building uClinux using OE

building uClinux using OE

[Sergey 'Jin' Bostandzhyan]

Hi,

I'd like to be able to build uClinux using OE and I hope to gather some
pointers to the right direction.

I think it would generally be a nice thing to have, so I would like to do
the work in a way that it could be incorporated in OE, provided that you 
guys are interested.

According to the post below the toolchain should not be a problem:
http://mailman.uclinux.org/pipermail/uclinux-dev/2007-May/042993.html
"uClinux development on ARM now uses a standard arm-linux targeted tool chain. 
 We add the elf2flt tool, but it is otherwise a standard arm-linux toolchain."

As far as I know the uClinux/ARM kernel patches are already in the mainline:
http://opensrc.sec.samsung.com/

uClibc is also already supported by OE, not sure if I would have to add
an option for uC-libc.

So basically it seems that almost everything that is needed is already there.

What is missing?

- applying elf2flt processing to produced binaries

- have a way of knowing that the particular build is done for the uClinux
  targets (maybe for some tweaks in .bb files if required or to apply patches
  only when necessary, allthough ifdef __uClinux__ defines could be used)

- not sure what else?

I do not have any uClinux experience yet, and it seems to be quite difficult
to gather all the bits and pieces of information, so I'd appreciate comments 
and suggestions, especially if you see that I am missing something.

I'd also be interested in your thoughts on what would be the best way to
integrate it into OE.

Kind regards,
Jin

Re: building uClinux using OE

[Koen Kooi]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Sergey 'Jin' Bostandzhyan schreef:
| Hi,
|
| I'd like to be able to build uClinux using OE and I hope to gather some
| pointers to the right direction.
|
| I think it would generally be a nice thing to have, so I would like to do
| the work in a way that it could be incorporated in OE, provided that you
| guys are interested.
|
| According to the post below the toolchain should not be a problem:
| http://mailman.uclinux.org/pipermail/uclinux-dev/2007-May/042993.html
| "uClinux development on ARM now uses a standard arm-linux targeted
tool chain.
|  We add the elf2flt tool, but it is otherwise a standard arm-linux
toolchain."
|
| As far as I know the uClinux/ARM kernel patches are already in the
mainline:
| http://opensrc.sec.samsung.com/
|
| uClibc is also already supported by OE, not sure if I would have to add
| an option for uC-libc.
|
| So basically it seems that almost everything that is needed is already
there.
|
| What is missing?
|
| - applying elf2flt processing to produced binaries

That should happen automagically, we just need to stage some more
binutils-cross headers for elf2flt to build

| - have a way of knowing that the particular build is done for the uClinux
|   targets (maybe for some tweaks in .bb files if required or to apply
patches
|   only when necessary, allthough ifdef __uClinux__ defines could be used)
|
| - not sure what else?

Since you can't (practically) do shared libraries, all packaging (and
probably staging) will be wrong, since you won't have libfoo.so.1, but
something different.

| I do not have any uClinux experience yet, and it seems to be quite
difficult
| to gather all the bits and pieces of information, so I'd appreciate
comments
| and suggestions, especially if you see that I am missing something.
|
| I'd also be interested in your thoughts on what would be the best way to
| integrate it into OE.

I had a go at this a while ago, but I had to halt working on it since
the uboot on the blackfin site refuses to load the uImage on the
blackfin site, leaving me without a good testing target.
I think forcing static linking would be the fastest way to get an image
built, we can work on details (flat, shared-flat, fdpic, etc) after that.

regards,

Koen

- --
koen@dominion.kabel.utwente.nl will go go away in december 2007, please
use k.kooi@student.utwente.nl instead.

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Re: building uClinux using OE

[Alan Carvalho de Assis]

Hi Jin,

2008/2/14, Sergey 'Jin' Bostandzhyan <jin@mediatomb.cc>:
> Hi,
sic
>
> uClibc is also already supported by OE, not sure if I would have to add
> an option for uC-libc.
>
Although uC-libc is not so "up to date" I think it can be important to
device with small flash memory (like Netburn MOD5272) since it create
smallest binary footprint.

> So basically it seems that almost everything that is needed is already there.
>
> What is missing?
>
> - applying elf2flt processing to produced binaries
>
> - have a way of knowing that the particular build is done for the uClinux
>   targets (maybe for some tweaks in .bb files if required or to apply patches
>   only when necessary, allthough ifdef __uClinux__ defines could be used)
>
> - not sure what else?
>
> I do not have any uClinux experience yet, and it seems to be quite difficult
> to gather all the bits and pieces of information, so I'd appreciate comments
> and suggestions, especially if you see that I am missing something.
>
> I'd also be interested in your thoughts on what would be the best way to
> integrate it into OE.
>

Do you add all kernels supported by uClinux distro (2.0.x, 2.4.x and 2.6.x) ?

I think your idea to add uClinux support on OE is fantastic!

> Kind regards,
> Jin
>
>
>
> _______________________________________________
> Openembedded-devel mailing list
> Openembedded-devel@lists.openembedded.org
> http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/openembedded-devel
>

Re: building uClinux using OE

[Sergey 'Jin' Bostandzhyan]

Hi,

On Thu, Feb 14, 2008 at 05:47:07PM +0100, Koen Kooi wrote:

[...]

> | What is missing?
> |
> | - applying elf2flt processing to produced binaries
> 
> That should happen automagically, we just need to stage some more
> binutils-cross headers for elf2flt to build

OK, I'll see that I get elf2flt to build, I'll surely have some questions
about the "automagically" part later on :)

> | - have a way of knowing that the particular build is done for the uClinux
> |   targets (maybe for some tweaks in .bb files if required or to apply
> patches
> |   only when necessary, allthough ifdef __uClinux__ defines could be used)
> |
> | - not sure what else?
> 
> Since you can't (practically) do shared libraries, all packaging (and
> probably staging) will be wrong, since you won't have libfoo.so.1, but
> something different.

OK, I'll keep that in mind.

> | I do not have any uClinux experience yet, and it seems to be quite
> difficult
> | to gather all the bits and pieces of information, so I'd appreciate
> comments
> | and suggestions, especially if you see that I am missing something.
> |
> | I'd also be interested in your thoughts on what would be the best way to
> | integrate it into OE.
> 
> I had a go at this a while ago, but I had to halt working on it since
> the uboot on the blackfin site refuses to load the uImage on the
> blackfin site, leaving me without a good testing target.
> I think forcing static linking would be the fastest way to get an image
> built, we can work on details (flat, shared-flat, fdpic, etc) after that.

How far did you come with the stuff you did back then? Did you merge anything
of it into OE and if yes, could you please point me to the things you did
so I can pick up from there?

Thanks,
Jin

Re: building uClinux using OE

[Sergey 'Jin' Bostandzhyan]

Hi, 

On Sun, Feb 17, 2008 at 12:28:27PM -0300, Alan Carvalho de Assis wrote:
> > uClibc is also already supported by OE, not sure if I would have to add
> > an option for uC-libc.
> >
> Although uC-libc is not so "up to date" I think it can be important to
> device with small flash memory (like Netburn MOD5272) since it create
> smallest binary footprint.

I will probably start with uClibc since it's already in OE, I am not sure
if my project requires uC-libc, I guess I will look at that when I get a
little further.

> > I do not have any uClinux experience yet, and it seems to be quite difficult
> > to gather all the bits and pieces of information, so I'd appreciate comments
> > and suggestions, especially if you see that I am missing something.
> >
> > I'd also be interested in your thoughts on what would be the best way to
> > integrate it into OE.
> >
> 
> Do you add all kernels supported by uClinux distro (2.0.x, 2.4.x and 2.6.x) ?

I will focus on 2.6.x, I do not have any hardware to test with the 
older kernels and the project I am working on also requires a 2.6.x version.
 
> I think your idea to add uClinux support on OE is fantastic!

Let's hope we succeed in doing so :)

Kind regards,
Jin

Re: building uClinux using OE

[Sergey 'Jin' Bostandzhyan]

[-- Attachment #1: Type: text/plain, Size: 1805 bytes --]

Hi Koen,
   
On Thu, Feb 14, 2008 at 05:47:07PM +0100, Koen Kooi wrote:
> That should happen automagically, we just need to stage some more
> binutils-cross headers for elf2flt to build

OK... I am not sure if I got the idea, so please correct me if I am wrong:
elf2flt needs to be told what target arch it will be used for, but it
should be compiled using native libiberty.a and libbfd.a?

At least running ./elf2flt without any options prints me
"Compiled for arm architecture" at the end of the usage summary.

I am not yet sure if it produces any meaningful output or how I could test it
to be sure (it asks for some relocation info files), so any hints would be
greatly appreciated.

And also... how would this "automagically" part work, what do I do next?

> I had a go at this a while ago, but I had to halt working on it since
> the uboot on the blackfin site refuses to load the uImage on the
> blackfin site, leaving me without a good testing target.
> I think forcing static linking would be the fastest way to get an image
> built, we can work on details (flat, shared-flat, fdpic, etc) after that.

I found your elf2flt_svn.bb recipe and used it as a starting point.

I had to apply the patch from here in order to compile binutils with uclibc:
http://bugs.openembedded.org/show_bug.cgi?id=3178

I attached my diffs.

Kind regards,
Jin

> 
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> Openembedded-devel mailing list
> Openembedded-devel@lists.openembedded.org
> http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/openembedded-devel

[-- Attachment #2: elf2flt_svn.patch --]
[-- Type: text/plain, Size: 616 bytes --]

--- ../../../../org.openembedded.dev/packages/uclibc/elf2flt_svn.bb	2008-02-20 16:11:45.000000000 +0100
+++ elf2flt_svn.bb	2008-02-22 18:51:13.000000000 +0100
@@ -9,7 +9,8 @@
 
 S = "${WORKDIR}/${PN}"
 
-EXTRA_OECONF = " --with-libbfd=${STAGING_DIR}/${TARGET_SYS}/lib/libbfd.a \
-                 --with-libiberty=${STAGING_DIR}/${TARGET_SYS}/lib/libiberty.a \
+EXTRA_OECONF = " --with-libbfd=${STAGING_LIBDIR_NATIVE}/libbfd.a \
+                 --with-libiberty=${STAGING_LIBDIR_NATIVE}/libiberty.a \
                  --with-bfd-include-dir=${STAGING_DIR}/${TARGET_SYS}/include \
                "
+

[-- Attachment #3: binutils_stage_and_libm.patch --]
[-- Type: text/plain, Size: 2556 bytes --]

diff -Naur ../../../../org.openembedded.dev/packages/binutils/binutils-2.18/binutils-uclibc-configure-add-libm.patch ./binutils-2.18/binutils-uclibc-configure-add-libm.patch
--- ../../../../org.openembedded.dev/packages/binutils/binutils-2.18/binutils-uclibc-configure-add-libm.patch	1970-01-01 01:00:00.000000000 +0100
+++ ./binutils-2.18/binutils-uclibc-configure-add-libm.patch	2008-02-22 15:07:54.000000000 +0100
@@ -0,0 +1,12 @@
+*** binutils-2.18/gas/configure.orig	2007-11-08 10:44:45.000000000 +0100
+--- binutils-2.18/gas/configure	2007-11-08 10:43:50.000000000 +0100
+*************** _ACEOF
+*** 12855,12860 ****
+--- 12855,12861 ----
+  fi
+  done
+  
++ need_libm=yes
+  # do we need the math library?
+  case "${need_libm}" in
+  yes)
--- ../../../../org.openembedded.dev/packages/binutils/binutils.inc	2008-02-20 16:11:36.000000000 +0100
+++ ./binutils.inc	2008-02-22 19:07:04.000000000 +0100
@@ -84,9 +84,14 @@
 	install -m 0644 ${S}/include/dis-asm.h ${STAGING_INCDIR}/
 	install -m 0644 ${S}/include/symcat.h ${STAGING_INCDIR}/
 	install -m 0644 ${S}/include/libiberty.h ${STAGING_INCDIR}/
+	install -m 0644 ${S}/include/filenames.h ${STAGING_INCDIR}/
 	install -m 0644 ${S}/include/ansidecl.h ${STAGING_INCDIR}/
 	install -m 0644 ${S}/include/bfdlink.h ${STAGING_INCDIR}/
 	install -m 0644 bfd/bfd.h ${STAGING_INCDIR}/
+    
+    mkdir -p ${STAGING_INCDIR}/elf
+	install -m 0644 ${S}/include/elf/arm.h ${STAGING_INCDIR}/elf
+	install -m 0644 ${S}/include/elf/reloc-macros.h ${STAGING_INCDIR}/elf
 }
 
 do_install () {
--- ../../../../org.openembedded.dev/packages/binutils/binutils-cross.inc	2008-02-20 16:11:36.000000000 +0100
+++ ./binutils-cross.inc	2008-02-22 18:20:14.000000000 +0100
@@ -10,6 +10,9 @@
 
 do_stage () {
 	oe_runmake install
+   
+    oe_libinstall -a -C ${B}/libiberty libiberty ${STAGING_LIBDIR_NATIVE}/
+    oe_libinstall -a -C ${B}/bfd libbfd ${STAGING_LIBDIR_NATIVE}/
 
 	# We don't really need these, so we'll remove them...
 	rm -rf ${CROSS_DIR}/lib/ldscripts
--- ../../../../org.openembedded.dev/packages/binutils/binutils_2.18.bb	2008-02-20 16:11:36.000000000 +0100
+++ ./binutils_2.18.bb	2008-02-22 15:11:38.000000000 +0100
@@ -11,6 +11,7 @@
      file://binutils-uclibc-300-001_ld_makefile_patch.patch;patch=1 \
      file://binutils-uclibc-300-006_better_file_error.patch;patch=1 \
      file://binutils-uclibc-300-012_check_ldrunpath_length.patch;patch=1 \
+     file://binutils-uclibc-configure-add-libm.patch;patch=1 \
      "
 
 # powerpc patches