Re: [ECOS] Redboot run image issues

[joseph biswal <joseph.biswal@gmail.com>]

Hi Chris/GAry:

My NAND boot works fine with this particular image. The issue looks
like whe i do a "RUN" of this same working piece of image out of RAM,
it seems to get stuck.

I debugged using BDI breakpoints as well as "diag_printfs" and looks
like it does not go beyond  HAL_MMU_OFF in
packages/hal/arm/mx31/ads/current/src/redboot_cmds.c. I don't
understand the flow in LaunchrunImage()  since it falls on the thin
line of swtching the MMU on and off. Any hints?

Would it be related to any of the relocations

void launchRunImg(unsigned long addr)
{
    asm volatile ("mov r12, r0;");
    HAL_CLEAN_INVALIDATE_L2();
    HAL_DISABLE_L2();
    HAL_MMU_OFF();


Thanks in Advance!
-Munro.



On Mon, Feb 23, 2009 at 3:42 AM, Chris Zimman <czimman@bloomberg.com> wrote:
>> My final intent is to get my redboot port to boot from the NAND flash.
>> I am trying to run this image  from NAND flash but it gets stuck even
>> before spitting anything on the console. Hence i turn to the BDI
>> debugger where i try running the image from RAM and see if it works.
>
> Without having seen your code, I don't know exactly what you're doing at
> startup, but booting from flash vs. starting from memory *typically* will use
> a different code path as far as the startup is concerned.
>
> Because NAND isn't linearly addressable, in a typical NAND boot scenario, it
> usually copies a very small amount of code from the NAND into a local buffer
> and starts executing from there.  That code is responsible for getting the
> rest of the code out of NAND and into memory.  Just taking a quick look at
> the Freescale site, it appears that for at least some version of Redboot,
> they've made the necessary change to copy the Redboot image from NAND into
> SDRAM.
>
> See:
>
> http://www.freescale.com/files/dsp/doc/app_note/AN3672.pdf?fpsp=1&WT_TYPE=App
> lication%20Notes&WT_VENDOR=FREESCALE&WT_FILE_FORMAT=pdf&WT_ASSET=Documentatio
> n
>
> --Chris
>

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