To standardize the adjustment of the CPU debug UART baud rate (for example, setting it to 115200), follow the steps below:
1. Modify the UART baud rate during the U-Boot stage
According to the “Rockchip_Developer_Guide_DDR_CN.pdf” document, the SDK provides the ddrbin_tool tool for modification.
Edit the DDR parameter configuration file:
Modify the uart baudrate in the neardi-rk3588-linux/rkbin/tools/ddrbin_param.txt file to 115200.
Regenerate the DDR initialization firmware:
neardi-rk3588-linux$ ./rkbin/tools/ddrbin_tool ./rkbin/tools/ddrbin_param.txt ./rkbin/bin/rk35/rk3588_ddr_lp4_2112MHz_lp5_2736MHz_v1.08.bin
The current bin file used by RK3588 can be obtained from the FlashData parameter in neardi-rk3588-linux/rkbin/RKBOOT/RK3588MINIALL.ini,
FlashData=bin/rk35/rk3588_ddr_lp4_2112MHz_lp5_2736MHz_v1.08.bin
2. Modify the UART baud rate during the Linux Kernel stage
Edit the device tree file:
+++ b/kernel/arch/arm64/boot/dts/rockchip/rk3588-linux.dtsi
@@ -45,7 +45,7 @@ fiq_debugger: fiq-debugger {
rockchip,wake-irq = <0>;
/* If enabled, UART uses IRQ instead of FIQ */
rockchip,irq-mode-enable = <1>;
- rockchip,baudrate = <1500000>; /* Only 115200 and 1500000 are supported */
+ rockchip,baudrate = <115200>; /* Only 115200 and 1500000 are supported */
interrupts = <GIC_SPI 423 IRQ_TYPE_LEVEL_LOW>;
pinctrl-names = "default";
pinctrl-0 = <&uart2m0_xfer>;
3. Rebuild and flash the firmware
neardi-rk3588-linux$ ./build.sh
After completing the build, reflash the full firmware (by default, this is the Buildroot firmware).
If you need the Ubuntu firmware, re-execute the Ubuntu packaging steps.