JP2003280937A - Firmware download system and its method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a system which downloads a firmware from the outside without having an influence on a process of a device main control part even though the system is in an operation state, which is operated without damaging duplicate mode of a service as much as possible, and which improves the redundancy and reliability. <P>SOLUTION: This system is provided with a host device A13 which informs an update request, the device main control unit A1 connected to a main bus B1, a work memory A3, a bus control unit A8, and firmware memories A6 and A7 which are connected to a sub bus B2 connected to the bus control unit A8, and the bus control unit A8 stores an updated firmware in the firmware memory where a working firmware is not stored, based on storing its own information according to the update request from the host device A13. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for downloading firmware to various function block devices in the system in order to deal with system malfunctions, improve functions, etc. The present invention relates to a firmware download system and method during operation of a backbone communication network system that emphasizes the reliability of the operating state of a service, such as a central office telephone exchange.

[0002]

2. Description of the Related Art Generally, it is necessary to download firmware to each functional block device for the purpose of coping with a defect or improving its function. Conventionally, as a technique for performing this download, in the case of a system in a redundant operation mode including a function block device for downloading firmware and a function block device having the same function as this function block device, firmware replacement or When the function block device that needs updating or the like is in a non-operational state, the firmware is downloaded or the function block device is exchanged manually in the station. On the other hand, in the case of a system that is not in the redundant operation mode, the firmware is downloaded to each functional block device while the system is temporarily stopped or the system function is deteriorated.

However, in performing the firmware download for each functional block device, in recent years, there has been concern about a reduction in personnel cost in terms of system operation and a decrease in reliability due to a temporary unification of the system during operation. Has been done.

To solve these problems, Japanese Unexamined Patent Application Publication No. 11-7382 discloses a firmware memory area divided into a storage area for the current firmware and an area for storing the new firmware. By doing so, a method of downloading the firmware without suspending the system has been proposed.

[0005]

However, in the technique disclosed in the above-mentioned publication, the state of the system is changed from the dual operation mode to the single operation mode during the firmware download, and the reliability of the system is improved. It had lowered.

Further, in the above-mentioned state, the system is in the single operation mode, and therefore, when a failure occurs in the active function block device in which the current firmware is stored, it is impossible to switch to the non-active function block device. Therefore, there is a drawback that the reliability of the entire system cannot be maintained and the service is stopped depending on the content of the failure that has occurred.

Further, since the technique disclosed in the above-mentioned publication has a configuration in which the apparatus main control unit and the firmware are directly connected, downloading the firmware during the normal operation processing imposes a great load on the apparatus main control unit. It was feared that this would affect normal operations.

Further, in the technique disclosed in the above-mentioned publication, it is necessary to provide a synchronization point when updating the firmware data, and if a large amount of firmware update occurs, a large number of synchronization points must be provided. However, this method is difficult to realize.

Therefore, the present invention has been invented in view of the above problems, and an object thereof is to externally install a firmware without affecting the processing of the main controller of the apparatus while the system is in an operating state. It is an object of the present invention to provide a system for improving redundancy and reliability by performing downloading and operating the system without impairing the duplication of services as much as possible.

[0010]

[Means for Solving the Problems] First to solve the above problems
Is a system for downloading firmware from a higher-level device, which includes a main bus, a sub-bus,
A work memory unit that is connected to the main bus and stores the current firmware used for system operation,
A first firmware memory unit connected to the sub-bus and storing firmware, a second firmware memory unit connected to the sub-bus and storing firmware, and the current firmware to the first firmware memory unit or It is connected to the main control unit for reading the firmware from the second firmware memory unit and storing the read firmware in the work memory unit, and the sub-bus,
Between the external interface unit that stores the updated firmware in either the first firmware memory unit or the second firmware memory unit in response to the firmware update request from the host device, and between the main bus and the sub-bus. Is stored in the first firmware memory unit or the second firmware memory unit, and stores stored information indicating whether the current firmware is stored in the first firmware memory unit or the second firmware memory unit, and gives an instruction to read the current firmware from the main control unit. In response, the firmware memory unit storing the active firmware is instructed based on the stored information, and in response to the request from the external interface unit, the active firmware is not stored based on the stored information. Instruct the firmware memory section to confirm the firmware And having a bus control unit for storing the update firmware Amemori unit.

A second invention for solving the above problems is as follows.
In the first invention, the bus control unit is stored in either the first firmware memory unit or the second firmware memory unit in response to an execution request for error detection of updated firmware from a higher-level device. Error detecting means for detecting an error in the updated firmware, and if the result of the error detecting means is normal, a collating means for collating versions of the current firmware and the updated firmware, and based on the result of the collating means, Means for updating the firmware memory unit in which the active firmware is stored to the firmware memory unit in which the updated firmware is stored.

A third invention for solving the above problems is
In the first invention and the second invention, the main control unit, when a failure occurs, sends the current firmware to either the first firmware memory unit or the second firmware memory unit storing the current firmware. Of the access request to the bus control unit, the bus control unit being responsive to the notification to access the firmware memory unit in which the current firmware is stored based on the stored information. It is characterized by having means for instructing the main control unit.

A fourth invention for solving the above-mentioned problems is as follows.
A program of an information processing device for downloading firmware from a host device, wherein the information processing device is
A main bus, a sub-bus, a work memory unit connected to the main bus and storing active firmware used for system operation, and a first firmware memory unit connected to the sub-bus and storing firmware, A second firmware memory unit connected to the sub-bus and storing firmware,
The program includes the information processing device, the active firmware, a first firmware memory unit, and a second firmware.
And a main control unit that reads the firmware from the firmware memory unit and stores the read firmware in the work memory unit,
In response to a firmware update request from a higher-level device, an external interface unit that stores update firmware in either the first firmware memory unit or the second firmware memory unit, and the main bus and the sub-bus are separated. However, the storage information indicating whether the active firmware is stored in either the first firmware memory unit or the second firmware memory unit is retained, and in response to the instruction to read the active firmware from the main control unit. A firmware memory unit in which the active firmware is stored based on the stored information, and in response to a request from the external interface unit, a firmware memory in which the active firmware is not stored based on the stored information. The firmware, and To function as a bus control unit for storing the update firmware Li section.

The fifth invention for solving the above-mentioned problems is as follows.
In the fourth aspect of the present invention, the program causes the bus control unit to respond to an execution request for error detection of update firmware from a higher-level device, and to determine whether the bus control unit is the first firmware memory unit or the second firmware memory unit. Error detection means for detecting an error in the update firmware stored in the storage device, and if the result of the error detection means is normal, a verification means for verifying the version of the current firmware and the updated firmware; and a result of the verification means. On the basis of the above, it is characterized by further functioning as means for updating from the firmware memory section in which the current firmware is stored to the firmware memory section in which the updated firmware is stored.

A sixth invention for solving the above-mentioned problems is as follows.
In the fourth invention and the fifth invention, the program causes the main control unit to store the working firmware in the first firmware memory unit or the second firmware memory when a failure occurs. Part to notify the bus control unit of an access request to any one of the units, and the bus control unit is responsive to the notification to respond to the notification based on the stored information. It is characterized in that it further functions as means for transferring the active firmware stored in any of the second firmware memory units to the main control unit.

A seventh invention for solving the above-mentioned problems is as follows.
A main bus, a sub bus, a work memory unit connected to the main bus and storing current firmware, first and second firmware memory units connected to the sub bus, and an external interface connected to the sub bus A method for downloading firmware from an upper-level device, wherein an information processing device having a unit, a main control unit connected to the main bus, and a bus control unit provided between the main bus and the sub-bus, The first
Based on the current firmware stored in the work memory unit, the bus control unit holding stored information indicating whether the current firmware is stored in the firmware memory unit of the second firmware memory unit or the second firmware memory unit. Then, when the main control unit is operating the system, the bus control unit responds to the request for downloading the updated firmware from the external interface unit, and based on the stored information, sets the firmware memory unit in which the current firmware is not stored. , The external interface unit is instructed, and the external interface unit stores the downloaded update firmware in a firmware memory unit in which the current firmware is not stored, according to the instruction of the bus control unit. That.

An eighth invention for solving the above-mentioned problems is as follows.
A main bus, a sub bus, a work memory unit connected to the main bus, first and second firmware memory units connected to the sub bus, an external interface unit connected to the sub bus, and the main bus A method of downloading firmware from an upper-level device by an information processing device, comprising: a main control unit connected to the main bus; and a bus control unit provided between the main bus and the sub-bus. Section or the second firmware memory section stores the storage information indicating whether the current firmware is stored in the bus control section, and the main control section stores the current information in the bus control section when the boot is started. Inquiring a firmware memory unit in which firmware is stored, and the bus control unit Responding to the inquiry, based on the stored information, notifying the main control unit of the firmware memory unit in which the current firmware is stored; and the main control unit based on the notification of the bus control unit. And reading the active firmware from the firmware memory unit in which the active firmware is stored and storing it in the work memory unit; and the main control unit, based on the active firmware stored in the work memory unit, And the main control unit is operating the system, the bus control unit responds to a request for downloading updated firmware from the external interface unit, and the current firmware is not stored based on the stored information. The firmware memory unit is connected to the external interface And the external interface unit stores the downloaded updated firmware in a firmware memory unit in which the current firmware is not stored according to the instruction of the bus control unit. .

[0018]

1 and 2 show an embodiment of the present invention. FIG. 1 is a schematic diagram of a block configuration of a functional block device and its peripheral devices mounted in a system according to the present invention. FIG. 2 is a detailed configuration diagram of the functional block device.

As shown in FIG. 1, the system according to the present invention comprises a functional block device A10 and a host device A13.

The functional block device A10 includes a device main control unit A1, a boot start program memory unit A2, a work memory unit A3 for storing data used by the device main control unit A1, and a control of the device main control unit A1. The target individual function unit A4 and individual function unit A5, the bus control unit A8 having a memory selection control function, the firmware memory units A6 and A7 for storing firmware, the system main controller A1 and the host device A13 It has an external interface control unit A9 used for control.

The device main control unit A1, the boot start program memory unit A2, the work memory unit A3, the individual function unit A4 and the individual function unit A5, and the bus control unit A8 are connected to the main bus B1 between the blocks. Connected. A bus control unit A8, firmware memory units A6 and A7,
The external interface controller is connected by a sub-bus B2 between the blocks.

Next, details of the configuration will be described with reference to FIG.

The device main control unit A1 controls the individual function unit A4 and the individual function unit A5 during system operation.

The boot start program memory section A2 stores a program which the apparatus main control section A1 first reads when the apparatus main control section A1 is powered on when the system is installed.

The work memory unit A3 is a device main control unit A1.
The firmware used by is stored.

One of the firmware memory unit A6 and the firmware memory unit A7 stores the currently operating firmware, and the other stores the updated firmware.

The bus control unit A8 is a functional block device A1.
0 holds the storage identification information indicating in which firmware memory section the currently used firmware is stored, and when the firmware update request is received from the host device A13, the update firmware is stored based on the storage identification information. Either the firmware memory unit A6 or the firmware memory unit A7 is selected, and the selection result is notified to the external interface A9 as selection information.

The external interface A9 is a DMA (Di
The rect memory access) transfer function is provided, the firmware memory unit of the transfer destination is recognized from the selection information from the bus control unit A8, and the update firmware data is DMA-transferred.

The host device A13 is a functional block device A1.
0 is monitored and controlled, and the updated firmware is transferred to the external interface A9.

The main bus B1 includes an apparatus main control unit A1 and
The boot activation program memory unit A2, the work memory unit A3, the individual function unit A4 and the individual function unit A5, and the bus control unit A8 are connected.

The sub-bus B2 is separated from the main bus B1 via the bus control unit A8, and the bus control unit A
8, the firmware memory units A6 and A7, and the external interface A9 are connected.

The external interface B3 is the host device A1.
3 and the external interface control unit A9 are connected.

Next, details of the functional block device A10 during system operation will be described with reference to FIG.
Here, of the firmware memory unit A6 and the firmware memory unit A7, the firmware memory unit A
It is assumed that 6 stores the firmware used for the current operation.

When the functional block device A10 is powered on when the system is installed, the functional block device A10 is transited to the initial state in accordance with the program held in the boot activation program memory unit A2.

The device main control unit A1 controls the processing of the individual function unit A4 and the individual function unit A5, and at the same time, the working firmware stored in the firmware memory unit A6 or the firmware memory unit A7 is used as the work memory unit A3.
Transfer read data to. And the functional block device A
Reference numeral 10 shifts the system to an operating state under the control of the system main controller A11.

The host device A13 notifies the bus controller A8 of the firmware update request via the external interface controller A9.

When the bus control unit A8 receives the firmware update request, the bus control unit A8 selects the firmware memory unit A6 or the firmware memory unit A7 in which the updated firmware is to be stored, based on the storage identification information held by itself.

In this example, since the storage identification information indicates the firmware memory unit A6, it is determined that the currently used firmware is stored in the firmware memory unit A6, and the firmware memory unit which should store the updated firmware. The firmware memory unit A7 is selected as. Then, the bus control unit A8 notifies the external interface control unit A9 of the selection information which is the result of the selection of the firmware memory unit. Further, the bus control unit A8 notifies the upper-level device A13 of firmware update permission.

After receiving the update permission, the upper-level device A13 notifies the bus control unit A8 of the functional block device A10, which is the device for which the firmware is downloaded, of the start of the transfer of the data to be the updated firmware, and the external interface A9.
The transfer of the updated firmware data is started.

The update firmware transferred as data from the host device A13 is the external interface A9.
Will be received at. The external interface A9 DMAs the updated firmware data to the firmware memory unit A7 based on the selection information notified from the bus control unit A8.
Forward.

When the transfer of the updated firmware data is completed, the host device A13 notifies the bus controller A8 of the completion of the transfer. After notifying the end of transfer, the host device A13
Requests the bus control unit A8 to execute error detection of the updated firmware.

In response to the update firmware error detection execution request from the host device A13, the bus control unit A8 performs error detection of the update firmware stored in the firmware memory unit A7, and the result of the error detection is sent to the host device A13.
Notify 13

The basic operation of this embodiment will be described.

FIG. 3 is a sequence diagram for explaining the operation of downloading the updated firmware, and FIG. 4 is a sequence diagram for explaining the operation after the completion of downloading the firmware.

First, the operation of downloading the firmware to the functional block device constituting the system of the present invention will be described with reference to FIG. Here, here, the firmware memory unit A6 and the firmware memory unit A7
Among them, it is assumed that the firmware used in the current operation is stored in the firmware memory unit A6.

When the power is turned on when the system is installed, the functional block device A10 is transited to the initial state according to the program held in the boot activation program memory unit A2. The device main control unit A1 includes a firmware memory unit A6.
The active firmware stored in the system is transferred to the work memory unit A3, and the system transitions to the operating state.

When downloading the update firmware to the functional block device A10 in the operating state (C1), the upper device A13 notifies the bus controller A8 of the update request (C2).

After receiving the update request (C2), the bus control unit A8 selects (C3) the firmware memory unit A6 or the firmware memory unit A7 which does not store the current firmware, based on the storage identification information.

In this example, since the storage identification information indicates the firmware memory unit A6, it is determined that the currently used firmware is stored in the firmware memory unit A6, and the firmware memory unit which should store the updated firmware. The firmware memory unit A7 is selected as.

Then, the bus control unit A8 notifies the external interface control unit A9 of the selection information (C4) which is the selection result of the firmware memory unit.

After receiving the selection information (C4), the external interface control unit A9 notifies the bus control unit A8 of the memory selection information response (C5) as a response. The bus control unit A8 that has received the memory selection information response (C5)
13 is notified of the update request response (C6).

Upon receiving the update request response (C6), the host device A13 notifies the bus controller A8 of the transfer start (C7) of the update firmware. The bus control unit A8 notifies the higher-level device A13 of a transfer start response (C8) which is a response to the received transfer start notification of the updated firmware.

Upon receiving the transfer start response (C8), the host device A13 starts the transfer of the updated firmware data (C9) to the external interface control unit A9.

The external interface control unit A9 notifies the update firmware data transferred from the higher-level device A13 of the selection information (C4) notified from the bus control unit A8.
Based on the above, DMA transfer (C10) is performed to the firmware memory unit A7. Update firmware data DMA
Transfers (C9) and (C10) are repeatedly performed until the transfer of the update firmware data from the higher-level device A13 is completed.

When the transfer (C9) and (C10) of the updated firmware data is completed, the host device A13 sends a transfer completion notification (C11) to the bus control unit A8. The bus control unit A8 notifies the higher-level device A13 of the transfer completion notification response (C12) in the received transfer completion notification (C11).

Upon receiving the transfer completion notification response (C12), the host device A13 requests the bus controller A8 to start error detection of the updated firmware (C13) in order to confirm whether the transferred updated firmware has an error. To do.

Start error detection of updated firmware (C
Upon receiving 13), the bus control unit A8 executes error detection (C14) of the updated firmware stored in the firmware memory unit A7. The bus control unit A8 determines the result of the error detection (C15), notifies the transfer failure (C16) when it determines that the transfer of the update firmware has failed, and updates it when it determines that the transfer of the update firmware has succeeded. The notification of completion of firmware error detection (C17) is sent to the higher-level device A13.

Next, an outline of operation in the functional block device A10 after completion of error detection will be described with reference to FIG.

As shown in FIG. 4, the device main control unit A1 is in the operating state (D3), the firmware memory unit A6 stores the firmware (D1) currently used by the device main control unit A1, and the firmware memory The updated firmware (D2) is stored in the section A7. In this state, the bus control unit A8 collates the versions of the current firmware and the updated firmware (D4).

The bus control unit A8 determines the comparison result of the version of the updated firmware (D) in order to update the stored information of the current firmware held by itself.
Perform 5). At this time, if it is determined that the version of the updated firmware is newer than the version of the current firmware, the firmware memory unit A7 (D6) is
When it is determined that the version of the updated firmware is older than the version of the active firmware, the firmware memory unit A6 (D7) is updated (D9) as the storage information of the active firmware.

After the downloading of the updated firmware, a failure occurs or a system switching (D8) of the duplex system causes the main controller A1 of the apparatus to request a bus controller A8 an access request (D10) to the firmware memory A6 or the firmware memory A7. If there is, the bus control unit A8 performs access switching (D11) based on the stored information of the current firmware, and the device main control unit A1 accesses the firmware memory unit A6 or the firmware memory unit A7 that stores the current firmware ( D12).

The apparatus main control unit A1 starts the read data transfer (D13) of the data of the current firmware from the firmware memory unit A6 or the firmware memory unit A7, and transfers the current firmware to the work memory unit A3.
(D14).

In the embodiment described above, when the update firmware is downloaded, the active firmware and the update firmware are stored in each of the two-sided firmware memory units. However, since the dual-sided firmware memory unit during normal operation stores the current firmware and the non-operation firmware, the non-operation firmware stores information on the failure that has occurred in the functional block device. If it is stored in the existing firmware memory unit, the firmware memory unit in which the non-operation firmware is stored can be used as a function unit that collects failure information.

Although the above embodiment is based on the configuration shown in FIG. 1, FIG. 1 is merely an example in which the functions are divided. For example, as shown in FIG. 5, a bus control unit and an external interface control unit are provided. May be integrated into the same element as the control unit A89. In the case of this configuration, transmission / reception can be performed between the bus control unit A8 and the external interface unit A9 without using the sub-bus that was used at the time of transmitting / receiving information, and the effect of efficiency improvement in the mounting surface on the functional block device A10 is obtained. To be

[0065]

According to the present invention, the firmware memory unit connected to the main bus directly connected to the apparatus main control unit in the prior art is disconnected and connected to the sub-bus via the bus control unit. Even when the block device is in the system operating state under the control of the device main control unit, the update firmware can be downloaded independently and in parallel under the control of the bus control unit without affecting the normal operation processing.

Further, the present invention has a structure in which the working firmware used by the apparatus main control unit is stored in the work memory unit, and the working firmware and the updated firmware are stored in each of the two-sided firmware memory units. Therefore, even if a failure occurs in the normal operation processing while downloading the updated firmware, the device main control unit can switch to the firmware memory unit that stores the current firmware and maintain system reliability. be able to.

Further, as described above, since it becomes possible to switch the selection of the firmware to be used by the apparatus main control unit by the memory control unit, the verification before the system operation and the
It is also possible to obtain the effects of improving the efficiency of work and shortening the work time in checking functions and the like.

[Brief description of drawings]

FIG. 1 is a schematic view of an embodiment according to the present invention.

FIG. 2 is a detailed configuration diagram of an embodiment according to the present invention.

FIG. 3 is a sequence diagram showing an operation of each part in downloading the updated firmware according to the present invention.

FIG. 4 is a sequence diagram showing an operation of each unit after downloading the updated firmware according to the present invention.

FIG. 5 is a configuration diagram of a second embodiment according to the present invention.

[Explanation of symbols]

A1 Device main control unit A2 Boot startup program memory section A3 work memory section A4, A5 Individual function unit A6, A7 Firmware memory part A8 bus controller A9 External interface controller A10 Function block device A11 System main controller A12 External maintenance control device A13 Host device B1 main bus B2 sub bus B3 external interface

Claims (8)

[Claims] 1. A system for downloading firmware from a host device, comprising: a main bus, a sub-bus, a work memory unit connected to the main bus, for storing a current firmware used for operating the system, A first firmware memory unit connected to the sub-bus for storing the firmware; a second firmware memory unit connected to the sub-bus for storing the firmware; Read from the firmware memory section of 2.
A main control unit that stores the read firmware in a work memory unit, and either the first firmware memory unit or the second firmware memory unit that is connected to the sub-bus and responds to a firmware update request from a higher-level device. An external interface unit for storing updated firmware, and an active firmware is stored in either the first firmware memory unit or the second firmware memory unit provided between the main bus and the sub bus. Stored information is stored, and in response to an instruction to read the active firmware from the main control unit, the firmware memory unit in which the active firmware is stored is instructed based on the stored information, and the external interface In response to the request from the department, based on the stored information Download system that have been working firmware instructs the firmware memory portion that is not stored, and having a bus control unit for storing the update firmware to the firmware memory unit. 2. The update control stored in either the first firmware memory unit or the second firmware memory unit in response to an error detection execution request of update firmware from a host device. Error detection means for detecting an error in the firmware, and if the result of the error detection means is normal, a checking means for checking the version of the current firmware and the updated firmware; and a current firmware based on the result of the checking means. 2. The firmware download system according to claim 1, further comprising: means for updating the firmware memory section storing the update firmware to the firmware memory section storing the update firmware. 3. The main control unit, when a failure occurs,
The bus control unit has means for notifying the bus control unit of an access request to either the first firmware memory unit or the second firmware memory unit in which the current firmware is stored. 3. In response to the above, there is provided means for instructing the main control section to access the firmware memory section in which the current firmware is stored based on the stored information. Firmware download system. 4. A program for an information processing device that downloads firmware from a host device, wherein the information processing device is connected to a main bus, a sub bus, and the main bus, and is a current firmware used for system operation. Which is connected to the sub-bus and stores the firmware,
And a second firmware memory unit that is connected to the sub-bus and stores firmware, the program stores the information processing device, the active firmware stores the first firmware memory unit, Read from the second firmware memory section,
A main control unit that stores the read firmware in the work memory unit, and stores the updated firmware in either the first firmware memory unit or the second firmware memory unit in response to a firmware update request from a host device. An external interface unit that separates the main bus and the sub-bus, and holds stored information indicating whether the current firmware is stored in either the first firmware memory unit or the second firmware memory unit, In response to an instruction to read the active firmware from the main control unit, instruct a firmware memory unit in which the active firmware is stored based on the stored information, and in response to a request from the external interface unit, Stores the current firmware based on the stored information Is instructed firmware memory unit is not, the program for causing to function as a bus control unit for storing the update firmware to the firmware memory unit. 5. The program causes the bus control unit to respond to a request for execution of error detection of updated firmware from a higher-level device, and to cause the bus control unit to operate in either the first firmware memory unit or the second firmware memory unit. Error detecting means for detecting an error in the stored update firmware, and if the result of the error detecting means is normal, a verifying means for verifying a version of the current firmware and the updated firmware; and a verifying means based on the result of the verifying means. 5. The program according to claim 4, further functioning as means for updating from the firmware memory unit storing the current firmware to the firmware memory unit storing the update firmware. 6. The program requests the main control unit to access either the first firmware memory unit or the second firmware memory unit in which active firmware is stored when a failure occurs. The bus control unit to access the firmware memory unit in which the working firmware is stored based on the stored information, in response to the notification. The program according to claim 4 or 5, characterized by further functioning as means for instructing a section. 7. A main bus, a sub-bus, a work memory unit connected to the main bus and storing current firmware, and first and second units connected to the sub-bus.
Information processing including a firmware memory unit, an external interface unit connected to the sub-bus, a main control unit connected to the main bus, and a bus control unit provided between the main bus and the sub-bus A method for a device to download firmware from a host device, wherein the bus control unit retains storage information indicating whether the current firmware is stored in either the first firmware memory unit or the second firmware memory unit. The step of performing, based on the current firmware stored in the work memory unit, during the system operation of the main control unit, the bus control unit responds to the request for downloading the update firmware from the external interface unit, The current firmware is stored based on the stored information A non-firmware memory unit to the external interface unit, and the external interface unit stores the downloaded update firmware in the firmware memory unit in which the current firmware is not stored according to the instruction of the bus control unit. And a download step. 8. A main bus, a sub-bus, a work memory unit connected to the main bus, first and second firmware memory units connected to the sub-bus, and an external interface unit connected to the sub-bus. And a main control unit connected to the main bus, and a bus control unit provided between the main bus and the sub bus, wherein the information processing apparatus downloads firmware from a host device. A step in which the bus control section retains storage information indicating whether the current firmware is stored in either the first firmware memory section or the second firmware memory section; Inquiring about the firmware memory section in which the current firmware is stored in the bus control section, The bus control unit, in response to the inquiry, notifies the main control unit of a firmware memory unit in which active firmware is stored, based on the storage information, and the main control unit is configured to control the bus control unit. The current firmware is read from the firmware memory unit in which the current firmware is stored based on the notification of the unit, and is stored in the work memory unit; and the main control unit is configured to store the current firmware in the work memory unit. And operating the system based on the stored information, the bus control unit responds to a download firmware update request from the external interface unit when the main control unit operates the system. The firmware memory part that does not store The external interface unit has a step of instructing the interface unit and a step of storing the downloaded update firmware in a firmware memory unit in which the current firmware is not stored, according to the instruction of the bus control unit. And how to download.