[U-Boot] Problems using vxboot

[U-Boot] Problems using vxboot

[Reinhard.Arlt at t-online.de]

 
Hello,
 
i do not find a requirement that the cache needs to be off in the vxWorks manuals.
 
The entry point sysInit(int) intended by Windriver to be called from the vxWorks bootrom, a very small vxWorks system.
The routine is called by the go() handler in the bootrom, that clears the cache from start of image to end of usable memory.
 
The POWERPC implementations only invalidates and disable the cache, the ARM implementations also flush it.
 
 U-boot will be on the save side, if it disables the data cache before calling vxWorks sysInit(int).

Reinhard

-----Original-Nachricht-----
Subject: Re: [U-Boot] Problems using vxboot
Date: Wed, 10 Aug 2011 11:40:43 +0200
From: Detlev Zundel <dzu@denx.de>
To: Reinhard Arlt <reinhard.arlt@t-online.de>
Cc: u-boot at lists.denx.de
 
Hi Reinhard,
 
> i run into a strange problem booting vxWorks on the cpci750 and vme8349
> using u-boot 2011.06.
>
> The decrementer slot contains old code. The problem is starting vxWorks
> with the data cache enabled.
>
> The code below fix the problem.
> It disable (and flush) the data cache, and set the start parameter to
> cold boot for the vxWorks sysInit(int p0) routine.
>
> Is this code acceptable?
 
If vxworks needs the caches disabled to start, then sure why shouldn't
it?  Isn't there some vxWorks documentation item for that?  It would be
good to reference that in a comment.
 
Cheers
Detlev
 
--
Less talking -- more hacking
-- Olin Shivers
--
DENX Software Engineering GmbH,      MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich,  Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-40 Fax: (+49)-8142-66989-80 Email: dzu at denx.de
 
 

[U-Boot] Problems using vxboot

[Detlev Zundel]

Hi Reinhard,

> i do not find a requirement that the cache needs to be off in the vxWorks manuals.
>  
> The entry point sysInit(int) intended by Windriver to be called from
> the vxWorks bootrom, a very small vxWorks system.
> The routine is called by the go() handler in the bootrom, that clears
> the cache from start of image to end of usable memory.
>  
> The POWERPC implementations only invalidates and disable the cache,
> the ARM implementations also flush it.
>  
>  U-boot will be on the save side, if it disables the data cache before
> calling vxWorks sysInit(int).

Then put this information in the commit log and resend your patch - I
don;t see why it should not be merged.

Thanks
  Detlev

-- 
Music scenes ain't real life / They won't get rid of the bomb
Won't eliminate rape / Or bring down the banks / any kind of change
Takes more time and work / than changing channels on a TV set
                                        -- Jello Biafra
--
DENX Software Engineering GmbH,      MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich,  Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-40 Fax: (+49)-8142-66989-80 Email: dzu at denx.de

[U-Boot] Problems using vxboot

[Detlev Zundel]

Hi Reinhard,

> i run into a strange problem booting vxWorks on the cpci750 and vme8349 
> using u-boot 2011.06.
>
> The decrementer slot contains old code. The problem is starting vxWorks 
> with the data cache enabled.
>
> The code below fix the problem.
> It disable (and flush) the data cache, and set the start parameter to 
> cold boot for the vxWorks sysInit(int p0) routine.
>
> Is this code acceptable?

If vxworks needs the caches disabled to start, then sure why shouldn't
it?  Isn't there some vxWorks documentation item for that?  It would be
good to reference that in a comment.

Cheers
  Detlev

-- 
Less talking -- more hacking
                                        -- Olin Shivers
--
DENX Software Engineering GmbH,      MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich,  Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-40 Fax: (+49)-8142-66989-80 Email: dzu at denx.de

[U-Boot] Problems using vxboot

[Reinhard Arlt]

Hello,

i run into a strange problem booting vxWorks on the cpci750 and vme8349 
using u-boot 2011.06.

The decrementer slot contains old code. The problem is starting vxWorks 
with the data cache enabled.

The code below fix the problem.
It disable (and flush) the data cache, and set the start parameter to 
cold boot for the vxWorks sysInit(int p0) routine.

Is this code acceptable?


diff --git a/common/cmd_elf.c b/common/cmd_elf.c
index bf32612..c3f0986 100644
--- a/common/cmd_elf.c
+++ b/common/cmd_elf.c
@@ -230,7 +230,8 @@ int do_bootvx (cmd_tbl_t *cmdtp, int flag, int argc, 
char * const argv[])
                         (char *) bootaddr);
         printf ("## Starting vxWorks at 0x%08lx ...\n", addr);

-       ((void (*)(void)) addr) ();
+       dcache_disable();
+       ((void (*)(int)) addr) (0);

         puts ("## vxWorks terminated\n");
         return 1;

Kind regards

Reinhard Arlt