topic Re: ROM boot code documentation. in i.MX Processors

ROM boot code documentation.

RandyGraham — Wed, 16 Jan 2013 03:33:59 GMT

Hello,

I am trying to boot a custom i.mx28 board from an SD card and am seeing the following hex codes displayed from the UART.

0x80502008

0x8020a014
0x8020a014
Prefetch Abort
r14_abt: 0xffff

The SD card contains a version of u-boot that works on the imx28-evk dev board.

Where are these codes documented?

I couldn't find them in the processor reference manual.

Thanks for any help,

-Randy

Re: ROM boot code documentation.

Yuri — Wed, 16 Jan 2013 03:49:14 GMT

0x80502008 means ERROR_ROM_USB_CONNECT_TIMEOUT

If the boot ROM is unable to boot from the device, indicated by the boot mode

(say, SD), then it falls back to the USB interface. This error code indicates that

the USB boot failed as well.

0x8020A014 means ERROR_DDI_SD_MMC_DEVICE_NOT_SUPPORTED, that is the device is

not supported, or the device cannot be seen.

Perhaps it makes sense to try the SSP polarity patch.

https://www.freescale.com/webapp/Download?colCode=L2.6.35_10.12_SSP_CLK_PATCH_UP&appType=license&location=null

The mx28_polarity_issue_ssp1.sb is just SD1 boot applet,

which should be burned to EEPROM. I.MX28-based board

should be configured to boot from the EEPROM.

Re: ROM boot code documentation.

MarekVasut — Wed, 16 Jan 2013 13:12:23 GMT

Check the following document:

http://sasamy.narod.ru/IMX23_ROM_Error_Codes.pdf

I didn't manage to google up the MX28 ones, but they should match.

Re: ROM boot code documentation.

RandyGraham — Wed, 16 Jan 2013 16:47:46 GMT

Thanks Yuri, I'll check this out.

Re: ROM boot code documentation.

RandyGraham — Wed, 16 Jan 2013 16:49:06 GMT

Thanks Marek.
Yes, I had googled this as well, but was hoping there were official docs from Freescale for the mx28.

Re: ROM boot code documentation.

RandyGraham — Wed, 16 Jan 2013 18:56:29 GMT

Also, where do I find the source code for the rootfs/boot binaries, e.g. power_prep and boot_prep ?

I am using LTIB with a 2.6.35 linux kernel and can successfully build, but can't find the source for these binaries and would like to apply some patches.

-Randy

Re: ROM boot code documentation.

MarekVasut — Wed, 16 Jan 2013 18:57:49 GMT

I briefly checked the MX28 bootrom source and it really contains file "return_codes.h" with comments that look identical to what's in the PDF document. So it seems someone just crunched this file and rolled out a PDF. You should be safe with using the PDF as a reference documentation to decode ROM error codes.

... and FSL should provide it as official documentation too!

Re: ROM boot code documentation.

MarekVasut — Wed, 16 Jan 2013 19:00:04 GMT

I'd like to give you a zealous suggestions to use upstream Linux 3.7 and upstream U-Boot 2013.01 instead, but that's really up to you ;-)

As for power_prep and this other junk, it's in imx-bootlets.

Re: ROM boot code documentation.

RandyGraham — Wed, 16 Jan 2013 19:06:34 GMT

Thanks Marek !

Yes, I have linux 3.7 running on my mx28-evk board with u-boot 2012.10, but have started with Freescale's 'official' release of linux 2.6.35 with LTIB for our custom board to sort out some hardware issues.

I have been using buildroot for our 3.7 builds and it seems to work quite well for our dev board.

But maybe I should just upstream as you say :smileywink:

-Randy

Re: ROM boot code documentation.

MarekVasut — Wed, 16 Jan 2013 19:11:20 GMT

Haha, don't worry, I'm just overzealous and I expect sooner or later, someone will run out of patience with me propagating upstream all around the place :smileygrin:

Anyway, just put down the issues you're facing and someone might come around and help ;-)

Re: ROM boot code documentation.

RandyGraham — Thu, 17 Jan 2013 16:53:48 GMT

Hi Marek,

Where did you find the mx28 bootrom source ?

It would be very helpful to have as a reference.

-Randy

Re: ROM boot code documentation.

MarekVasut — Thu, 17 Jan 2013 16:56:36 GMT

Please ask your freescale guy, he should be able to arrange it for you.

Re: ROM boot code documentation.

RandyGraham — Thu, 17 Jan 2013 16:58:04 GMT

I think it is good advice.

I am going to focus on getting u-boot 2013.01 up and running since I am going to need u-boot anyway for netboot during development.

I am also using buildroot to build my filesystem since it seems to be under active development.

Re: ROM boot code documentation.

RandyGraham — Thu, 17 Jan 2013 16:59:50 GMT

Wow, you are fast :smileywink:

Thanks !

Re: ROM boot code documentation.

MarekVasut — Thu, 17 Jan 2013 17:06:17 GMT

Sorry I can't help you more with this, you will need some NDA etc. to get it.

Re: ROM boot code documentation.

MarekVasut — Thu, 17 Jan 2013 17:07:42 GMT

That should be really quick, just look at mx28evk or m28evk , that should give you some idea on how to port it. Basically, just copy it, add entry to boards.cfg , adjust iomux.c / spl_boot.c for the pinmux, adjust MMC WP/CD GPIOs etc. and that should be it.

Re: ROM boot code documentation.

RandyGraham — Sat, 19 Jan 2013 17:50:34 GMT

Thanks Marek.

Our custom mx28 board is of course based on the reference design.
I am trying to get u-boot 2013.01 running on it and am seeing no output at all.

Our board is configured to boot from SD0, and without an SD card installed I am seeing '0x8020a014' on my debug console, which seems correct.

But when I try to boot from an sd card with u-boot, I see no output at all.

The same sd card runs u-boot fine on my mx28-evk board.

Since our board copies the reference design minus a few components (no SD1, no FEC1, no sound), I assume that I should at least see some output from my u-boot sd card ?

Is there anything obvious I should look at before digging into the u-boot source ?

Thanks again,

-Randy

Re: ROM boot code documentation.

MarekVasut — Sat, 19 Jan 2013 18:11:08 GMT

Check board/<yourboard>/iomux.c or spl_boot.c and look for DUART configuration. That's what is probably misconfigured.

Otherwise you can enable CONFIG_SPL_SERIAL_SUPPORT in your include/configs/<yourboard>.h and then edit arch/arm/cpu/arm926ejs/mxs/spl_boot.c , put serial_initialize() and serial_puts("foo") all around the place. That'll allow you to check if the board boots at all, as it'll output debugging stuff from U-Boot SPL.

Re: ROM boot code documentation.

RandyGraham — Sat, 19 Jan 2013 18:30:36 GMT

Marek, do you ever sleep ?? :smileyhappy:

Thank you very much, my next step was to start inserting debug print prints and you have helped point me in the right direction.

Thanks again.

Re: ROM boot code documentation.

RandyGraham — Mon, 21 Jan 2013 18:46:05 GMT

u-boot.2013.01 is booting on my board. I have added serial_puts() to debug the boot process and am seeing the output on my serial console.

So, this is very good.

From my debug output, I see that the board is resetting itself during memory initialization while setting the EMI clock divider :

/* Set EMI clock divider for EMI clock to 411 / 2 = 205MHz */

serial_puts("***** set emi clk div *****\n");

writel((2 << CLKCTRL_EMI_DIV_EMI_OFFSET) |

(1 << CLKCTRL_EMI_DIV_XTAL_OFFSET),

&clkctrl_regs->hw_clkctrl_emi);

My hardware guy assures me that our board configuration is identical to the mx28-evk reference board with respect to clock and memory. The same SD card with u-boot boots fine on the mx28-evk board.

Is it possible that mx28-evk contains special boot rom initialization code that I don't have on my stock i.mx28 SOC ?

-Randy