Booting over UART

Sam Fergusson

Hi,

I have a DM814x/AM387x EVM kit (rev D.) Last week, I have been doing the first stage booting from the SD card, but the remaining stages are over ethernet. Then I power-cycled the board (using the power switch) and the boot process failed to find the image and locked-up minicom.

This is a problem in itself. So I tried to get around this by booting from UART. I recompiled the image to give me the u-boot.min.uart file. I then attempted to flash the chip by following the instructions given in the TI Manual; TI81XX PSP U-Boot. But was unable to transfer - via TeraTerm - the u-boot.min.uart file.

Can any light be shed on this? I did notice that when I power-cycled the board and it failed to boot from ethernet, minicom gave me a new messages ;

NAND: HW ECC Hamming Code Selected

256 MiB

*** Warning - bad CRC or NAND, using default environment

When the board was successfully booting over the network, it was displaying;

NAND: HW ECC BCH8 Selected

No NAND device found!!!

0 MiB

Any advice available, either on the mysterious failure to suddenly not boot over network? Or how I cant transfer the boot file over a serial line via TeraTerm?

Thanks.

over 12 years ago

0 Vladimir-XID over 12 years ago

TI__Genius 11470 points

Hello,

What do you refer with "first stage booting from the SD card"? Is the kernel image on the SD card or you use tftp for that? Are you following this guide?

http://processors.wiki.ti.com/index.php?title=DM816x_AM389x_EMAC_Boot

Vladimir

0 Vimal Jain over 12 years ago in reply to Vladimir-XID

TI__Expert 6535 points

Hi,

There are switch settings on the board for enabling Nand. Please modify the switch setting accordingly.

Regards

Vimal

0 Sam Fergusson over 12 years ago in reply to Vimal Jain

Prodigy 30 points

Hi Vimal,

The switch settings are set correctly.

Sam

0 Sam Fergusson over 12 years ago in reply to Vladimir-XID

Prodigy 30 points

Vladimir,

The kernel image was on the SD card. Just to clarify, prior to the board not being able to boot, we had it booting from SD card and from over the network. Then when it couldn't boot, we tried booting from SD card, network and UART; none of which worked.

We have primarily been using:

http://processors.wiki.ti.com/index.php/DM814x_AM387x_PSP_U-Boot

Sam

0 John Lin57981 over 12 years ago in reply to Sam Fergusson

Intellectual 830 points

hi, i meet the same problem. Have you solved it? If you have solved this problem, please share your solution. Thank you!

0 Vladimir-XID over 12 years ago in reply to John Lin57981

TI__Genius 11470 points

Hello,

Please provide more details. What exactly kind of boot you are attempting and what is the error?

Vladimir

0 John Lin57981 over 12 years ago in reply to Vladimir-XID

Intellectual 830 points

dm8148 board we design, dm8127 appro ipnc RDK

When we erase the whole nand flash with CCS nand flash writer, the uart output 'c'. When we write the uboot.min to nand with CCS, everything seems ok. However, the uart output nothing when we power on the board. We set the btmode[4:0] to 10011. When we power on the board, there are datas reading on the nand flash data bus. So i wonder if i miss something to config. Please give me some suggestions. BTW, we use 1G byte DDR3.

0 Vladimir-XID over 12 years ago in reply to John Lin57981

TI__Genius 11470 points

Hello,

I think there are 3 likely possibilities (but could be something else of course).

Bugged u-boot images
Problem in the CCS flashing procedure
Switches/ cables / config / hardware problem

I would try to flash these u-boot images to the NAND from another u-boot and see whether or not everything is working now (e.g. started form SD card). You should have doc folder containing u-boot related pdf, where it is explained how to flash NAND from u-boot. This way if it works you will exclude the 1) and 3), if it is not working you could try some pre-built u-boots to exclude 3).

I hope this helps.

Vladimir

0 John Lin57981 over 12 years ago in reply to Vladimir-XID

Intellectual 830 points

Thanks for you reply.

Bugged u-boot images

the u-boot image is ok. because i flash it to the appro dm8127, and it works.

Problem in the CCS flashing procedure

when i flash the nand in ccs, the gpmc clock frequency is almost 40Mhz. And the data signal is ok. However, when the board boots up from nand, the data read clock frequency is 80Mhz. The data signal is abnormal. So i decide to speed up the gpmc clock frequency when i flash the nand in ccs. I change the L3 PLL in the Dm8148 gel. But it's not work. Could you tell me how to do it. Is there a way to reduce the frequency of nand read clock when the board powers on.

One more thing, are you sure the Dm8148 and Dm8127 are the same when they power on?

0 Vladimir-XID over 12 years ago in reply to John Lin57981

TI__Genius 11470 points

Hello John,

John Lin57981 said:
the u-boot image is ok. because i flash it to the appro dm8127, and it works.

I think it would be best if try the DM814x pre-built u-boot image, otherwise you cannot be sure.

I cannot tell whether or not the power on cycle has something to do with this. I think you should definitely try to flash the NAND from u-boot. This way you will determine is issue in the hardware or in the flashing procedure.

Vladimir

0 Wang Bing-qing over 11 years ago in reply to John Lin57981

Prodigy 30 points

I have encountered the same situation with you ,and I don't know how to solve it ,have you?

0 Pavel Botev over 11 years ago in reply to Wang Bing-qing

TI__Guru**** 170625 points

Hi Wang,

Please see the below E2E thread:

http://e2e.ti.com/support/dsp/davinci_digital_media_processors/f/716/t/318746.aspx

Best regards,
Pavel

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Booting over UART