From: Wolfgang Denk <wd@denx.de>
To: "Muaddi, Cecilia" <cecilia.muaddi@alloptic.com>
Cc: "'linuxppc-embedded@lists.linuxppc.org'"
<linuxppc-embedded@lists.linuxppc.org>
Subject: Re: MMU on the power pc 860
Date: Sat, 21 Dec 2002 21:59:00 +0100 [thread overview]
Message-ID: <20021221205905.1518EC6139@atlas.denx.de> (raw)
In-Reply-To: Your message of "Fri, 20 Dec 2002 11:01:43 PST." <885489B3B89FB6449F93E525DF78777F06451E@srvnt506.ALLOPTIC.COM>
Dear Cecilia,
in message <885489B3B89FB6449F93E525DF78777F06451E@srvnt506.ALLOPTIC.COM> you wrote:
>
> I am porting the timeSys Linux to a custom Power PC 860 board. Our board
> currently runs
> windRiver VxWorks. I have modified the VxWorks bootrom to allow me to
> download a motorola
> hex record, and I have modified the timeSys bootcode
> arch/ppc/boot/mbx/misc.c:decompress_kernel
This is the generic Linux bootstrap loader, it has nothing to do with
TimeSys.
> loaded at: 00400000 0040C30C
> board data at: 004001C0 004001E4
> relocated to: 0040C0E8 0040C10C
> zimage at: 0040C30C 004BC440
> avail ram: 004BD000 00800000
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
This loos strange to me. Didn't you map RAM to 0x0000?
> I was able to use the VisionICE BDM to single step, and see it does jump to
> the address 0, and
> begin execute the instruction in kernel/arch/ppc/kernel/head_8xx.S:_start
You will not get far with the Vision*; better use a tool that
understands the MMU, like the Abatron BDI2000.
> I think the MMU TLB setup I have is not exactly correct, since the vxWorks
> BOOTROM does not
> initialize any MMU registers. Can someone tell me if I need to initialize
> the M_TWB register for the
MMU should be switched off when starting Linux.
> to be the value for this register? My physical memory map consists of RAM
> at location 0 to 0x1ffffff
This is not what I see above.
> and my IMMR is set to 0x2b00 0000
And this is plain wrong. The IMMR _must_ be mapped above 0xF0000000.
Best regards,
Wolfgang Denk
--
Software Engineering: Embedded and Realtime Systems, Embedded Linux
Phone: (+49)-8142-4596-87 Fax: (+49)-8142-4596-88 Email: wd@denx.de
Use C++ to confuse your enemies; use C to produce stable code.
** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
next prev parent reply other threads:[~2002-12-21 20:59 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-12-20 19:01 MMU on the power pc 860 Muaddi, Cecilia
2002-12-21 20:59 ` Wolfgang Denk [this message]
2002-12-23 4:01 ` Joe Hamman
-- strict thread matches above, loose matches on Subject: below --
2003-01-02 18:10 Muaddi, Cecilia
2003-01-02 19:04 ` Joe Hamman
2003-01-02 19:19 Muaddi, Cecilia
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