i.MX ProcessorsのトピックRe: Custom IMX28 board, no boot

Custom IMX28 board, no boot

dgotfroi — Thu, 30 Oct 2014 13:26:02 GMT

Hello,

I design my own board with an imx28 CPU. I configured the board (resistors on LCD_D0 to LCD_05) to boot on SSP0 (SD card).

When I try to boot without SD card connected, I have the 0x8020a014 error code on the debug console. So it seems it want to boot on Sd card. So it's good.

But when I connect the SD card, I have absolutely nothing on the debug console.

I measured voltage and everything is good except VDD4P2. It equal to 0.8V !!!!!

This is the schematic :

Can you help me ?

Re: Custom IMX28 board, no boot

Yuri — Fri, 31 Oct 2014 07:33:12 GMT

Please look at my comments below.

The problem may be concerned with the low available current from internal i.MX28
regulators in default (start) configuration. This may take place when external parts
(say, DDR) are fed from i.MX28 PMU. Perhaps it makes sense to test the board (only)
with i.MX28 (+ minimal USB) mounted.

You may try connecting a diode between VDD5V main and the DCDC_BATT/BATTERY signals,
this made the power supply stabilized. If this approach will be tested - please pay

attention on maximum allowed voltage on the BATTERY pin (4.2 V).

The cod 0x8020A014 means ERROR_DDI_SD_MMC_DEVICE_NOT_SUPPORTED,
that is, the device is not supported, or the device cannot be seen.

Perhaps, the SSP_SCK Polarity issue in ROM also takes place here.
Instability in SD read may cause the error. Special patch for this issue
should be applied.

Have a great day,
Yuri

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Re: Custom IMX28 board, no boot

dgotfroi — Fri, 31 Oct 2014 08:24:05 GMT

Hello Yuri,

Many thanks for your answer.

Unfortunately, I don't have the possibility to connecting a Diode because I use small SMD package so it will be very difficult.

I have the error code only when the SD card is not in place. So, I think that means Bootmode is well define on SSP0.

I used the reference Design from APF28. If I use the APF28 instead of my own CPU board, everything works fine and the only difference is the CPU power : See the AP28 : schematic below :

All the rest is the same between my own board :

Same U-Boot, same Kernel, same rootfs, same schematic (except power circuit).Is not the same RAM memory but it's 100% pin to pin compatible.

Is it possible that the problem comes from the imx-bootlets configuration ? I didn't set the config to VDD5V only because I use Yocto and I don't know how to do that.

Many thanks

Re: Custom IMX28 board, no boot

victorien — Fri, 31 Oct 2014 08:55:59 GMT

Did you try to boot from usb with mxsldr ?

In the errata document for imx28 ( http://cache.freescale.com/files/32bit/doc/errata/IMX28CE.pdf?fasp=1&WT_TYPE=Errata&WT_VENDOR=FREESCALE&WT_FILE_FORMAT=p… ) you can see that there is and hardware bug for the boor from an SD card. During my test, I saw that same SD card work and some other don't. So, you can try with another kind of SD card.

Did you measure the current from your power supply and the voltage on LCD0...5 ?

Re: Custom IMX28 board, no boot

dgotfroi — Fri, 31 Oct 2014 09:48:43 GMT

Thanks for your answer.

The current consumtion is 1 mA and the voltage on LCD0..5 is :

LCD0 : 3.14V

LCD1 : 0V

LCD2 : 0V

LCD3 : 3.14V

LCD4 : 0V

LCD5 : 0V

I didn't try with mxsldr because I didn't route USB OTG on my board.

Thank you

Re: Custom IMX28 board, no boot

victorien — Fri, 31 Oct 2014 10:07:05 GMT

The current of 1mA is strange if your board is supplied by 5V power. On my board the current is between 120 and 180 mA.

Another question ; did you generate your bootloader with HAB mode or not ?

Re: Custom IMX28 board, no boot

dgotfroi — Fri, 31 Oct 2014 10:18:46 GMT

I think it don't start the 4V2 regulator at all. It's why I have 1mA.

I use Yocto (with bitbake) but I'm not familiar with it so I don't know what is HAB mode and how to generate bootloader with it ?

Re: Custom IMX28 board, no boot

victorien — Fri, 31 Oct 2014 13:27:17 GMT

I don't work with Yocto, so I don't know but somewhere there is a script u-boot.bd or u-boot_ivt.bd (if you use uboot). And when you program your sd card you write sudo dd if=header.bin of=/dev/sdX1 ibs=512 conv=sync before your bootloader

Re: Custom IMX28 board, no boot

dgotfroi — Thu, 06 Nov 2014 08:54:53 GMT

Thank you for your answer.

I don't have this u-boot.bd or u-boot_ivt.db. Neither the header.bin.

Re: Custom IMX28 board, no boot

Yuri — Tue, 11 Nov 2014 03:31:35 GMT

Damien, good day !

Your configuration meets the app note AN4199 (Figure 9. Hardware connections for VDD5V-only applications).
According to the section "Limitations" under the Figure :
"During the early stage of device startup, before on-chip ROM execution, the input current on

VDD5V is limited to 100 mA.

The device is running on internal LinRegs on power up, and it needs to wait for the software to set

up the 4P2 rail before switching to the DC-DC converter as the power supply. The output current

from LinRegs is much lower than that of the DC-DC converter.

It is strongly suggested to use the i.MX28 power supply to power the i.MX28 ..."

From section 4.1.2.2 (VDD5V source only: software configuration) :

"For an application that uses the VDD5V source only, NO_DCDC_BATT_SOURCE must be defined on

power_prep.c in the bootlet codes. Additionally, the programmer should ensure that

NO_VDD5V_SOURCE is not defined".

Perhaps it makes sense to use the bootlets of the L2.6.35_1.1.0 release, where such

configuration is supported.

For more information please take a look at the next thread :

Custom HW based on imx28 unable to boot from linux-3.14 (yocto)

Regards,

Yuri.

Re: Custom IMX28 board, no boot

dgotfroi — Tue, 18 Nov 2014 11:31:06 GMT

Thanks for your answer. I will try with LTIB.

Another little question, what is the role of the shottky diode between VDD4P2 and Battery/DCDC_BATT in the reference schematic ?

EDIT :

I found on this forum that the problem can come from a bad inductor.

I use the 744025150 from Wurth. Do you think I need to choose another one ?

Re: Custom IMX28 board, no boot

dgotfroi — Thu, 20 Nov 2014 10:36:36 GMT

I tried with LTIB.

I've defined NO_DCDC_BATT_SOURCE an recompile the boot stream.

I've defined MEMORY_TEST in boot_prep.c

and I've blown HW_OCOTP_ROM7 ENABLE_SSP_12MA_DRIVE bit.

Now, when I power up my board, I have the following message continuously on the debug console :

PowerPrep start initialize power...

Configured for 5v only power source. Battery powered operation disabled.

Nov 20 201410:49:11

FRAC 0x92925552

memory type is DDR2

Wait for ddr ready 1power 0x00820710

Frac 0x92925552

start change cpu freq

hbus 0x00000003

cpu 0x00010001

start test memory accress

ddr2 0x40000000

finish simple test

Undefined Ins

Do you have any idea what is the problem ?

Thank you

Re: Custom IMX28 board, no boot

dgotfroi — Tue, 25 Nov 2014 14:42:10 GMT

I'm sorry to post a new answer but someone can help me ?

If I plug my sd card in my custom board I have the following on the debug console :

PowerPrep start initialize power...

Configured for 5v only power source. Battery powered operation disabled.

Nov 20 201410:49:11

FRAC 0x92925552

memory type is DDR2

Wait for ddr ready 1power 0x00820710

Frac 0x92925552

start change cpu freq

hbus 0x00000003

cpu 0x00010001

start test memory accress

ddr2 0x40000000

finish simple test

Undefined Ins

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If I plug my SD card in IMX28EVK board I have the following on the debug console :

PowerPrep start initialize power...

Configured for 5v only power source. Battery powered operation disabled.

Nov 25 201414:09:42

FRAC 0x92925552

memory type is DDR2

Wait for ddr ready 1power 0x00820710

Frac 0x92925552

start change cpu freq

hbus 0x00000003

cpu 0x00010001

start test memory accress

ddr2 0x40000000

finish simple test

U-Boot 2009.08 (Nov 25 2014 - 14:23:15)

Freescale i.MX28 family

CPU: 454 MHz

BUS: 151 MHz

EMI: 205 MHz

GPMI: 24 MHz

DRAM: 128 MB

MMC: IMX_SSP_MMC: 0, IMX_SSP_MMC: 1

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

In: serial

Out: serial

Err: serial

Net: got MAC address from IIM: 00:04:9f:02:09:37

FEC0

Hit any key to stop autoboot: 0

Re: Custom IMX28 board, no boot

Yuri — Wed, 26 Nov 2014 05:53:45 GMT

As the shottky diode :

First, if VDD4P2 may be used as power source for peripheral, such as

backlight, the diode can keep the power available while VDD5V is removed.

Second, if the DCDC power source is switched from the battery to VDD4P2 in

battery charging period, the diode can keep the DCDC power stream continually at

the meantime it is switched back to the battery while VDD5V is removed .

The Schottky diode can be removed if VDD4P2 will not be used continually at the

meantime it is switched back to the battery while VDD5V is removed. The Schottky

diode can be removed if VDD4P2 will not be used as power source of the external

peripherals and the internal DCDC. Any Schottky diode with low forward voltage

and 1A forward current can be used.

~Yuri.

Re: Custom IMX28 board, no boot

Yuri — Wed, 26 Nov 2014 06:01:37 GMT

The "Undefined Ins" message may be caused because of memory bug.

Also the follwoing may be helpful :

What does 'Undefined Ins' mean in u-boot?

iMX28evk u-boot sd-card -> Undefined Ins

~Yuri.

Re: Custom IMX28 board, no boot

dgotfroi — Thu, 27 Nov 2014 12:09:18 GMT

Thanks for your help.

I followed the tutorial here :

git.denx.de Git - u-boot.git/blob - doc/README.mxs

with U-boot 2015.01-rc2.

But the problem still appears.

What can I do ?

I have HTLLC message on debug console continuously.

I also try to blow HAB_DISABLE fuse with BitBurner (saw in a topic on this forum), but the problem was not solved and now I can't unblow this fuse because when I select the IMX28 in "Select device" in Bitburner, the IMX28 is automatically disconnected from my computer. Do you have any idea ?

Re: Custom IMX28 board, no boot

fabio_estevam — Thu, 27 Nov 2014 12:50:06 GMT

First thing you need to debug is why VDD4P2 only outputs 0.8V.

I would suggest following the VDD4P2 circuitry as in mx28evk or apf28 circuit that you pointed to.

Re: Custom IMX28 board, no boot

dgotfroi — Thu, 27 Nov 2014 14:31:41 GMT

I'm sorry, I didn't update you about that.

Since I patched uboot for VDD5V only, all voltages are good.

I've solid 5V, 3V3 and 1V8.

But when I've the "Undefined ins" message, the imx28 reset and 4V2 fall down (we can see the capacitor discharge curve on the scope).

Then, when the imx28 restart, 4V2 goes directly to the 4.2V target voltage.

Re: Custom IMX28 board, no boot

fabio_estevam — Thu, 27 Nov 2014 14:36:19 GMT

Ok, got it.

Then the next step is to understand why you get "Undefined ins".

This could be due to:

- Wrong toolchain: for example building with a toolchain for mx6, which is an armv7. That can cause Undefined Ins on a mx28, which is arm926ejs.

- Incorrect DDR initialization: if your DDR model is not the same as the mx28evk, then you probably need to adapt the DDR settings to match the required ones as per your DDR datasheet.

Re: Custom IMX28 board, no boot

dgotfroi — Thu, 27 Nov 2014 14:52:07 GMT

Many thanks for your help.

I use : arm-none-linux-gnueabi (generated by yocto) and my U-boot works on the imx28EVK so i think this is not the problem.

But effectively, I didn't use the same DDR (my board is 512Mb and EVK is 128Mb) so it could be the problem.

Do you have a tutorial or a procedure to change the ddr settings ?

Thank you