[patch] Re: Kernels > 2.6.1-mm3 do not boot. - SOLVED

[Adrian Bunk <bunk@fs.tum.de>]

On Sun, Jan 25, 2004 at 06:11:27PM +0100, Fabio Coatti wrote:
> Alle Sunday 25 January 2004 17:21, Adrian Bunk ha scritto:
> 
> >
> > What's your gcc version ("gcc --version")?
> 
> gcc (GCC) 3.3.1 (Mandrake Linux 9.2 3.3.1-2mdk)
> 
> 
> >
> > Could you back out ("patch -p1 -R < ..." or manually remove the lines)
> > the patch below and retry?
> 
> Yep, and now it works :)
> Now I'm running  2.6.1-mm4, tested both UP and SMP (SMT) and it boots just 
> fine. Later I'll try with more recents releases, but I'm pretty sure that 
> these will work.
> 
> Many thanks, the patch has solved this issue :)


Many thanks to Eric and you for your help in tracking the problem down!


@Andi,Andrew:

It seems use-funit-at-a-time breaks with distributions shipping a gcc
3.3 that supports -funit-at-a-time.

Th patch below replaces use-funit-at-a-time.patch and uses 
scripts/gcc-version.sh from add-config-for-mregparm-3-ng* to use 
-funit-at-a-time only with gcc >= 3.4 .

cu
Adrian


--- linux-2.6.2-rc1-mm3/Makefile.old	2004-01-25 18:22:25.000000000 +0100
+++ linux-2.6.2-rc1-mm3/Makefile	2004-01-25 18:26:56.000000000 +0100
@@ -441,6 +441,15 @@
 CFLAGS		+= -g
 endif
 
+# Enable unit-at-a-time mode when possible. It shrinks the
+# kernel considerably.
+#
+# Check the gcc version since -funit-at-a-time is available since gcc 3.4,
+# but some distributions ship a gcc 3.3 patched with a broken
+# -funit-at-a-time implementation
+GCC_VERSION = $(shell $(CONFIG_SHELL) scripts/gcc-version.sh $(CC))
+CFLAGS += $(shell if [ $(GCC_VERSION) -ge 0304 ] ; then echo "-funit-at-a-time"; fi ;)
+
 # warn about C99 declaration after statement
 CFLAGS += $(call check_gcc,-Wdeclaration-after-statement,)