Re: [PATCH v3 1/3] Loongson-2F: Flush the branch target history such as BTB and RAS

[Wu Zhangjin <wuzhangjin@gmail.com>]

On Sat, 2010-04-10 at 10:10 +0200, Andreas Barth wrote:
> * Wu Zhangjin (wuzhangjin@gmail.com) [100407 09:38]:
> > On Tue, 2010-04-06 at 21:10 +0200, Andreas Barth wrote:
> > [...]
> > > 
> > > The kernel vmlinuz-2.6.33-lemote2f-bfs inside of
> > > http://www.anheng.com.cn/loongson/install/loongson2_debian6_20100328.tar.lzma
> > > (linked via linux-loongson-community) fails at the same place:
> > > 
> > > touch stamp-picdir
> > > if [ x"-fPIC" != x ]; then \
> > >           gcc -c -DHAVE_CONFIG_H -g -O2  -I. -I../../libiberty/../include 
> > >  -W -Wall -Wwrite-strings -Wc++-compat -Wstrict-prototypes -pedantic  
> > > -fPIC ../../libiberty/regex.c -o pic/regex.o; \
> > >         else true; fi
> > > gcc -c -DHAVE_CONFIG_H -g -O2  -I. -I../../libiberty/../include  -W -Wall 
> > > -Wwrite-strings -Wc++-compat -Wstrict-prototypes -pedantic  
> > > ../../libiberty/regex.c -o regex.o
> > > if [ x"-fPIC" != x ]; then \
> > >           gcc -c -DHAVE_CONFIG_H -g -O2  -I. -I../../libiberty/../include 
> > >  -W -Wall -Wwrite-strings -Wc++-compat -Wstrict-prototypes -pedantic  
> > > -fPIC ../../libiberty/cplus-dem.c -o pic/cplus-dem.o; \
> > >         else true; fi
> > > 
> > 
> > When & where did you get the above information?
> > 
> > do you mean the kernel can not boot or there are some other problems
> > after the kernel booting?
> > 
> > I guess: the whole system crashed when you was compiling something? then
> > please ensure the as & ld is ok via fixing the NOPS with the tool
> > (fix-nop.c) from  http://dev.lemote.com/code/linux-loongson-community :
> 
> The kernel does boot, but the whole machines crashes.
> 
> I know the fixups (I have adjusted binutils), but I need an kernel
> that userland cannot crash (otherwise it gets a bit hard to run that
> as debian buildd).
> 
> 

The userland canot be prevented from crash without user-space fixups,
that's why we need the fix-nop.c to fix the NOPs in the binaries of
user-land applications or using the -mfix-loongson-nop to compile the
user-land applications.

If you just need to rebuild debian, you just need to fix the NOPs in the
as and ld with fix-nop.c as I have mentioned before:

$ ./fix-nop $(which as)
$ ./fix-nop $(which ld)

Regards,
        Wu Zhangjin