How to use uart_AO_B?

How to activate uart_AO_B?

I added on /common/arch/arm64/boot/dts/amlogic/kvim.dts

uart_AO_B: serial@c81004e0 {
compatible = “amlogic, meson-uart”;
reg = <0x0 0xc81004e0 0x0 0x18>;
interrupts = <0 197 1>;
current-speed = <9600>;
status = “okay”;
clocks = <&clock CLK_XTAL>;
clock-names = “clk_uart”;
fifosize = < 64 >;
pinctrl-names = “default”;
pinctrl-0 = <&ao_b_uart_pins>;

after that I made:

$ source device/khadas/kvim/
$ ./vendor/amlogic/tools/aml_upgrade/aml_image_v2_packer -r out/target/product/kvim/upgrade/aml_upgrade_package.conf out/target/product/kvim/upgrade

but I have not found the new port “ttyS”

What is the name of the port in “uart_AO_B”?

Nougat or Mmallow?
I tried it , The uart_AO_B is work.

Vim:/dev # ls -l ttyS4                                                         
crw------- 1 root root 244,   4 2015-01-01 00:00 ttyS4
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You need to copy the dtb ‘out/target/product/kvim/obj/KERNEL_OBJ/arch/arm64/boot/dts/kvim.dtb’ to the path ‘out/target/product/kvim/dtb.img’ before packing update image.

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But “dtb.img” not a folder. How can I copy?

You can rename the kvim.dtb as dtb.img

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Does your issue got resolved?

Yes, uart_AO_B is work as ttyS4 (on Mmallow)

How to do it on Nougat?

It is the same as Mmallow

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uart_AO_B work is well with my uart gps/glonass receiver

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It is feel very good :laughing: