On 02/11/17 15:04, Nicolas Pitre wrote:

On Thu, 2 Nov 2017, Chris Brandt wrote:

quoted

Oops, I meant to show this:

$ arm-linux-gnueabihf-as -version
GNU assembler (Linaro_Binutils-2017.01) 2.25.2 Linaro 2016_02
Copyright (C) 2014 Free Software Foundation, Inc.
This program is free software; you may redistribute it under the terms of
the GNU General Public License version 3 or later.
This program has absolutely no warranty.
This assembler was configured for a target of `arm-linux-gnueabihf'.

This is very strange. Here's a quick test with all the binutils versions 
I have lying around on my system:

$ echo -e "mov r0, #'\\\r'\nmov r1, '\\\r'"
mov r0, #'\r'
mov r1, '\r'
$ echo -e "mov r0, #'\\\r'\nmov r1, '\\\r'" > /tmp/t.s
$ for as in $(find /opt -name arm-linux-\*-as); do \

quoted

$as --version | head -1; \
$as /tmp/t.s -o /tmp/t.o; done

GNU assembler (Linaro_Binutils-2017.05) 2.27.0.20161019
/tmp/t.s: Assembler messages:
/tmp/t.s:2: Error: immediate expression requires a # prefix -- `mov r1,13'
GNU assembler (crosstool-NG linaro-1.13.1-4.7-2013.02-01-20130221 - Linaro GCC 2013.02) 2.23.1
/tmp/t.s: Assembler messages:
/tmp/t.s:2: Error: immediate expression requires a # prefix -- `mov r1,13'
GNU assembler (Linaro_Binutils-2017.05) 2.25.2 Linaro 2016_02
/tmp/t.s: Assembler messages:
/tmp/t.s:2: Error: immediate expression requires a # prefix -- `mov r1,13'
GNU assembler (crosstool-NG linaro-1.13.1-4.9-2014.09 - Linaro GCC 4.9-2014.09) 2.24.0.20140829 Linaro 2014.09
/tmp/t.s: Assembler messages:
/tmp/t.s:2: Error: immediate expression requires a # prefix -- `mov r1,13'
GNU assembler (GNU Binutils) Linaro 2014.11-3-git 2.24.0.20141017
/tmp/t.s: Assembler messages:
/tmp/t.s:2: Error: immediate expression requires a # prefix -- `mov r1,13'
GNU assembler (Linaro_Binutils-2017.08) 2.28.2.20170706
/tmp/t.s: Assembler messages:
/tmp/t.s:2: Error: immediate expression requires a # prefix -- `mov r1,13'

They all fail, including the version that looks like the one you have.

Note that for UAL syntax, GAS follows the ARM ARM recommendation and
considers the '#' on immediate values optional everywhere. I'm going to
hazard a guess that Chris might be building a Thumb-2 kernel or somehow
otherwise has ARM_ASM_UNIFIED turned on.

Robin.

Could you try that little test above on your side?

quoted

quoted

So, as far as ARM assembly in the Linux kernel goes, all constants must
be preceded by # whether or not binutils requires it - no exceptions.
Please always test assembly changes with a binutils version that is not
gratuitously broken!

Somewhat ironic since Nicolas works for Linaro.

I'm not involved with the toolchain people though, other than using 
their output.


Nicolas