Linux/PROCESSOR-SDK-AM335X: Kernel boot hangs on custom board

Hello Srinivasa,

Since your board is am335x-evmsk based. Can you try to boot with am335x-evmsk.dtb?

Best regards,
Kemal

Hi Kemal,

Thanks for very quick response.

We tried with both am335x-evm.dtb and am335x-evmsk.dtb.  Still the same result.

Regards

Srinivasa

Can you enter this command in U-Boot console and retry?

=> setenv fdt_high 0x8c000000

Tried the below command as below, still the same result.

setenv fdt_high 0x8c000000

fatload mmc 0:1 0x88000000 am335x-evm.dtb
fatload mmc 0:1 0x82000000 uImage
setenv bootargs console=ttyS0, 115200
bootm 0x82000000 - 0x88000000

Last message displayed is "Starting Kernel ...".  No further output.

Regards

Srinivasa

Can you remove everything from the device tree except UART, I2C, MMC, and PMIC nodes then try to boot in that way?

We have created a minimum dts file with UART0 node only. 

Still the Kernel is not coming up and no console logs observed.  

Same built zImage and dtb we run on Beaglebone black which worked but zImage doesnt run on our custom board.

Please find the dts file attached.

Regards,

Srinivashttps://e2e.ti.com/cfs-file/__key/communityserver-discussions-components-files/791/am335x_2D00_evmsk.7z

Just few updates:

1. Hardware is working fine, because old U-boot and old kernel is working fine.
2. We are using u-boot and Linux kernel from TI-SDK 5.03.
3. In u-boot we have modified few  things and I have attached the patch file for reference.  After attaching the path file only u-boot was working.

Considerin this, I have looked at the patch file and in my opion there are no similar changes required for  Kernel.  

Can you please look at the patch file and let us know if there is any modification to be done for kernel also?

Regards

Srinivasahttps://e2e.ti.com/cfs-file/__key/communityserver-discussions-components-files/791/8182.u_2D00_booth_5F00_patch.7z

I can boot my board with your patch applied, with the prebuilt kernel. Can you revert your changes and apply the patch from this post to hardcode the board name to "A335X_SK" and check whether the board boots?

Hi Kemal,

I just referred to the patch file.  We don't have EEPROM on our target board and we have commented EEPROM section in our code (in do_board_detect()  as below:

#ifdef CONFIG_TI_I2C_BOARD_DETECT
void do_board_detect(void)
{

enable_i2c0_pin_mux();
i2c_init(CONFIG_SYS_OMAP24_I2C_SPEED, CONFIG_SYS_OMAP24_I2C_SLAVE);

//OFFSET(usb1_drvvbus)
// printf("Srini usb1_drvbus 0x%x %ld\n",OFFSET(usb1_drvvbus));

#if(0)

if (ti_i2c_eeprom_am_get(CONFIG_EEPROM_BUS_ADDRESS,
CONFIG_EEPROM_CHIP_ADDRESS))
printf("ti_i2c_eeprom_init failed\n");

#endif

}
#endif

We are manually loading the dtb and kernel to SDRAM and booting form 0x80000000 using below commands:

load mmc 0:1 0x88000000 am335x-evm.dtb
load mmc 0:1 0x82000000 zImage
setenv bootargs console=ttyS0,115200
bootz 0x82000000 - 0x88000000

Regards

Srinivasa

I am able to book the kernel on beagblebone black with our build TI-SDK kernel but not on our customized target board.

We are porting from Kervel 3.2 to latest available kernel available in TI SDK. Old u-boot and kernel are working fine on target board.
We don't have .dts files in our old linux or u-boot tree. Now we need to modify dts file as per our target board (which is similar to EVMSK).

Regards
Srinivasa

Can you check whether your custom board will boot with these attached images?

https://e2e.ti.com/cfs-file/__key/communityserver-discussions-components-files/791/AM335x_5F00_boot_5F00_part_5F00_with_5F00_hardcoded_5F00_A335X_5F00_SK_5F00_board_5F00_name_5F00_dtb_5F00_and_5F00_kernel_5F00_images.tar.xz

Extracted above attached file

Step 1:

Copied “am335x-evmsk.dts” to the ti-sdk linux tree i.e) arch/arm/boot/dts and compiled the dts file using below command.

make CROSS_COMPILE=arm-criticallink-linux-gnueabi- am335x-evmsk.dtb.

Copied the generated am335x-evmsk.dtb file to the boot partition of SD card.

Copied u-boot.img, MLO, and zImage-am335x-evm.bin to boot partition of SD card.

Result:

No messages on console and u-boot did not come up.

Step 2:

Copied our u-boot files to boot partition of SD card. Our u-boot files are generated from TI-SDK u-boot with path applied which I have shared earlier.

U-boot did come up and performed below steps:

load mmc 0:1 0x88000000 am335x-evmsk.dtb

load mmc 0:1 0x82000000 zImage-am335x-evm.bin

setenv bootargs console=ttyS0,115200

bootz 0x82000000 - 0x88000000

Result is as below:

=> load mmc 0:1 0x88000000 am335x-evmsk.dtb

30545 bytes read in 6 ms (4.9 MiB/s)

=> load mmc 0:1 0x82000000 zImage-am335x-evm.bin

3871232 bytes read in 329 ms (11.2 MiB/s)

=> setenv bootargs console=ttyS0,115200

=> bootz 0x82000000 - 0x88000000

## Flattened Device Tree blob at 88000000

   Booting using the fdt blob at 0x88000000

   Loading Device Tree to 8df0b000, end 8df15750 ... OK

Srini kernel_entry address -2113929216

## Transferring control to Linux (at address 82000000)...

 Srini debug @ line 169 in function device_remove in file ../drivers/core/device-remove.c

Srini debug @ line 213 in function device_remove in file ../drivers/core/device-remove.c

Srini debug @ line 213 in function device_remove in file ../drivers/core/device-remove.c

Srini debug @ line 107 in function announce_and_cleanup in file ../arch/arm/lib/bootm.c

machid : 3589

Srini r2 : 8df0b000

Jumping to 82000000

Bye bye u-boot :(

I have put some debug messages to see if there is any problem in u-boot.  U-boot seems to fine.  I have right R2 and jump address printed but still kernel is not coming up.

Regards

Srinivasa

Just noticed that am335x-evmsk uses “TPS65910A3” for power management and “am335x-evmsk.dtsi” has included #include "tps65910.dtsi".

Our target board uses “TPS51200” for VTT regulartor.

Is tps65910.dtsi compatible for TPS51200?

Is this making any difference?

How important the nodes of &tps play in bringing the board?

Regards

Srinivasa

Your main PMIC is TPS65910A3 right?

Yes, that is correct.

Regards

Srinivasa

We have probed the DDR_VTT_EN pin and it is always HIGH.

Do we need to specify the SDRAM size anywhere in the Kernel source (other than .dts) file?

Regards

Srinivasa

Can you enter this option in U-Boot console and check whether the kernel will start to load?

=> setenv optargs mem=256M nomodule

Our board SDRAM size is 256 MB, tried above option but no luck.

Since Beaglebone DRAM is of 512 MB, performed negative testing with below option:

setenv optargs mem=128M nomodule

Beaglebone black kernel comes up.  So I am not sure if above env variable is making any impact.

Regards

Srinivasa

Now I want to increase the SDRAM clock speed or want to try by chaning the timing of clock in u-boot.

It you be very helpful if you can suggest which is the macro in file "\arch\arm\include\asm\arch-am33xx\ddr_defs.h" will be ideal for this?

Regards

Srinivasa

Hello Srinivasa,

I am wondering if you have updated your rootfs partition on your SD card. I understand you are migrating from older Uboot/Kernel versions to newer versions and I recommend running the create-sdcard.sh script to format the SD card again. Then, copy the MLO+u-boot.img to the boot partition and copy the zImage+dtb to the rootfs/boot partition of the SD card.

I do not think you need to manually load all the Kernel images from Uboot. As long as the SD card is formatted correctly and the appropriate images are in the boot partition and rootfs/boot partition, the board should boot without any problems. Also, in the following post, I noticed you were using the wrong cross-compiler and we only support the arm-linux-gnueabihf-.

In Uboot, please stop at the Uboot environment and run the command "env default -f -a" and "saveenv" to remove any old saved data. 

Regards,
Krunal

Hi Krunal,

As suggested, created new sd-card from  create-sdcard.sh script and copied only our customized MLO and u-boot.img to boot partition.  Also copied zImage + dtb fiels to root/boot partition of th SD Card.

Kernel is not booting up, please find message log below

U-Boot SPL 2018.01-00569-g7b4e473842-dirty (Jul 10 2019 - 12:55:03)
Trying to boot from MMC1

U-Boot 2018.01-00569-g7b4e473842-dirty (Jul 10 2019 - 12:55:03 +0530)

CPU : AM335X-GP rev 2.1
Model: TI AM335x EVM
DRAM: 256 MiB
NAND: 0 MiB
MMC: OMAP SD/MMC: 0
Net: No ethernet found.
Hit any key to stop autoboot: 0
switch to partitions #0, OK
mmc0 is current device
SD/MMC found on device 0
** Unable to read file boot.scr **
** 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
2318848 bytes read in 358 ms (6.2 MiB/s)
30545 bytes read in 25 ms (1.2 MiB/s)
## Flattened Device Tree blob at 88000000
Booting using the fdt blob at 0x88000000
Loading Device Tree to 8df0a000, end 8df14750 ... OK

Starting kernel ...

Srini machid : 3589

Srini r2 : 8df0a000

Jumping to 82000000

Bye bye u-boot :(

The purpose of manullay loding the kernal manually is to avoid any dependency on u-boot environment variables.

We are using arm-linux-gnueabihf- only.

Regards

Srinivasa

Hello Srinivasa,

In the following thread, I noticed you loaded zImage-am335x-evm.bin and I just wanted to confirm if you meant "zImage". Also, please add the UART, I2C, MMC, and PMIC nodes because they are necessary for booting.

Regards,
Krunal

Hello Srinivasa,

I am happy to hear that you resolved the issue. Please, do not forget to mark the thread as resolved.

Thanks,
Kemal