[U-Boot-Users] U-Boot booting from NAND

[U-Boot-Users] U-Boot booting from NAND

[Alan Carvalho de Assis]

Hi,
I am trying to port U-Boot to MX31PDK board, but I getting a problem
related to lowlevel initialization to boot from NAND flash memory.

The problem is because cpu/arm1136/start.S waste so much space with
IRQ/FIQ handling and stack initialization then lowlevel_init function
is placed at 0x400 position. As the NAND controller from i.MX31 copy
just 2KB to NANDFC internal buffer and lowlevel_init has about 0x6b0
bytes then the final position is after 0x800 (2KB) then the SDRAM
initialization routine and NAND block copy to SDRAM doesn't work.

Comparing with RedBoot I verified it place the lowlevel routines at
0x120 position then it fit in 2KB and all works fine.

I need help to modify cpu/arm1136/start.S and place the lowlevel_init
at 0x120 position instead 0x400. I am not ARM assembly expert then any
help is welcome.

Best Regards,

Alan

[U-Boot-Users] U-Boot booting from NAND

[Kenneth Johansson]

On Fri, 2008-06-13 at 10:24 -0300, Alan Carvalho de Assis wrote:
> Hi,
> I am trying to port U-Boot to MX31PDK board, but I getting a problem
> related to lowlevel initialization to boot from NAND flash memory.
> 
> The problem is because cpu/arm1136/start.S waste so much space with
> IRQ/FIQ handling and stack initialization then lowlevel_init function
> is placed at 0x400 position. As the NAND controller from i.MX31 copy
> just 2KB to NANDFC internal buffer and lowlevel_init has about 0x6b0
> bytes then the final position is after 0x800 (2KB) then the SDRAM
> initialization routine and NAND block copy to SDRAM doesn't work.
> 
> Comparing with RedBoot I verified it place the lowlevel routines at
> 0x120 position then it fit in 2KB and all works fine.
> 
> I need help to modify cpu/arm1136/start.S and place the lowlevel_init
> at 0x120 position instead 0x400. I am not ARM assembly expert then any
> help is welcome.
> 

I ditched the entire reuse thing when I implemented nand boot for a
5121e platform. 2k was to little space to try to force in the generic
files. just make a new start.S that do only the things it needs to. 

basically it only sets up the stack pointer to the internal SRAM. then
the C code relocates the code from the nand controllers internal 2k into
internal SRAM. sets up the memory controller , then reads out u-boot
into dram and jumps to _start.

[U-Boot-Users] U-Boot booting from NAND

[Wolfgang Denk]

In message <1213364825.29745.17.camel@localhost.localdomain> you wrote:
> 
> I ditched the entire reuse thing when I implemented nand boot for a
> 5121e platform. 2k was to little space to try to force in the generic
> files. just make a new start.S that do only the things it needs to. 

I seriously hope you based your code on the nand_spl/ frame work,  so
it has a chance to get merged into mainline, and I also hope you will
post patches soon?

Viele Gr??e,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
There is is no reason for any individual to have a computer in  their
home.      -- Ken Olsen (President of Digital Equipment Corporation),
              Convention of the World Future Society, in Boston, 1977

[U-Boot-Users] U-Boot booting from NAND

[Kenneth Johansson]

On Sat, 2008-06-14 at 23:50 +0200, Wolfgang Denk wrote:
> In message <1213364825.29745.17.camel@localhost.localdomain> you wrote:
> > 
> > I ditched the entire reuse thing when I implemented nand boot for a
> > 5121e platform. 2k was to little space to try to force in the generic
> > files. just make a new start.S that do only the things it needs to. 
> 
> I seriously hope you based your code on the nand_spl/ frame work,  so
> it has a chance to get merged into mainline, and I also hope you will
> post patches soon?
> 
> Viele Gr??e,
> 
> Wolfgang Denk
> 

It is based on the nand boot support that existed for some 4xx boards.

The code is going to be made available in someway sometime but I do not
think that anyone will ever try to merge it into the mainline. 

Maybe I will have some time between project to port the stuff over to
the ads5121 board but it's not going to be in near time.  

[U-Boot-Users] U-Boot booting from NAND

[Wolfgang Denk]

In message <1213611724.9272.7.camel@localhost.localdomain> you wrote:
> 
> > > I ditched the entire reuse thing when I implemented nand boot for a
> > > 5121e platform. 2k was to little space to try to force in the generic
> > > files. just make a new start.S that do only the things it needs to. 
...
> It is based on the nand boot support that existed for some 4xx boards.
> 
> The code is going to be made available in someway sometime but I do not
> think that anyone will ever try to merge it into the mainline. 
> 
> Maybe I will have some time between project to port the stuff over to
> the ads5121 board but it's not going to be in near time.  

Please post patches. This would allow to avoid a lot of duplicated
efforts.

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
The best things in life are for a fee.