PROCESSOR-SDK-AM437X: MMC boot failure

Dear Friends:
Anyone can help me ? Thanks in advance.

Dear Kemal:
Thank you very much for your help.
We have apply this path to our u-boot. board-support\u-boot-2017.01+gitAUTOINC+c68ed086bd-gc68ed086bd\board\ti\commonboard_detect.c

But the issue still exist. our board can't boot up, there is no conole message when power on.
Do you have another advice ?

Dear Kemal:
We think that board will print CCCCCCCC symbol even if without SD card inserted.
Now our board can't print CCCCCCC symbol when power on.
Do you think about this abnormal behaviour ?
maybe power sequence issue ?

Dear Kemal:
We have try your files, it does't work.

we change power sequence UART0-->NAND_I2C--->NAND--->MMC0 by set SYSBOOT[4:0] to 11001b.
so board will try to boot from UART0, if fail, then try NAND_I2C,if fail, then try NAND, if fail, MMC0

but now, it won't print CCCCCCCC symbol.

Dear Kemal:
I am in charge of this device bring up work for am437x, Our HW engineer have measure the power sequence of the device during power up. It seems that the power sequence for the CPU is OK. But what we can do to make sure the CPU is alive because of the UART0 no "CCCCC" string output when we debug it.
And we are sure that the console line works and check with other product before we plug to our device.
When we use the xds110 to read the register value of CPU, it return's "????????" in the CCSv7.
Thanks for your help.
Rance

I am not sure but sounds like the processor is burned out or not soldered correctly.

Hi Kemal:
Thanks for your help. Our MLO can not work, but yours MLO can work. Could you please share your .config and am43xx_evm_defconfig to us please. How to make sure the MLO build process?

Hi Kemal:
what different MLO between the rt SDK and standard SDK ? What SDK do u used?

Hi Kemal:
What does your patch really do Hardcode-EEPROM-board-name-to-AM43__SK.patch? skip the eeprom?
If we don't use the patch, the device show nothing. if we use the your patch, please see the log.
We boot up from MMC0 interface from the SDCARD, why it shows 'MMC: no card present'
Could you please help to explaination about this?

ÿ
U-Boot SPL 2017.01-00458-gccd1c34-dirty (Apr 26 2018 - 18:54:13)
Trying to boot from MMC1
SPL: Please implement spl_start_uboot() for your board
SPL: Direct Linux boot not active!
reading u-boot.img
reading u-boot.img
reading u-boot.img
reading u-boot.img


U-Boot 2017.01-00458-gccd1c34-dirty (Apr 26 2018 - 18:54:13 +0800)

CPU : AM437X-GP rev 1.2
Model: TI AM437x SK EVM
DRAM: 1 GiB
PMIC: TPS65218
NAND: 0 MiB
MMC: OMAP SD/MMC: 0
MMC: no card present
** Bad device mmc 0 **
Using default environment

Net: <ethaddr> not set. Validating first E-fuse MAC
Could not get PHY for cpsw: addr 4
cpsw, usb_ether
Hit any key to stop autoboot: 0
MMC: no card present
MMC: no card present
MMC: no card present
MMC: no card present
starting USB...
USB0: Register 2000440 NbrPorts 2
Starting the controller
USB XHCI 1.00
scanning bus 0 for devices... 1 USB Device(s) found
scanning usb for storage devices... 0 Storage Device(s) found

USB device 0: unknown device
Booting from nand ...

no devices available

no devices available

Dear kemal:
According to the log files shown, Does this mean the MLO didn't boot up finished? And it didn't load the u-boot.img successfully? Because our UART0 can not input any command, that maybe to uart0 not successfully initialized, right?
Thanks
Rance

Another things to mentioned that we don't have external eeprom for the design. In this design, How can we skip the MLO reading the board ids if no eeprom, this will block the boot up I think.
Thanks

You have skipped the EEPROM checks by applying my patch, the MLO boot has finished and the console has successfully initialized. Now the U-Boot cannot find a valid MMC device to boot. Can you enter in U-Boot console and post the output of these commands?
=> mmc list
=> mmc info
=> mmc dev

Hi Kemal:
But the uart can not execute any command, it hanged here. We can not input anything. As you mentioned that the console have already initialized, We need to check the console voltage of HW settings about this.

Hi Kemal:
Appreciate for your help, it is a HW issue for the input signal. Please see the mmc command feedback.
If the device can not detect SDCard, why it can boot up from it?

=> mmc list
OMAP SD/MMC: 0
=> mmcinfo
MMC: no card present
=> mmc dev
MMC: no card present

Hi Kermal:
with the command "mmc dev 0", it shows MMC: no card present as well.
Thanks