From mboxrd@z Thu Jan  1 00:00:00 1970
From: robherring2@gmail.com (Rob Herring)
Date: Fri, 28 Jan 2011 09:10:41 -0600
Subject: [PATCH v2] ARM: map ATAGs when not in first 1MB of RAM
In-Reply-To: <20110128141031.GB12976@n2100.arm.linux.org.uk>
References: <1296223246-2934-1-git-send-email-robherring2@gmail.com>
	<20110128141031.GB12976@n2100.arm.linux.org.uk>
Message-ID: <4D42DC71.5080606@gmail.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

Russell,

On 01/28/2011 08:10 AM, Russell King - ARM Linux wrote:
> On Fri, Jan 28, 2011 at 08:00:46AM -0600, Rob Herring wrote:
>> @@ -206,11 +206,17 @@ __create_page_tables:
>>   #endif
>>
>>   	/*
>> -	 * Then map first 1MB of ram in case it contains our boot params.
>> +	 * Then map boot params address in r2 or
>> +	 * the first 1MB of ram if boot params address is not specified.
>>   	 */
>> -	add	r0, r4, #PAGE_OFFSET>>  18
>> -	orr	r6, r7, r8
>> -	str	r6, [r0]
>> +	mov	r0, r2, lsr #20
>> +	movs	r0, r0, lsl #20
>> +	moveq	r0, r8
>> +	sub	r3, r0, r8
>> +	add	r3, r3, #PAGE_OFFSET
>> +	add	r3, r4, r3, lsr #18
>> +	orr	r6, r7, r0
>> +	str	r6, [r3]
>
> Wouldn't:
> 	str	r6, [r4, r3, lsr #18]
> work here?

Not on Thumb2:

arch/arm/kernel/head.S:218: Error: Thumb supports only LSL in shifted 
register indexing -- `str r6,[r4,r3,lsr#18]'

Rob