[Buildroot] Fwd: [PATCH 1/1] uboot: Strip "-Wl," from LDFLAGS

[Buildroot] Fwd: [PATCH 1/1] uboot: Strip "-Wl," from LDFLAGS

[Jeroen Roovers]

---------- Forwarded message ----------
From: Jeroen Roovers <jer@airfi.aero>
Date: 10 February 2016 at 12:15
Subject: [PATCH 1/1] uboot: Strip "-Wl," from LDFLAGS
To: buildroot at buildroot.org
Cc: Jeroen Roovers <jer@airfi.aero>


    If we want to set proper LDFLAGS, then we need to mangle that in the
    uboot build system as it calls ld(1) (in fact ld.bfd) directly,
    where the "-Wl," prefix should only be used when the linker is
    called indirectly through gcc(1).

Signed-off-by: Jeroen Roovers <jer@airfi.aero>
---
 boot/uboot/uboot.mk | 1 +
 1 file changed, 1 insertion(+)

diff --git a/boot/uboot/uboot.mk b/boot/uboot/uboot.mk
index d539b31..9996aca 100644
--- a/boot/uboot/uboot.mk
+++ b/boot/uboot/uboot.mk
@@ -83,6 +83,7 @@ endif

 UBOOT_MAKE_OPTS += \
        CROSS_COMPILE="$(TARGET_CROSS)" \
+       LDFLAGS="$(TARGET_LDFLAGS:-Wl,%=%)" \
        ARCH=$(UBOOT_ARCH)

 ifeq ($(BR2_TARGET_UBOOT_NEEDS_DTC),y)
--
2.4.10

[Buildroot] Fwd: [PATCH 1/1] uboot: Strip "-Wl," from LDFLAGS

[Thomas Petazzoni]

Hello,

Thanks for this patch! See some comments below.

On Wed, 10 Feb 2016 16:03:23 +0100, Jeroen Roovers wrote:
> ---------- Forwarded message ----------
> From: Jeroen Roovers <jer@airfi.aero>
> Date: 10 February 2016 at 12:15
> Subject: [PATCH 1/1] uboot: Strip "-Wl," from LDFLAGS
> To: buildroot at buildroot.org
> Cc: Jeroen Roovers <jer@airfi.aero>
> 
> 
>     If we want to set proper LDFLAGS, then we need to mangle that in the
>     uboot build system as it calls ld(1) (in fact ld.bfd) directly,
>     where the "-Wl," prefix should only be used when the linker is
>     called indirectly through gcc(1).
> 
> Signed-off-by: Jeroen Roovers <jer@airfi.aero>

What specific/real problem is this fixing? I.e in which
situation/configuration are you seeing that TARGET_LDFLAGS contains a
-Wl option?

Thanks,

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

[Buildroot] Fwd: Fwd: [PATCH 1/1] uboot: Strip "-Wl, " from LDFLAGS

[Jeroen Roovers]

Apparently this didn't make it to the list.

---------- Forwarded message ----------
From: Jeroen Roovers <jeroen.roovers@airfi.aero>
Date: 10 February 2016 at 17:47
Subject: Re: [Buildroot] Fwd: [PATCH 1/1] uboot: Strip "-Wl," from LDFLAGS
To: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: buildroot at buildroot.org


I set BR2_TARGET_LDFLAGS="-Wl,-O1 -Wl,--as-needed" in .config.
Everywere else, the resulting LDFLAGS is correctly used, i.e. as
linker flags passed to GCC.

The specific problem I am fixing is that ld.bfd, as called by uboot,
does not know what -Wl,-O1 or -Wl,--as-needed are, but does know what
-O1 and --as-needed are. So it's sort of a build failure, which that
patch fixes.


On 10 February 2016 at 17:41, Thomas Petazzoni
<thomas.petazzoni@free-electrons.com> wrote:
> Hello,
>
> Thanks for this patch! See some comments below.
>
> On Wed, 10 Feb 2016 16:03:23 +0100, Jeroen Roovers wrote:
>> ---------- Forwarded message ----------
>> From: Jeroen Roovers <jer@airfi.aero>
>> Date: 10 February 2016 at 12:15
>> Subject: [PATCH 1/1] uboot: Strip "-Wl," from LDFLAGS
>> To: buildroot at buildroot.org
>> Cc: Jeroen Roovers <jer@airfi.aero>
>>
>>
>>     If we want to set proper LDFLAGS, then we need to mangle that in the
>>     uboot build system as it calls ld(1) (in fact ld.bfd) directly,
>>     where the "-Wl," prefix should only be used when the linker is
>>     called indirectly through gcc(1).
>>
>> Signed-off-by: Jeroen Roovers <jer@airfi.aero>
>
> What specific/real problem is this fixing? I.e in which
> situation/configuration are you seeing that TARGET_LDFLAGS contains a
> -Wl option?
>
> Thanks,
>
> Thomas
> --
> Thomas Petazzoni, CTO, Free Electrons
> Embedded Linux, Kernel and Android engineering
> http://free-electrons.com

[Buildroot] Fwd: [PATCH 1/1] uboot: Strip "-Wl," from LDFLAGS

[Thomas Petazzoni]

Hello,

On Wed, 10 Feb 2016 16:03:23 +0100, Jeroen Roovers wrote:
> ---------- Forwarded message ----------
> From: Jeroen Roovers <jer@airfi.aero>
> Date: 10 February 2016 at 12:15
> Subject: [PATCH 1/1] uboot: Strip "-Wl," from LDFLAGS
> To: buildroot at buildroot.org
> Cc: Jeroen Roovers <jer@airfi.aero>
> 
> 
>     If we want to set proper LDFLAGS, then we need to mangle that in the
>     uboot build system as it calls ld(1) (in fact ld.bfd) directly,
>     where the "-Wl," prefix should only be used when the linker is
>     called indirectly through gcc(1).
> 
> Signed-off-by: Jeroen Roovers <jer@airfi.aero>

I have not been able to reproduce a build problem, since TARGET_LDFLAGS
are currently not passed to U-Boot. So the following defconfig builds
fine:

BR2_arm=y
BR2_TOOLCHAIN_EXTERNAL=y
BR2_TOOLCHAIN_EXTERNAL_CUSTOM=y
BR2_TOOLCHAIN_EXTERNAL_DOWNLOAD=y
BR2_TOOLCHAIN_EXTERNAL_URL="http://autobuild.buildroot.org/toolchains/tarballs/br-arm-full-2016.05-rc2-3-g011d4e2.tar.bz2"
BR2_TOOLCHAIN_EXTERNAL_GCC_4_8=y
BR2_TOOLCHAIN_EXTERNAL_HEADERS_3_10=y
BR2_TOOLCHAIN_EXTERNAL_LOCALE=y
# BR2_TOOLCHAIN_EXTERNAL_HAS_THREADS_DEBUG is not set
BR2_TOOLCHAIN_EXTERNAL_INET_RPC=y
BR2_TOOLCHAIN_EXTERNAL_CXX=y
BR2_TARGET_LDFLAGS="-Wl,--as-needed"
BR2_INIT_NONE=y
BR2_SYSTEM_BIN_SH_NONE=y
# BR2_PACKAGE_BUSYBOX is not set
# BR2_TARGET_ROOTFS_TAR is not set
BR2_TARGET_UBOOT=y
BR2_TARGET_UBOOT_BUILD_SYSTEM_KCONFIG=y
BR2_TARGET_UBOOT_BOARD_DEFCONFIG="clearfog"

So maybe your patch is also about *passing* LDFLAGS down to U-Boot ?

In any case, your commit log had some "mail forwarding" related
contents. Could you resend an updated version, which explains a bit
better that the patch also *passes* LDFLAGS down to U-Boot, and with
fixed up commit log?

Thanks a lot!

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

[Buildroot] Fwd: [PATCH 1/1] uboot: Strip "-Wl," from LDFLAGS

[Jeroen Roovers]

The patch *doesn't* pass LDFLAGS down; GNU make simply picks up the
exported LDFLAGS from buildroot and integrates it with its own flags.
I only found out because when I set BR2_TARGET_LDFLAGS using the usual
GCC flags and did a complete rebuild, I found that only uboot failed
to build.

I'll resend the patch when I find the time.

On 3 June 2016 at 15:18, Thomas Petazzoni
<thomas.petazzoni@free-electrons.com> wrote:
> Hello,
>
> On Wed, 10 Feb 2016 16:03:23 +0100, Jeroen Roovers wrote:
>> ---------- Forwarded message ----------
>> From: Jeroen Roovers <jer@airfi.aero>
>> Date: 10 February 2016 at 12:15
>> Subject: [PATCH 1/1] uboot: Strip "-Wl," from LDFLAGS
>> To: buildroot at buildroot.org
>> Cc: Jeroen Roovers <jer@airfi.aero>
>>
>>
>>     If we want to set proper LDFLAGS, then we need to mangle that in the
>>     uboot build system as it calls ld(1) (in fact ld.bfd) directly,
>>     where the "-Wl," prefix should only be used when the linker is
>>     called indirectly through gcc(1).
>>
>> Signed-off-by: Jeroen Roovers <jer@airfi.aero>
>
> I have not been able to reproduce a build problem, since TARGET_LDFLAGS
> are currently not passed to U-Boot. So the following defconfig builds
> fine:
>
> BR2_arm=y
> BR2_TOOLCHAIN_EXTERNAL=y
> BR2_TOOLCHAIN_EXTERNAL_CUSTOM=y
> BR2_TOOLCHAIN_EXTERNAL_DOWNLOAD=y
> BR2_TOOLCHAIN_EXTERNAL_URL="http://autobuild.buildroot.org/toolchains/tarballs/br-arm-full-2016.05-rc2-3-g011d4e2.tar.bz2"
> BR2_TOOLCHAIN_EXTERNAL_GCC_4_8=y
> BR2_TOOLCHAIN_EXTERNAL_HEADERS_3_10=y
> BR2_TOOLCHAIN_EXTERNAL_LOCALE=y
> # BR2_TOOLCHAIN_EXTERNAL_HAS_THREADS_DEBUG is not set
> BR2_TOOLCHAIN_EXTERNAL_INET_RPC=y
> BR2_TOOLCHAIN_EXTERNAL_CXX=y
> BR2_TARGET_LDFLAGS="-Wl,--as-needed"
> BR2_INIT_NONE=y
> BR2_SYSTEM_BIN_SH_NONE=y
> # BR2_PACKAGE_BUSYBOX is not set
> # BR2_TARGET_ROOTFS_TAR is not set
> BR2_TARGET_UBOOT=y
> BR2_TARGET_UBOOT_BUILD_SYSTEM_KCONFIG=y
> BR2_TARGET_UBOOT_BOARD_DEFCONFIG="clearfog"
>
> So maybe your patch is also about *passing* LDFLAGS down to U-Boot ?
>
> In any case, your commit log had some "mail forwarding" related
> contents. Could you resend an updated version, which explains a bit
> better that the patch also *passes* LDFLAGS down to U-Boot, and with
> fixed up commit log?
>
> Thanks a lot!
>
> Thomas
> --
> Thomas Petazzoni, CTO, Free Electrons
> Embedded Linux, Kernel and Android engineering
> http://free-electrons.com

[Buildroot] Fwd: [PATCH 1/1] uboot: Strip "-Wl," from LDFLAGS

[Thomas Petazzoni]

Hello,

On Fri, 3 Jun 2016 16:00:42 +0200, Jeroen Roovers wrote:

> The patch *doesn't* pass LDFLAGS down; GNU make simply picks up the
> exported LDFLAGS from buildroot and integrates it with its own flags.
> I only found out because when I set BR2_TARGET_LDFLAGS using the usual
> GCC flags and did a complete rebuild, I found that only uboot failed
> to build.

Buildroot does not export LDFLAGS, and only passes it down to packages
if it's explicitly done in the package .mk file.

Try the defconfig I posted, it built just fine, even though it has
-Wl,--as-needed in BR2_TARGET_LDFLAGS.

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

[Buildroot] Fwd: [PATCH 1/1] uboot: Strip "-Wl," from LDFLAGS

[Jeroen Roovers]

Hm, OK. I did just discover that I'm on an AllWinner fork of uboot, so
maybe it doesn't apply to mainline uboot at all. If you cannot
reproduce the issue, then that may be the cause, in which case I guess
you would want to drop that patch.


Regards,
     jer

On 3 June 2016 at 16:03, Thomas Petazzoni
<thomas.petazzoni@free-electrons.com> wrote:
> Hello,
>
> On Fri, 3 Jun 2016 16:00:42 +0200, Jeroen Roovers wrote:
>
>> The patch *doesn't* pass LDFLAGS down; GNU make simply picks up the
>> exported LDFLAGS from buildroot and integrates it with its own flags.
>> I only found out because when I set BR2_TARGET_LDFLAGS using the usual
>> GCC flags and did a complete rebuild, I found that only uboot failed
>> to build.
>
> Buildroot does not export LDFLAGS, and only passes it down to packages
> if it's explicitly done in the package .mk file.
>
> Try the defconfig I posted, it built just fine, even though it has
> -Wl,--as-needed in BR2_TARGET_LDFLAGS.
>
> Thomas
> --
> Thomas Petazzoni, CTO, Free Electrons
> Embedded Linux, Kernel and Android engineering
> http://free-electrons.com