Hi All,
On Tue, 3 Feb 2009, Julian Calaby wrote:
On Mon, Feb 2, 2009 at 16:48, Sam Ravnborg <sam@xxxxxxxxxxxx> wrote:
On Sun, Feb 01, 2009 at 09:51:13PM +0000, Mark Fortescue wrote:
Hi all.
Silly question. If ARCH=sparc is not 64bit then how do you make a 32bit
sparc kernel?
make arch=sparc menuconfig give you the option to select
if the kernel is 64 bit or not.
And this "64 bit?" option is what is causing us troubles for the
all*config targets.
allyesconfig and allmodconfig will both set this option to 'y'
so we cannot in any simple way generate a 32bit all{yes,mod}config.
Why not have a sparc32 arch also, which would force 64bit to false. So:
1. If we detect a 32 bit sparc, we select sparc32.
2. If we detect a 64 bit sparc, we select sparc64.
3. Otherwise we select sparc and let the user decide.
I believe that powerpc also works in this manner, as does x86.
I always cross compile as building on a sun4c takes days so detection is
not an option.
Having an ARCH alias to preset the 32/64bit flag would seem to me to make
sence i.e.:
ARCH=sparc would give the current or previous characteristics (see below)
ARCH=sparc32 would overide CONFIG_64BIT to N (is not set)
ARCH=sparc64 would overide CONFIG_64BIT to Y
Using a 2.6.28.3 kernel source tree for reference (my sparc git trees are
on a machine that is not turned on at the moment):
The current toplevel Makefile explicitaly processes the x86 alias. This
could be changed to use a small script/alias file (so that, where
apropriate for other architectures, it can easilly be extended) to get
SRCARCH e.g.:
SRCARCH=$(shell $(srctree)/scripts/get_srcarch $(ARCH))
get_srcarch could use a simple 'case $1 in' statement get SRCARCH
e.g.:
#! /bin/sh
case "$1" in
# ARCH SRCARCH
i386) echo "x86" ;;
x86_64) echo "x86" ;;
sparc32) echo "sparc" ;;
sparc64) echo "sparc" ;;
*) echo "$1" ;;
esac
In the arch/sparc/Kconfig some alterations would be needed to get the
desired overriding of CONFIG_64BIT. Maybe somthing like:
# Select 32 or 64 bit
config 64BIT
bool "64-bit kernel" if ARCH = "sparc"
default ARCH = "sparc64"
# default !(ARCH = "sparc32") would be an alternative
help
Say yes to build a 64-bit kernel - formerly known as sparc64
Say no to build a 32-bit kernel - formerly known as sparc
Sam, given your work on the sparc32/64 merge, you probably know your
way arround recent changes and the current plans for the future a
lot better than I ever will. Would this set of ideas be somthing that
would be in keeping with current plans?
If you think it worth while, I could probably find a few hours this week
to generate a patch along these lines and do some simple testing.
Regards
Mark.
--
To unsubscribe from this list: send the line "unsubscribe sparclinux" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
