WO2021120960A1

WO2021120960A1 - Usb serial port realization method for linux system console, and related product

Info

Publication number: WO2021120960A1
Application number: PCT/CN2020/129511
Authority: WO
Inventors: 吴天准; 贺传敏
Original assignee: 深圳先进技术研究院
Priority date: 2019-12-18
Filing date: 2020-11-17
Publication date: 2021-06-24
Also published as: CN111045977B; CN111045977A

Abstract

A USB serial port realization method for a Linux system console. The method comprises the following steps: when a console terminal is started, invoking a kernel to configure a kernel command line cmdline to be a multi-terminal start, and registering a USB serial port as a terminal; when the console terminal detects that a USB cable is inserted, configuring the connection state of the USB cable to be a connected state, and invoking a function to adjust the state of the USB serial port to be open; when it is determined that a first USB serial port at a peer end of the USB serial port is open, configuring the state of the USB serial port to be an open state; and the console terminal acquiring printk information, and invoking a write function of a console port to send the printk information and data in a preset cache region to a peer device by means of the USB serial port. The method has the advantage of a high transmission speed.

Description

Implementation method of USB serial port of Linux system console and related products

Technical field

This application relates to the field of software, in particular to a method for implementing a USB serial port of a Linux system console and related products.

Background technique

Embedded Linux is an operating system that tailors the increasingly popular Linux operating system to make it run on an embedded computer system. Embedded Linux not only inherits the unlimited open source code resources on the Internet, but also has the characteristics of an embedded operating system. Embedded Linux is characterized by free copyright fees, free software developers around the world to provide support, and excellent performance, easy software transplantation, open code, support for many application software, short application product development cycle, rapid launch of new products, and Many public codes can be referenced and transplanted. The information generated during the startup and operation of the Linux system will be sent to the terminal. The console (console) is a buffer concept, which actually provides information printing for the kernel; embedded Linux terminals generally use uart serial ports. The transmission speed of the existing uart serial port is very slow and low in efficiency.

Summary of the invention

In order to solve the above problems, this application discloses a method for implementing a USB serial port of a Linux system console, which can realize the printing of kernel information through the USB serial port, which improves the data transmission speed and efficiency.

The first aspect of the embodiments of the present application provides a method for implementing a USB serial port of a Linux system console. The method includes the following steps:

When the console terminal is started, call the kernel kernel to configure the kernel command line cmdline as a multi-terminal startup, and register the USB serial port as a terminal;

When the console terminal detects that the USB cable is inserted, it sets the connection status of the USB cable to the connected status, and calls the function to adjust the status of the USB serial port to open;

When the console terminal determines that the first USB serial port opposite to the USB serial port is open, the console terminal sets the status of the USB serial port to an open state;

The console terminal obtains the printk information, and calls the write function of the console port to send the printk information and the data in the preset buffer area to the peer device through the USB serial port.

Optionally, the registering the USB serial port as a terminal specifically includes:

When driving module_init in the gadget serial driver code, register the USB serial port as a terminal through the register_console function.

Optionally, the calling function to adjust the status of the USB serial port to open specifically includes:

The console terminal calls the open function to adjust the status of the USB serial port to the open state.

Optionally, the method further includes:

When the console terminal determines that the first USB serial port opposite to the USB serial port is closed, the console terminal caches the acquired printk information in the preset cache area.

In a second aspect, a terminal is provided, the terminal is an embedded Linux system, the terminal further includes a USB serial port, and the terminal further includes:

The startup unit is used to call the kernel kernel to configure the kernel command line cmdline as a multi-terminal startup, and to register the USB serial port as a terminal;

The processing unit is used to set the connection status of the USB cable to the connected status when detecting that the USB cable is inserted, and call a function to adjust the status of the USB serial port to open; determine that the first USB serial port opposite to the USB serial port is open At this time, the console terminal sets the status of the USB serial port to the open state; obtains the printk information, and calls the write function of the console port to send the printk information and the data in the preset buffer area to the opposite device through the USB serial port.

Optionally, the processing unit is specifically configured to register the USB serial port as a terminal through the register_console function when the module_init is driven in the gadget serial driver code.

Optionally, the processing unit is specifically configured to call an open function to adjust the state of the USB serial port to an open state.

Optionally, the processing unit is further configured to determine that when the first USB serial port opposite to the USB serial port is closed, the console terminal caches the acquired printk information in the preset cache area

In a third aspect, a Linux hardware system is provided, and the Linux hardware system includes: a peer device and a console terminal;

The console terminal is used to invoke the kernel kernel to configure the kernel command line cmdline as a multi-terminal startup and register the USB serial port as a terminal; when the USB cable is detected, the connection status of the USB cable is set to the connected state and called The function adjusts the status of the USB serial port to open;

The opposite device is used to start the terminal application, start the first USB serial port corresponding to the USB serial port, and set the state of the first USB serial port to the open state; send the start action to the console terminal;

The console terminal is also used to determine that when the first USB serial port opposite to the USB serial port is opened, the console terminal sets the status of the USB serial port to the open state; obtains printk information, and calls the write function of the console port to set the printk information and presets The data in the buffer area is sent to the peer device through the USB serial port.

The fourth aspect of the embodiments of the present application provides a computer-readable storage medium that stores a computer program, and the computer program includes program instructions that, when executed by a processor, cause the processor to Perform the method described in the first aspect of the embodiments of the present application.

When implementing the embodiments of this application, it has the following beneficial effects:

The technical solution provided by this application modifies the console terminal so that the console terminal can print (ie, transmit and display) printk information through the USB serial port. Since the transmission speed of the USB serial port is much faster than that of the ordinary serial port, this The technical solution provided by the application has the advantage of increasing the transmission speed.

Description of the drawings

In order to explain the technical solutions of the embodiments of the present invention more clearly, the following will briefly introduce the drawings used in the description of the embodiments. Obviously, the drawings in the following description are some embodiments of the present invention. Ordinary technicians can obtain other drawings based on these drawings without creative work.

Figure 1 is a schematic diagram of the hardware system structure in an embodiment of the application;

FIG. 2 is a schematic diagram of a flow diagram of a method for implementing a USB serial port of a Linux system console in an embodiment of the application;

FIG. 3 is a schematic structural diagram of a terminal in an embodiment of the application;

Fig. 4 is a schematic structural diagram of a Linux hardware system in an embodiment of the application.

Detailed ways

In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be described clearly and completely in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only These are a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

The terms "including" and "having" in the specification and claims of the present invention and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally also includes Other steps or units inherent in a process, product, or equipment.

Reference to "embodiments" herein means that a specific feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art clearly and implicitly understand that the embodiments described herein can be combined with other embodiments.

Refer to Figure 1. Figure 1 is a schematic diagram of a hardware system structure provided by this application. As shown in Figure 1, the operating system of the host side device (which can be a personal computer or a server) can be windows or Linux, and the host side can include: CAC ACM or generic USB serial driver; it can also include expanded US host controller hardware module. The gadget device side device may also be called the terminal side, the system running on the gadget device side may be embedded Linux, and the gadget device side device may include a gadget serial driver and a USB device controller hardware module. The host-side device and the terminal-side device are connected through a USB cable, and the USB cable may be a universal USB data cable.

Refer to Figure 2. Figure 2 provides a method for implementing the USB serial port of the Linux system console. This method is implemented in the hardware system shown in Figure 1. For the convenience of description, the host side device is determined to be PC (windows) here. Determine the device on the Gadget device side as the console terminal. As shown in Figure 2, the method includes the following steps:

Step S201: When the console terminal is started, the kernel is called to configure cmdline (kernel command line) as a multi-terminal startup, and the USB serial port is registered as a terminal;

The aforementioned USB serial port may be: a USB gadget serial port.

Optionally, the foregoing implementation method of registering the USB serial port as a terminal may specifically include:

Step S202: When the console terminal detects that the USB cable is inserted, it sets the connection state of the USB cable to the connected state, and calls the function to adjust the state of the USB serial port to open;

The above calling function to adjust the status of the USB serial port to open may specifically include:

The console terminal calls the open function to adjust the status of the USB serial port to the open state. The above-mentioned open function can be specifically: do_gs_open. Of course, in practical applications, a close function needs to be set, specifically: do_gs_close, which is used to adjust the state of the USB serial port to the closed state.

Step S203: The PC starts the terminal application program, starts the first USB serial port corresponding to the USB serial port, and sets the state of the first USB serial port to the open state; sends the start action to the console terminal;

Step S204: The console terminal sets the status of the USB serial port to an open state, obtains printk information, and calls the write function of the console port to send the printk information and the data in the preset buffer area to the PC through the USB serial port;

Optionally, the write function of the aforementioned console port may specifically include: do_gs_write.

Step S205: The PC receives the printk information and the data of the preset buffer area through the first USB serial port, and displays the printk information and the data of the preset buffer area.

The foregoing preset cache area may be 128k bytes in size, and the preset cache area is used to store the print information output by the kernel.

Optionally, the aforementioned do_gs_open, do_gs_write, and do_gs_close functions are shared with the open, write, and close functions in the file_operations of the USB tty serial port. This setting can make the corresponding open/close operations interoperable between the terminal and tty file operations, and also make the code more cohesive.

The above method may also include:

If the first USB serial port is in the closed state, the printk information is stored in the preset buffer area.

Example one

The first embodiment of the present application provides a method for implementing a USB serial port of a Linux system console. The method is implemented in the hardware system as shown in FIG. 1. The method may specifically include:

When the system is started, configure the console terminal in the cmdline (kernel command line) of the kernel as a multi-terminal startup, including ordinary serial ports (RS232 serial ports) and USB gadget serial ports. The gadget serial port has the highest priority.

The implementation process of the USB serial port implementation method of the Linux system console is as follows. When the module_init is driven in the gadget serial driver code, the USB serial port is registered as a terminal through the register_console function, and a ring buffer memory area is allocated in the terminal at this time. The size of the buffer memory area can be 128K bytes. Next, when the USB cable is inserted into the terminal, the terminal calls the gserial_connect function to set the connection status of the USB cable to 1 (that is, the connection status), and the terminal calls the function of opening/closing the USB serial port;

The above open or close function can be operated through the work struct of the Linux kernel work queue. The specific operation can be: open the USB serial port in the started work queue, and set the open state of the terminal console port to 1.

If you use Windows PC to connect to the USB serial port terminal device through the USB cable, start the terminal application on the PC side (such as Putty, SecureCRT, etc.), and start the first USB serial port corresponding to the USB serial port, open the first USB serial port, and embed The gadget serial driver code of the embedded terminal device can receive this opening action (PC opening action), and the embedded terminal device sets the status of the USB serial port to the open state; next, when the embedded terminal device has printk information to be output , The embedded terminal device will call the write function of the console port, that is, the do_gs_write function can be used here to send all terminal print information to the PC through the USB serial port, including the content previously cached in the ring buffer memory area. The Windows PC receives the printk information and the cached content and displays it.

If the Windows PC peer end closes the serial port in the terminal application, such as Putty, SecureCRT, etc. At this time, the Linux kernel printk information will be saved in the 128K byte ring buffer allocated by the driver. In addition, if the output printk information exceeds 128K bytes, the print information output by the previous kernel will be lost. If the USB serial line is unplugged next, it will trigger the execution of the task queue to open and close the serial port in the gserial_disconnect function that is called subsequently, call the do_gs_close function in the task queue to close the USB serial port, and set the USB line connection status and interrupt start The status is all 0.

Here do_gs_open, do_gs_write, do_gs_close functions are shared with the corresponding functions in the file_operations call of the USB tty serial port. Doing so can make the corresponding open/close operations interoperable between the terminal and the tty file operation, and also make the code more cohesive.

Referring to Fig. 3, Fig. 3 provides a terminal, the terminal is an embedded Linux system, the terminal further includes a USB serial port, and the terminal further includes:

Optionally, the processing unit is further configured to determine that when the first USB serial port opposite to the USB serial port is closed, the console terminal caches the acquired printk information in the preset cache area.

Referring to Figure 4, Figure 4 provides a Linux hardware system. The hardware Linux system includes: a peer device and a console terminal;

An embodiment of the present application also provides a computer storage medium, wherein the computer storage medium stores a computer program for electronic data exchange, and the computer program causes a computer to execute all or part of the method steps in FIG. 2.

The foregoing computer-readable storage medium may be the internal storage unit of the foregoing server in any of the foregoing embodiments, such as the hard disk or memory of the server. The aforementioned computer-readable storage medium may also be an external storage device of the aforementioned server, such as a plug-in hard disk equipped on the aforementioned server, a Smart Media Card (SMC), a Secure Digital (SD) card, and a flash memory card. (Flash Card) and so on. Further, the above-mentioned computer-readable storage medium may also include both an internal storage unit of the above-mentioned server and an external storage device. The aforementioned computer-readable storage medium is used to store the aforementioned computer program and other programs and data required by the aforementioned server. The aforementioned computer-readable storage medium can also be used to temporarily store data that has been output or will be output.

A person of ordinary skill in the art may be aware that the units and algorithm steps of the examples described in the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of both, in order to clearly illustrate the hardware and software Interchangeability, in the above description, the composition and steps of each example have been generally described in accordance with the function. Whether these functions are executed by hardware or software depends on the specific application and design constraint conditions of the technical solution. Professionals and technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered as going beyond the scope of the present invention.

Those skilled in the art can clearly understand that, for the convenience and conciseness of description, the specific working process of the server and unit described above can refer to the corresponding process in the foregoing method embodiment, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed server and method may be implemented in other ways. For example, the terminal embodiments described above are merely illustrative. For example, the division of the above-mentioned units is only a logical function division, and there may be other divisions in actual implementation, for example, multiple units or components may be combined or may be Integrate into another system, or some features can be ignored or not implemented. In addition, the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, terminals or units, and may also be electrical, mechanical or other forms of connection.

The units described above as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the objectives of the solutions of the embodiments of the present invention.

In addition, the functional units in the various embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units may be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or software functional unit.

If the above integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the existing technology, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium. Among them, several instructions are included to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the above-mentioned method in each embodiment of the present invention. The aforementioned storage media include: U disk, mobile hard disk, read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), magnetic disk or optical disk and other media that can store program code . In the above-mentioned embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in an embodiment, reference may be made to related descriptions of other embodiments.

Claims

A method for implementing a USB serial port of a Linux system console is characterized in that the method includes the following steps:

When the console terminal is started, call the kernel kernel to configure the kernel command line cmdline as a multi-terminal startup, and register the USB serial port as a terminal;

When the console terminal detects that the USB cable is inserted, it sets the connection status of the USB cable to the connected status, and calls the function to adjust the status of the USB serial port to open;

When the console terminal determines that the first USB serial port opposite to the USB serial port is open, the console terminal sets the status of the USB serial port to an open state;

The console terminal obtains and prints printk information, and calls the write function of the console port to send the printk information and the data in the preset buffer area to the opposite device through the USB serial port.
The method according to claim 1, wherein the registering the USB serial port as a terminal specifically comprises:

When driving module_init in the gadget serial driver code, register the USB serial port as a terminal through the register_console function.
The method according to claim 1, wherein the calling function to adjust the status of the USB serial port to open specifically comprises:

The console terminal calls the open function to adjust the status of the USB serial port to the open state.
The method according to claim 1, wherein the method further comprises:

When the console terminal determines that the first USB serial port opposite to the USB serial port is closed, the console terminal caches the acquired printk information in the preset cache area.
A terminal, the terminal is an embedded Linux system, the terminal further includes: a USB serial port, characterized in that the terminal further includes:

The startup unit is used to call the kernel kernel to configure the kernel command line cmdline as a multi-terminal startup, and to register the USB serial port as a terminal;

The processing unit is used to set the connection status of the USB cable to the connected status when detecting that the USB cable is inserted, and call a function to adjust the status of the USB serial port to open; determine that the first USB serial port opposite to the USB serial port is open At this time, the console terminal sets the status of the USB serial port to the open state; obtains the printk information, and calls the write function of the console port to send the printk information and the data in the preset buffer area to the opposite device through the USB serial port.
The terminal according to claim 5, wherein:

The processing unit is specifically configured to register the USB serial port as a terminal through the register_console function when the module_init is driven in the gadget serial driver code.
The terminal according to claim 5, wherein:

The processing unit is specifically configured to call an open function to adjust the state of the USB serial port to an open state.
The terminal according to claim 5, wherein:

The processing unit is further configured to determine that when the first USB serial port opposite to the USB serial port is closed, the console terminal buffers the acquired printk information in the preset buffer area.
A Linux hardware system, characterized in that the Linux hardware system includes: a peer device and a console terminal;

The console terminal is used to invoke the kernel kernel to configure the kernel command line cmdline as a multi-terminal startup and register the USB serial port as a terminal; when the USB cable is detected, the connection status of the USB cable is set to the connected state and called The function adjusts the status of the USB serial port to open;

The opposite device is used to start the terminal application, start the first USB serial port corresponding to the USB serial port, and set the state of the first USB serial port to the open state; send the start action to the console terminal;

The console terminal is also used to determine that when the first USB serial port opposite to the USB serial port is opened, the console terminal sets the status of the USB serial port to the open state; obtains printk information, and calls the write function of the console port to set the printk information and presets The data in the buffer area is sent to the peer device through the USB serial port.
A computer-readable storage medium, wherein the computer storage medium stores a computer program, the computer program includes program instructions, and when executed by a processor, the program instructions cause the processor to execute as claimed in claim 1. The method of any one of ~4.