am335x boot from NAND Spansion S34ML01G1

Hi Francisco,

For NAND compatibility please check the AM335X TRM Rev. K, section 26.1.7.4. Important things are processor pins used for NAND connection, whether the NAND is ONFI compliant or else listed in the compatible devices table, and also the state of SYSBOOT9 pin.

Dear Biser,

     first of all thank you for your quick repply. 

The Spansion S34ML01G1 (8 bits NAND FLASH) Device ID is 0xF1, it appears in the table 26.14, so it is supported.

It is also Open NAND Flash Interface (ONFI) 1.0 compliant. The pins mach exactly with the  AM335X TRM Rev. K, Figure 7.5. Please have attached the pin mux file configuration. I have tried sysboot[9] =  1 and 0, and none of then boots. In uboot mode, the nandboot command loads the kernel and the linux shell starts, what can i try next?

Best Regars.

Francisco.

3201.Pegasus.dat

Which CS and WAIT signals are connected? For NAND boot it must be tied to GPMC_CS0 and WAIT0. Which SDK are you using and how is the NAND programmed? Have you seen this wiki: http://processors.wiki.ti.com/index.php/AM335x_U-Boot_User's_Guide#NAND_2 ?

Biser,

         GPMC_CSN0 and GPMC_WA0. 

SDK -> ti-sdk-am335x-evm-06.00.00.00.

I have tried for programming the flash Uniflash and via Network using isc-dhcp and tftp servers. (  http://processors.wiki.ti.com/index.php/Ubuntu_12.04_Set_Up_to_Network_Boot_an_AM335x_Based_Platform)

I have fllowed all the steps shown on 

http://processors.wiki.ti.com/index.php/AM335x_U-Boot_User's_Guide#NAND_2 ?.

Even I have checked from uboot that the u-boot-spl.bin, u-boot.img, uboot and rootfs are placed in the right area, based on the nand layout. By the way, the reading of these areas of the nand is the same with the nand read and nand read.raw commands, does it make sense?

Best Regards.

Francisco. 

Francisco,

I have asked a software expert for help on this. One last question on the hardware side - what are the voltage rails for GPMC and NAND?

And do you have an external pullup resistor on WAIT0?

Biser, 

  3.3V.

Francisco.

Biser,

   yes, I hace pull-up resistors in the lines WA0, WP and CS0.

Francisco.

Hi Francisco,

Try to boot into U-Boot from UART using the u-boot-spl.bin file from the <u-boot>/spl/ folder. Then follow these steps to flash the NAND (please note that I'm using picocom and the commands for your terminal emulator may differ):

IMPORTANT: Depending on whether you're using kermit or ymodem mode use one of these two commands to load the image files to RAM:

loadb - load binary file over serial line (kermit mode)
loady - load binary file over serial line (ymodem mode)

U-Boot# nand erase.chip
U-Boot# loady 0x81000000
- (when prompted press CTRL+A; CTRL+S; and send MLO via UART)
U-Boot# cp.b 0x81000000 0x81020000 20000
U-Boot# cp.b 0x81000000 0x81040000 20000
U-Boot# cp.b 0x81000000 0x81060000 20000
U-Boot# loady 0x81080000 -> u-boot.img
- (when prompted press CTRL+A; CTRL+S; and send u-boot.img via UART)
U-Boot# nand write 0x81000000 0x0 0x280000
U-Boot# saveenv

Then set the boot switches for NAND boot mode and try to boot into U-Boot from the NAND flash. This is how it works on the TI AM335x evaluation modules.

Best regards,
Miroslav

Dear Mirostav,

                     I have gone throught the procedure that you suggest me to do, the result has been the same as I got in the other ways(ethernet, uniflash). The sysboot pins are in UART0 SPI0 NAND NANDI2C. 

The console starts to show CCCCCCCCCCC, it stops and no more characters on it.

Thanks.

Best Regards.

 Francisco.

Francisco,

How do you build MLO and u-boot that you write to the NAND? Can you post the commands you use?

Biser,

sudo make ARCH=arm CROSS_COMPILE=/home/francisco/ti-sdk-am335x-evm-06.00.00.00/linux-devkit/sysroots/i686-arago-linux/usr/bin/arm-linux-gnueabihf- spl/u-boot-spl.bin

sudo make ARCH=arm CROSS_COMPILE=/home/francisco/ti-sdk-am335x-evm-06.00.00.00/linux-devkit/sysroots/i686-arago-linux/usr/bin/arm-linux-gnueabihf- u-boot.img

Francisco.

Francisco,

Try the following command:

make ARCH=arm CROSS_COMPILE=/home/francisco/ti-sdk-am335x-evm-06.00.00.00/linux-devkit/sysroots/i686-arago-linux/usr/bin/arm-linux-gnueabihf- am335x_evm

This will generate everything you need.

Best regards,
Miroslav

Miroslav,

            I have got the same result, it doesn´t fix the problem.

Thanks.

Francisco.

I'm sorry, I'm out of ideas.

Best regards,
Miroslav

Francisco,

Have you tried what Miroslav suggested with SYSBOOT9 tied low?

Biser,

             yes I have tried sysboot[9] tied low and sysboot[9] high. And nothing happen

F.

The fact that CCCCC... printout stops on your console leads me to think that the processor reads out the MLO from the NAND and hangs somewhere early in its execution. I'm afraid that I can give no additional help over the forum. Please check very carefully your MLO/u-boot, if possible read and compare what you have in NAND with what you have on SD card.

Biser,

       both MLO/u-boot are exactly the same, so could it be because a ECC problem? 

Regards.

Francisco.

I'm not a software expert. I think SDK 6.0 uses BCH8 by default.

Francisco,

There are additional restriction when booting from NAND compare to accessing NAND at run time.
As a first step you could check first the NAND access at run time then you can look at booting from NAND (as the bootloader is more restrictive):

-- NAND run time access:
The AM335x starterware does provide none OS based example on setting up GPMC for NAND:
http://processors.wiki.ti.com/index.php/StarterWare_GPMC
This would be a good starting point to use the code provided and adapt it to the NAND you do use.
The NAND portion of the Starterware was tested on the AM335x EVM.

-- NAND boot :
 For boot you need to check that the NAND you picked meet the ROM bootloader specification as there are some restriction on the NAND in order to boot from it (for example timings on GPMC during NAND boot, supported NAND geometrie, using I2C for supporting additional geometry, ..etc).
Please refer to section 26 of the AM335x TRM - SPRUH73J.
As a test you could boot a simple C application from NAND. See the Starterware too:
http://processors.wiki.ti.com/index.php/AM335X_StarterWare_Booting_And_Flashing

-Additional consideration need to be looked at to boot a complete Linux system from NAND.
For example ECC scheme used for SPL U-boot and Linux, how the file system is built, code Layout in NAND..etc.
The easiest is probably to start with a RAMFS built in the Linux kernel.
For u-boot see as well the ECC that are currently supported in the actual U-boot version:
http://processors.wiki.ti.com/index.php/AM335x_U-Boot_User%27s_Guide

-See also the NAND related wiki pages below.
The below might not apply 100% to AM335x but it provides some general consideration that need to be looked at:
http://processors.wiki.ti.com/index.php/Davinci/Sitara/Integra_Nand_Boot_FAQ (for some Sitara and Davinci devices)
http://processors.wiki.ti.com/index.php/Raw_NAND_ECC (for Sitara devices including AM335x)
Also some information and board bring up and training on U-boot/Linux board port that show how to use CCS to debug:
http://processors.wiki.ti.com/index.php/AM335x_board_bringup_tips

Anthony

More practically:

1st we have to check if the NAND is at all recognized by the RBL and if NAND boot starts at all.
- How do the NAND and GPMC timings look like compared to what is documented at page 4684 of the TRM SPRUH73?

- Can you hook a JTAG emulator to the board? In this case you could check the tracing vector (see board bring up wiki above and TRM). It would tell if the NAND boot has at least started.

- How much activity do you see on the GPMC interface during bootload? Depending on the activity of the control pins you could assess if the boot fails early or late in the NAND boot process.

- The RBL should copy the SPL to internal OCP RAM. Is there a way you can check the internal OCM RAM is written using CCS?
Could you modify the SPL to blink a LED or toggle a GPIO for example so that it can it tells it runs?
If the SPL runs it should setup the DDR. Do you see any activities on the DDR?

- As part of the starterware (non OS based C code) you can burn a simple C application to NAND via CCS. There AM335x side executable (see \tools\flash_writer\src\nand-flash-writer_AM335x\src) that you can adapt (layout, timing, ..etc) to your NAND device (as only the EVM and SK are supported out of the box).
As the first step you could replace the starterware bootloader by a simple while (1) loop. At boot the RBL will copy it to the OCM RAM. You can easily check with CCS if this step happens.
Then when it is working then you could use the starterware bootloader and a while (1) as application.
The starterware loader will be loaded in OCM RAM. It will run and should load the application to DDR.
Also the Startweware documentation does provides some high level information:
http://processors.wiki.ti.com/index.php/AM335X_StarterWare_Booting_And_Flashing#Booting_Via_NAND

You could do something comparable with SPL and U-boot. The advantage of using the Starterware is that you would have a better visibility using CCS as CCS is part of the build and debug flow of the Starterware.

Anthony