CN103853383B - A kind of method realizing touch-screen driving in Uboot - Google Patents

Abstract

The invention discloses a method for realizing a touch screen driver in Uboot, comprising: modifying and cutting the touch screen driver in the operating system kernel; transplanting the touch screen driver into Uboot; compiling Uboot after the transplantation is completed; transplanting the compiled Uboot to On the development board; after the development board is powered on, run Uboot to initialize the touch screen. If the user has operations on the touch screen during the Uboot running phase, he will choose to continue the operation, and the touch screen will display a list of the applications available to the user. The user clicks on the screen to select the application he needs, and after detecting the coordinates of the touch point, compare the application program and the touch point coordinates The mapping relationship of the scope, the program jumps to the program entry of the corresponding application program for execution, exits after the execution is completed, and continues to execute the Uboot code to start the operating system. If the user does not operate the touch screen during the Uboot running phase, then exit and continue to execute the Uboot code to start the operating system. The invention solves the problem that the touch screen can only be used after the operating system is started.

Description

A method of realizing touch screen driver in Uboot

technical field

The invention relates to the field of embedded technology, in particular to a method for realizing touch screen driving in Uboot.

Background technique

In miniaturized devices such as tablet computers and smart phones, the input and output devices occupy a large volume. The touch screen is a device that integrates input and output, which can effectively reduce the size of the device and is durable, so that people can get rid of it. It eliminates the operation of keyboard and mouse, makes the computer interaction more direct, and is widely used in various embedded products.

The current touch screen driver is mainly integrated in the kernel of the operating system in the form of modules, and the touch screen driver with simple functions can also be run in the bare metal environment. After the operating system is successfully started, the user can operate the touch screen. After the tablet and other mobile devices are powered on, the system boot program Uboot will first run the system boot program, which will guide the kernel and pass parameters to the kernel to start the operating system. Uboot does not have a touch screen driver, so it runs on Uboot. At this stage, the touch screen cannot be used, and the user needs to perform related operations through key input.

Uboot (Universal Bootloader Loader) is a bootloader bootloader that can support a variety of embedded systems. It is mainly responsible for initializing hardware devices before the operating system starts, creating memory space maps, etc. In a suitable state, the correct environment is prepared for the final call to the operating system kernel. Therefore, implementing the touch screen driver at the Uboot layer can enhance the human-computer interaction of the mobile device during the Uboot startup stage, facilitate the user's selection operation, realize the use of the touch screen before the operating system starts, and provide convenience for the user to develop other functional applications during the Uboot stage.

The current touch screen technology is mainly used in the interaction between people and mobile handheld or fixed devices after the operating system is started, or in the related testing of touch screens in a bare metal environment. There is no research on touch screen drivers at the Uboot layer at home and abroad.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for realizing the touch screen drive in Uboot in view of the deficiencies in the prior art, to realize the operation of the touch screen device in the Uboot startup stage, and to solve the problem that the touch screen can only be used after the operating system is started .

For solving the problems of the technologies described above, the technical solution adopted in the present invention is: a method for realizing touch screen drive in Uboot, the method is:

1) Delete the kernel-related parts of the touch screen driver code in the operating system kernel to obtain the modified touch screen driver code, transplant the modified touch screen driver code to Uboot, configure Uboot, and compile the configured Uboot;

2) Download the compiled Uboot to the development board, and execute the Uboot code sequentially after the development board is powered on;

3) Initialize the touch screen during Uboot running;

4) Run the touch screen display driver, if the user uses the touch screen during the Uboot running phase, go to step 5), otherwise go to step 8);

5) The touch screen list displays a list of user-selectable applications;

6) The touch screen controller judges whether the touch screen is clicked, if yes, the touch screen controller generates a pressed interrupt signal, and enters step 7); otherwise, returns to step 5);

7) The touch screen controller enters the interrupt service program, sets the appropriate coordinate conversion mode and registers to read the position of the contact, after the coordinate conversion is completed, the touch screen controller returns to the waiting interrupt mode; establish the mapping between the contact coordinate range and the application program relationship, when the user clicks on the touch screen to select the application program, according to the coordinate value of the touch point obtained by analog-to-digital conversion, the corresponding application program is executed according to the mapping relationship between the coordinate range of the touch point and the application program; the touch point refers to the contact point on the touch screen point;

8) Determine whether the user continues to operate the touch screen in step 4) or whether the application program in 7) has been executed, if not, exit the operation on the touch screen; if so, return to step 5);

9) Continue to execute the Uboot code and start the operating system.

Compared with the prior art, the present invention has the beneficial effects that: the present invention frees the use of the touch screen from dependence on the operating system, realizes the bottom layer's support for the touch screen, and the user can still use The touch screen is not operated through buttons, etc., and the screen will display a user-selectable application list. After the user selects, the touch screen contact detection can be realized, and the corresponding operation can be entered after determining the contact coordinate information; the method of the present invention enhances It improves the human-computer interaction of mobile devices, facilitates the user's selection operation, realizes the use of the touch screen before the operating system starts, and provides convenience for users to develop other functional applications in the Uboot stage.

Description of drawings

Fig. 1 is a system block diagram of an embodiment of the present invention;

Fig. 2 is a method flowchart of an embodiment of the present invention;

Fig. 3 is a functional block diagram of an analog-to-digital converter and a touch screen interface according to an embodiment of the present invention;

FIG. 4 is a flowchart of touch screen driving according to an embodiment of the present invention.

detailed description

The invention realizes the support of the touch screen in the environment without an operating system by performing a series of additions, deletions, modifications and other operations on the touch screen drive code in the operating system kernel and then transplanting it into the Uboot. Using this method, the use of the touch screen can get rid of the dependence on the operating system, and realize the bottom layer's support for the touch screen. In the Uboot running stage of the approximate bare metal environment, the user can still use the touch screen instead of pressing the buttons to operate, and the screen will display the user The optional application list, after the user selects, can realize the detection of the touch screen contact, determine the coordinate information of the contact point and enter the corresponding operation and other functions. The block diagram of the system is shown in Figure 1.

For the system block diagram structure shown in Figure 1, the overall flow chart of the technical method adopted in the present invention is shown in Figure 2, specifically including the following steps:

1): Transplant the touch screen driver to Uboot, and add the touch screen driver in the board-level configuration-related file directory in Uboot. Recompile Uboot after the porting is complete.

2): Download the recompiled Uboot to the development board.

3): The development board is powered on, and the Uboot code is executed sequentially. The Uboot code is divided into assembly language and C language stage. The calling function of the touch screen driver is located in the C language stage, which is the second stage of Uboot execution.

4): Configure and initialize the touch screen: add the initialization program of the touch screen in the C file corresponding to the development board under the Uboot directory. The initialization process includes creating events, initializing touch screen interrupts and timer interrupts. Under normal conditions, if an external force acts on a point of the touch screen, a corresponding voltage signal will be generated, and the voltage signal will be converted by the analog-to-digital converter to obtain the coordinates of the contact point. The functional block diagram of the interface between the analog-to-digital converter and the touch screen is shown in Figure 3 .

5): Choose whether to continue, if the user needs to use the touch screen in the Uboot running stage, choose to continue to enter step 6), if the user does not need to run the touch screen at this stage, then choose to exit and enter step 9).

6): After selecting continue, the screen will display a list of application options available for the user to choose from, and the user can select the application option he needs according to the list.

7): At this time, if the user clicks the screen, enter 8), if the user's click operation cannot be detected, then continue to execute step 6).

8): The touch screen controller is generally in the waiting interrupt mode. After the stylus is pressed, the program will enter the interrupt service program to read the position of the contact point. After the coordinate conversion is completed, the controller returns to the waiting interrupt mode. Here, it is necessary to establish a mapping relationship between the application program and the coordinate point range. After determining the coordinates of the touch point, jump to the entry point of the corresponding application program to execute the code according to the range of its coordinate value.

9): Check whether the execution of the application program is completed. If the execution is not successful, return to step 6), and if the execution is completed, enter step 10).

10): If the user chooses not to continue the operation or the application program is executed, exit the operation on the touch screen.

11): Continue to execute Uboot to start the operating system.

The present invention will be further elaborated below in conjunction with an example.

This example is based on the smart mobile terminal development board OK6410. The mobile device platform includes: 4.3-inch TFT LCD, ARM architecture CPU, model S3C6410; wired network card, model DM9000; key module; storage module is 2G Nand Flash, which is a four-wire Resistive touch screen, supports LCD models from 3.5 to 10.4 inches.

This example uses Uboot1.6 as an example of Uboot. The touch screen driver in the kernel is modified, cut and transplanted to Uboot1.6, so that the user can operate the touch screen when Uboot1.6 starts.

S1: Transplant the touch screen driver to Uboot1.6, add the touch screen driver file in the board/smdk6410 directory in Uboot1.6, add the touch screen initialization program in the smdk6410.c file, and set the hardware parameters of the touch screen in include. Modify the C language function start_armboot of Uboot1.6, and add the function of calling the touch screen driver. start_armboot is the function started by C language, and it is also the main function of C language in the entire startup code and the main function of the entire Uboot1.6. Recompile Uboot1.6 after the porting is completed, and enter the command #arm-linux-gcc –V to view the version number of the cross compiler; #Make distclean to clear the link generated before; #make xxx_config compile; #make CROSS-COMPILE=arm-linux -, the uboot.bin file will be generated.

S2: Download the recompiled Uboot1.6 to the development board.

S3: The development board is powered on, and the Uboot1.6 code is executed sequentially.

S4: Configure and initialize the touch screen: add a program to initialize the touch screen in the C file related to the development board. The initialization process includes creating events, initializing touch screen interrupts and timer interrupts. The flow chart of the touch screen driver is shown in Figure 4.

S5: Choose whether to continue. Run the LCD display driver, the screen will display the option of "continue to operate" to ask the user whether to continue to execute the touch screen driver code, if the user needs to use the touch screen during the Uboot1.6 running stage, choose to continue, if the user does not need to run the touch screen at this stage then opt out.

S6: After choosing to continue, the screen will display the applications that the user can choose to use, and the user selects the application he needs according to the application list.

S7: The user clicks the touch screen with the stylus to select the application program he needs. After detecting that the stylus is pressed, the touch screen controller generates a pressed interrupt signal and enters step S8. If the stylus is not detected, continue to execute the steps. S6.

S8: The touch screen controller is generally in the waiting interrupt mode. When the touch screen controller generates an interrupt signal that the stylus is pressed, the program will enter the interrupt service routine, set the appropriate conversion mode and set the register to read the position of the contact point, coordinate conversion There are two modes: separate X/Y axis coordinate conversion mode or automatic X/Y axis coordinate conversion mode. After the conversion is completed, the controller returns to the waiting interrupt mode. Establish the mapping relationship between the application program and the coordinate point range. After determining the coordinates of the contact point, jump to the entry point of the corresponding application program to execute the code according to the range of its coordinate value.

S9: Detect whether the execution of the application program is completed, if the execution fails, return to step S6, and if the execution is completed, enter step S10.

S10: Exit the operation on the touch screen if the user chooses not to continue the operation or after the download of the application program is completed.

S11: Continue to execute Uboot1.6 to start the operating system.

Compared with the prior art, a method for realizing the touch screen driver in Uboot of the present invention, by writing and modifying the touch screen driver, transplanting the touch screen driver to Uboot, modifying the Uboot startup code, recompiling Uboot, etc., realizes that the user does not operate Operation of the touch screen in the system environment. The use of the touch screen does not depend on the characteristics of the operating system, which is convenient for smart terminal users.

Claims (2)

1. a method for realizing touch screen driver in Uboot, is characterized in that, the method is: 1) Delete the kernel-related parts of the touch screen driver code in the operating system kernel to obtain the modified touch screen driver code, transplant the modified touch screen driver code to Uboot, configure Uboot, and compile the configured Uboot; 2) Download the compiled Uboot to the development board, and execute the Uboot code sequentially after the development board is powered on; 3) Initialize the touch screen during Uboot running; 4) Run the touch screen display driver, if the user uses the touch screen during the Uboot running phase, go to step 5), otherwise go to step 8); 5) The touch screen list displays a list of user-selectable applications; 6) The touch screen controller judges whether the touch screen is clicked, if yes, the touch screen controller generates a pressed interrupt signal, and enters step 7); otherwise, returns to step 5); 7) The touch screen controller enters the interrupt service program, sets the appropriate coordinate conversion mode and registers to read the position of the contact, after the coordinate conversion is completed, the touch screen controller returns to the waiting interrupt mode; establish the mapping between the contact coordinate range and the application program relationship, when the user clicks on the touch screen to select the application program, according to the coordinate value of the touch point obtained by analog-to-digital conversion, the corresponding application program is executed according to the mapping relationship between the coordinate range of the touch point and the application program; the touch point refers to the contact point on the touch screen point; 8) Determine whether the user continues to operate the touch screen in step 4) or whether the application program in 7) has been executed, if not, exit the operation on the touch screen; if so, return to step 5); 9) Continue to execute the Uboot code and start the operating system. 2. the method for realizing touch-screen drive in Uboot according to claim 1 is characterized in that, the method for realizing LCD touch-screen drive in Uboot1.6 is as follows: 1) Transplant the LCD touch screen driver to Uboot1.6, add the LCD touch screen driver file in the board/smdk6410 directory in Uboot1.6, add the touch screen initialization program in the smdk6410.c file, and set the hardware parameters of the LCD touch screen in include ; Modify the C language function start_armboot of Uboot1.6 to increase the function of calling the touch screen driver; recompile Uboot1.6 after the transplantation is completed, and enter the command #arm-linux-gcc –V to check the version number of the cross compiler; #Make distclean before clearing Generated link; compile #make xxx_config; #make CROSS-COMPILE=arm-linux-, generate uboot.bin file; 2) Download the recompiled Uboot1.6 to the development board, power on the development board, and execute the Uboot1.6 code in sequence; 3) Add the program for LCD to initialize the touch screen in the C file of Uboot1.6 related to the development board. The initialization process includes creating events, initializing touch screen interrupts and timer interrupts; 4) Run the LCD touch screen display driver, if the user uses the LCD touch screen in the Uboot1.6 running stage, then go to step 5); otherwise, go to step 8); 5) The LCD touch screen displays the application programs that can be selected by the user; 6) The LCD touch screen controller judges whether the LCD touch screen is clicked, if so, the LCD touch screen controller generates a pressed interrupt signal, and enters step 7); otherwise, returns to step 5); 7) The touch screen controller enters the interrupt service program, sets the appropriate coordinate conversion mode and registers to read the position of the contact, the coordinate conversion mode adopts the separate X/Y axis coordinate conversion mode or automatic X/Y axis coordinate conversion Mode, after the coordinate conversion is completed, the LCD touch screen controller returns to the waiting interrupt mode; establish the mapping relationship between the operating system type and the coordinate point range, and when the coordinates of the touch point are determined, jump to the application download according to the range of the touch point coordinate value Execute code at the entrance to download the application; 8) If the user chooses not to continue the operation in step 4) or the application download is completed in step 7), exit the operation on the LCD touch screen; otherwise, return to step 5); 9) Continue to execute Uboot1.6 to start the operating system.