Junzheng 4750 Development Board use diary 1-hardware connectivity

Recently, two jz4750 APUs development boards are required for trial. This is also the first contact. I encountered a lot of problems in the middle and finally spent a lot of time doing a good job. Here I will summarize all the process records (for the time being, I cannot upload a picture, and I will try it again if I have a chance ).

 

This diary is divided into the following points:

1. hardware connectivity

2. Linux environment construction and kernel Compilation

3. root file system, startup file, and helloworld

4. Configuration and compilation of QT embedded, tslib, and QT for vs2008

 

Hardware connectivity

 

After getting the Development Board, I found that there were no accessories and there was only one CD with development documents and burning programs. One of the items is a qtopia desktop by default, and the speed is still relatively fast; the other is a Linux desktop, playing a bit, the speed is extremely slow; if you connect the network cable, by default, the network cannot be connected. You must manually set the DHCP gateway DNS using the command line (udhcpc eth0.

 

The touch screen is very difficult to use, and it is estimated that there is no registration. So I found a USB mouse and connected it to the USB port (the mouse is connected to the large USB host port on the lower navigation board, the small one above is used to burn, charge, and simulate a USB flash drive.) The result is useless. Later, I changed my mouse and it went on again. The Linux system on the Development Board only supports a specific USB mouse driver.

 

Next, test the connection to the COM port. Because the Development Board does not have a com line by default, I also asked my colleagues to buy it in the computer city. At first, I looked at the panel behind my computer and found that there was no comport, so I spent tens of dollars buying a com-to-USB converter. After buying the driver, install the usb com driver and connect the driver. I usually use windows, so I use Putty to connect to the Comport and set the baud rate to 57600bps OF THE jz4750 Development Board. However, no output is made to com.

 

At this time, I found that there was a COM1 port on my computer hardware, and then I thought that the motherboard seemed to have a com-lead accessory. So I found the motherboard specification, and the motherboard had a comport. I thought that since the USB comport is not good, maybe the motherboard can come with it, so I found a com lead in the accessories and opened the chassis to bring the comport to the rear panel of the chassis.

 

Connect to the com line, open putty, Boot, LINUX started, com still did not respond. At this time, a technical support on QQ reminded me that the com line must be a 2-3 pair connection, and cannot be a direct connection; then I tested it with a multimeter, and there was a problem. The com line was a direct connection. The solution is to change the com direct line: carefully cut the skin from the middle, do not break the line inside, then use a multimeter to connect one end to 2 or 3 feet, the other side with a needle, one by one needle test to find out the corresponding line of 2 and 3 feet, and then cut, interconnect, weld it, and use a tape or rope to prevent disconnection. After a good try, OK. uboot information can be output at startup.

 

By the way, the Development Board's variable-voltage DC power supply, the original Development Board is not powered, so let the seller with a high noise, there is a huge noise when playing music. My USB to comport cannot work when using this power supply, but you can use the USB port for power supply. During the installation, if the power supply goes on, it is often prone to verification errors, So I simply don't need it and directly use USB for power supply.

 

Then, you can burn it. I burned a built-in Linux demo Rom, and the running result is no different from the original one. Later, I burned a self-built ucosii demo Rom. This time, instead of using USB _ boot, I installed a dedicated USB _ boottool.exe in the demo file/ucos. the same principle is also true, however, after selecting the ROM file, the USB is automatically installed immediately after it is connected, such as an automatic burning tool on the production line. After the installation, it is found that the startup and running speed is very fast, which is much better than that of Linux. Unfortunately, the UCOS development cost is too high. Later, I decided to use Linux + QT to give up UCOS.

 

After completing these steps, you can basically confirm that the hardware is connected. Up to five wires are connected to the Development Board: power cord, USB burning cord, comport cable, network cable, and mouse. Next, let's talk about how to configure the jz4750 Linux software development environment.