[Buildroot] [PATCH 0/2] xtensa: add -mtext-section-literals to xtensa ABI

[Buildroot] [PATCH 0/2] xtensa: add -mtext-section-literals to xtensa ABI

[Max Filippov]

Hi Thomas,

these two patches are the second part of fixes for building huge sources,
like wireshark or mplayer: adding trampolines support to binutils allows
assembling of such files, but with literals placed into separate section
build fails at the linking step.

First patch allows building uclibc with -mtext-section-literals, it is
posted to the uclibc list, but not reviewed/checked in yet.
Second patch adds -mtext-section-literals flag to xtensa ABI.

Max Filippov (2):
  uclibc: add missing .literal_position directives
  Makefile.in: add -mtext-section-literals to xtensa ABI

 package/Makefile.in                                |  2 +-
 ...-add-missing-.literal_position-directives.patch | 62 ++++++++++++++++++++++
 2 files changed, 63 insertions(+), 1 deletion(-)
 create mode 100644 package/uclibc/7bf35c8b7d4a1f97174eb49f47f33946b282114c/uclibc-0001-xtensa-add-missing-.literal_position-directives.patch

-- 
1.8.1.4

[Buildroot] [PATCH 1/2] uclibc: add missing .literal_position directives

[Max Filippov]

This allows building uclibc with -mtext-section-literals flag.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 ...-add-missing-.literal_position-directives.patch | 62 ++++++++++++++++++++++
 1 file changed, 62 insertions(+)
 create mode 100644 package/uclibc/7bf35c8b7d4a1f97174eb49f47f33946b282114c/uclibc-0001-xtensa-add-missing-.literal_position-directives.patch

diff --git a/package/uclibc/7bf35c8b7d4a1f97174eb49f47f33946b282114c/uclibc-0001-xtensa-add-missing-.literal_position-directives.patch b/package/uclibc/7bf35c8b7d4a1f97174eb49f47f33946b282114c/uclibc-0001-xtensa-add-missing-.literal_position-directives.patch
new file mode 100644
index 0000000..f5577c6
--- /dev/null
+++ b/package/uclibc/7bf35c8b7d4a1f97174eb49f47f33946b282114c/uclibc-0001-xtensa-add-missing-.literal_position-directives.patch
@@ -0,0 +1,62 @@
+From 04d7bd868b300c8150231d7a37e62150eaf810d0 Mon Sep 17 00:00:00 2001
+From: Max Filippov <jcmvbkbc@gmail.com>
+Date: Mon, 24 Mar 2014 01:06:35 +0400
+Subject: [PATCH] xtensa: add missing .literal_position directives
+
+This addition allows building uClibc with -mtext-section-literals
+
+Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
+---
+ ldso/ldso/xtensa/dl-startup.h | 1 +
+ ldso/ldso/xtensa/resolve.S    | 1 +
+ libc/string/xtensa/strcmp.S   | 5 +++--
+ 3 files changed, 5 insertions(+), 2 deletions(-)
+
+diff --git a/ldso/ldso/xtensa/dl-startup.h b/ldso/ldso/xtensa/dl-startup.h
+index 45af82d..b135a4c 100644
+--- a/ldso/ldso/xtensa/dl-startup.h
++++ b/ldso/ldso/xtensa/dl-startup.h
+@@ -11,6 +11,7 @@
+ __asm__ (
+     "	.text\n"
+     "	.align  4\n"
++    "	.literal_position\n"
+     "	.global _start\n"
+     "	.type   _start, @function\n"
+     "	.hidden _start\n"
+diff --git a/ldso/ldso/xtensa/resolve.S b/ldso/ldso/xtensa/resolve.S
+index 61c2c5d..d1ae8aa 100644
+--- a/ldso/ldso/xtensa/resolve.S
++++ b/ldso/ldso/xtensa/resolve.S
+@@ -27,6 +27,7 @@
+ 
+ 	.text
+ 	.align	4
++	.literal_position
+ 	.global	_dl_linux_resolve
+ 	.type	_dl_linux_resolve, @function
+ _dl_linux_resolve:
+diff --git a/libc/string/xtensa/strcmp.S b/libc/string/xtensa/strcmp.S
+index d3d72e0..8ed1ed0 100644
+--- a/libc/string/xtensa/strcmp.S
++++ b/libc/string/xtensa/strcmp.S
+@@ -34,13 +34,14 @@
+ 
+ #define MASK4 0x40404040
+ 
++	.text
++	.align 4
++	.literal_position
+ 	.literal .Lmask0, MASK0
+ 	.literal .Lmask1, MASK1
+ 	.literal .Lmask2, MASK2
+ 	.literal .Lmask3, MASK3
+ 	.literal .Lmask4, MASK4
+-
+-	.text
+ ENTRY (strcmp)
+ 	/* a2 = s1, a3 = s2 */
+ 
+-- 
+1.8.1.4
+
-- 
1.8.1.4

[Buildroot] [PATCH 2/2] Makefile.in: add -mtext-section-literals to xtensa ABI

[Max Filippov]

Collecting literals into separate section can be advantageous if that
section is placed into DTCM at link time. This is applicable for code
running on bare metal, but makes no sense under linux, where userspace
is isolated from the physical memory details. OTOH placing literals into
separate section breaks build of huge source files, because l32r
instruction can only access literals in 256 KBytes range.

Add -mtext-section-literals into xtensa ABI to fix build issues of
packages with huge sources.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 package/Makefile.in | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package/Makefile.in b/package/Makefile.in
index eea7043..31c72a0 100644
--- a/package/Makefile.in
+++ b/package/Makefile.in
@@ -73,7 +73,7 @@ endif
 # code size and performance, the linker can usually optimize away the
 # overhead when a call ends up within a certain range.
 ifeq ($(BR2_xtensa),y)
-TARGET_ABI += -mlongcalls
+TARGET_ABI += -mlongcalls -mtext-section-literals
 endif
 
 STAGING_SUBDIR = usr/$(GNU_TARGET_NAME)/sysroot
-- 
1.8.1.4

[Buildroot] [PATCH 2/2] Makefile.in: add -mtext-section-literals to xtensa ABI

[Baruch Siach]

Hi Max,

On Sun, Mar 30, 2014 at 08:22:01PM +0400, Max Filippov wrote:
> Collecting literals into separate section can be advantageous if that
> section is placed into DTCM at link time. This is applicable for code
> running on bare metal, but makes no sense under linux, where userspace
> is isolated from the physical memory details. OTOH placing literals into
> separate section breaks build of huge source files, because l32r
> instruction can only access literals in 256 KBytes range.
> 
> Add -mtext-section-literals into xtensa ABI to fix build issues of
> packages with huge sources.
> 
> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
> ---
>  package/Makefile.in | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/package/Makefile.in b/package/Makefile.in
> index eea7043..31c72a0 100644
> --- a/package/Makefile.in
> +++ b/package/Makefile.in
> @@ -73,7 +73,7 @@ endif
>  # code size and performance, the linker can usually optimize away the
>  # overhead when a call ends up within a certain range.

Please add the commit log explanation to the comment here.

>  ifeq ($(BR2_xtensa),y)
> -TARGET_ABI += -mlongcalls
> +TARGET_ABI += -mlongcalls -mtext-section-literals

With this in place a follow-up patch should remove local 
-mtext-section-literals that I sprinkled on various packages to fix xtensa 
build failures.

Thanks,
baruch

>  endif
>  
>  STAGING_SUBDIR = usr/$(GNU_TARGET_NAME)/sysroot

-- 
     http://baruch.siach.name/blog/                  ~. .~   Tk Open Systems
=}------------------------------------------------ooO--U--Ooo------------{=
   - baruch at tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -

[Buildroot] [PATCH 2/2] Makefile.in: add -mtext-section-literals to xtensa ABI

[Max Filippov]

On Sun, Mar 30, 2014 at 8:36 PM, Baruch Siach <baruch@tkos.co.il> wrote:
> Hi Max,
>
> On Sun, Mar 30, 2014 at 08:22:01PM +0400, Max Filippov wrote:
>> Collecting literals into separate section can be advantageous if that
>> section is placed into DTCM at link time. This is applicable for code
>> running on bare metal, but makes no sense under linux, where userspace
>> is isolated from the physical memory details. OTOH placing literals into
>> separate section breaks build of huge source files, because l32r
>> instruction can only access literals in 256 KBytes range.
>>
>> Add -mtext-section-literals into xtensa ABI to fix build issues of
>> packages with huge sources.
>>
>> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
>> ---
>>  package/Makefile.in | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/package/Makefile.in b/package/Makefile.in
>> index eea7043..31c72a0 100644
>> --- a/package/Makefile.in
>> +++ b/package/Makefile.in
>> @@ -73,7 +73,7 @@ endif
>>  # code size and performance, the linker can usually optimize away the
>>  # overhead when a call ends up within a certain range.
>
> Please add the commit log explanation to the comment here.

Ok.

>>  ifeq ($(BR2_xtensa),y)
>> -TARGET_ABI += -mlongcalls
>> +TARGET_ABI += -mlongcalls -mtext-section-literals
>
> With this in place a follow-up patch should remove local
> -mtext-section-literals that I sprinkled on various packages to fix xtensa
> build failures.

Ok, will add it.

-- 
Thanks.
-- Max