[U-Boot-Users] U-boot + Linux + SMP question

[U-Boot-Users] U-boot + Linux + SMP question

[syoder at austin.rr.com]

I have a high level question about how U-boot interacts with the Linux kernel on a PowerPC SMP system.
 
CPU 0 starts at the boot vector in U-boot, configures system, boots the Linux kernel.   In the kernel, CPU 0 takes action to start CPU 1 and waits for CPU 1 to start.
 
CPU 1 also starts execution at the boot vector.   Does CPU 1 take a different execution path through U-boot?   Does CPU 1 also decompress the kernel into SDRAM (over top of the one put there by CPU0)?
 
The CONFIG_SMP define in u-boot seems be isolated mostly to the asm-ppc/bitops.h header file.
 
Any pointers to where I could find info on this would be appreciated.
 
Thanks,
Stuart Yoder

[U-Boot-Users] U-boot + Linux + SMP question

[Wolfgang Denk]

In message <6c44b46c58b9.6c58b96c44b4@texas.rr.com> you wrote:
> I have a high level question about how U-boot interacts with the Linux kernel on a PowerPC SMP system.

I am not aware of any port of U-Boot to a MP system yet.

> The CONFIG_SMP define in u-boot seems be isolated mostly to the asm-ppc/bitops.h header file.

These are files copied from the Linux  kernel.  CONFIG_SMP  is  never
used in U-Boot (yet).

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
I have a theory that it's impossible to prove anything, but  I  can't
prove it.

[U-Boot-Users] U-boot + Linux + SMP question

[Frank]

Actually, I ported u-boot to a quad 7450 sbc a few months ago. I
wanted to submit a patch, but unfortunately, my client wouldn't
approve it. I explained to them that they had to publish the
source if they shipped the product. They got around it by
replacing it with their brain dead boot loader instead. So we
only used it to bring up the hardware.:-(


--- Wolfgang Denk <wd@denx.de> wrote:
> In message <6c44b46c58b9.6c58b96c44b4@texas.rr.com> you wrote:
> > I have a high level question about how U-boot interacts with
> the Linux kernel on a PowerPC SMP system.
> 
> I am not aware of any port of U-Boot to a MP system yet.
> 
> > The CONFIG_SMP define in u-boot seems be isolated mostly to
> the asm-ppc/bitops.h header file.
> 
> These are files copied from the Linux  kernel.  CONFIG_SMP  is
>  never
> used in U-Boot (yet).
> 
> Best regards,
> 
> Wolfgang Denk
> 
> -- 
> Software Engineering:  Embedded and Realtime Systems, 
> Embedded Linux
> Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email:
> wd at denx.de
> I have a theory that it's impossible to prove anything, but  I
>  can't
> prove it.
> 
> 
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