Re: compiling a bootable kernel for ia64 (itanium2, mckinley, rx2620)

Hi Daniel,

On Wed, 31 Jan 2018, Dániel Kasza wrote:

> I think I also ran into this issue on my RX2600 a few months ago.
> Are you working on resolving this issue? Do you need any help with testing?

Yes, in some sense. We have tried to compile and boot a few kernels on 
real hardware. (Don't you mind me replying to the debian-ia64 list, too, 
so that the information gets to more people who may need it.)

Gleb glebfm@ has been doing the attempts; the last one being compiling the 
squeeze mckinley kernel (which boots successfully for us with a newer 
gcc-4.6 from wheezy. The result: it didn't boot.

> On Wed, Jan 31, 2018 at 6:33 PM, Ivan Zakharyaschev <[email protected]>
> wrote:

>> Issue 711135 seems to never have been resolved yet (since Debian 6
>> "squeeze", which has the last kernel which boots on rx2620:
>> 2.6.32-5-mckinley)
>>
>> Maybe this works:
>>
>> https://lists.debian.org/debian-ia64/2013/07/msg00009.html (Will Deacon):
>>
>> ...
>> Ok, after some more experimentation, this is looking more and more like
>> a compiler problem. Using 4.6.3, I *can* build a bootable kernel from the
>> Squeeze sources but only if I hack the kernel Makefile to pass -O1 instead
>> of -O2 or -Os.

Last night I learned the idea with -O1; so in the same build environment 
that Gleb has created and with the same unpacked package sources (modified 
to use gcc-4.6), I did the change for -O1:

root@rx2620:~# diff -du 
/media/home/imz/linux-2.6-2.6.32/Makefile{.orig_Os,}
--- /media/home/imz/linux-2.6-2.6.32/Makefile.orig_Os   2009-12-03 
06:51:21.000000000 +0300
+++ /media/home/imz/linux-2.6-2.6.32/Makefile   2018-02-01 
05:09:08.485066439 +0400
@@ -520,11 +520,7 @@
  # Defaults vmlinux but it is usually overridden in the arch makefile
  all: vmlinux

-ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
-KBUILD_CFLAGS  += -Os
-else
-KBUILD_CFLAGS  += -O2
-endif
+KBUILD_CFLAGS  += -O1

  include $(srctree)/arch/$(SRCARCH)/Makefile

and started debuild -b -us -uc. The packages have just been built, but not 
tested yet. Let's see (a bit later) what the results will be.