Here is a scenario, i have a working version of the u-boot on my board, and am trying my changes.  Am not sure it is going to freeze the board, so would like the present version to load the new version for testing before it can be burned to flash.  Is it possible to do this or is it already done?

Thanks S

The board is based on MPC8377ERDB

S

________________________________ From: Mike Frysinger vapier@gentoo.org To: u-boot@lists.denx.de; Sridhar Addagada sridhar_a@yahoo.com Sent: Tuesday, November 29, 2011 11:20 AM Subject: Re: [U-Boot] uboot to load uboot

On Tuesday 29 November 2011 00:38:40 Sridhar Addagada wrote:

Here is a scenario, i have a working version of the u-boot on my board, and am trying my changes.  Am not sure it is going to freeze the board, so would like the present version to load the new version for testing before it can be burned to flash.  Is it possible to do this or is it already done?

i think it depends on the architecture.  most cannot do this.  what arch/cpu/SoC/board exactly are you using ?

please fix your e-mail client to wrap long lines -mike

On Tuesday 29 November 2011 02:00:38 Wolfgang Denk wrote:

Sridhar Addagada you wrote:

...

Here is a scenario, i have a working version of the u-boot on my board, and am trying my changes. Am not sure it is going to freeze the board, so would like the present version to load the new version for testing before it can be burned to flash. Is it possible to do this or is it already done?

In the strict sense, this usually cannot be done - one of the most critical parts (that most oftenly is incorrect and thus bricks your system) is the low-level initialization, like initializing the memory controller. And you usually cannot re-do this while already running from RAM.

Note that this is covered in the FAQ: http://www.denx.de/wiki/view/DULG/CanUBootBeConfiguredSuchThatItCanBeStarte dInRAM

i like this one: Answer: Well, yes. Of course this is possible. This is software, so *everything* is possible.

not to keep harping, but the Blackfin arch does support this. and does so stable-ly/cleanly imo. the cpu offers a few advantages though that most cores don't (afaik) which makes it possible: dedicated on-chip L1 SRAM that can be directly accessed (which is not cache). and since the majority of the code we have to have anyways for normal booting, the additional "i'm being booted from external RAM" logic adds like ~6 insns of overhead. so when we detect we're in RAM, we copy the initcode to on-chip memory, put external memory into self refresh, reprogram everything, take external memory out of self refresh, and then resume execution from RAM.

only caveat i know of is that you can't change some addressing modes (like # of cols used to program the SDRAM chips). otherwise, this changes how bytes are laid out in RAM, so you end up having stride-ed data. what was: 0xab 0xcd 0xef 0x00 ... is now something like: 0xab <garbage> 0xcd <garbage> 0xef <garbage> 0x00 <garbage> (the specifics here are probably wrong, but you get the general idea)

in this case, we aren't about to kick off a DMA to re-pack the data, so that is unsupported. but we find that's significantly less of an issue compared to what people actual want: to play with memory/clock timings.

</braindump> -mike

Freescale folks! no suggestions:(

________________________________ From: Sridhar Addagada sridhar_a@yahoo.com To: "u-boot@lists.denx.de" u-boot@lists.denx.de Sent: Tuesday, December 20, 2011 8:59 AM Subject: Boot Count Support for MPC8377E

It's been almost a month and have not heard any suggestions from anyone..

Can Freescale folks on the list suggest some reg's or memory location where boot count value can be saved across reboots.

Thanks S

________________________________ From: Sridhar Addagada sridhar_a@yahoo.com To: "u-boot@lists.denx.de" u-boot@lists.denx.de Sent: Friday, November 25, 2011 5:24 PM Subject: CONFIG_BOOTCOUNT_LIMIT

I' need to enable CONFIG_BOOTCOUNT_LIMIT, which is based one MPC8377ERDB,  and am looking for recommended address for CONFIG_BOOTCOUNT_ADDR, any suggestions.

Thanks S

On 12/21/2011 05:16 AM, Sridhar Addagada wrote:

Freescale folks! no suggestions:(

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From: Sridhar Addagada sridhar_a@yahoo.com To: "u-boot@lists.denx.de" u-boot@lists.denx.de Sent: Tuesday, December 20, 2011 8:59 AM Subject: Boot Count Support for MPC8377E

It's been almost a month and have not heard any suggestions from anyone..

Can Freescale folks on the list suggest some reg's or memory location where boot count value can be saved across reboots.

It's quite likely that no such thing exists (other than flash/EEPROM/etc.), that you can rely on. If it does exist, it's most likely an accident that few if any people know about (especially on a mailing list populated by people who do software, not hardware). I forwarded your mail to an internal Freescale list a couple days ago (also software -- the hardware people don't have mailing lists that I know of), and got no responses.

Note that this time of year a lot of people are out on vacation, so all types of inquiries are less likely to be answered promptly, especially in a forum such as this which is not an official support channel.

You could try e-mailing support@freescale.com.

-Scott