running 64-bit kernel on 32-bit distro
Robert P. J. Day
before i try this, i want to verify that it should (theoretically)
work. i want to run a 64-bit kernel (with 32-bit emulation mode) on
my 32-bit install of fedora core.
as i understand it, i can use my (currently building) x86-64
toolchain to cross-compile the kernel for 64 bits, plus the 32-bit
emulation, after which i should just be able to boot the new 64-bit
kernel, is that right?
am i missing anything critical there? thanks.
rday
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Robert P. J. Day
Linux Consulting, Training and Annoying Kernel Pedantry
Waterloo, Ontario, CANADA
http://fsdev.net/wiki/index.php?title=Main_Page
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Mike Frysinger
> before i try this, i want to verify that it should (theoretically)
> work. i want to run a 64-bit kernel (with 32-bit emulation mode) on
> my 32-bit install of fedora core.
it works just fine
> as i understand it, i can use my (currently building) x86-64
> toolchain to cross-compile the kernel for 64 bits, plus the 32-bit
> emulation, after which i should just be able to boot the new 64-bit
> kernel, is that right?
yes
-mike
Robert P. J. Day
> On 4/30/07, Robert P. J. Day <rpj...@mindspring.com> wrote:
> > before i try this, i want to verify that it should (theoretically)
> > work. i want to run a 64-bit kernel (with 32-bit emulation mode) on
> > my 32-bit install of fedora core.
>
> it works just fine
>
> > as i understand it, i can use my (currently building) x86-64
> > toolchain to cross-compile the kernel for 64 bits, plus the 32-bit
> > emulation, after which i should just be able to boot the new 64-bit
> > kernel, is that right?
>
> yes
ok, i'm almost there. so far, i've:
1) built an (apparently) working x86_64 toolchain using crosstool
2) used that toolchain to build and install a 64-bit kernel
3) booted (successfully) under the new 64-bit kernel, verifying that
it's 64-bit with "uname -a"
4) used the aforementioned toolchain to compile "hello, world"
but here's where i run into trouble -- when i try to run the
resulting a.out for "hello, world", i get "No such file or directory".
i'm running it in the current directory with:
$ ./a.out
but still no luck. the "file" command shows me that it's there, with
type "ELF 64-bit LSB executable, AMD x86-64 ..." but every attempt to
run it gives me that error message.
i'm sure i'm forgetting something trivial. ideas?
rday
Mike Frysinger
> but here's where i run into trouble -- when i try to run the
> resulting a.out for "hello, world", i get "No such file or directory".
you're assuming too much ... you have a 32bit install, not a 64bit
install, so unless you build that hello world statically, it's going
to require the 64bit ldso and shared libraries from glibc in the
proper lib directories in /
the no such file or directory is because the kernel could not execute
the associated ELF interpreter for that binary
-mike
Robert P. J. Day
> On 4/30/07, Robert P. J. Day <rpj...@mindspring.com> wrote:
> > but here's where i run into trouble -- when i try to run the
> > resulting a.out for "hello, world", i get "No such file or directory".
>
> you're assuming too much ... you have a 32bit install, not a 64bit
> install, so unless you build that hello world statically, it's going
> to require the 64bit ldso and shared libraries from glibc in the
> proper lib directories in /
>
> the no such file or directory is because the kernel could not
> execute the associated ELF interpreter for that binary -mike
sigh ... i realized that seconds after i posted. it's been a long
day.
rday
--
========================================================================
Robert P. J. Day
Linux Consulting, Training and Annoying Kernel Pedantry
Waterloo, Ontario, CANADA
http://fsdev.net/wiki/index.php?title=Main_Page
========================================================================
--
Octavian Purdila
>
> ok, i'm almost there. so far, i've:
>
> 1) built an (apparently) working x86_64 toolchain using crosstool
> 2) used that toolchain to build and install a 64-bit kernel
> 3) booted (successfully) under the new 64-bit kernel, verifying that
> it's 64-bit with "uname -a"
> 4) used the aforementioned toolchain to compile "hello, world"
>
> but here's where i run into trouble -- when i try to run the
> resulting a.out for "hello, world", i get "No such file or directory".
>
> i'm running it in the current directory with:
>
> $ ./a.out
>
> but still no luck. the "file" command shows me that it's there, with
> type "ELF 64-bit LSB executable, AMD x86-64 ..." but every attempt to
> run it gives me that error message.
>
> i'm sure i'm forgetting something trivial. ideas?
>
You are probably missing 64bit libraries since you mentioned that you are using 32bit userspace. Try compiling it with -static and see if it works.
Regards.
tavi
Robert P. J. Day
> On 4/30/07, Robert P. J. Day <rpj...@mindspring.com> wrote:
> > but here's where i run into trouble -- when i try to run the
> > resulting a.out for "hello, world", i get "No such file or directory".
>
> you're assuming too much ... you have a 32bit install, not a 64bit
> install, so unless you build that hello world statically, it's going
> to require the 64bit ldso and shared libraries from glibc in the
> proper lib directories in /
another option being building those 64-bit libs and installing them
elsewhere and playing games with "rpath" and the like, right?
rday
Robert P. J. Day
> On Monday 30 April 2007 23:31, Robert P. J. Day wrote:
>
> >
> > ok, i'm almost there. so far, i've:
> >
> > 1) built an (apparently) working x86_64 toolchain using crosstool
> > 2) used that toolchain to build and install a 64-bit kernel
> > 3) booted (successfully) under the new 64-bit kernel, verifying that
> > it's 64-bit with "uname -a"
> > 4) used the aforementioned toolchain to compile "hello, world"
> >
> > but here's where i run into trouble -- when i try to run the
> > resulting a.out for "hello, world", i get "No such file or directory".
> >
> > i'm running it in the current directory with:
> >
> > $ ./a.out
> >
> > but still no luck. the "file" command shows me that it's there, with
> > type "ELF 64-bit LSB executable, AMD x86-64 ..." but every attempt to
> > run it gives me that error message.
> >
> > i'm sure i'm forgetting something trivial. ideas?
> >
>
> You are probably missing 64bit libraries since you mentioned that
> you are using 32bit userspace. Try compiling it with -static and see
> if it works.
naturally, that works. thanks.
rday
p.s. i'm assuming that, until i cross-compile and install the 64-bit
libs, there's really nothing else i can do with this 64-bit kernel
other than run static 64-bit binaries, right?
--
========================================================================
Robert P. J. Day
Linux Consulting, Training and Annoying Kernel Pedantry
Waterloo, Ontario, CANADA
http://fsdev.net/wiki/index.php?title=Main_Page
========================================================================
--
Mike Frysinger
> On Mon, 30 Apr 2007, Mike Frysinger wrote:
> > On 4/30/07, Robert P. J. Day <rpj...@mindspring.com> wrote:
> > > but here's where i run into trouble -- when i try to run the
> > > resulting a.out for "hello, world", i get "No such file or directory".
> >
> > you're assuming too much ... you have a 32bit install, not a 64bit
> > install, so unless you build that hello world statically, it's going
> > to require the 64bit ldso and shared libraries from glibc in the
> > proper lib directories in /
>
> another option being building those 64-bit libs and installing them
> elsewhere and playing games with "rpath" and the like, right?
off the top of my head, you'd just need to override -rpath and -dynamic-linker
-mike
Robert P. J. Day
> On 4/30/07, Robert P. J. Day <rpj...@mindspring.com> wrote:
> > On Mon, 30 Apr 2007, Mike Frysinger wrote:
> > > On 4/30/07, Robert P. J. Day <rpj...@mindspring.com> wrote:
> > > > but here's where i run into trouble -- when i try to run the
> > > > resulting a.out for "hello, world", i get "No such file or directory".
> > >
> > > you're assuming too much ... you have a 32bit install, not a 64bit
> > > install, so unless you build that hello world statically, it's going
> > > to require the 64bit ldso and shared libraries from glibc in the
> > > proper lib directories in /
> >
> > another option being building those 64-bit libs and installing them
> > elsewhere and playing games with "rpath" and the like, right?
>
> off the top of my head, you'd just need to override -rpath and
> -dynamic-linker
actually, it's "--dynamic-linker" but i think i have enough to play
with and this is getting pretty far afield from kernel topics.
thanks.
rday
p.s. if there's a more appropriate place to discuss this topic, by
all means, let me know. i suspect i'm going to be digging into this
in some detail.
--
========================================================================
Robert P. J. Day
Linux Consulting, Training and Annoying Kernel Pedantry
Waterloo, Ontario, CANADA
http://fsdev.net/wiki/index.php?title=Main_Page
========================================================================
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