Sagar Heroorkar sagar.heroorkar@gmail.com wrote on 2010/07/21 17:21:31:
Hi All,
Before i start using your ( Joakim )approach. I would like to get some tips from Wolfgang or someone who can assist me here.
I am working on nor flash which is 128 mb flash for the PPC4XX.
My goal is to make uboot redundant. having other copy of uboot if one fails to boot. Architechure follows like this.
Totally there will be 3 uboots. Golden uboot is the one which has basic logic to pick which uboot from uboot 1 or uboot 2 (different copy). uboot 1 and uboot 2 is flashed into some location of 16mb nor flash.
Seems sane.
Steps follows like this.
1)G-boot picks up uboot1/uboot2 based on environment variable. Basically we jumps to that uboot and start booting it from there.
Doesn't need to be an env var. I image one could mark each image (uboot 1 or uboot 2) with a flag instead. That way you don't need to parse the env.
When i analysed the approach what Joakim implemented in http://www.mail- archive.com/u-boot@lists.denx.de/msg26918.html. He uses something like link_off() for each of the global data.
- There will be too many link_offs() i have to use in uboot to make sure each
of the global data.
There are a few link_offs() but not too many IMHO. Remember that my patches were complete for my board.
- As i will have 2 uboots which resides into seperate partitions. This requies
to build 2 uboots with different relotate_code logic/something .
Yes, this is the other way, you need to build two images linked to different addresses and select the right one at install.
I have read comments about this approach in the link what i pasted above.
I would really appriciate if anyone replies (especially Wolfgang ) about whether to go head with this approach before i spent much time on this. Also if anyone has already done similar implentation for any of the boards let me know.
-Sagar On Mon, Jul 19, 2010 at 4:36 PM, Joakim Tjernlund joakim.tjernlund@transmode.se wrote:
Sagar Heroorkar sagar.heroorkar@gmail.com wrote on 2010/07/19 15:26:20:
Hi Wlfgang,
resending this.
Please do reply
-Sagar
On Fri, Jul 16, 2010 at 3:12 PM, Sagar Heroorkar sagar.heroorkar@gmail.com wrote: Hi Joakim,
Graeme referred me to contact you for this.
I am working on U-boot making it PIC for ppc 405ex based boards. I see in the following link http://www.mail-archive.com/u-boot@lists.denx.de/ msg26918.html that you have implemented similar thing on 83xx board.
I have downloaded latest u-boot from ftp server of denx. I dont see the functions what you have modified like LINKF_OFF() etc. I would like to know where is the source code for that. Also is there any document other than the mail thread that explains what you have chagned.
Hi Sagar
The source isn't in u-boot. It is only available as the patches I sent at the time. I don't have the patches handy as I am on vacation for 2 more weeks.
Thanks in advance.
-Sagar