[U-Boot-Users] Re: [PATCH] 8xx: fix initialization bug/race condition between u-boot & linux

Tom Rini trini at kernel.crashing.org
Thu Jun 19 16:40:06 CEST 2003

On Thu, Jun 19, 2003 at 09:23:37AM +0300, Pantelis Antoniou wrote:
> Dan Malek wrote:
> >Pantelis Antoniou wrote:
> >
> >> The u-boot loader upon finishing the decompression of the
> >>kernel image it just jumps into the kernel without
> >>resetting the CP. The kernel however resets the CP only when
> >>configured to apply a u-patch. The UART in the CP is
> >>still active however, and the descriptors in dpram
> >>end up overlapping.
> >
> >
> >The UART console has a number of subtle assumptions built around the
> >initialization to support kgdb/xmon debugging.  The quick answer is
> >we don't want to reset the CPM so we can proper support this debugging.
> >This has all been described in archives before...........
> >
> >When the kernel is first booted, kgdb/xmon use the CPM as it was set
> >up by the boot rom.  There is a second initialization of the UART driver,
> >but before the console is initialized.  This changes the BDs, but the
> >UART still operates for kgdb/xmon.  The final stage initialization occurs
> >when the console is initialized, and all of the "normal path" debugging
> >and messages can occur after this point.
> OK. Shouldn't there be at least a comment in the code to mention that?

Yes, there should.  Throwing that into head_8xx.S now..

Tom Rini

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