the magnetic disk.

  Here, the firmware existing in the magnetic disk is read out and executed in the RAM. In order to save the area for this, for example, a module required when receiving a command from the host is read from the magnetic disk. It is easily imagined that the RAM is shared, such as reading to the shared RAM area.

  For example, in Japanese Patent Application Laid-Open No. 9-231084, which is a prior art document, firmware that is read from a disk at the time of startup of a computer system and developed in each processing apparatus is recorded in a flash ROM, and this is read from the next time onward. A method for restraining activation is known. That is, the prior art document discloses that means for omitting reading from the disk is provided only when the system is started.

Japanese Patent Laid-Open No. 9-231084 (Outline)

  However, in the case of the above-described prior art documents, (1) the frequency of the operation of reading the required module from the magnetic disk increases. (2) A command stored on the magnetic disk cannot be executed without rotating a spindle motor (hereinafter referred to as SPM). There is a problem.

  Therefore, the present invention has been made to solve the above-described problem, and while suppressing an increase in the RAM area, the frequency of a read operation from a disk medium of a necessary module is suppressed, and a command from the host system is requested. An object of the present invention is to provide a disk device that can be executed without rotation of SPM depending on the type of the disk.

  In order to solve the above-described problems, a disk device according to the present invention includes a CPU, a CPU bus to which the CPU is connected, and one or more connected to the CPU bus for selectively storing program modules. A RAM having a plurality of areas, a flash ROM having one or more areas for selectively storing program modules connected to the CPU and expanded in the RAM, and expanded in the RAM When the disk medium having a plurality of areas for storing all program modules and the necessary program module corresponding to the execution content of the program do not exist in the RAM, the program module exists in the flash ROM. From the flash ROM, the program module is transferred to the flash RO. Means for reading out from the disk medium and expanding it in the RAM, means for determining a priority order for storage in the flash ROM according to the frequency of use of the program module, and storage in the flash ROM. The program module includes means for sequentially replacing a program module having a low priority with a program module having a high priority.

The disk device of the present invention includes a CPU, a CPU bus to which the CPU is connected,
A RAM that is connected to the CPU bus and has one or more areas for selectively storing program modules, and a program module that is connected to the CPU and developed in the RAM. A flash ROM having one or a plurality of areas, a disk medium having a plurality of areas for storing all program modules developed in the RAM, and necessary program modules according to the execution contents of the program. If not present in the RAM, the program module is read from the flash ROM if it is present in the flash ROM, and is read from the disk medium if the program module is not present in the flash ROM, and is expanded in the RAM. In the flash ROM. It is characterized in that a means for specifying and specify cancel program module disposed.

  According to the present invention, with the configuration as described above, a program module having a high frequency of use and importance is preferentially arranged in a flash ROM having a short access time, thereby increasing the RAM capacity and executing commands. Therefore, it is possible to simultaneously suppress the access frequency to the disk medium.

  Also, by preferentially placing a program module for executing a specific command specified by the host system in a flash ROM with a short access time, the drive of the mechanism system for executing the command can be suppressed. It is possible to perform an optimum operation with respect to the configuration of the host system.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
A structure of a magnetic disk device (HDD) which is a disk device according to an embodiment of the present invention will be described with reference to FIG.
<Device configuration>
FIG. 1 is a block diagram showing the configuration of the present invention.
In the figure, the CPU 1 controls the entire apparatus and the motor driver 6 in a time-sharing manner. The motor driver 6 is a spindle motor (hereinafter referred to as SPM) 8 for rotating the magnetic disk 9 as a disk medium under the control of the CPU 1 and a voice coil motor (moving the magnetic head 13 to a target position). (Hereinafter referred to as VCM) 7 is supplied to SPM 8 and VCM 7 with a current for driving.

  The CPU bus 12 has a program (hereinafter referred to as initial load: IPL) for copying the firmware for controlling the device from the flash ROM 15 to the RAM 10 in the CPU when the power is turned on (hereinafter referred to as initial load). IPL ROM 11 in which is recorded), a program for performing device control, a RAM 10 for storing variables, a disk controller (hereinafter referred to as hard disk controller: HDC) 3, and various signals necessary for control A gate array 2 that performs generation is connected.

  The control registers of the HDC 3 and the gate array 2 are respectively allocated to a part of the memory space of the CPU 1, and the CPU 1 controls the HDC 3 and the gate array 2 by reading and writing to this area.

  The read / write IC circuit 5 is roughly divided into a servo block that mainly performs signal processing necessary for positioning processing of the magnetic head 13 and a read / write block that performs signal processing for reading / writing data. .

  On the magnetic disk 9, an area where servo data signals for positioning are recorded (hereinafter referred to as servo areas) and an area for recording data transferred from the host system (hereinafter referred to as data areas) are alternated. Are arranged at regular intervals.

  Further, data tracks (hereinafter simply referred to as tracks) are arranged on the magnetic disk 9 concentrically around the rotation axis, and positioning for causing the magnetic head 13 to follow the tracks is performed on the servo data signal described above. Based on information obtained from

  Specifically, an analog signal read from the magnetic head 13 when the magnetic head 13 is positioned and amplified by the head IC circuit 16 is sent to the read / write IC circuit 5, and the read / write IC circuit 5 The servo block 21 extracts the servo data. The extracted servo data is further processed by the gate array 2, and the CPU 1 controls the motor driver 6 based on this data and supplies a current for positioning the magnetic head 13 to the VCM 7.

  The HDC 3 is connected to the gate array 2, the buffer RAM 4, and the read / write IC circuit 5 in addition to the CPU bus 12. Further, the HDC 3 is further connected to the host block for controlling the interface with the host system 17 for each function, the buffer block for controlling the buffer RAM, the read / write IC circuit 5 and the gate array 2, and performs read / write processing. / Divided into light blocks.

  At the time of reading, the analog signal read from the magnetic disk 9 by the magnetic head 13 and amplified by the head IC circuit 16 is decoded by the read / write IC circuit 5, and the HDC 3 controls the analog signal from the gate array 2. Data to be transferred to the host system 17 is generated by processing according to each signal. This data is once stored in the buffer RAM 4 and then transferred to the host system 17.

  At the time of writing, the data transferred from the host system 17 to the HDC 3 is temporarily stored in the buffer RAM 4, and then sent from the HDC 3 to the read / write IC circuit 5 in accordance with each control signal from the gate array 2. The write data encoded by the IC circuit 5 is written to the magnetic disk 9 by the magnetic head 13 via the head IC 16.

<Firmware code placement and device activation>
FIG. 2 is a region layout diagram showing the firmware layout.
In the address space of the CPU 1, the RAM 10 in the CPU, the HDC 3, the register of the gate array 2 (specifically, the CPU / gate array control register 114), and the IPLROM 11 are arranged. The RAM 10 in the CPU further includes a basic area. 101 and a load area 102.

  Only the firmware code that exists in the address space of the CPU 1 can be executed. Since the firmware code does not exist in the RAM 10 in the CPU immediately after the apparatus is turned on, the firmware code is expanded here. The code is IPL115.

  The code developed in the RAM 10 in the CPU by the IPL 115 exists in the flash ROM 15, but the flash ROM 15 is not connected to the CPU bus 12, and this address space is independent of the address space of the CPU 1. .

  The area in the flash ROM 15 is further divided into a non-update area 121 and a code holding area 112. The former includes firmware codes (hereinafter referred to as basic codes 131) which are the minimum required for starting the apparatus, servo control, and reading / writing to the magnetic disk 9. And an optimization parameter A132 describing the adjustment and setting contents for each apparatus.

  When the hardware reset state is released when the apparatus is turned on, the CPU 1 starts executing the program from the top of the IPL 115. The IPL 115 reads the contents of the non-update area 121 in the flash ROM 15 and copies it to the basic area 101 in the RAM 10 in the CPU 1.

  As a result, program codes necessary for starting the apparatus, servo control, and reading / writing to the magnetic disk 9 are prepared in the basic code area 111 and parameter area A112. The processing is branched and the operation of the IPL 115 is completed.

  When the processing is moved to the head of the basic code area 111, first, preparation for reading data on the magnetic disk 9 is performed such as initialization of the entire apparatus and self-diagnosis. This initialization operation includes copying of the load area management table master 133 to the load area management table 116 and initialization of the code holding area management table 117 (that is, no registered items are present).

Subsequently, after the SPM 8 is rotated and the magnetic head 13 is moved to a predetermined position, the optimization parameter B141 is read and copied to the parameter area B113.
The optimization parameter B141 is not necessary for starting the apparatus, but data necessary for executing a command from the host system (for example, defect list, security information, etc.) is stored, and the reading is completed. The device startup process is completed.

  It is also possible to set the SPM 8 not to rotate when the device is started. In this case, these readings are not performed, and the command received from the host system 17 is executed. Read out.

<Executing commands from the host system>
FIG. 3 shows a table format for managing the load area 102 on the RAM 10 in the CPU and the code holding area 122 on the flash ROM 15.
A load area management table 116 for managing the load area 102 and a code holding area management table 116 for managing the code holding area 122 are arranged in the variable area 103 in the RAM 10 in the CPU. Each format is shown in FIG. 3, and the meaning of each item is as follows.

Area number 201: A number of a sub area (specifically, a load sub area or a code holding sub area) represented by the row.
Module number 202: Identification number of a runtime code (module) existing in the sub area. When there is no module, it is FFFFh.
Priority 203: The priority at the time of overwriting determined from the usage frequency of the module, etc., the higher the value is, the higher the value is (that is, the more difficult it is to be overwritten). Checksum 204: Checksum for confirming the consistency of the module.

  The load area 102 is an area for expanding and executing a module in which firmware codes are grouped for each function as needed, and is equally divided into NR sub areas (load sub area 1 to load sub area NR), 1 Depending on its size, one or more sub-areas are used to store one module. Each module developed here has an identification number.

  When it is necessary to perform a new process such as receiving a command from the host system 17, the section of the module 202 in the load area management table 116 is first searched. If the necessary module number is found here, the module already exists in the corresponding load sub-area in the load area 102, so that the processing can be continued, but if the necessary module does not exist, before that, The necessary modules must be read from the code holding area 122 in the flash ROM 15 or the code area 142 on the magnetic disk 9 and developed in the load area 102. Such processing is performed on one or a plurality of modules, and the initial processing is continued when all necessary modules are expanded in the load area 102.

  When a module is expanded to the load area 102, it is checked whether there is a value (FFFFh) indicating a vacancy in the module number 202, and if a vacancy is found, the module is expanded to the load area 102. The term of the priority 203 is searched to find the one having the smallest value, that is, the one having the lowest priority, and developed in such a manner that it is overwritten.

  Here, the priority 203 is calculated based on the use frequency of the module, but the last use time is also taken into consideration so that the module just developed is not overwritten immediately. The calculation of the priority 203 is sequentially performed, and is stored in a nonvolatile storage area such as the flash ROM 15 or the magnetic disk 9 as necessary.

Next, the expansion source of the module expanded in the load area 102 will be described.
The expansion source of the module is either the code holding area 122 in the flash ROM 15 or the code area 142 on the magnetic disk 9, and the former is fast and can always be read (ie, even when the SPM 8 is stopped). However, there is not enough capacity to store all the modules, and since the latter may involve the start of the SPM 8 and the movement of the magnetic head 13 for reading, all the modules are stored.

  For this reason, when a module is expanded in the load area 102, it is first checked whether it exists in the code holding area 122. If it exists, it is used, and if it does not exist, it is read from the code area 142. become.

  Because of these characteristics, it is desirable to store a module that is frequently used in the code holding area 122 or a module that does not want to operate the SPM 8 or move the magnetic head 13 during use. Further, since the flash ROM 15 can be erased and written in a certain unit (for example, the code holding sub-area in this embodiment), the module held in this area can be dynamically changed.

  Management in the code holding area 122 is performed using the code holding area management table 117 in the same manner as the load area 102 is managed using the load area management table 116. When it is necessary to expand the module to the load area 102, first the term of the module number 202 in the table is searched, and if the corresponding module number is found, it is expanded to the load area 102 and then the load sub-area of the expansion destination Is checked against the corresponding value in the checksum 204 term.

  If the checksums match, the expansion process is completed, but if the checksums do not match or if the corresponding module is not found, the data is read from the code area 142 and expanded. When a checksum mismatch occurs, the corresponding code holding subarea in the code holding area 122 is also updated.

  The update of the module stored in the code holding area 122 is also performed according to the priority determined by the use frequency and the last update time as in the case of the module in the load area 102. A condition of “overwrite prohibition” (FFFFh) that is distinguished from the priority determined in (1) is added. This value does not drop automatically, and the automatically determined priority does not reach this value.

  When the load area management table 116 is updated, the load area management table master 133 in the code holding area 122 is updated at the same time. At this time, since the flash ROM 15 often has a limit such as the upper limit number of rewrites, it is necessary to determine a priority comparison determination condition so that these tables are not updated too frequently.

  Further, a command is provided so that the host system 17 can set and cancel the above-described “overwrite prohibited” (FFFFh) state. In this case, since it becomes complicated if the host system 17 directly specifies the module number, the specification is made in command units.

  That is, when a command that is always executed at high speed or a command code of a command that is executed without starting SPM 8 is specified and an “overwrite prohibited” (FFFFh) command is executed, the apparatus enumerates necessary modules and After expansion into the code holding area 122, the code holding area management table 117 is updated. Of course, the priority recorded at this time is FFFFh representing “overwrite prohibited”.

  On the other hand, in order to cancel this state, the registration of the module used in these commands can be canceled by specifying the command code and executing the “overwrite prohibition” cancel command. As an operation for this, the corresponding module is not deleted, and the priority value is lowered to a normal one, so that when a module with a higher priority appears later, the module is replaced.

  This function prevents, for example, a decrease in command responsiveness in a system in which other commands are frequently mixed with a read / write command and is activated while the SPM 8 is stopped, and the SPM 8 is rotated. This can be used to prevent SPM rotation in a “preliminary” command in a system in which a command (for example, temperature measurement or the like) for determining whether to execute the accompanying command is issued in advance.

  As a result, the frequency of the read operation of the necessary module from the magnetic disk 9 is suppressed while suppressing the increase in the capacity of the RAM 10 in the CPU 1, and depending on the type of the host system 17, the SPM 8 can be started permanently. It is possible to provide a magnetic disk device that can be executed without accompanying.

  Needless to say, the present invention is not limited to a magnetic disk device, but can be applied to other disk devices that record information on a disk-shaped medium, for example, a magneto-optical disk device or an optical disk device.

1 is a block diagram showing a hardware configuration of a magnetic disk device (HDD) according to an embodiment of the present invention. Area arrangement diagram showing code area on magnetic disk of HDD according to this embodiment Area layout diagram showing address space in flash ROM of HDD according to this embodiment Area arrangement diagram showing CPU address space of HDD according to this embodiment Code holding area / load area management table of HDD according to the present embodiment

Explanation of symbols

1 …… CPU
2 ... Gate array 3 ... Hard disk controller (HDC)
4 ... Buffer RAM
5: Read / write IC circuit 6: Voice coil motor (VCM) / spindle motor (SPM) driver 7: Voice coil motor (VCM)
8 ... Spindle motor (SPM)
9 …… Disk medium (magnetic disk)
10 …… CPURAM
11 …… ROM with initial program loader
12 ... CPU bus 13 ... Magnetic head 15 ... Flash ROM
16 …… Head IC circuit 17 …… Host system 18 …… Host interface 101 …… Basic area 102 …… Load area 103 …… Variable area 111 …… Basic code area 112 …… Parameter area A
113 …… Parameter area B
114... HDC / gate array control register 115... Initial program loader storage area (IPL)
116 …… Load area management table 117 …… Code holding area management table 121 …… Non-update area 122 …… Code holding area 131 …… Basic code area 132 …… Optimization parameter A
133 ... Load area management table master 141 ... Optimization parameter B
142 ... Code area 201 ... Area number 202 ... Module number 203 ... Priority 204 ... Checksum

Claims (4)

CPU,
A CPU bus to which the CPU is connected;
A RAM connected to the CPU bus and having one or more areas for selectively storing program modules;
A flash ROM connected to the CPU and having one or more areas for selectively storing program modules developed in the RAM;
A disk medium having a plurality of areas for storing all program modules developed in the RAM;
If the program module necessary for the execution content of the program does not exist in the RAM, the program module must exist in the flash ROM from the flash ROM if the program module exists in the flash ROM. Means for reading from the disk medium and expanding it into the RAM;
Means for obtaining a priority order for storage in the flash ROM according to the frequency of use of the program module;
A disk device comprising: means for sequentially replacing a program module stored in the flash ROM having a lower priority with a program module having a higher priority. Means for verifying whether the program module in the flash ROM is correct when the program module in the flash ROM is expanded in the RAM;
When it is determined that the program module is not correct, the program module is read from the disk medium and expanded in the RAM, and at the same time, the program module in the flash ROM determined to be incorrect is updated with the correct one. Means of
The disk device according to claim 1, comprising: CPU,
A CPU bus to which the CPU is connected;
A RAM connected to the CPU bus and having one or more areas for selectively storing program modules;
A flash ROM connected to the CPU and having one or more areas for selectively storing program modules developed in the RAM;
A disk medium having a plurality of areas for storing all program modules developed in the RAM;
If the program module necessary for the execution content of the program does not exist in the RAM, the program module must exist in the flash ROM from the flash ROM if the program module exists in the flash ROM. Means for reading from the disk medium and expanding it into the RAM;
A disk device comprising: means for designating and dedesignating program modules that are always arranged in the flash ROM. Means for verifying whether the program module in the flash ROM is correct when the program module in the flash ROM is expanded into the RAM;
When it is determined that the program module is not correct, the program module is read from the disk medium and expanded in the RAM, and at the same time, the program module in the flash ROM determined to be incorrect is updated with the correct one. The disk device according to claim 3, further comprising:

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