JP7577985B2 - Information processing device and method - Google Patents

Description

The present invention relates to an information processing device and method.

Traditionally, fault analysis of embedded systems has been time-consuming and laborious. For example, one type of fault is an operating system stall (hang-up). When this fault occurs, it is not possible to execute commands for debugging purposes, and it is also not possible to use the debugging functions provided by the operating system, making fault analysis difficult.

Patent document 1 discloses a main processing unit that provides functions, and a fault detection unit/monitoring control unit that detects faults and collects information. During normal operation, the main processing unit periodically sends a specified signal to the fault detection unit/monitoring control unit, and when a certain amount of time has passed since the last information transmission, the fault detection unit/monitoring control unit fault is deemed to be a fault by the main control unit.

However, in conventional technology, to correctly determine the cause of a fault, the device status must be periodically sent to the fault detection unit/monitoring control unit fault, which requires allocating CPU resources to this operation. Embedded systems often have CPUs with lower performance than general PCs, and using this method poses a very high risk of degrading product performance.

The present invention has been made in consideration of the above problems, and aims to provide an information processing device and method capable of collecting information when a failure occurs even in an environment where the processing power of the embedded system is limited.

In order to solve the above-mentioned problems and achieve the object, an information processing device of the present invention has a function providing unit that provides normal functions through the operation of a first CPU, a fault information collecting unit that, through the operation of a second CPU, collects addresses of memory areas of fault information notified from the function providing unit of the first CPU , and a Watch Dog as a notification unit that notifies the fault information collecting unit of the second CPU of the occurrence of a fault in the function providing unit, wherein the Watch Dog notifies the fault information collecting unit of the occurrence of a fault in the function providing unit by notifying the second CPU of an interrupt signal when a refresh operation for the Watch Dog, which is performed periodically by the first CPU, is not performed for a certain period of time, and when the fault information collecting unit is notified of the occurrence of a fault in the function providing unit by the interrupt signal from the Watch Dog, it reads out data of the address indicating the fault information from the memory area corresponding to the function providing unit and stores the data in a storage unit.

The present invention has the advantage of being able to collect information when a failure occurs even in an environment where the processing power of an embedded system is limited.

FIG. 1 is a diagram illustrating an example of a configuration of an information processing apparatus according to an embodiment. FIG. 2 is a diagram illustrating an example of a process flow for notifying a second CPU of an allocation area of a function providing unit from a first CPU.

The following describes in detail an embodiment of an information processing device and method with reference to the attached drawings.

(Embodiment)
Fig. 1 is a diagram showing an example of the configuration of an information processing device according to an embodiment. Fig. 1 shows the configuration of an information processing device of an embedded system such as a printer. The information processing device 1 has a hardware configuration including a CPU (Central Processing Unit), a RAM (Random Access Memory) 13 which is a volatile memory, a non-volatile memory 23, and a network device 24. The CPUs are a plurality of CPUs, for example a first CPU 11 and a second CPU 21. The information processing device 1 also includes a timer 12 and a watch dog 14 as hardware. The timer 12 is used by the first CPU 11.

As shown in FIG. 1, the information processing device 1 includes a function providing means 10 and a fault information collecting means 20. The function providing means 10 provides normal functions through software function units (corresponding to "function providing units") 15 such as an OS 151 and various applications operated by the first CPU 11. The fault information collecting means 20 provides a function for collecting fault information through software function units (corresponding to "fault information collecting units") 25 such as an information collection module 252 operated by the second CPU 21. Here, OS 151 refers to a general-purpose OS (Operating System)/real-time OS incorporated into an embedded system.

The function providing means 10 corresponds to a processing circuit that provides a printing function in an embedded system of a printer, for example. The fault information collecting means 20 has various components for collecting and storing information when a fault occurs in the function providing means 10.

In this configuration, the first CPU 11 notifies the second CPU 21 of the allocated area of the RAM 13 used by the function providing unit 15. First, the process of notifying the second CPU 21 of the allocated area of the function providing unit 15 from the first CPU 11 will be described.

Figure 2 is a diagram showing an example of a process flow in which the first CPU 11 notifies the second CPU 21 of the allocation area of the function providing unit 15. As shown in Figure 2, when the first CPU 11 starts the OS (S11), it allocates a log area on the RAM 13 (S12), notifies the second CPU 21 of the address d1 of the log area (S13), and further notifies the second CPU 21 of the address d2 of the OS area (S14).

The second CPU 21 starts the information collection module 252 (S21), receives the address d1 of the log area sent from the first CPU 11 and sets it in the information collection module 252 (S22), and further receives the address d2 of the OS area sent from the first CPU 11 and sets it in the information collection module 252 (S23). The information collection module 252 reads data such as the OS from the above set address when a failure occurs in the function providing means 10.

Returning to FIG. 1, the method of collecting data when a failure occurs will be described. The function providing unit 15 reads a periodic signal from the timer 12 using the timer handler 152, and refreshes the Watch Dog 14 at that timing.

Here, Watch Dog 14 is hardware for detecting system runaway, and issues a non-maskable interrupt (NMI) after a certain period of time has elapsed. In most cases, the system is restarted when this interrupt is detected. Since Watch Dog 14 sends an interrupt to second CPU 21, it may be implemented on the same ASIC as second CPU 21, or it may be implemented separately and have a signal line connected to the interrupt terminal of second CPU 21.

The function providing unit 15 performs an operation called "refresh" on the Watch Dog 14 at regular intervals. If the function providing unit 15 falls into a fatal abnormal state, a certain period of time will pass without "refreshing" being performed. If a certain period of time passes without a refresh operation being performed, the Watch Dog 14, as a "notification unit", notifies the second CPU 21 with a signal (interrupt signal).

The second CPU 21 monitors the occurrence of a fault by an interrupt signal. When the second CPU 21 detects an interrupt signal, the NMI interrupt handler 251 performs interrupt processing of the information collection module 252. The information collection module 252 reads memory data from a set address (log area or OS area) of the RAM 13 as the interrupt processing. For example, the information collection module 252 reads memory data M1 from an address of the OS area of the RAM 13. Furthermore, the information collection module 252 outputs the read memory data to the network device 24, and transmits the memory data from the network device 24 to a storage unit such as an external server or cloud storage via the connected network. Note that the memory data is not limited to a storage destination outside the information processing device 1, and may be stored in a storage unit such as a non-volatile memory 23 provided inside the information processing device 1.

Then, for example, the system is restarted and an analyst uses the data in the storage unit to analyze the cause of the failure.

In this manner, in this embodiment, a form has been shown in which separate CPUs are implemented for the function providing means that provides normal functions such as the OS and applications, and the fault information collecting means that collects fault information. If the OS accesses an invalid memory space or falls into a state called a stall, it will enter a state called a "hang-up." However, in this configuration, the debug function operates only when a fault occurs, and reads the area of data on RAM 13 that corresponds to the function providing unit 15, so there is no need to allocate CPU resources to operations that are not directly related to the normal functions provided by the product. Therefore, the risk of degrading the performance of the product is extremely low.

In addition, the time it takes to collect fault information can be shortened by limiting the data to be read when a fault occurs to an area such as the OS. If a normal user process (command) accesses an invalid memory space, the OS has a mechanism to detect this and forcibly terminate the process in question. Therefore, it is rare for the user process itself to experience a stall-type fault. On the other hand, the OS can access areas such as hardware registers where erroneous access would have fatal consequences. In other words, it is often the OS that is the software that experiences fatal faults such as stalls. Therefore, when reading information required for fault analysis, the time it takes to collect fault information can be reduced by limiting the range to the OS area, etc.

The data that is read is stored in the storage unit, so the designer can use this data later to analyze the cause. Also, by reading data from the OS area, the cause of the failure can be correctly determined.

In addition, even if a fault occurs in a large-scale embedded system, the time required for fault analysis can be shortened.

As a result, it is possible to collect information when a failure occurs even in environments where the processing power of embedded systems is limited.

Although the embodiments have been described above, the above embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims.

Reference Signs List 1 Information processing device 10 Function providing means 11 First CPU
12 Timer 13 RAM
14 Watch Dog
15 Software function unit (corresponding to the "function providing unit")
20: fault information collecting means 21: second CPU
23 Non-volatile memory 24 Network device 25 Software function unit (corresponding to "fault information collection unit")
151 OS
152 Timer handler 251 NMI interrupt handler 252 Information collection module M1 Memory data

JP 2017-207903 A

Claims (5)

a function providing unit that provides a normal function through the operation of the first CPU;
a fault information collection unit that collects, by operation of a second CPU, addresses of memory areas of fault information notified from the function provision unit of the first CPU ;
a Watch Dog as a notification unit that notifies the fault information collection unit of the second CPU of the occurrence of a fault in the function providing unit;
having
the Watch Dog notifies the second CPU of an occurrence of a fault in the function providing unit by notifying the fault information collecting unit of an interrupt signal when a refresh operation for the Watch Dog, which is periodically performed by the first CPU, is not performed for a certain period of time;
when the fault information collection unit is notified of the occurrence of a fault in the function providing unit by the interrupt signal from the Watch Dog, the fault information collection unit reads data of the address indicating the fault information from the memory area corresponding to the function providing unit and stores the data in a storage unit.
Information processing device. the fault information collection unit stores the data in an external storage unit via a network;
The information processing device according to claim 1 . the fault information collection unit reads the data from an address of an OS area, which is the memory area notified by the function provision unit after startup;
3. The information processing device according to claim 1 or 2. the first CPU is a CPU of a printer embedded system;
The function providing unit provides a printing function.
The information processing device according to claim 1 . A method for an embedded system to collect and store normal function failure information, comprising:
providing the normal function through operation of a first CPU;
a second CPU operates to collect addresses of memory areas of the fault information notified from the first CPU;
performing a refresh operation on a Watch Dog from the first CPU at regular intervals;
When the refresh operation is not performed by the first CPU for a certain period of time, an interrupt signal is sent from the Watch Dog to the second CPU;
When the interrupt signal from the Watch Dog is notified, the second CPU reads data at the address indicating the fault information from the memory area corresponding to the normal function as an interrupt process when a fault occurs in the normal function , and stores the data in a storage unit.
method.

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