Linux/PROCESSOR-SDK-AM335X: Changing debug UART

Hi Biser,

Thanks a lot for a quick reply. I'm able to boot the board at uart3 upto u-boot but getting stuck at kernel as shown in the logs below. Could you please provide support for kernel console.

U-Boot 2016.05-00305-g3b08611-dirty (Feb 16 2017 - 20:12:16 +0530)

CPU  : AM335X-GP rev 2.1

Inside show_board_info
Model: TI AM335x BeagleBone Black
       Watchdog enabled
DRAM:  256 MiB
NAND:  0 MiB
MMC:   OMAP SD/MMC: 0, OMAP SD/MMC: 1
reading uboot.env

** Unable to read "uboot.env" from mmc0:1 **
Using default environment

<ethaddr> not set. Validating first E-fuse MAC
Press SPACE to abort autoboot in 2 seconds
=>   setenv console "ttyO0,115200n8"
=>   setenv console "ttyO2,115200n8"
=> boot
switch to partitions #0, OK
mmc0 is current device
SD/MMC found on device 0
reading boot.scr
** Unable to read file boot.scr **
reading uEnv.txt
** Unable to read file uEnv.txt **
switch to partitions #0, OK
mmc0 is current device
Scanning mmc 0:1...
switch to partitions #0, OK
mmc0 is current device
SD/MMC found on device 0
3392464 bytes read in 251 ms (12.9 MiB/s)
36283 bytes read in 14 ms (2.5 MiB/s)
Kernel image @ 0x82000000 [ 0x000000 - 0x33c3d0 ]
## Flattened Device Tree blob at 88000000
   Booting using the fdt blob at 0x88000000
   Loading Device Tree to 8ef20000, end 8ef2bdba ... OK

Starting kernel ...

Thanks and Regards

Deshvir Malik

Hi Yordan,

Below are the changes done in kernel for UART3

diff --git a/arch/arm/boot/dts/am335x-bone-common.dtsi b/arch/arm/boot/dts/am335x-bone-common.dtsi

index 07ed84c..1f2848e 100644

--- a/arch/arm/boot/dts/am335x-bone-common.dtsi

+++ b/arch/arm/boot/dts/am335x-bone-common.dtsi

@@ -104,6 +95,22 @@

                       0x174 (PIN_OUTPUT_PULLDOWN | MUX_MODE0) /* uart0_txd.uart0_txd */

               >;

       };

+      

+

+       uart3_pins: pinmux_uart3_pins {

+                        pinctrl-single,pins = <

+                                0x134 (PIN_INPUT_PULLUP | MUX_MODE1)    /* mii1_rxd3.uart3_rxd */

+                                0x138 (PIN_OUTPUT_PULLDOWN | MUX_MODE1) /* mii1_rxd2.uart3_txd */

+                        >;

+                };

+

       clkout2_pin: pinmux_clkout2_pin {

               pinctrl-single,pins = <

       clkout2_pin: pinmux_clkout2_pin {

               pinctrl-single,pins = <

@@ -194,6 +201,21 @@

       status = "okay";

};

+      

+&uart3 {

+        pinctrl-names = "default";

+        pinctrl-0 = <&uart3_pins>;

+

+        status = "okay";

+};

+

&usb {

       status = "okay";

};

We have disabled ethernet as it was conflicting with uart3.

What other changes are required?

Thanks and Regards

Deshvir Malik