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From: "Sauce.Cheng" <chmhou@sina.com>
To: linuxppc-dev@ozlabs.org
Subject: Re: issue at the beginning of kernel booting
Date: Tue, 7 Apr 2009 07:39:44 -0700 (PDT)	[thread overview]
Message-ID: <22930588.post@talk.nabble.com> (raw)
In-Reply-To: <20090402161209.GA19088@ld0162-tx32.am.freescale.net>


thanks Scott 's following

> I don't quite follow the above, but what I meant is that you need to
> put a mapping in place that covers your LED I/O once you have the MMU on.
> Any mappings that U-boot made will be gone at that point.

i am sorry for my poor expression. i think i have got your meaning about
that.
the suggestion from others that the situation that external access will be
disabled at early booting time. i guess that means like yours, sometimes I/O
disabled due to cache operating or something.

certainly, if i have to turn LEDs at booting time, the way your said is the
best. but i supposed i could operate LEDs after early booting time. 

>> i tried 
>> CONFIG_PPC_EARLY_DEBUG_CPM=y 
>> CONFIG_PPC_EARLY_DEBUG_CPM_ADDR=0xf00000008	
>> how can i make sure CPM_ADDR, 0xf0000008 is default value 

> Look at the u-boot source, or dump the memory and see if it looks like a
> ring buffer.

sorry, i mean that CPM_ADDR is address of what? address of CPM registers or
something?

> This is a dts-v0 tree, which implies it's fairly old.
dose later dts be used in corresponding kernel version ?

i guess i must read "booting-without-of.txt". many of contents in dts i have
no idea.

in addition, there is one more question. 
my RAM size is 32MBytes, my "vmlinux" size is 30MBytes, "vmlinux.o" size is
58MBytes. so , will there be something wrong at uncompressing time ?

Sauce
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View this message in context: http://www.nabble.com/issue-at-the-beginning-of-kernel-booting-tp22741532p22930588.html
Sent from the linuxppc-dev mailing list archive at Nabble.com.

  parent reply	other threads:[~2009-04-07 14:39 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-03-27  8:36 issue at the beginning of kernel booting chmhou
2009-03-27 16:15 ` Scott Wood
2009-04-01 15:00   ` Sauce.Cheng
2009-04-02  3:23   ` Sauce.Cheng
2009-04-02 16:12     ` Scott Wood
2009-04-02 21:54       ` Benjamin Herrenschmidt
2009-04-07 14:39       ` Sauce.Cheng [this message]
2009-04-07 19:41         ` Scott Wood
2009-04-07 15:02       ` Sauce.Cheng

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