JP2018147285A - Electronic device, starting method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extend a period until a storage area of data used by a boot loader reaches a rewriting life. A NAND flash memory 18 stores a Vup flag 36 which is data indicating a mode of activation of an in-vehicle device 10 and which can be updated while a power source of the in-vehicle device 10 is turned on. .. The CPU 20 executes the boot loader 30 and the OS 32 when the power of the vehicle-mounted device 10 is turned on. When the Vup flag 36 is stored in the DRAM 14, the boot loader 30 activates the OS 32 in the mode indicated by the Vup flag 36. The boot loader 30 starts the OS 32 in the special mode when the Vup flag 36 is not stored in the DRAM 14. The OS 32 started in the special mode stores the Vup flag 36 stored in the NAND flash memory 18 in the DRAM 14 and executes a soft reset. [Selection diagram] Figure 1

Description

  The present invention relates to a data processing technique, and more particularly to an electronic device, a startup method, and a program.

  In recent years, flash memory is sometimes used as data storage for electronic devices. A flash memory has a relatively short rewrite life of a sector, and if the same sector is updated many times, the rewrite life is reached early. As a countermeasure, a technique for extending the period until the rewrite life is reached by automatically circulating or equalizing the data write destination for a large set of sectors (also called a partition) is adopted. Sometimes. This technique is called journaling file system or wear leveling.

  Further, the semiconductor memory device of Patent Document 1 below copies data in the flash memory to a DRAM having no rewriting life, rewrites data in the DRAM during system operation, and transfers data from the DRAM to the flash memory when the system is terminated such as when the power is turned off. Write back. As a result, the number of times the flash memory is rewritten is reduced while ensuring the non-volatility of the data.

JP 2008-59007 A

  In the technique described in Patent Document 1, the flash memory is rewritten every time the power is turned off. In the case of a system that has a long product life and is frequently turned off, such as an in-vehicle device, even if the technology described in Patent Document 1 is adopted alone, the rewrite life will be reached, so a combination with wear leveling is required. . However, wear leveling requires many sectors. Therefore, it is possible to apply wear leveling to a NAND flash memory with a large number of sectors, but it is difficult to apply wear leveling to a NOR flash memory with a small number of sectors.

  Here, the above-described problem will be described in more detail. A relatively large memory capacity is required for mounting a NAND flash memory driver and a file system corresponding to wear leveling. On the other hand, depending on the system environment (for example, in the case of an in-vehicle device), the boot loader needs to operate with a small-capacity internal RAM. In this case, the boot loader cannot access the NAND flash memory, and data used by the boot loader is usually stored in the NOR flash memory. When data that is updated relatively frequently is stored in a NOR flash memory, it is difficult to apply a life-span extension technique (for example, wear leveling), and the rewrite life may be reached early. .

  The present invention has been made in view of such circumstances, and one object is to extend the period until the storage area of data used by the boot loader reaches the rewrite life.

  In order to solve the above-described problem, an electronic device according to an aspect of the present invention is data indicating a start-up mode of the electronic device and can be updated while the power of the electronic device is on. A NAND flash memory storing at least special data, a volatile memory, and a processor that executes a boot loader and an OS (Operating System) when the electronic apparatus is powered on. When the special data is stored in the volatile memory, the boot loader starts the OS in a mode indicated by the special data. When the special data is not stored in the volatile memory, the boot loader starts the OS in the special mode. The OS activated in the special mode stores the special data stored in the NAND flash memory in the volatile memory and restarts the electronic device.

  Another aspect of the present invention is an activation method. This method is a NAND flash memory in which at least special data that is data indicating an activation mode of the electronic device and can be updated while the power of the electronic device is on, and volatile A startup method executed by an electronic device including a memory and a processor that executes a boot loader and an OS (Operating System) when the power of the electronic device is turned on, and stores special data in a volatile memory If the special data is not stored in the volatile memory, the OS is started in the special mode, and the special data stored in the NAND flash memory is stored in the volatile memory. And restart the electronic device.

  Note that any combination of the above components, the expression of the present invention converted between a computer program, a recording medium on which the computer program is recorded, a vehicle equipped with the present apparatus, and the like are also effective as an aspect of the present invention. It is.

  According to the present invention, it is possible to extend the period until the storage area of data used by the boot loader reaches the rewrite life.

It is a figure which shows the structure of the vehicle-mounted apparatus of 1st Example. It is a flowchart which shows operation | movement of the vehicle-mounted apparatus of 1st Example. It is a flowchart which shows operation | movement of the vehicle-mounted apparatus of 2nd Example. It is a flowchart which shows the operation | movement following FIG.

[First embodiment]
Before describing the configuration of the in-vehicle device of the embodiment, an outline will be described. As described above, the flash memory that can be accessed by the boot loader that is executed at the initial stage of startup of the in-vehicle device may be limited to the NOR flash memory. The NOR type flash memory has a higher capacity unit price than the NAND type flash memory. Therefore, if the storage area is rotated in order to extend the life of the storage area of data referred to by the boot loader (referred to herein as “special data”), it costs more than the NAND flash memory.

  The special data is data that can be read and written and can be rewritten during the operation of the in-vehicle device. The special data is data indicating a mode of starting the in-vehicle device. In other words, the special data is data instructing the boot loader to start in a specific mode. The special data in the embodiment is assumed to be a version upgrade flag (hereinafter referred to as “Vup flag 36”) that designates necessity of version upgrade (in other words, program update). However, the special data is not limited to the version upgrade flag. The special data may be data related to customization by the user. For example, it may be a customized image flag indicating whether or not to replace an image displayed on the display when the in-vehicle device is activated with a user-specified image.

  The in-vehicle device according to the embodiment is configured such that the boot loader can refer to special data stored in the NAND flash memory. Specifically, the in-vehicle device includes a memory (in the embodiment, a DRAM, but may be a predetermined register) that is volatile but continues to store data when restarted by software control. Hereinafter, restart by software control is referred to as software reset. Note that soft reset can also be called software reboot or software reset. When the power of the in-vehicle device is turned on, the boot loader first starts up the OS in a special data read mode (hereinafter referred to as “special mode”). The OS loads special data from the NAND flash memory to the DRAM, performs a soft reset immediately after loading, and returns control to the boot loader. After the soft reset, the boot loader can start the OS in the manner indicated by the special data stored in the DRAM.

  According to the in-vehicle device of the embodiment, the special data storage area referred to by the boot loader can be set in the NAND flash memory. Therefore, the period until the special data storage area reaches the rewrite life can be extended. Furthermore, in the NAND flash memory, data can be updated via a file system to which wear leveling is applied. Therefore, the period until the special data storage area reaches the rewrite life can be extended more easily.

  FIG. 1 shows a configuration of an in-vehicle device 10 of the first embodiment. The in-vehicle device 10 is an electronic device mounted on a vehicle, and may be a car navigation device or an IVI (In-Vehicle Infotainment) device, for example.

  The in-vehicle device 10 includes an SOC (System On a Chip) 12, a DRAM 14, a NOR flash memory 16, and a NAND flash memory 18. The in-vehicle device 10 further includes a communication unit (not shown) that communicates with an external device via a communication network such as the Internet. In the embodiment, the communication unit communicates with a server outside the vehicle and receives an update program transmitted from the server. The in-vehicle device 10 may further include a display (not shown) that displays various information.

  The SOC 12 includes a CPU 20, a built-in ROM 22, and a built-in RAM 24. The built-in RAM 24 is a small capacity RAM of about 16 Kbytes, and may be an SRAM. The built-in RAM 24 stores a boot loader 30 read from the NOR flash memory 16. Actually, those skilled in the art can easily understand that the function determined by the program is exhibited when the CPU 20 executes the program stored in the predetermined area.

  The DRAM 14 stores the OS 32 read from the NOR flash memory 16. The DRAM 14 also stores a Vup detection App 34 and a Vup flag 36 read from the NAND flash memory 18. Although not shown in FIG. 1, the DRAM 14 is provided with an area corresponding to the initialization completion flag. The initialization completion flag is a flag indicating whether or not a predetermined initialization process has been completed, and is off in the initial state. When the Vup flag 36 is stored in a predetermined area of the DRAM 14, the initialization completion flag is switched on.

  The NOR flash memory 16 stores a boot loader 30 and an OS 32. The NAND flash memory 18 stores a Vup detection App 34 and a Vup flag 36. The Vup detection App 34 is an application program that runs on the OS 32, communicates with the server via the communication unit, and detects whether it is time to update the program installed in the in-vehicle device 10. The Vup flag 36 is data indicating whether the OS 32 should be started in the upgrade mode or the normal mode.

  In the in-vehicle device 10, known wear leveling control (in other words, a journaling file system) for smoothing the number of rewrites to each storage element of the NAND flash memory 18 is implemented. The wear leveling control may be implemented as hardware hardware leveling, or may be implemented as software wear leveling. In the embodiment, the application operating on the OS 32 is a file system provided by the firmware of the OS 32 or the NAND flash memory 18, and updates the data of the NAND flash memory 18 through the file system to which wear leveling is applied. To do.

  The DRAM 14 functions as a main memory of the in-vehicle device 10. When the in-vehicle device 10 is restarted under software control (soft reset), the DRAM 14 of the embodiment stores data before the restart even after the restart. Note that the DRAM 14 may have a backup function. In this backup function, at least in the case of a soft reset, the storage data of the DRAM 14 before the restart may be temporarily stored in the nonvolatile memory, and the storage data may be written back to the DRAM 14 after the start.

The operation of the in-vehicle device 10 having the above configuration will be described.
FIG. 2 is a flowchart showing the operation of the in-vehicle device 10 of the first embodiment. When the power of the in-vehicle device 10 is turned on (Y in S10), the CPU 20 reads the boot loader 30 from a predetermined area of the NOR flash memory 16 stored in the built-in ROM 22. The CPU 20 stores the read boot loader 30 in the built-in RAM 24 and executes it. The boot loader 30 (actually the process of the boot loader 30) confirms the initialization completion flag in the DRAM 14, in other words, confirms whether the value of the area corresponding to the initialization completion flag is a value indicating ON or OFF. To do.

  When the initialization completion flag is off (N in S12), the boot loader 30 starts up the OS 32 in the special mode (S14). For example, the boot loader 30 may start a program of the OS 32 by adding a parameter indicating the special mode. The special mode can be said to be an operation mode for reading the Vup flag 36. The OS 32 activated in the special mode reads the Vup flag 36 stored in the NAND flash memory 18 and stores it in a predetermined area of the DRAM 14 (S16). The OS 32 sets the initialization completion flag of the DRAM 14 to ON (S18), and soft resets the in-vehicle device 10 (S20).

  By the software reset in S20, for example, the program counter of the CPU 20 returns to 0 and returns to S12. As described above, the DRAM 14 retains data (including at least the Vup flag 36 and the initialization completion flag) stored at the time of the soft reset even after the soft reset. The CPU 20 stores the boot loader 30 in the built-in RAM 24 and executes it. When the initialization completion flag of the DRAM 14 is on (Y in S12), the boot loader 30 checks whether the Vup flag 36 of the DRAM 14 is on.

  When the Vup flag 36 is on (Y in S22), the boot loader 30 loads the program of the OS 32 into the DRAM 14 and starts the OS 32 in the upgrade mode (S24). The OS 32 (actually the process of the OS 32) starts a predetermined application (hereinafter also referred to as “Vup execution App”) that executes version upgrade (program update or the like) (S26). For example, the Vup execution App communicates with an external server to acquire an update program, and updates the system by storing the update program in the NAND flash memory 18 or the like (S28).

  The Vup execution App sets the Vup flag 36 of the DRAM 14 to OFF and also sets the Vup flag 36 of the NAND flash memory 18 to OFF (S30). At this time, the Vup execution App updates the Vup flag 36 of the NAND flash memory 18 via the file system to which wear leveling is applied. The Vup execution App may update both flags synchronously or asynchronously. For example, the flag of the DRAM 14 may be updated first, and the flag of the NAND flash memory 18 may be updated later (at the time of soft reset or the like). The Vup execution App uses the function of the OS 32 to soft reset the in-vehicle device 10 (S32).

  The process returns to S12 again by the soft reset in S32. The CPU 20 stores the boot loader 30 in the built-in RAM 24 and executes it. When the initialization completion flag of the DRAM 14 is on (Y in S12) and the Vup flag 36 of the DRAM 14 is off (N in S22), the boot loader 30 starts the OS 32 in the normal mode (S34). The OS 32 activates a predetermined application that executes various functions of the in-vehicle device 10 (S36). Thereafter, the in-vehicle device 10 is in a steady state, and executes a car navigation function, for example.

  The application activated in S36 includes Vup detection App34. When receiving the upgrade start trigger from the external server (Y in S38), the Vup detection App 34 sets the Vup flag 36 of the DRAM 14 to ON and sets the Vup flag 36 of the NAND flash memory 18 to ON (S40). ). At this time, the Vup detection App 34 updates the Vup flag 36 of the NAND flash memory 18 via the file system to which wear leveling is applied. Similarly to the Vup execution App, the Vup detection App 34 may update both flags synchronously or asynchronously. The Vup detection App 34 uses the function of the OS 32 to soft reset the in-vehicle device 10 (S42). When the soft reset in S42 is performed, the system is updated by Vup execution App, following the path of Y in S12 and Y in S22.

  If a version upgrade start trigger has not been received in a steady state (N in S38) and an end condition such as power off is satisfied (Y in S44), the flow of FIG. If the termination condition is not satisfied (N in S44), the process returns to S38 and the steady state is maintained. If the power of the in-vehicle device 10 is not turned on (N in S10), the subsequent processing is skipped, and the flow of this figure is ended.

  In FIG. 2, when the upgrade start trigger is received, the Vup flag 36 of the DRAM 14 and the Vup flag 36 of the NAND flash memory 18 are set to ON in S40, and a soft reset is executed in S42. As a modification, the process may proceed to S44 after S40, that is, the steady state may be maintained after the Vup flag 36 is updated. In this case, S14 to S18 are executed at the timing when the power is turned off and then turned on again, and the Vup flag 36 of the NAND flash memory 18 is loaded into the DRAM 14. Then, S24 to S28 are executed, and the system is updated.

[Second Embodiment]
In the second embodiment, a technique for realizing quick start-up of the in-vehicle device 10 is proposed. The configuration of the in-vehicle device 10 of the second embodiment is the same as that of the first embodiment (FIG. 1). Hereinafter, the description of the same contents as in the first embodiment will be omitted as appropriate.

  In the second embodiment, at least one of the boot loader 30 and the OS 32 (both in the embodiment) has a limited initial value when the Vup flag 36 is not stored in the DRAM 14 as compared with the case where the Vup flag 36 is stored in the DRAM 14. Execute the conversion process. When the Vup flag 36 is not stored in the DRAM 14, it can be said that the initialization completion flag of the DRAM 14 is off. When the Vup flag 36 is stored in the DRAM 14, it can be said that the initialization completion flag of the DRAM 14 is on. The initialization process is a series of procedures for initializing the internal state of the device and enabling access such as reading and writing by the CPU 20.

  Specifically, the boot loader 30 and the OS 32 perform a plurality of types of initialization processes executed in the startup process when the Vup flag 36 is not stored in the DRAM 14 in the startup process when the Vup flag 36 is not stored in the DRAM 14. Run part. In other words, when the Vup flag 36 is not stored in the DRAM 14, the boot loader 30 and the OS 32 execute a smaller number of initialization processes than the initialization process executed in the normal startup process. That is, when the Vup flag 36 is not stored in the DRAM 14, the boot loader 30 and the OS 32 execute a minimum initialization process necessary for loading the Vup flag 36 from the NAND flash memory 18 to the DRAM 14.

An example of the minimum necessary initialization process executed when the Vup flag 36 is not stored in the DRAM 14 is shown.
(1) SOC 12 pin multi setting (S52 in FIG. 3):
It is set which terminal of the SOC 12 is assigned to which function. Including pin function setting and GPIO (General Purpose Input / Output) initialization.
(2) Initialization of the NOR flash memory 16: (S54 in FIG. 3)
It includes two processes: an initialization process by a program stored in the built-in ROM 22 and an initialization process by the boot loader 30. The former is necessary for loading the boot loader 30 from the NOR flash memory 16 to the built-in RAM 24 (S56 in FIG. 3). The latter is necessary for loading the OS 32 from the NOR flash memory 16 to the DRAM 14 (S64 in FIG. 3).

(3) Initialization of DRAM 14 (S62 in FIG. 3):
This is necessary for loading the OS 32 from the NOR flash memory 16 to the DRAM 14 (S64 in FIG. 3). Further, it is necessary for loading the Vup flag 36 from the NAND flash memory 18 to the DRAM 14 (S70 in FIG. 3).
(4) Initialization of the NAND flash memory 18 (S68 in FIG. 3):
This is necessary for loading the Vup flag 36 from the NAND flash memory 18 to the DRAM 14 (S70 in FIG. 3).

  The SOC 12 can be connected to various external devices (not shown in FIG. 1), and during normal startup, initialization processing for many external devices is required. However, when the Vup flag 36 is not stored in the DRAM 14, it is necessary to complete the loading of the Vup flag 36 by limiting the initialization process necessary for loading the Vup flag 36 from the NAND flash memory 18 to the DRAM 14. You can save time.

  In the second embodiment, at least one of the boot loader 30 and the OS 32 (both in the embodiment) executes a plurality of operations executed when the Vup flag 36 is not stored in the DRAM 14 when the Vup flag 36 is stored in the DRAM 14. At least a part of the initialization process is skipped. It can be said that the initialization process executed when the Vup flag 36 is not stored in the DRAM 14 is the initialization process executed before the soft reset. Further, when the Vup flag 36 is stored in the DRAM 14, it can be said that it is after a soft reset (after a restart).

  A large effect can be expected by skipping is initialization of an external device (for example, DRAM 14 in FIG. 1) connected to the SOC 12. The initialization of the external device is generally completed by repeating a sequence of 1) sending an initialization command from the SOC 12 to the external device and 2) notifying completion of the initialization from the external device to the SOC 12. Here, the time for which the SOC 12 waits for a response from the external device may be several milliseconds to several hundred milliseconds, and may occupy a large proportion of the time from the start of the in-vehicle device 10 to the completion of the start. Many. Therefore, the time required for starting the in-vehicle device 10 can be shortened by skipping initialization of the external device as much as possible.

  In order to skip the initialization of the external device, the following two points need to be considered. 1) Do not turn off the power of the external device when the SOC 12 is restarted. This is because, generally, when an external device is turned off, the set value is cleared and reinitialization is required. In the in-vehicle device 10 of the second embodiment, when the SOC 12 is soft reset, the power supply to the DRAM 14, the NOR flash memory 16, and the NAND flash memory 18 is maintained. 2) After the SOC 12 is restarted, before the SOC 12 accesses the external device, the internal settings of the SOC 12 related to the device (for example, the setting value of the IO register) are reset to the same contents as before the restart. The SOC 12 of the second embodiment has a configuration for this resetting, and is mounted on a program in the built-in ROM 22, for example.

  In the second embodiment, the initialization process to be skipped after restarting is (3) initialization of the DRAM 14 and (4) initialization of the NAND flash memory 18. In any case, since the time required for initialization is relatively long, the effect of shortening time by skipping can be expected.

  The above (1) initialization of the NOR flash memory 16 and (2) the pin multi setting of the SOC 12 are executed again without being skipped even after restarting. (1) can be skipped if the following two preconditions are satisfied. However, since the NOR flash memory 16 generally requires a short time for initialization and the delay is small even if it is re-executed, the process (1) is re-executed in the embodiment. The first precondition is that the setting value set by the program in the built-in ROM 22 of the SOC 12 and the setting value set by the boot loader 30 completely match. The second precondition is that the program in the built-in ROM 22 of the SOC 12 is mounted so that initialization can be skipped. Also, (2) is not initialization of the external device but initialization of the SOC 12, and the setting time is negligibly short. Therefore, in the embodiment, the processing of (2) is re-executed.

The operation of the in-vehicle device 10 having the above configuration will be described.
FIG. 3 is a flowchart showing the operation of the in-vehicle device 10 of the second embodiment. When the power of the in-vehicle device 10 is turned on (Y in S50), the CPU 20 executes a program stored in the built-in ROM 22 (herein referred to as “built-in ROM program”). The built-in ROM program performs pin multi setting of the SOC 12 (S52). The built-in ROM program executes an initialization process for the NOR flash memory 16 (S54). The built-in ROM program loads the boot loader 30 from the NOR flash memory 16 to the built-in RAM 24 (S56).

  The boot loader 30 executes an initialization process for the NOR flash memory 16 (S58). When the initialization completion flag of the DRAM 14 is off, or when the initialization of the DRAM 14 is not executed and the initialization completion flag of the DRAM 14 cannot be referred to (N in S60), the boot loader 30 executes the initialization process for the DRAM 14. (S62) The OS 32 is loaded from the NOR flash memory 16 to the DRAM 14 (S64). The boot loader 30 starts up the OS 32 in the special mode (S66).

  The OS 32 executes initialization processing for the NAND flash memory 18 (S68), and loads the Vup flag 36 from the NAND flash memory 18 to the DRAM 14 (S70). The OS 32 sets the initialization completion flag of the DRAM 14 to ON (S72), and executes a soft reset (S74). After the soft reset, the processes from S52 to S58 are executed again. If the initialization completion flag of the DRAM 14 is on (Y in S60), the boot loader 30 proceeds to the process of FIG.

  FIG. 4 is a flowchart showing the operation following FIG. Following Y in S60 in FIG. 3, if the Vup flag 36 of the DRAM 14 is on (Y in S76), the boot loader 30 skips the initialization process (S62 in FIG. 3) for the DRAM 14 and performs the NOR flash memory. The OS 32 is loaded from 16 to the DRAM 14 (S78). The boot loader 30 starts up the OS 32 in the upgrade mode (S80). The OS 32 skips the initialization process (S68 in FIG. 3) for the NAND flash memory 18 in the course of the startup process. Subsequent S82 to S88 are the same as S26 to S32 in FIG.

  3, if the Vup flag 36 of the DRAM 14 is OFF (N in S76), the boot loader 30 skips the initialization process for the DRAM 14 and transfers the OS 32 from the NOR flash memory 16 to the DRAM 14. Load (S90). The boot loader 30 starts up the OS 32 in the normal mode (S92). The OS 32 skips the initialization process for the NAND flash memory 18 during the boot process. Subsequent S94 to S102 are the same as S36 to S44 in FIG. After the soft reset in S88 and S100, the process returns to S52 in FIG. If the power of the in-vehicle device is turned off in FIG. 3 (N in S50), the processing of FIG. 3 and FIG. 4 is skipped and the flow of FIG.

  The present invention has been described based on the first and second embodiments. These embodiments are examples, and it will be understood by those skilled in the art that various modifications can be made to each component or combination of processing processes, and such modifications are within the scope of the present invention.

  In the above-described embodiment, the technology that enables the boot loader to refer to the data stored in the NAND flash memory is applied to the in-vehicle device. As described above, the vehicle is frequently turned on and off repeatedly. Further, with the spread of automatic driving, it is assumed that the vehicle is required to have higher security and that the program needs to be updated frequently. Therefore, the technology of the embodiment that facilitates extending the period until the storage area of the data used by the boot loader reaches the rewrite life is suitable for the in-vehicle device. However, the application target of the technology of the embodiment is not limited to the in-vehicle device, and can be applied to various electronic devices. For example, it can be applied to a PC, a tablet terminal, a smartphone, and an embedded system.

  In the above embodiment, the soft reset is executed as the restart process for returning the control of the in-vehicle device 10 from the OS 32 to the boot loader 30. As a modification, another type of restart process may be executed. For example, when the in-vehicle apparatus 10 includes a suspend / resume function that is implemented so that control is once returned from the OS 32 to the boot loader 30, the suspend / resume may be executed as the restart process.

Note that the techniques described in the examples and the modifications may be specified by the following items.
[Item 1]
NAND type flash memory storing at least special data that is data indicating a mode of activation of the electronic device and that can be updated while the electronic device is powered on;
Volatile memory,
A processor that executes a boot loader and an OS (Operating System) when the electronic device is powered on;
With
When the special data is stored in the volatile memory, the boot loader boots the OS in a mode indicated by the special data,
The boot loader boots the OS in a special mode when the special data is not stored in the volatile memory,
An electronic device in which the OS activated in the special mode stores the special data stored in the NAND flash memory in the volatile memory and restarts the electronic device.
The boot loader of this electronic device cannot directly access the NAND flash memory, but it can refer to the special data stored in the NAND flash memory in cooperation with the OS, and the OS is started in the manner indicated by the special data. can do. Further, by storing the special data in the NAND flash memory, it becomes easy to extend the period until the area for storing the special data reaches the rewrite life.
[Item 2]
The electronic device according to Item 1, wherein the predetermined application operating on the OS updates the special data stored in the NAND flash memory via a file system to which wear leveling is applied.
According to this aspect, the period until the special data storage area in the NAND flash memory reaches the rewrite life can be easily extended.
[Item 3]
When the special data is stored in the volatile memory, at least one of the boot loader and the OS is at least one of a plurality of initialization processes executed when the special data is not stored in the volatile memory. Item 3. The electronic device according to Item 1 or 2, wherein part initialization processing is skipped.
According to this aspect, it is possible to reduce the number of initialization processes to be executed when restarting, and to shorten the time until startup is completed.
[Item 4]
4. The electronic device according to item 3, wherein the skipped at least part of the initialization process includes an initialization process of the volatile memory and an initialization process of the NAND flash memory.
According to this aspect, it is possible to reduce the number of initialization processes to be executed when restarting, and to shorten the time until startup is completed.
[Item 5]
A NOR-type flash memory in which the boot loader is stored;
The processor is implemented as an SOC (System On a Chip),
The SOC multi-pin setting and the NOR flash memory initialization process are executed both when the special data is stored in the volatile memory and when the special data is not stored in the volatile memory. The electronic device according to any one of items 1 to 4.
According to this aspect, the initialization process with a short execution time is executed regardless of whether or not the special data is stored in the volatile memory, thereby facilitating mounting of the electronic device.
[Item 6]
When the special data is not stored in the volatile memory, at least one of the boot loader and the OS performs at least a part of initialization processing that is skipped when the special data is stored in the volatile memory. The electronic device according to any one of items 1 to 3 to be executed.
According to this aspect, the initialization process required when the special data is stored in the volatile memory is executed in advance when the special data is not stored in the volatile memory. It is possible to reduce the time required for the initialization process when special data is stored in the.
[Item 7]
7. The electronic device according to item 6, wherein at least a part of the initialization process skipped includes an initialization process of the volatile memory and an initialization process of the NAND flash memory.
According to this aspect, the time required for the initialization process when special data is stored in the volatile memory can be reduced.
[Item 8]
A NOR-type flash memory in which the boot loader is stored;
The processor is implemented as an SOC (System On a Chip),
The initialization process executed when the special data is not stored in the volatile memory includes the SOC pin multi setting, the NOR flash memory initialization process, the volatile memory initialization process, The electronic device according to any one of items 1 to 7, including an initialization process of the NAND flash memory.
According to this aspect, the initialization process required when special data is stored in the volatile memory can be executed in advance when the special data is not stored in the volatile memory.
[Item 9]
NAND type flash memory storing at least special data that is data indicating a mode of activation of the electronic device and that can be updated while the electronic device is powered on;
Volatile memory,
A processor that executes a boot loader and an OS (Operating System) when the electronic device is powered on;
A startup method executed by an electronic device comprising:
When the special data is stored in the volatile memory, the OS is started in a mode indicated by the special data,
If the special data is not stored in the volatile memory, the OS is started in a special mode,
A startup method for storing special data stored in the NAND flash memory in the volatile memory and restarting the electronic device.
According to this startup method, the boot loader cannot directly access the NAND flash memory, but by cooperation with the OS, the special data stored in the NAND flash memory can be referred to, and the OS is displayed in a manner indicated by the special data. Can be launched. Further, by storing the special data in the NAND flash memory, it becomes easy to extend the period until the area for storing the special data reaches the rewrite life.
[Item 10]
NAND type flash memory storing at least special data that is data indicating a mode of activation of the electronic device and that can be updated while the electronic device is powered on;
Volatile memory,
A processor that executes a boot loader and an OS (Operating System) when the electronic device is powered on;
A program executed in an electronic device comprising:
When the special data is stored in the volatile memory, the OS is started in a mode indicated by the special data,
If the special data is not stored in the volatile memory, the OS is started in a special mode,
A program for storing special data stored in the NAND flash memory in the volatile memory and restarting the electronic apparatus.
According to this program, the boot loader cannot directly access the NAND flash memory, but by cooperation with the OS, the special data stored in the NAND flash memory can be referred to, and the OS is displayed in the manner indicated by the special data. Can be activated. Further, by storing the special data in the NAND flash memory, it becomes easy to extend the period until the area for storing the special data reaches the rewrite life.

  Any combination of the above-described embodiments and modifications is also useful as an embodiment of the present invention. The new embodiment resulting from the combination has the effects of the combined example and modification. Further, it should be understood by those skilled in the art that the functions to be fulfilled by the constituent elements described in the claims are realized by the individual constituent elements shown in the embodiments and the modified examples or by their cooperation.

  10 on-vehicle device, 14 DRAM, 16 NOR type flash memory, 18 NAND type flash memory, 20 CPU, 30 boot loader, 32 OS.

Claims (10)

NAND type flash memory storing at least special data that is data indicating a mode of activation of the electronic device and that can be updated while the electronic device is powered on;
Volatile memory,
A processor that executes a boot loader and an OS (Operating System) when the electronic device is powered on;
With
When the special data is stored in the volatile memory, the boot loader boots the OS in a mode indicated by the special data,
The boot loader boots the OS in a special mode when the special data is not stored in the volatile memory,
The OS started in the special mode stores the special data stored in the NAND flash memory in the volatile memory, and restarts the electronic device.
Electronics. The predetermined application operating on the OS updates the special data stored in the NAND flash memory via a file system to which wear leveling is applied.
The electronic device according to claim 1. When the special data is stored in the volatile memory, at least one of the boot loader and the OS is at least one of a plurality of initialization processes executed when the special data is not stored in the volatile memory. Part initialization processing is skipped,
The electronic device according to claim 1. The skipped at least part of the initialization process includes an initialization process of the volatile memory and an initialization process of the NAND flash memory.
The electronic device according to claim 3. A NOR-type flash memory in which the boot loader is stored;
The processor is implemented as an SOC (System On a Chip),
The SOC multi-pin setting and the NOR flash memory initialization process are executed both when the special data is stored in the volatile memory and when the special data is not stored in the volatile memory. To be
The electronic device according to claim 1. When the special data is not stored in the volatile memory, at least one of the boot loader and the OS performs at least a part of initialization processing that is skipped when the special data is stored in the volatile memory. Run,
The electronic device according to claim 1. The skipped at least part of the initialization process includes an initialization process of the volatile memory and an initialization process of the NAND flash memory.
The electronic device according to claim 6. A NOR-type flash memory in which the boot loader is stored;
The processor is implemented as an SOC (System On a Chip),
The initialization process executed when the special data is not stored in the volatile memory includes the SOC pin multi setting, the NOR flash memory initialization process, the volatile memory initialization process, Including initialization processing of the NAND flash memory,
The electronic device according to claim 1. NAND type flash memory storing at least special data that is data indicating a mode of activation of the electronic device and that can be updated while the electronic device is powered on;
Volatile memory,
A processor that executes a boot loader and an OS (Operating System) when the electronic device is powered on;
A startup method executed by an electronic device comprising:
When the special data is stored in the volatile memory, the OS is started in a mode indicated by the special data,
If the special data is not stored in the volatile memory, the OS is started in a special mode,
Storing special data stored in the NAND flash memory in the volatile memory and restarting the electronic device;
starting method. NAND type flash memory storing at least special data that is data indicating a mode of activation of the electronic device and that can be updated while the electronic device is powered on;
Volatile memory,
A processor that executes a boot loader and an OS (Operating System) when the electronic device is powered on;
A program executed in an electronic device comprising:
When the special data is stored in the volatile memory, the OS is started in a mode indicated by the special data,
If the special data is not stored in the volatile memory, the OS is started in a special mode,
Storing special data stored in the NAND flash memory in the volatile memory and restarting the electronic device;
program.

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