To apply and experimentally verify the PRU's high‑speed UARTs based on SDK 11.1, the PRU UART driver must first be added to the native kernel. Apply the following commands and the corresponding patch.

1. Apply the kernel patch to the SDK 11.1 kernel, recompile the kernel, and install the new kernel image (Image), modules, and k3‑am625‑sk.dtb into the root file system (rootfs) on the SD card.

   
   host# patch -p1 < pru-tty-driver-v6.12-20251204.diff
   host# make linux
   host# sudo DESTDIR=/media/tony/root make linux_install

2. Copy the PRU firmware to the /lib/firmware/ directory of the root file system, and then create a soft link named am62x‑pru0‑fw pointing to it.

   # ln -sf PRU_UART_12Mb.out.v1.1 am62x-pru0-fw

3. Boot the AM62x SK EVM development board. The new pru‑tty driver is built into the kernel image and creates 4 UART nodes:

   
   # ls /dev/ttyPRU*
     /dev/ttyPRU0  /dev/ttyPRU1  /dev/ttyPRU2  /dev/ttyPRU3

4. Run the following command to start PRU0.

   
   root@am62xx-evm:~# echo start > /sys/class/remoteproc/remoteproc2/state
   [  703.729726] remoteproc remoteproc2: powering up 30074000.pru
   [  703.737406] remoteproc remoteproc2: Booting fw image am62x-pru0-fw, size 25852
   [  703.744705] remoteproc remoteproc2: remote processor 30074000.pru is now up
   

   Now you can run UART applications to write data to these UART nodes. Currently, simply using the open() and write() functions enables high‑speed UART data transmission via the PRU. The following is reference code for transmitting data using the open() and write() functions.

   
   write(fp0, data, data_len);
   fp0 = open("/dev/ttyPRU0",  O_RDWR | O_NONBLOCK);
   

Figure 3-3 shows the waveform measured using a logic analyzer to verify the entire data path from the application layer to the underlying hardware by transmitting the data randomly generated on the Linux side.