Arm9 (TQ2440) transplantation summary ---- transplantation preparation

   Here we mainly need to prepare some necessary software. There are two under Windows: dnw and SecureCRT (HyperTerminal is also OK). First, we test SecureCRT, which is used as a serial port console. The setting is very simple. Follow the serial port settings (protocol: serial; baud rate: 115200, the port is selected according to the actual situation; 8-bit data; 1-bit stop bit; no parity check; no hardware flow control). dnw sets the baud rate (115200) and download address (0x30000000).

   There are many ways to burn the program into the development board: jtag, usb and network. The manuals of some development boards have detailed instructions.

   Here I will explain the problems encountered when burning uboot. There are special places for burning uboot as a startup program. TQ2440 has two flash chips, nand flash and nor flash, which can be used as startup options. And both chips have uboot programs. If uboot does not exist in the chip, then you must first burn the uboot of nor flash. The burning method is in the manual, and I have not tried it. However, it can only be burned using the jtag port here. The following is the situation where uboot exists in nor flash but not in nand flash. First select nor flash to start, select 9 after starting the development board, and then select 2, that is, format nand flash. After completion, restart the development board, select 1, and burn uboot into nand flash. I use the USB burning method here, which is simple and fast. After selecting, you will see a prompt asking you to insert the USB interface. After connecting the USB. You can see that the serial terminal shows that the connection is successful. At this time, open dnw and burn uboot directly. After completion, first select nand flash to start, and then restart the development board. Now you can see that uboot has been successfully burned into nand flash (you can select 3 to burn the kernel and 6 to burn the file system).

  Here, we should pay attention to the order of burning. We must first use nor flash to burn uboot into nand flash, and then use nand flash to burn kernel and file system. We can use the image experiment prepared by Tianyan. According to my observation, although we can also choose to burn kernel and file system into nand flash under nor flash, the result is unsuccessful, which wastes a lot of time. The specific reason is unknown, and we need to study the uboot source code carefully.

  Another thing to mention is the network programming method. The manual mentions using tftp software to program in Windows, but I haven't tried it. I have used tftp to program several bare metal programs in Linux, which are the programs mentioned above. Of course, the terminal uses Linux's minicom. Since there is only one serial port, Linux and Windows cannot open terminal programs at the same time. For minicom, the settings are also very simple. Just modify the serial port name and serial port parameters and you can use it. For tftp transmission, the first thing is to ensure that the network can be pinged, that is, the development board can ping the virtual machine's Linux. The second is to put the file to be transferred in the tftpboot file in the root directory of Linux. Of course, you must select the tftp server when installing Linux (if you are not familiar with which one, you can only select all the installation options for the server). After meeting the two prerequisites, you can directly use the tftp command in the uboot of the development board: tftp 0x30008000 *.* After the transfer is completed, use the go command: go 0x30008000 to run the program. Since it is transferred to sdram, the development board cannot be restarted midway.

  Now you can transplant the Linux kernel