Re: kbuild: disable depmod in cross-compile kernel build

Re: kbuild: disable depmod in cross-compile kernel build

[Geert Uytterhoeven]

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On Fri, 19 Oct 2007, Linux Kernel Mailing List wrote:
> Gitweb:     http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=50a8ec31c3a00594ceb7c5f1dcf2ecdaf6a5b847
> Commit:     50a8ec31c3a00594ceb7c5f1dcf2ecdaf6a5b847
> Parent:     6f67a00498abf8f0b29c2cecfce188c70be309d0
> Author:     Sam Ravnborg <sam@neptun.(none)>
> AuthorDate: Thu Oct 18 21:24:21 2007 +0200
> Committer:  Sam Ravnborg <sam@neptun.(none)>
> CommitDate: Thu Oct 18 23:17:06 2007 +0200
> 
>     kbuild: disable depmod in cross-compile kernel build
>     
>     When building embedded systems in a cross-compile environment and
>     populating a target's file system image, we don't want to run the
>     depmod on the host as we may be building for a completely different
>     architecture. Since there's no such thing as a cross-depmod, we
>     just disable running depmod in the cross-compile case and we just
>     run depmod on the target at bootup.
>     
>     Inspired by patches from Christian, Armin and Deepak.
>     
>     This solves: http://bugzilla.kernel.org/show_bug.cgi?id=3881
>     
>     Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
>     Cc: Christian Bjølevik <nafallo@magicalforest.se>
>     Cc: Deepak Saxena <dsaxena@mvista.com> and
>     Cc: Armin Kuster <akuster@mvista.com>,

Euh, is these really necessary?

At work I have no problems running depmod on an i386 system for ppc64 modules
after I installed module-init-tools 3.3-pre2 (from Debian).
I did have problems (depmod SEGV) using the depmod that came with CentOS
4 (from module-init-tools 3.1-pre5).

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds

Re: kbuild: disable depmod in cross-compile kernel build

[Frans Pop]

Geert Uytterhoeven wrote:
> Euh, is these really necessary?
> 
> At work I have no problems running depmod on an i386 system for ppc64
> modules after I installed module-init-tools 3.3-pre2 (from Debian).

That's right. I do depmod on i386 and amd64 for _all_ Debian architectures 
without any problems and I don't see why it should be a problem when running 
on other arches. It used to be a problem with depmod from modutils, but with 
depmod from module-init-tools it works perfectly.

All it needs is the -b option and correct kernel version.

Re: kbuild: disable depmod in cross-compile kernel build

[Sam Ravnborg]

> 
> Euh, is these really necessary?
> 
> At work I have no problems running depmod on an i386 system for ppc64 modules
> after I installed module-init-tools 3.3-pre2 (from Debian).
> I did have problems (depmod SEGV) using the depmod that came with CentOS
> 4 (from module-init-tools 3.1-pre5).

The patch was solely done due to people complaining and I even had a bugzilla
entry about it.
I expext Armin or Christian to speak up if this is a real problem for them.

PS. I did not do a revert since the original patch contained a nice cleanup.

	Sam

I have just committed the following:

>From d2c83557493c8595e2d3f31d0469bcf43d19b560 Mon Sep 17 00:00:00 2001
From: Sam Ravnborg <sam@neptun.(none)>
Date: Mon, 22 Oct 2007 11:30:45 +0200
Subject: [PATCH] kbuild: allow depmod in cross builds again

depmod from module-init-tools 3.3-pre2 are reported
to work fine in cross build.
depmod from module-init-tools 3.1-pre5 are know to SEGV

Do not workaround older module-init-tools bug here.
The right fix is for users to upgrade module-init-tools.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
---
 Makefile |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/Makefile b/Makefile
index f4238b2..264f37b 100644
--- a/Makefile
+++ b/Makefile
@@ -1505,7 +1505,7 @@ quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files))
 # and we build for the host arch
 quiet_cmd_depmod = DEPMOD  $(KERNELRELEASE)
       cmd_depmod = \
-	if [ -r System.map -a -x $(DEPMOD) -a "$(SUBARCH)" = "$(ARCH)" ]; then \
+	if [ -r System.map -a -x $(DEPMOD) ]; then                              \
 		$(DEPMOD) -ae -F System.map                                     \
 		$(if $(strip $(INSTALL_MOD_PATH)), -b $(INSTALL_MOD_PATH) -r)   \
 		$(KERNELRELEASE);                                               \
-- 
1.5.3.4.1157.g0e74-dirty