[U-Boot] [RFC 00/10] clang support for ARM

[U-Boot] [RFC 00/10] clang support for ARM

[Jeroen Hofstee]

Hi, I rebased some patches with should compile a working u-boot
with clang and gcc (besides a couple which don't have memset),
but I didn't bother too much about that for now.

Obviously this is not intended for the next release, but a
request for comment. Clang is not really fond of the gd
assignment and I tried to get rid of them since crt0.S already
handles this. I also added clearing gd (in a broken way) to
crt0.S to prevent all board_init_f having to do it again and
again (i2c / serial typically depends on it).

The most important question is if these patches break any
existing board. Your feedback is welcome.

Kind regards,
Jeroen

patches are also at (with some twister board specific ones):
https://github.com/jhofstee/u-boot/commits/v2014.07-rc2-clang

Jeroen Hofstee (10):
  ARM: crt0.S: clear the global data
  ARM: omap3/board: add spl specific board_init_f
  board_r: only assign gd when requested
  ARM: do not set gd in generic board again
  ARM: SPL: do not set gd again
  cc-option: make it work with clang
  ARM: make gd a function a function for clang
  inline: use the gcc inline version instead of the c99 one.
  eabi_compat: add __aeabi_memcpy __aeabi_memset
  README.clang: build command with clang

 arch/arm/cpu/armv7/omap3/board.c   | 15 ++++++++++-----
 arch/arm/include/asm/config.h      |  2 --
 arch/arm/include/asm/global_data.h | 17 +++++++++++++++++
 arch/arm/lib/crt0.S                |  6 ++++++
 arch/arm/lib/eabi_compat.c         | 15 +++++++++++++--
 arch/arm/lib/spl.c                 |  3 ---
 common/board_r.c                   |  2 +-
 doc/README.clang                   | 15 +++++++++++++++
 include/linux/compiler-gcc.h       |  7 ++++---
 scripts/Kbuild.include             |  4 ++--
 10 files changed, 68 insertions(+), 18 deletions(-)
 create mode 100644 doc/README.clang

-- 
1.8.3.2

[U-Boot] [RFC 01/10] ARM: crt0.S: clear the global data

[Jeroen Hofstee]

NOTE: smdk5420 snow smdkv310 apf27 arndale origen vpac270_ond_256 smdk5250
don't have a memset available.
---
 arch/arm/lib/crt0.S | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm/lib/crt0.S b/arch/arm/lib/crt0.S
index dfc2de9..52b6f74 100644
--- a/arch/arm/lib/crt0.S
+++ b/arch/arm/lib/crt0.S
@@ -70,6 +70,12 @@ ENTRY(_main)
 	sub	sp, sp, #GD_SIZE	/* allocate one GD above SP */
 	bic	sp, sp, #7	/* 8-byte alignment for ABI compliance */
 	mov	r9, sp		/* GD is above SP */
+
+	mov	r0, r9		/* Clear the global data */
+	mov	r1, #0
+	mov	r2, #GENERATED_GBL_DATA_SIZE
+	bl	memset
+
 	mov	r0, #0
 	bl	board_init_f
 
-- 
1.8.3.2

[U-Boot] [RFC 02/10] ARM: omap3/board: add spl specific board_init_f

[Jeroen Hofstee]

gd is already setup when calling board_init_f and
preloader_console_init depends on it. Therefore move
the SPL specific part to its own board_init_f as it
prevents the need for a temporarily gd.
---
 arch/arm/cpu/armv7/omap3/board.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/arch/arm/cpu/armv7/omap3/board.c b/arch/arm/cpu/armv7/omap3/board.c
index 9bb1a1c..2e2ec14 100644
--- a/arch/arm/cpu/armv7/omap3/board.c
+++ b/arch/arm/cpu/armv7/omap3/board.c
@@ -239,17 +239,22 @@ void s_init(void)
 	ehci_clocks_enable();
 #endif
 
+	if (!in_sdram)
+		mem_init();
+}
+
 #ifdef CONFIG_SPL_BUILD
-	gd = &gdata;
+void board_init_f(ulong dummy)
+{
+	/* Clear the BSS. */
+	memset(__bss_start, 0, __bss_end - __bss_start);
 
 	preloader_console_init();
-
 	timer_init();
-#endif
 
-	if (!in_sdram)
-		mem_init();
+        board_init_r(NULL, 0);
 }
+#endif
 
 /*
  * Routine: misc_init_r
-- 
1.8.3.2

[U-Boot] [RFC 03/10] board_r: only assign gd when requested

[Jeroen Hofstee]

When CONFIG_SYS_GENERIC_GLOBAL_DATA is not set the arch handles
the assignment of gd. At least in case of ARM/Aarch64 this means
board_init_r is alteady called with the new gd. Therefore only
assign gd if CONFIG_SYS_GENERIC_GLOBAL_DATA is defined.
---
 common/board_r.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/common/board_r.c b/common/board_r.c
index 602a239..18bbe26 100644
--- a/common/board_r.c
+++ b/common/board_r.c
@@ -927,7 +927,7 @@ void board_init_r(gd_t *new_gd, ulong dest_addr)
 	int i;
 #endif
 
-#ifndef CONFIG_X86
+#ifdef CONFIG_SYS_GENERIC_GLOBAL_DATA
 	gd = new_gd;
 #endif
 
-- 
1.8.3.2

[U-Boot] [RFC 04/10] ARM: do not set gd in generic board again

[Jeroen Hofstee]

Since crt0.S / crt0_64.S already allocate gd and assing it there
is no need to do it again board_f / board_r as it only wastes
stack space.
---
 arch/arm/include/asm/config.h | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/arm/include/asm/config.h b/arch/arm/include/asm/config.h
index 2a20a77..abf79e5 100644
--- a/arch/arm/include/asm/config.h
+++ b/arch/arm/include/asm/config.h
@@ -7,8 +7,6 @@
 #ifndef _ASM_CONFIG_H_
 #define _ASM_CONFIG_H_
 
-#define CONFIG_SYS_GENERIC_GLOBAL_DATA
-
 #define CONFIG_LMB
 #define CONFIG_SYS_BOOT_RAMDISK_HIGH
 
-- 
1.8.3.2

[U-Boot] [RFC 05/10] ARM: SPL: do not set gd again

[Jeroen Hofstee]

---
 arch/arm/lib/spl.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/arch/arm/lib/spl.c b/arch/arm/lib/spl.c
index dfcc596..75ab546 100644
--- a/arch/arm/lib/spl.c
+++ b/arch/arm/lib/spl.c
@@ -28,9 +28,6 @@ void __weak board_init_f(ulong dummy)
 	/* Clear the BSS. */
 	memset(__bss_start, 0, __bss_end - __bss_start);
 
-	/* Set global data pointer. */
-	gd = &gdata;
-
 	board_init_r(NULL, 0);
 }
 
-- 
1.8.3.2

[U-Boot] [RFC 06/10] cc-option: make it work with clang

[Jeroen Hofstee]

By default clang will return echo a warning if an option is unknown.
Therefore turn warnings into errors when polling for options.
---
 scripts/Kbuild.include | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index c664e39..4c33359 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -113,12 +113,12 @@ as-instr = $(call try-run,\
 # Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
 
 cc-option = $(call try-run,\
-	$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
+	$(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
 
 # cc-option-yn
 # Usage: flag := $(call cc-option-yn,-march=winchip-c6)
 cc-option-yn = $(call try-run,\
-	$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
+	$(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
 
 # cc-option-align
 # Prefix align with either -falign or -malign
-- 
1.8.3.2

[U-Boot] [RFC 07/10] ARM: make gd a function a function for clang

[Jeroen Hofstee]

---
 arch/arm/include/asm/global_data.h | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/arch/arm/include/asm/global_data.h b/arch/arm/include/asm/global_data.h
index 63e4ad5..646d694 100644
--- a/arch/arm/include/asm/global_data.h
+++ b/arch/arm/include/asm/global_data.h
@@ -44,10 +44,27 @@ struct arch_global_data {
 
 #include <asm-generic/global_data.h>
 
+#ifdef __clang__
+
+#define DECLARE_GLOBAL_DATA_PTR
+#define gd	get_gd()
+
+static __inline volatile gd_t *get_gd(void)
+{
+	gd_t *gd_ptr;
+
+	__asm__ volatile("mov %0, r9\n" : "=r" (gd_ptr));
+
+	return gd_ptr;
+}
+
+#else
+
 #ifdef CONFIG_ARM64
 #define DECLARE_GLOBAL_DATA_PTR		register volatile gd_t *gd asm ("x18")
 #else
 #define DECLARE_GLOBAL_DATA_PTR		register volatile gd_t *gd asm ("r9")
 #endif
+#endif
 
 #endif /* __ASM_GBL_DATA_H */
-- 
1.8.3.2

[U-Boot] [RFC 08/10] inline: use the gcc inline version instead of the c99 one.

[Jeroen Hofstee]

---
This fixes errors like:

make[1]: Entering directory `/home/jeroen/software/u-boot/arch/arm/cpu/armv7/omap-common'
arm-linux-gnueabi-ld.bfd  -r -o libomap-common.o  reset.o timer.o utils.o
timer.o: In function `get_tbclk':
/home/jeroen/software/u-boot/include/asm/io.h:81: multiple definition of `__raw_writesb'
reset.o:/home/jeroen/software/u-boot/include/asm/io.h:81: first defined here
timer.o: In function `__udelay':
/home/jeroen/software/u-boot/include/asm/io.h:88: multiple definition of `__raw_writesw'
reset.o:/home/jeroen/software/u-boot/include/asm/io.h:88: first defined here
timer.o: In function `get_ticks':
/home/jeroen/software/u-boot/include/asm/io.h:95: multiple definition of `__raw_writesl'
reset.o:/home/jeroen/software/u-boot/include/asm/io.h:95: first defined here
timer.o: In function `__raw_readsb':
/home/jeroen/software/u-boot/include/asm/io.h:102: multiple definition of `__raw_readsb'
reset.o:/home/jeroen/software/u-boot/include/asm/io.h:102: first defined here
timer.o: In function `__raw_readsw':
/home/jeroen/software/u-boot/include/asm/io.h:109: multiple definition of `__raw_readsw'
reset.o:/home/jeroen/software/u-boot/include/asm/io.h:109: first defined here
timer.o: In function `__raw_readsl':
/home/jeroen/software/u-boot/include/asm/io.h:116: multiple definition of `__raw_readsl'
reset.o:/home/jeroen/software/u-boot/include/asm/io.h:116: first defined here
make[1]: *** [libomap-common.o] Error 1
make[1]: Leaving directory `/home/jeroen/software/u-boot/arch/arm/cpu/armv7/omap-common'
make: *** [arch/arm/cpu/armv7/omap-common/libomap-common.o] Error 2
---
 include/linux/compiler-gcc.h | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index 9896e54..99c6dcc 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -44,9 +44,10 @@
  */
 #if !defined(CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING) || \
     !defined(CONFIG_OPTIMIZE_INLINING) || (__GNUC__ < 4)
-# define inline		inline		__attribute__((always_inline))
-# define __inline__	__inline__	__attribute__((always_inline))
-# define __inline	__inline	__attribute__((always_inline))
+/* XXX: check __GNUC_STDC_INLINE__, fix line length */
+# define inline		inline		__attribute__((always_inline)) __attribute__((__gnu_inline__))
+# define __inline__	__inline__	__attribute__((always_inline)) __attribute__((__gnu_inline__))
+# define __inline	__inline	__attribute__((always_inline)) __attribute__((__gnu_inline__))
 #endif
 
 #define __deprecated			__attribute__((deprecated))
-- 
1.8.3.2

[U-Boot] [RFC 09/10] eabi_compat: add __aeabi_memcpy __aeabi_memset

[Jeroen Hofstee]

fixes this:

common/libcommon.o: In function `env_callback_init':
/home/jeroen/software/u-boot/common/env_callback.c:47: undefined reference to `__aeabi_memset'
common/libcommon.o: In function `parse_stream_outer':
/home/jeroen/software/u-boot/common/hush.c:3154: undefined reference to `__aeabi_memset'
disk/libdisk.o: In function `get_device_and_partition':
/home/jeroen/software/u-boot/disk/part.c:596: undefined reference to `__aeabi_memcpy'
/home/jeroen/software/u-boot/disk/part.c:605: undefined reference to `__aeabi_memcpy'
fs/fat/libfat.o: In function `fat_set_blk_dev':
/home/jeroen/software/u-boot/fs/fat/fat.c:60: undefined reference to `__aeabi_memcpy'
fs/ubifs/libubifs.o: In function `ubifs_tnc_locate':
/home/jeroen/software/u-boot/fs/ubifs/tnc.c:1457: undefined reference to `__aeabi_memcpy'
fs/ubifs/libubifs.o: In function `tnc_insert':
/home/jeroen/software/u-boot/fs/ubifs/tnc.c:2008: undefined reference to `__aeabi_memcpy'
fs/ubifs/libubifs.o:/home/jeroen/software/u-boot/fs/ubifs/tnc.c:2333: more undefined references to `__aeabi_memcpy' follow
arm-linux-gnueabi-ld.bfd: BFD (GNU Binutils for Ubuntu) 2.23.2 assertion fail ../../bfd/elf32-arm.c:7683
arm-linux-gnueabi-ld.bfd: BFD (GNU Binutils for Ubuntu) 2.23.2 assertion fail ../../bfd/elf32-arm.c:7683
arm-linux-gnueabi-ld.bfd: error: required section '.rel.plt' not found in the linker script
arm-linux-gnueabi-ld.bfd: final link failed: Invalid operation
---
 arch/arm/lib/eabi_compat.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/arch/arm/lib/eabi_compat.c b/arch/arm/lib/eabi_compat.c
index 10d1933..a2cb06e 100644
--- a/arch/arm/lib/eabi_compat.c
+++ b/arch/arm/lib/eabi_compat.c
@@ -20,8 +20,19 @@ int raise (int signum)
 /* Dummy function to avoid linker complaints */
 void __aeabi_unwind_cpp_pr0(void)
 {
-};
+}
 
 void __aeabi_unwind_cpp_pr1(void)
 {
-};
+}
+
+/* Copy memory like memcpy, but no return value required.  */
+void __aeabi_memcpy(void *dest, const void *src, size_t n)
+{
+	(void) memcpy(dest, src, n);
+}
+
+void __aeabi_memset(void *dest, size_t n, int c)
+{
+	(void) memset(dest, c, n);
+}
-- 
1.8.3.2

[U-Boot] [RFC 10/10] README.clang: build command with clang

[Jeroen Hofstee]

---
 doc/README.clang | 15 +++++++++++++++
 1 file changed, 15 insertions(+)
 create mode 100644 doc/README.clang

diff --git a/doc/README.clang b/doc/README.clang
new file mode 100644
index 0000000..59d39a4
--- /dev/null
+++ b/doc/README.clang
@@ -0,0 +1,15 @@
+NOTE: target compilation only work for (some) ARM boards
+at the moment. Also Aarch64 is not supported.
+
+The Debian clang package does not have ARM support. It must be
+compiled manually.
+
+To compile U-Boot with clang use e.g.:
+export CROSS_COMPILE=arm-linux-gnueabi-; make HOSTCC=clang CC="clang -no-integrated-as -target $CROSS_COMPILE -B/usr/arm-linux-gnueabi/lib/ -mllvm -arm-use-movt=0" V=1 twister_config all -j8
+
+If all is well you end up on the target with e.g.:
+
+ver
+U-Boot 2014.07-rc2-00067-gd410009 (May 31 2014 - 20:01:13)
+clang version 3.5.0 (https://github.com/llvm-mirror/clang.git 9d0a0d8e196610bb7fef57a5fa034b2f628f870f) (https://github.com/llvm-mirror/llvm.git f2928b9b5f3d2af68f724af16cdaed2628fddfc9)
+GNU ld (GNU Binutils for Ubuntu) 2.23.52.20130913
-- 
1.8.3.2

[U-Boot] [RFC 01/10] ARM: crt0.S: clear the global data

[Simon Glass]

Hi Jeroen,

On 31 May 2014 14:32, Jeroen Hofstee <jeroen@myspectrum.nl> wrote:
> NOTE: smdk5420 snow smdkv310 apf27 arndale origen vpac270_ond_256 smdk5250
> don't have a memset available.

You should add a message explaining the motivation for the change.

Can you add a memset()?

Regards,
Simon

[U-Boot] [RFC 03/10] board_r: only assign gd when requested

[Simon Glass]

On 31 May 2014 14:32, Jeroen Hofstee <jeroen@myspectrum.nl> wrote:
> When CONFIG_SYS_GENERIC_GLOBAL_DATA is not set the arch handles
> the assignment of gd. At least in case of ARM/Aarch64 this means
> board_init_r is alteady called with the new gd. Therefore only
> assign gd if CONFIG_SYS_GENERIC_GLOBAL_DATA is defined.

I think you might be missing a signoff (you might consider using
patman). Apart from that it looks good.

Acked-by: Simon Gass <sjg@chromium.org>

> ---
>  common/board_r.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/common/board_r.c b/common/board_r.c
> index 602a239..18bbe26 100644
> --- a/common/board_r.c
> +++ b/common/board_r.c
> @@ -927,7 +927,7 @@ void board_init_r(gd_t *new_gd, ulong dest_addr)
>         int i;
>  #endif
>
> -#ifndef CONFIG_X86
> +#ifdef CONFIG_SYS_GENERIC_GLOBAL_DATA
>         gd = new_gd;
>  #endif
>
> --
> 1.8.3.2
>
> _______________________________________________
> U-Boot mailing list
> U-Boot at lists.denx.de
> http://lists.denx.de/mailman/listinfo/u-boot

[U-Boot] [RFC 04/10] ARM: do not set gd in generic board again

[Simon Glass]

On 31 May 2014 14:32, Jeroen Hofstee <jeroen@myspectrum.nl> wrote:
> Since crt0.S / crt0_64.S already allocate gd and assing it there
> is no need to do it again board_f / board_r as it only wastes
> stack space.

Acked-by: Simon Gass <sjg@chromium.org>

> ---
>  arch/arm/include/asm/config.h | 2 --
>  1 file changed, 2 deletions(-)
>
> diff --git a/arch/arm/include/asm/config.h b/arch/arm/include/asm/config.h
> index 2a20a77..abf79e5 100644
> --- a/arch/arm/include/asm/config.h
> +++ b/arch/arm/include/asm/config.h
> @@ -7,8 +7,6 @@
>  #ifndef _ASM_CONFIG_H_
>  #define _ASM_CONFIG_H_
>
> -#define CONFIG_SYS_GENERIC_GLOBAL_DATA
> -
>  #define CONFIG_LMB
>  #define CONFIG_SYS_BOOT_RAMDISK_HIGH
>
> --
> 1.8.3.2
>
> _______________________________________________
> U-Boot mailing list
> U-Boot at lists.denx.de
> http://lists.denx.de/mailman/listinfo/u-boot

[U-Boot] [RFC 05/10] ARM: SPL: do not set gd again

[Simon Glass]

On 31 May 2014 14:32, Jeroen Hofstee <jeroen@myspectrum.nl> wrote:
> ---
>  arch/arm/lib/spl.c | 3 ---
>  1 file changed, 3 deletions(-)

Needs commit message/signoff, but this seems to be throughout the
series. Apart from that:

Acked-by: Simon Gass <sjg@chromium.org>


>
> diff --git a/arch/arm/lib/spl.c b/arch/arm/lib/spl.c
> index dfcc596..75ab546 100644
> --- a/arch/arm/lib/spl.c
> +++ b/arch/arm/lib/spl.c
> @@ -28,9 +28,6 @@ void __weak board_init_f(ulong dummy)
>         /* Clear the BSS. */
>         memset(__bss_start, 0, __bss_end - __bss_start);
>
> -       /* Set global data pointer. */
> -       gd = &gdata;
> -
>         board_init_r(NULL, 0);
>  }
>
> --
> 1.8.3.2
>
> _______________________________________________
> U-Boot mailing list
> U-Boot at lists.denx.de
> http://lists.denx.de/mailman/listinfo/u-boot

[U-Boot] [RFC 07/10] ARM: make gd a function a function for clang

[Simon Glass]

Hi Jeroen,

On 31 May 2014 14:32, Jeroen Hofstee <jeroen@myspectrum.nl> wrote:
> ---
>  arch/arm/include/asm/global_data.h | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
>
> diff --git a/arch/arm/include/asm/global_data.h b/arch/arm/include/asm/global_data.h
> index 63e4ad5..646d694 100644
> --- a/arch/arm/include/asm/global_data.h
> +++ b/arch/arm/include/asm/global_data.h
> @@ -44,10 +44,27 @@ struct arch_global_data {
>
>  #include <asm-generic/global_data.h>
>
> +#ifdef __clang__
> +
> +#define DECLARE_GLOBAL_DATA_PTR
> +#define gd     get_gd()
> +
> +static __inline volatile gd_t *get_gd(void)
> +{
> +       gd_t *gd_ptr;
> +
> +       __asm__ volatile("mov %0, r9\n" : "=r" (gd_ptr));
> +
> +       return gd_ptr;
> +}
> +
> +#else
> +
>  #ifdef CONFIG_ARM64
>  #define DECLARE_GLOBAL_DATA_PTR                register volatile gd_t *gd asm ("x18")
>  #else
>  #define DECLARE_GLOBAL_DATA_PTR                register volatile gd_t *gd asm ("r9")
>  #endif
> +#endif
>
>  #endif /* __ASM_GBL_DATA_H */

Probably a good idea to copy Albert on these patches. What happens if
you compile ARM64 with Clang?

Regards,
Simon

[U-Boot] [RFC 01/10] ARM: crt0.S: clear the global data

[Tim Harvey]

On Sat, May 31, 2014 at 1:32 PM, Jeroen Hofstee <jeroen@myspectrum.nl> wrote:
> NOTE: smdk5420 snow smdkv310 apf27 arndale origen vpac270_ond_256 smdk5250
> don't have a memset available.
> ---
>  arch/arm/lib/crt0.S | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/arch/arm/lib/crt0.S b/arch/arm/lib/crt0.S
> index dfc2de9..52b6f74 100644
> --- a/arch/arm/lib/crt0.S
> +++ b/arch/arm/lib/crt0.S
> @@ -70,6 +70,12 @@ ENTRY(_main)
>         sub     sp, sp, #GD_SIZE        /* allocate one GD above SP */
>         bic     sp, sp, #7      /* 8-byte alignment for ABI compliance */
>         mov     r9, sp          /* GD is above SP */
> +
> +       mov     r0, r9          /* Clear the global data */
> +       mov     r1, #0
> +       mov     r2, #GENERATED_GBL_DATA_SIZE
> +       bl      memset
> +
>         mov     r0, #0
>         bl      board_init_f
>
> --

Acked-by: Tim Harvey <tharvey@gateworks.com>

This resolves the issue I encountered and reported with IMX6 SPL.

Thanks,

Tim

[U-Boot] [RFC 05/10] ARM: SPL: do not set gd again

[Tim Harvey]

On Sat, May 31, 2014 at 1:32 PM, Jeroen Hofstee <jeroen@myspectrum.nl> wrote:
> ---
>  arch/arm/lib/spl.c | 3 ---
>  1 file changed, 3 deletions(-)
>
> diff --git a/arch/arm/lib/spl.c b/arch/arm/lib/spl.c
> index dfcc596..75ab546 100644
> --- a/arch/arm/lib/spl.c
> +++ b/arch/arm/lib/spl.c
> @@ -28,9 +28,6 @@ void __weak board_init_f(ulong dummy)
>         /* Clear the BSS. */
>         memset(__bss_start, 0, __bss_end - __bss_start);
>
> -       /* Set global data pointer. */
> -       gd = &gdata;
> -
>         board_init_r(NULL, 0);
>  }
>

Agree with Simon's comment

otherwise

Acked-by: Tim Harvey <tharvey@gateworks.com>

[U-Boot] [RFC 01/10] ARM: crt0.S: clear the global data

[Jeroen Hofstee]

Hello Simon,

On ma, 2014-06-02 at 20:02 -0600, Simon Glass wrote:
> Hi Jeroen,
> 
> On 31 May 2014 14:32, Jeroen Hofstee <jeroen@myspectrum.nl> wrote:
> > NOTE: smdk5420 snow smdkv310 apf27 arndale origen vpac270_ond_256 smdk5250
> > don't have a memset available.
> 
> You should add a message explaining the motivation for the change.
yes, I will actually check all commit messages, fix the typos and add
proper tags and cc's etc. Make the documentation a bit more generic and
add some comment about why gd needs to be treated special for llvm in
the first place.

That said, regarding this patch, the reason to clear gd at all is that
e.g. i2c depends on it and there have been issues with the serial
console flags etc as well. The reason to do it directly after allocating
gd is that there are several board_init_f's with the more wide spread
use of SPL. Another problem is that some code attempts to store values
in global data assuming it will survive relocation, but failed since gd
got reassigned again.

When just "allocating" global data once and clearing it directly, such
problem should be gone. It also matches the behavior of the generic
board CONFIG_SYS_GENERIC_GLOBAL_DATA, so this actually preserves current
behavior for the ARM boards using the generic board after the removal of
CONFIG_SYS_GENERIC_GLOBAL_DATA.

> Can you add a memset()?
Likely, one way or the other, it will be easily to fix. I posted it as
is since I was wondering what Albert thinks about it. (for completeness
a final version will include a similar change for aarch64).

Regards,
Jeroen

[U-Boot] [RFC 07/10] ARM: make gd a function a function for clang

[Jeroen Hofstee]

On ma, 2014-06-02 at 20:20 -0600, Simon Glass wrote:
> Hi Jeroen,
> 
> On 31 May 2014 14:32, Jeroen Hofstee <jeroen@myspectrum.nl> wrote:
> > ---
> >  arch/arm/include/asm/global_data.h | 17 +++++++++++++++++
> >  1 file changed, 17 insertions(+)
> >
> > diff --git a/arch/arm/include/asm/global_data.h b/arch/arm/include/asm/global_data.h
> > index 63e4ad5..646d694 100644
> > --- a/arch/arm/include/asm/global_data.h
> > +++ b/arch/arm/include/asm/global_data.h
> > @@ -44,10 +44,27 @@ struct arch_global_data {
> >
> >  #include <asm-generic/global_data.h>
> >
> > +#ifdef __clang__
> > +
> > +#define DECLARE_GLOBAL_DATA_PTR
> > +#define gd     get_gd()
> > +
> > +static __inline volatile gd_t *get_gd(void)
> > +{
> > +       gd_t *gd_ptr;
> > +
> > +       __asm__ volatile("mov %0, r9\n" : "=r" (gd_ptr));
> > +
> > +       return gd_ptr;
> > +}
> > +
> > +#else
> > +
> >  #ifdef CONFIG_ARM64
> >  #define DECLARE_GLOBAL_DATA_PTR                register volatile gd_t *gd asm ("x18")
> >  #else
> >  #define DECLARE_GLOBAL_DATA_PTR                register volatile gd_t *gd asm ("r9")
> >  #endif
> > +#endif
> >
> >  #endif /* __ASM_GBL_DATA_H */
> 
> Probably a good idea to copy Albert on these patches. What happens if
> you compile ARM64 with Clang?
> 
> Regards,
> Simon

[U-Boot] [RFC 07/10] ARM: make gd a function a function for clang

[Jeroen Hofstee]

Hi Simon (this time with reply..)

On ma, 2014-06-02 at 20:20 -0600, Simon Glass wrote:
> Hi Jeroen,
> 
> On 31 May 2014 14:32, Jeroen Hofstee <jeroen@myspectrum.nl> wrote:
> > ---
> >  arch/arm/include/asm/global_data.h | 17 +++++++++++++++++
> >  1 file changed, 17 insertions(+)
> >
> > diff --git a/arch/arm/include/asm/global_data.h b/arch/arm/include/asm/global_data.h
> > index 63e4ad5..646d694 100644
> > --- a/arch/arm/include/asm/global_data.h
> > +++ b/arch/arm/include/asm/global_data.h
> > @@ -44,10 +44,27 @@ struct arch_global_data {
> >
> >  #include <asm-generic/global_data.h>
> >
> > +#ifdef __clang__
> > +
> > +#define DECLARE_GLOBAL_DATA_PTR
> > +#define gd     get_gd()
> > +
> > +static __inline volatile gd_t *get_gd(void)
> > +{
> > +       gd_t *gd_ptr;
> > +
> > +       __asm__ volatile("mov %0, r9\n" : "=r" (gd_ptr));
> > +
> > +       return gd_ptr;
> > +}
> > +
> > +#else
> > +
> >  #ifdef CONFIG_ARM64
> >  #define DECLARE_GLOBAL_DATA_PTR                register volatile gd_t *gd asm ("x18")
> >  #else
> >  #define DECLARE_GLOBAL_DATA_PTR                register volatile gd_t *gd asm ("r9")
> >  #endif
> > +#endif
> >
> >  #endif /* __ASM_GBL_DATA_H */
> 
> Probably a good idea to copy Albert on these patches. What happens if
> you compile ARM64 with Clang?

As is it will complain that is has no idea what r9 is. At the moment
clang does not have a -ffixed-x18 so there is no polite way to make it
work. With a slightly hacked llvm it seems promising (it compiles at
least and disassembly seems fine). I have no hardware to test it on
though. It would be nice to know if it actually boots..

Perhaps the best thing to do for now is error out and point to the
README explaining why it doesn't work.

Regards,
Jeroen

[U-Boot] [RFC 07/10] ARM: make gd a function a function for clang

[Simon Glass]

Hi Jeroen,

On 3 June 2014 13:58, Jeroen Hofstee <jeroen@myspectrum.nl> wrote:
> Hi Simon (this time with reply..)
>
> On ma, 2014-06-02 at 20:20 -0600, Simon Glass wrote:
>> Hi Jeroen,
>>
>> On 31 May 2014 14:32, Jeroen Hofstee <jeroen@myspectrum.nl> wrote:
>> > ---
>> >  arch/arm/include/asm/global_data.h | 17 +++++++++++++++++
>> >  1 file changed, 17 insertions(+)
>> >
>> > diff --git a/arch/arm/include/asm/global_data.h b/arch/arm/include/asm/global_data.h
>> > index 63e4ad5..646d694 100644
>> > --- a/arch/arm/include/asm/global_data.h
>> > +++ b/arch/arm/include/asm/global_data.h
>> > @@ -44,10 +44,27 @@ struct arch_global_data {
>> >
>> >  #include <asm-generic/global_data.h>
>> >
>> > +#ifdef __clang__
>> > +
>> > +#define DECLARE_GLOBAL_DATA_PTR
>> > +#define gd     get_gd()
>> > +
>> > +static __inline volatile gd_t *get_gd(void)
>> > +{
>> > +       gd_t *gd_ptr;
>> > +
>> > +       __asm__ volatile("mov %0, r9\n" : "=r" (gd_ptr));
>> > +
>> > +       return gd_ptr;
>> > +}
>> > +
>> > +#else
>> > +
>> >  #ifdef CONFIG_ARM64
>> >  #define DECLARE_GLOBAL_DATA_PTR                register volatile gd_t *gd asm ("x18")
>> >  #else
>> >  #define DECLARE_GLOBAL_DATA_PTR                register volatile gd_t *gd asm ("r9")
>> >  #endif
>> > +#endif
>> >
>> >  #endif /* __ASM_GBL_DATA_H */
>>
>> Probably a good idea to copy Albert on these patches. What happens if
>> you compile ARM64 with Clang?
>
> As is it will complain that is has no idea what r9 is. At the moment
> clang does not have a -ffixed-x18 so there is no polite way to make it
> work. With a slightly hacked llvm it seems promising (it compiles at
> least and disassembly seems fine). I have no hardware to test it on
> though. It would be nice to know if it actually boots..
>
> Perhaps the best thing to do for now is error out and point to the
> README explaining why it doesn't work.

You make it no worse by implementing it with a warning comment in the
code. You could even use #warning perrhaps.

Regards,
Simon

[U-Boot] [RFC 03/10] board_r: only assign gd when requested

[Jeroen Hofstee]

Hello Wolfgang / Stefan.

On za, 2014-05-31 at 22:32 +0200, Jeroen Hofstee wrote:
> When CONFIG_SYS_GENERIC_GLOBAL_DATA is not set the arch handles
> the assignment of gd. At least in case of ARM/Aarch64 this means
> board_init_r is alteady called with the new gd. Therefore only
> assign gd if CONFIG_SYS_GENERIC_GLOBAL_DATA is defined.
> ---
>  common/board_r.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/common/board_r.c b/common/board_r.c
> index 602a239..18bbe26 100644
> --- a/common/board_r.c
> +++ b/common/board_r.c
> @@ -927,7 +927,7 @@ void board_init_r(gd_t *new_gd, ulong dest_addr)
>  	int i;
>  #endif
>  
> -#ifndef CONFIG_X86
> +#ifdef CONFIG_SYS_GENERIC_GLOBAL_DATA
>  	gd = new_gd;
>  #endif
>  

Can any of you confirm this change is fine for powerpc as well?

Regards,
Jeroen

[U-Boot] [RFC 03/10] board_r: only assign gd when requested

[Stefan Roese]

Hi Jeroen,

(added York to cc as he introduced CONFIG_SYS_GENERIC_GLOBAL_DATA with 
patch 2a1680e3 [common/board_f: Initialized global data for generic board])

On 03.06.2014 22:52, Jeroen Hofstee wrote:
> Hello Wolfgang / Stefan.
>
> On za, 2014-05-31 at 22:32 +0200, Jeroen Hofstee wrote:
>> When CONFIG_SYS_GENERIC_GLOBAL_DATA is not set the arch handles
>> the assignment of gd. At least in case of ARM/Aarch64 this means
>> board_init_r is alteady called with the new gd. Therefore only
>> assign gd if CONFIG_SYS_GENERIC_GLOBAL_DATA is defined.
>> ---
>>   common/board_r.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/common/board_r.c b/common/board_r.c
>> index 602a239..18bbe26 100644
>> --- a/common/board_r.c
>> +++ b/common/board_r.c
>> @@ -927,7 +927,7 @@ void board_init_r(gd_t *new_gd, ulong dest_addr)
>>   	int i;
>>   #endif
>>
>> -#ifndef CONFIG_X86
>> +#ifdef CONFIG_SYS_GENERIC_GLOBAL_DATA
>>   	gd = new_gd;
>>   #endif
>>
>
> Can any of you confirm this change is fine for powerpc as well?

powerpc doesn't define CONFIG_SYS_GENERIC_GLOBAL_DATA right now. And I'm 
not sure which powerpc boards use the common board_f/_r functions right 
now. Perhaps York knows?

Other than that I don't any problems, so:

Acked-by: Stefan Roese <sr@denx.de>

Thanks,
Stefan

[U-Boot] [RFC 03/10] board_r: only assign gd when requested

[York Sun]

On Jun 3, 2014, at 8:52 PM, Stefan Roese wrote:

> Hi Jeroen,
> 
> (added York to cc as he introduced CONFIG_SYS_GENERIC_GLOBAL_DATA with patch 2a1680e3 [common/board_f: Initialized global data for generic board])
> 
> On 03.06.2014 22:52, Jeroen Hofstee wrote:
>> Hello Wolfgang / Stefan.
>> 
>> On za, 2014-05-31 at 22:32 +0200, Jeroen Hofstee wrote:
>>> When CONFIG_SYS_GENERIC_GLOBAL_DATA is not set the arch handles
>>> the assignment of gd. At least in case of ARM/Aarch64 this means
>>> board_init_r is alteady called with the new gd. Therefore only
>>> assign gd if CONFIG_SYS_GENERIC_GLOBAL_DATA is defined.
>>> ---
>>>  common/board_r.c | 2 +-
>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>> 
>>> diff --git a/common/board_r.c b/common/board_r.c
>>> index 602a239..18bbe26 100644
>>> --- a/common/board_r.c
>>> +++ b/common/board_r.c
>>> @@ -927,7 +927,7 @@ void board_init_r(gd_t *new_gd, ulong dest_addr)
>>>  	int i;
>>>  #endif
>>> 
>>> -#ifndef CONFIG_X86
>>> +#ifdef CONFIG_SYS_GENERIC_GLOBAL_DATA
>>>  	gd = new_gd;
>>>  #endif
>>> 
>> 
>> Can any of you confirm this change is fine for powerpc as well?
> 
> powerpc doesn't define CONFIG_SYS_GENERIC_GLOBAL_DATA right now. And I'm not sure which powerpc boards use the common board_f/_r functions right now. Perhaps York knows?

I think this change is not right for powerpc. The idea of using CONFIG_SYS_GENERIC_GLOBAL_DATA is to use the stack for gd in board_init_f. PowerPC boards don't use this way. The gd is initialized and used before calling board_init_f.

PowerPC boards also use new_gd when calling board_init_r. If you add this macro, I don't think powerpc will continue to work.

This commit 15672c6dbd7e5a110773480ccfe47b98ba1dc6f8 converts some powerpc boards to use generic board.


York

[U-Boot] [RFC 06/10] cc-option: make it work with clang

[Masahiro Yamada]

Hi Jeroen,


On Sat, 31 May 2014 22:32:20 +0200
Jeroen Hofstee <jeroen@myspectrum.nl> wrote:

> By default clang will return echo a warning if an option is unknown.
> Therefore turn warnings into errors when polling for options.

As far as I tested with clang 3.5 on Ubuntu 14.04,
it looks different.

$ clang -fno-delete-null-pointer-checks  helloworld.c
clang: error: unknown argument: '-fno-delete-null-pointer-checks'
$ echo $?
1


Best Regards
Masahiro Yamada

[U-Boot] [RFC 06/10] cc-option: make it work with clang

[Albert ARIBAUD]

Hi Masahiro,

On Tue, 10 Jun 2014 17:39:03 +0900, Masahiro Yamada
<yamada.m@jp.panasonic.com> wrote:

> Hi Jeroen,
> 
> 
> On Sat, 31 May 2014 22:32:20 +0200
> Jeroen Hofstee <jeroen@myspectrum.nl> wrote:
> 
> > By default clang will return echo a warning if an option is unknown.
> > Therefore turn warnings into errors when polling for options.
> 
> As far as I tested with clang 3.5 on Ubuntu 14.04,
> it looks different.
> 
> $ clang -fno-delete-null-pointer-checks  helloworld.c
> clang: error: unknown argument: '-fno-delete-null-pointer-checks'
> $ echo $?
> 1

Possibly it depends on how the clang/LLVM toolchain in use has been
built and configured. In any case, explicitly turning warnings into
errors fixes those toolchains which only emit warnings for unknown
options, and it won't harm those such as the one above which already
do "the right thing".

> Best Regards
> Masahiro Yamada

Amicalement,
-- 
Albert.

[U-Boot] [RFC 06/10] cc-option: make it work with clang

[Jeroen Hofstee]

Hello Masahiro,

On 10-06-14 10:39, Masahiro Yamada wrote:
> Hi Jeroen,
>
>
> On Sat, 31 May 2014 22:32:20 +0200
> Jeroen Hofstee <jeroen@myspectrum.nl> wrote:
>
>> By default clang will return echo a warning if an option is unknown.
>> Therefore turn warnings into errors when polling for options.
> As far as I tested with clang 3.5 on Ubuntu 14.04,
> it looks different.
>
> $ clang -fno-delete-null-pointer-checks  helloworld.c
> clang: error: unknown argument: '-fno-delete-null-pointer-checks'
> $ echo $?
> 1

Yes it seems to be restricted to warning options. The -Werror=date-time
causes a lot of noise e.g. when building with clang 3.4. With 3.5 this 
option
seems to be added, but behavior for unrecognized warnings flags remained
the same, see below.

Regards,
Jeroen

[jeroen at freebsd /usr/home/jeroen]$ clang -v
FreeBSD clang version 3.4.1 (tags/RELEASE_34/dot1-final 208032) 20140512
Target: x86_64-unknown-freebsd11.0
Thread model: posix
Selected GCC installation:
[jeroen at freebsd /usr/home/jeroen]$ clang -Werror=date-time a.c
warning: unknown warning option '-Werror=date-time' 
[-Wunknown-warning-option]
1 warning generated.
[jeroen at freebsd /usr/home/jeroen]$ echo $?
0
[jeroen at freebsd /usr/home/jeroen]$ clang -Werror -Werror=date-time a.c
error: unknown warning option '-Werror=date-time' 
[-Werror,-Wunknown-warning-option]
[jeroen at freebsd /usr/home/jeroen]$ echo $?
1

jeroen at yellow:~$ clang -v
clang version 3.5.0 (git at github.com:jhofstee/clang.git 
f533fd477a50467a0d96293d116f4059aa806b65) 
(git at github.com:jhofstee/llvm.git 6b7ff6be9c1bcf8ce440c7f1c7646fbf059562e4)
Target: x86_64-unknown-linux-gnu
Thread model: posix
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/4.8
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/4.8.1
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.8
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.8.1
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.8
Candidate multilib: .;@m64
Selected multilib: .;@m64
jeroen at yellow:~$ clang -Werror=date-time a.c
jeroen at yellow:~$ clang -Werror=date-time-newer a.c
warning: unknown warning option '-Werror=date-time-newer'; did you mean 
'-Werror=date-time'? [-Wunknown-warning-option]
1 warning generated.
jeroen at yellow:~$ echo $?
0
jeroen at yellow:~$ clang -Werror -Werror=date-time-newer a.c
error: unknown warning option '-Werror=date-time-newer'; did you mean 
'-Werror=date-time'? [-Werror,-Wunknown-warning-option]
jeroen at yellow:~$ echo $?
1

[U-Boot] [RFC 01/10] ARM: crt0.S: clear the global data

[Jeroen Hofstee]

Hi,

On 31-05-14 22:32, Jeroen Hofstee wrote:
> NOTE: smdk5420 snow smdkv310 apf27 arndale origen vpac270_ond_256 smdk5250
> don't have a memset available.
> ---
>   arch/arm/lib/crt0.S | 6 ++++++
>   1 file changed, 6 insertions(+)
>
> diff --git a/arch/arm/lib/crt0.S b/arch/arm/lib/crt0.S
> index dfc2de9..52b6f74 100644
> --- a/arch/arm/lib/crt0.S
> +++ b/arch/arm/lib/crt0.S
> @@ -70,6 +70,12 @@ ENTRY(_main)
>   	sub	sp, sp, #GD_SIZE	/* allocate one GD above SP */
>   	bic	sp, sp, #7	/* 8-byte alignment for ABI compliance */
>   	mov	r9, sp		/* GD is above SP */
> +
> +	mov	r0, r9		/* Clear the global data */
> +	mov	r1, #0
> +	mov	r2, #GENERATED_GBL_DATA_SIZE
> +	bl	memset
> +
>   	mov	r0, #0
>   	bl	board_init_f
>   

this patch is superseded by http://patchwork.ozlabs.org/patch/368944/.

Regards,
Jeroen

[U-Boot] [PATCH v2 0/8] add clang support for some ARM boards

[Jeroen Hofstee]

Changes since v1 (RFC):
  - Update the commit message for -Werror when polling for cc-options.
    As pointed out by Masahiro this is not needed for all arguments,
    but only for warning options.
  - drop SOC specific patch from this patchset, I will post it seperately.
  - Do implement get_gd for AARCH64.
  - Drop the memset patch for clearing gd / not reassinging gd and use
    Simon his version.
  - Drop the patch for using gnu inline version, since targets using the
    generic board no longer need it.
  - Limit update gd in board_init_r to ARM / ARM64, since powerpc does
    need it.
  - change __inline to inline and drop volatile from get_gd to make
    checkpatch happy.
  - add patch workaround for generated constants
  - add patch default to cc for host compiler
  - update README.clang
  - add SOB / cc

This patchset depends on:
http://patchwork.ozlabs.org/patch/368944/ (pending dm pull)
http://patchwork.ozlabs.org/patch/362580/

Jeroen Hofstee (8):
  board_r: ARM[64] do not set gd again
  ARM: SPL: do not set gd again
  cc-option: also detect unsupported warnings options
  ARM: make gd a function for clang
  eabi_compat: add __aeabi_memcpy __aeabi_memset
  clang: workaround for generated constants
  Makefile: default to cc for host compiler
  README.clang: build command with clang

 Kbuild                             |  3 +-
 Makefile                           |  2 +-
 arch/arm/include/asm/global_data.h | 25 +++++++++++++++++
 arch/arm/lib/eabi_compat.c         | 15 ++++++++--
 arch/arm/lib/spl.c                 |  3 --
 common/board_r.c                   |  2 +-
 doc/README.clang                   | 56 ++++++++++++++++++++++++++++++++++++++
 include/linux/kbuild.h             |  6 ++--
 scripts/Kbuild.include             |  4 +--
 9 files changed, 103 insertions(+), 13 deletions(-)
 create mode 100644 doc/README.clang

-- 
1.9.1

[U-Boot] [PATCH v2 1/8] board_r: ARM[64] do not set gd again

[Jeroen Hofstee]

For ARM / ARM64 the relocation routines already updated
gd to the new value. Don't set it again. This allows
compilation with clang as it cannot update gd directly.

cc: Albert ARIBAUD <albert.u.boot@aribaud.net>
Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>
---
 common/board_r.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/common/board_r.c b/common/board_r.c
index 8e7a3ac..c01d9cd 100644
--- a/common/board_r.c
+++ b/common/board_r.c
@@ -911,7 +911,7 @@ void board_init_r(gd_t *new_gd, ulong dest_addr)
 	int i;
 #endif
 
-#ifndef CONFIG_X86
+#if !defined(CONFIG_X86) && !defined(CONFIG_ARM) && !defined(CONFIG_ARM64)
 	gd = new_gd;
 #endif
 
-- 
1.9.1

[U-Boot] [PATCH v2 2/8] ARM: SPL: do not set gd again

[Jeroen Hofstee]

Just before calling board_init_f, crt0.S has already
reserved space for the initial gd on the stack. There
should be no need to allocate it again.

cc: Albert ARIBAUD <albert.u.boot@aribaud.net>
Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>
---
 arch/arm/lib/spl.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/arch/arm/lib/spl.c b/arch/arm/lib/spl.c
index dfcc596..75ab546 100644
--- a/arch/arm/lib/spl.c
+++ b/arch/arm/lib/spl.c
@@ -28,9 +28,6 @@ void __weak board_init_f(ulong dummy)
 	/* Clear the BSS. */
 	memset(__bss_start, 0, __bss_end - __bss_start);
 
-	/* Set global data pointer. */
-	gd = &gdata;
-
 	board_init_r(NULL, 0);
 }
 
-- 
1.9.1

[U-Boot] [PATCH v2 3/8] cc-option: also detect unsupported warnings options

[Jeroen Hofstee]

By default clang will echo a warning if a warning option is
unknown. Turning warnings into errors when polling for options
also catches such cases and prevents passing arguments to the
compiler which cause warnings.

cc: Masahiro Yamada <yamada.m@jp.panasonic.com>
cc: Tom Rini <trini@ti.com>
Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>
---
 scripts/Kbuild.include | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index c664e39..4c33359 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -113,12 +113,12 @@ as-instr = $(call try-run,\
 # Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
 
 cc-option = $(call try-run,\
-	$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
+	$(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
 
 # cc-option-yn
 # Usage: flag := $(call cc-option-yn,-march=winchip-c6)
 cc-option-yn = $(call try-run,\
-	$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
+	$(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
 
 # cc-option-align
 # Prefix align with either -falign or -malign
-- 
1.9.1

[U-Boot] [PATCH v2 4/8] ARM: make gd a function for clang

[Jeroen Hofstee]

"clang does not support global register variables; this is
unlikely to be implemented soon because it requires additional
LLVM backend support" [1]

Workaround it by obtaining the value of gd/r9 by an inline
asm routine. Note there is no set routine added for ARM at the
moment, since most if not all updates of gd from c are actually
not needed for ARM.

[1] http://clang.llvm.org/docs/UsersManual.html

cc: Albert ARIBAUD <albert.u.boot@aribaud.net>
Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>
---
 arch/arm/include/asm/global_data.h | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/arch/arm/include/asm/global_data.h b/arch/arm/include/asm/global_data.h
index 63e4ad5..c69d064 100644
--- a/arch/arm/include/asm/global_data.h
+++ b/arch/arm/include/asm/global_data.h
@@ -44,10 +44,35 @@ struct arch_global_data {
 
 #include <asm-generic/global_data.h>
 
+#ifdef __clang__
+
+#define DECLARE_GLOBAL_DATA_PTR
+#define gd	get_gd()
+
+static inline gd_t *get_gd(void)
+{
+	gd_t *gd_ptr;
+
+#ifdef CONFIG_ARM64
+	/*
+	 * Make will already error that reserving x18 is not supported at the
+	 * time of writing, clang: error: unknown argument: '-ffixed-x18'
+	 */
+	__asm__ volatile("mov %0, x18\n" : "=r" (gd_ptr));
+#else
+	__asm__ volatile("mov %0, r9\n" : "=r" (gd_ptr));
+#endif
+
+	return gd_ptr;
+}
+
+#else
+
 #ifdef CONFIG_ARM64
 #define DECLARE_GLOBAL_DATA_PTR		register volatile gd_t *gd asm ("x18")
 #else
 #define DECLARE_GLOBAL_DATA_PTR		register volatile gd_t *gd asm ("r9")
 #endif
+#endif
 
 #endif /* __ASM_GBL_DATA_H */
-- 
1.9.1

[U-Boot] [PATCH v2 5/8] eabi_compat: add __aeabi_memcpy __aeabi_memset

[Jeroen Hofstee]

cc: Albert ARIBAUD <albert.u.boot@aribaud.net>
Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>
---
fixes this:

common/libcommon.o: In function `env_callback_init':
/home/jeroen/software/u-boot/common/env_callback.c:47: undefined reference to `__aeabi_memset'
common/libcommon.o: In function `parse_stream_outer':
/home/jeroen/software/u-boot/common/hush.c:3154: undefined reference to `__aeabi_memset'
disk/libdisk.o: In function `get_device_and_partition':
/home/jeroen/software/u-boot/disk/part.c:596: undefined reference to `__aeabi_memcpy'
/home/jeroen/software/u-boot/disk/part.c:605: undefined reference to `__aeabi_memcpy'
fs/fat/libfat.o: In function `fat_set_blk_dev':
/home/jeroen/software/u-boot/fs/fat/fat.c:60: undefined reference to `__aeabi_memcpy'
fs/ubifs/libubifs.o: In function `ubifs_tnc_locate':
/home/jeroen/software/u-boot/fs/ubifs/tnc.c:1457: undefined reference to `__aeabi_memcpy'
fs/ubifs/libubifs.o: In function `tnc_insert':
/home/jeroen/software/u-boot/fs/ubifs/tnc.c:2008: undefined reference to `__aeabi_memcpy'
fs/ubifs/libubifs.o:/home/jeroen/software/u-boot/fs/ubifs/tnc.c:2333: more undefined references to `__aeabi_memcpy' follow
arm-linux-gnueabi-ld.bfd: BFD (GNU Binutils for Ubuntu) 2.23.2 assertion fail ../../bfd/elf32-arm.c:7683
arm-linux-gnueabi-ld.bfd: BFD (GNU Binutils for Ubuntu) 2.23.2 assertion fail ../../bfd/elf32-arm.c:7683
arm-linux-gnueabi-ld.bfd: error: required section '.rel.plt' not found in the linker script
arm-linux-gnueabi-ld.bfd: final link failed: Invalid operation
---
 arch/arm/lib/eabi_compat.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/arch/arm/lib/eabi_compat.c b/arch/arm/lib/eabi_compat.c
index 10d1933..a2cb06e 100644
--- a/arch/arm/lib/eabi_compat.c
+++ b/arch/arm/lib/eabi_compat.c
@@ -20,8 +20,19 @@ int raise (int signum)
 /* Dummy function to avoid linker complaints */
 void __aeabi_unwind_cpp_pr0(void)
 {
-};
+}
 
 void __aeabi_unwind_cpp_pr1(void)
 {
-};
+}
+
+/* Copy memory like memcpy, but no return value required.  */
+void __aeabi_memcpy(void *dest, const void *src, size_t n)
+{
+	(void) memcpy(dest, src, n);
+}
+
+void __aeabi_memset(void *dest, size_t n, int c)
+{
+	(void) memset(dest, c, n);
+}
-- 
1.9.1

[U-Boot] [PATCH v2 6/8] clang: workaround for generated constants

[Jeroen Hofstee]

KBuild abuses the asm statement to write to a file and
clang chokes about these invalid asm statements. Hack it
even more by fooling this is actual valid asm code.

cc: Masahiro Yamada <yamada.m@jp.panasonic.com>
cc: Tom Rini <trini@ti.com>
Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>
---
 Kbuild                 | 3 ++-
 include/linux/kbuild.h | 6 +++---
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/Kbuild b/Kbuild
index 6e1698c..ef97787 100644
--- a/Kbuild
+++ b/Kbuild
@@ -53,7 +53,8 @@ targets += arch/$(ARCH)/lib/asm-offsets.s
 
 # Default sed regexp - multiline due to syntax constraints
 define sed-y
-	"/^->/{s:->#\(.*\):/* \1 */:; \
+	"s:[[:space:]]*\.ascii[[:space:]]*\"\(.*\)\":\1:; \
+	/^->/{s:->#\(.*\):/* \1 */:; \
 	s:^->\([^ ]*\) [\$$#]*\([-0-9]*\) \(.*\):#define \1 \2 /* \3 */:; \
 	s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
 	s:->::; p;}"
diff --git a/include/linux/kbuild.h b/include/linux/kbuild.h
index ab7805a..8a9f645 100644
--- a/include/linux/kbuild.h
+++ b/include/linux/kbuild.h
@@ -7,14 +7,14 @@
 #define __LINUX_KBUILD_H
 
 #define DEFINE(sym, val) \
-	asm volatile("\n->" #sym " %0 " #val : : "i" (val))
+	asm volatile("\n.ascii \"->" #sym " %0 " #val "\"" : : "i" (val))
 
-#define BLANK() asm volatile("\n->" : : )
+#define BLANK() asm volatile("\n.ascii \"->\"" : : )
 
 #define OFFSET(sym, str, mem) \
 	DEFINE(sym, offsetof(struct str, mem))
 
 #define COMMENT(x) \
-	asm volatile("\n->#" x)
+	asm volatile("\n.ascii \"->#" x "\"")
 
 #endif
-- 
1.9.1

[U-Boot] [PATCH v2 7/8] Makefile: default to cc for host compiler

[Jeroen Hofstee]

Since the host compiler might not be gcc but e.g. clang
default to cc to invoke it.

cc: Masahiro Yamada <yamada.m@jp.panasonic.com>
cc: Tom Rini <trini@ti.com>
Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>
---
 Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 80eb239..c19f7d9 100644
--- a/Makefile
+++ b/Makefile
@@ -204,7 +204,7 @@ CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
 	  else if [ -x /bin/bash ]; then echo /bin/bash; \
 	  else echo sh; fi ; fi)
 
-HOSTCC       = gcc
+HOSTCC       = cc
 HOSTCXX      = g++
 HOSTCFLAGS   = -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer
 HOSTCXXFLAGS = -O2
-- 
1.9.1

[U-Boot] [PATCH v2 8/8] README.clang: build command with clang

[Jeroen Hofstee]

Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>
---
 doc/README.clang | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 56 insertions(+)
 create mode 100644 doc/README.clang

diff --git a/doc/README.clang b/doc/README.clang
new file mode 100644
index 0000000..6d84f37
--- /dev/null
+++ b/doc/README.clang
@@ -0,0 +1,56 @@
+The biggest problem when trying to compile U-boot with clang is that
+almost all archs rely on storing gd in a global register and clang user
+manual states: "clang does not support global register variables; this
+is unlikely to be implemented soon because it requires additional LLVM
+backend support."
+
+Since version 3.4 the ARM backend can be instructed to leave r9 alone.
+Global registers themselves are not supported so some inline assembly is
+used to get its value. This does lead to larger code then strictly
+necessary, but at least works.
+
+NOTE: target compilation only work for _some_ ARM boards at the moment.
+Also Aarch64 is not supported: Most notably boards with aren't using
+the generic board will fail to compile, but since these are expected
+to be converted this will solve itself. Boards which reassign gd in c
+will also fail to compile, but there is in no strict reason to do so
+in the ARM world, since crt0.S takes care of this. These assignments
+can be avoided by changing init call but this is not in mainline yet.
+
+NOTE: without the -mllvm -arm-use-movt=0 flags u-boot will compile
+fine, but llvm might hardcode addresses in movw / movt pairs, which
+cannot be relocated and u-boot will fail at runtime.
+
+Debian (based)
+--------------
+The Debian based clang package does not have ARM support at the moment.
+It must be compiled manually.
+
+To compile U-Boot with clang on linux without IAS use e.g.:
+export CROSS_COMPILE=arm-linux-gnueabi-
+make HOSTCC=clang CC="clang -target $CROSS_COMPILE -B/usr/arm-linux-gnueabi/lib/ -mllvm -arm-use-movt=0 -no-integrated-as" rpi_b_defconfig
+make HOSTCC=clang CC="clang -target $CROSS_COMPILE -B/usr/arm-linux-gnueabi/lib/ -mllvm -arm-use-movt=0 -no-integrated-as" all V=1 -j8
+
+FreeBSD 11 (Current):
+--------------------
+Since llvm 3.4 is currently in the base system, the integrated as is
+incapable of building U-Boot. Therefore gas from devel/arm-eabi-binutils
+is used instead. It needs a symlinks to be picked up correctly though:
+
+ln -s /usr/local/bin/arm-eabi-as /usr/bin/arm-freebsd-eabi-as
+
+# The following commands compile U-Boot using the clang xdev toolchain.
+# NOTE: CROSS_COMPILE and target differ on purpose!
+export CROSS_COMPILE=arm-eabi-
+gmake CC="clang -target arm-freebsd-eabi --sysroot /usr/arm-freebsd -no-integrated-as -mllvm -arm-use-movt=0" rpi_b_defconfig
+gmake CC="clang -target arm-freebsd-eabi --sysroot /usr/arm-freebsd -no-integrated-as -mllvm -arm-use-movt=0" -j8
+
+Given that u-boot will default to gcc, above commands can be
+simplified with a simple wrapper script, listed below.
+
+/usr/local/bin/arm-eabi-gcc
+---
+#!/bin/sh
+
+exec clang -target arm-freebsd-eabi --sysroot /usr/arm-freebsd -no-integrated-as -mllvm -arm-use-movt=0 "$@"
+
-- 
1.9.1

[U-Boot] [PATCH v2 7/8] Makefile: default to cc for host compiler

[Masahiro Yamada]

Hi Jeroen,


On Wed, 30 Jul 2014 21:54:55 +0200
Jeroen Hofstee <jeroen@myspectrum.nl> wrote:

> Since the host compiler might not be gcc but e.g. clang
> default to cc to invoke it.
> 
> cc: Masahiro Yamada <yamada.m@jp.panasonic.com>
> cc: Tom Rini <trini@ti.com>
> Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>
> ---
>  Makefile | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/Makefile b/Makefile
> index 80eb239..c19f7d9 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -204,7 +204,7 @@ CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
>  	  else if [ -x /bin/bash ]; then echo /bin/bash; \
>  	  else echo sh; fi ; fi)
>  
> -HOSTCC       = gcc
> +HOSTCC       = cc
>  HOSTCXX      = g++
>  HOSTCFLAGS   = -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer
>  HOSTCXXFLAGS = -O2



For consistency,

HOSTCXX         = c++

?


Kconfig has a C++ host program.
(scripts/kconfig/qconf.cc)



Could you please consider posting this patch to
linux-kbuild ML  because this may be,
I think, acceptable in Linux too.

On systems where both gcc and clang are installed,
we can select gcc or clang
by using update-alternatives (or alternative)
command.





Best Regards
Masahiro Yamada

[U-Boot] [PATCH v2 7/8] Makefile: default to cc for host compiler

[Albert ARIBAUD]

Hi Jeroen, Masahiro,

On Thu, 31 Jul 2014 19:01:22 +0900, Masahiro Yamada
<yamada.m@jp.panasonic.com> wrote:

> >  HOSTCXX      = g++
> >  HOSTCFLAGS   = -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer

> For consistency,
> 
> HOSTCXX         = c++
> 
> ?

So, Jeroen, what is your pick ? Will you send a v3 7/8, or are you
sticking with g++?

(or if everyone agrees, I could to the change to v2 7/8 when applying
it, and add a comment about it in the commit message.)

Amicalement,
-- 
Albert.

[U-Boot] [PATCH v2 7/8] Makefile: default to cc for host compiler

[Jeroen Hofstee]

Hello Albert,

On 09-09-14 16:31, Albert ARIBAUD wrote:
> On Thu, 31 Jul 2014 19:01:22 +0900, Masahiro Yamada
> <yamada.m@jp.panasonic.com> wrote:
>
>>>   HOSTCXX      = g++
>>>   HOSTCFLAGS   = -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer
>> For consistency,
>>
>> HOSTCXX         = c++
>>
>> ?
> So, Jeroen, what is your pick ? Will you send a v3 7/8, or are you
> sticking with g++?
>
> (or if everyone agrees, I could to the change to v2 7/8 when applying
> it, and add a comment about it in the commit message.)

I did check Masahiro's statement that cpp is actually used in u-boot
and it is; make xconfig uses it, if I recall correctly. And as Masahiro
suggested I sent it to linux-kbuild mailinglist, but I am in the impression
it never arrived, perhaps I need to be subscribed or something...

Anyway, Masahiro's suggestion is sound and I am fine you changing
it while applying. I tested it on FreeBSD, Xubuntu and Debian.

Regards,
Jeroen

[U-Boot] [PATCH v2 7/8] Makefile: default to cc for host compiler

[Albert ARIBAUD]

Hi Jeroen,

On Tue, 09 Sep 2014 19:34:44 +0200, Jeroen Hofstee
<jeroen@myspectrum.nl> wrote:

> Hello Albert,
> 
> On 09-09-14 16:31, Albert ARIBAUD wrote:
> > On Thu, 31 Jul 2014 19:01:22 +0900, Masahiro Yamada
> > <yamada.m@jp.panasonic.com> wrote:
> >
> >>>   HOSTCXX      = g++
> >>>   HOSTCFLAGS   = -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer
> >> For consistency,
> >>
> >> HOSTCXX         = c++
> >>
> >> ?
> > So, Jeroen, what is your pick ? Will you send a v3 7/8, or are you
> > sticking with g++?
> >
> > (or if everyone agrees, I could to the change to v2 7/8 when applying
> > it, and add a comment about it in the commit message.)
> 
> I did check Masahiro's statement that cpp is actually used in u-boot
> and it is; make xconfig uses it, if I recall correctly. And as Masahiro
> suggested I sent it to linux-kbuild mailinglist, but I am in the impression
> it never arrived, perhaps I need to be subscribed or something...
> 
> Anyway, Masahiro's suggestion is sound and I am fine you changing
> it while applying. I tested it on FreeBSD, Xubuntu and Debian.

I've tried building rpi_b as per the README, but I keep getting

	/usr/bin/as: unrecognized option '-mfloat-abi=soft'
	clang: error: assembler command failed with exit code 1 (use -v
	to see invocation)

Shouldn't rpi_b build properly since it is the one given as an example
for Debian-based building?

> Regards,
> Jeroen

Amicalement,
-- 
Albert.

[U-Boot] [PATCH v2 7/8] Makefile: default to cc for host compiler

[Jeroen Hofstee]

Hi,

On 09-09-14 21:59, Albert ARIBAUD wrote:
> Hi Jeroen,
>
> On Tue, 09 Sep 2014 19:34:44 +0200, Jeroen Hofstee
> <jeroen@myspectrum.nl> wrote:
>
>> Hello Albert,
>>
>> On 09-09-14 16:31, Albert ARIBAUD wrote:
>>> On Thu, 31 Jul 2014 19:01:22 +0900, Masahiro Yamada
>>> <yamada.m@jp.panasonic.com> wrote:
>>>
>>>>>    HOSTCXX      = g++
>>>>>    HOSTCFLAGS   = -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer
>>>> For consistency,
>>>>
>>>> HOSTCXX         = c++
>>>>
>>>> ?
>>> So, Jeroen, what is your pick ? Will you send a v3 7/8, or are you
>>> sticking with g++?
>>>
>>> (or if everyone agrees, I could to the change to v2 7/8 when applying
>>> it, and add a comment about it in the commit message.)
>> I did check Masahiro's statement that cpp is actually used in u-boot
>> and it is; make xconfig uses it, if I recall correctly. And as Masahiro
>> suggested I sent it to linux-kbuild mailinglist, but I am in the impression
>> it never arrived, perhaps I need to be subscribed or something...
>>
>> Anyway, Masahiro's suggestion is sound and I am fine you changing
>> it while applying. I tested it on FreeBSD, Xubuntu and Debian.
> I've tried building rpi_b as per the README, but I keep getting
>
> 	/usr/bin/as: unrecognized option '-mfloat-abi=soft'
> 	clang: error: assembler command failed with exit code 1 (use -v
> 	to see invocation)
>
> Shouldn't rpi_b build properly since it is the one given as an example
> for Debian-based building?
>
>

As discussed with Albert there seems to be some Debian / Ubuntu
specific changes to the package causing trouble. Checking out the
llvm 3.5 branch works fine, using the package fails with above
mentioned error.

No idea why at the moment, patches are fine...

Regards,
Jeroen

[U-Boot] [PATCH v2 7/8] Makefile: default to cc for host compiler

[Jeroen Hofstee]

Hello Albert,

On 09-09-14 21:59, Albert ARIBAUD wrote:
> Hi Jeroen,
>
> On Tue, 09 Sep 2014 19:34:44 +0200, Jeroen Hofstee
> <jeroen@myspectrum.nl> wrote:
>
>
> I've tried building rpi_b as per the README, but I keep getting
>
> 	/usr/bin/as: unrecognized option '-mfloat-abi=soft'
> 	clang: error: assembler command failed with exit code 1 (use -v
> 	to see invocation)
>
> Shouldn't rpi_b build properly since it is the one given as an example
> for Debian-based building?
>

ok, this turns out to be a simple issue. The gas for arm is not
found since CROSS_COMPILE has a trailing dash. When it is removed
the correct as is picked up (and libs is found automagically as well).
Both the 3.4 and 3.5 binary packages from Ubuntu are able to
compile u-boot with this change, so the README should be updated.

Regards,
Jeroen

This should work:
make HOSTCC=clang CC="clang -target arm-linux-gnueabi -mllvm 
-arm-use-movt=0 -no-integrated-as" V=1 all

[U-Boot] [PATCH v3 0/8] add clang support for some ARM boards

[Jeroen Hofstee]

Changes since v2:
   - As Albert pointed out the clang instructions don't work with
     Debian based binary packages. While I was aware of that it is
     for a different reason then I thought, it is not that ARM is not
     enabled as a backend but older versions are a bit more picky on
     the target argument and don't tolerate a trailing dash to it as
     used for CROSS_COMPILE etc. The README is updated accordingly.

     As a side note clang3.5-svn as shipped in Ubuntu is not the 3.5
     release but an snapshot of some svn commit and hence explain why
     the recompiled 3.5 can behave different then the ubuntu clang-3.5.
     Since it misses some patches, the clang3.5-svn can build less
     boards then 3.4 or an actual 3.5 release.

   - While add it, include Masahiro suggestion to also use c++ instead
     of g++.
   - Drop dependencies from the cover-letter as they are merged.
   - only patch 7/8 and 8/8 are reposted. 1..6 are the same as v2.

Changes since v1 (RFC):
  - Update the commit message for -Werror when polling for cc-options.
    As pointed out by Masahiro this is not needed for all arguments,
    but only for warning options.
  - drop SOC specific patch from this patchset, I will post it seperately.
  - Do implement get_gd for AARCH64.
  - Drop the memset patch for clearing gd / not reassinging gd and use
    Simon his version.
  - Drop the patch for using gnu inline version, since targets using the
    generic board no longer need it.
  - Limit update gd in board_init_r to ARM / ARM64, since powerpc does
    need it.
  - change __inline to inline and drop volatile from get_gd to make
    checkpatch happy.
  - add patch workaround for generated constants
  - add patch default to cc for host compiler
  - update README.clang
  - add SOB / cc

Jeroen Hofstee (8):
  board_r: ARM[64] do not set gd again
  ARM: SPL: do not set gd again
  cc-option: also detect unsupported warnings options
  ARM: make gd a function for clang
  eabi_compat: add __aeabi_memcpy __aeabi_memset
  clang: workaround for generated constants
  Makefile: default to cc for host compiler
  README.clang: build command with clang

 Kbuild                             |  3 +-
 Makefile                           |  4 +--
 arch/arm/include/asm/global_data.h | 25 +++++++++++++++++
 arch/arm/lib/eabi_compat.c         | 15 ++++++++--
 arch/arm/lib/spl.c                 |  3 --
 common/board_r.c                   |  2 +-
 doc/README.clang                   | 56 ++++++++++++++++++++++++++++++++++++++
 include/linux/kbuild.h             |  6 ++--
 scripts/Kbuild.include             |  4 +--
 9 files changed, 104 insertions(+), 14 deletions(-)
 create mode 100644 doc/README.clang

-- 
2.1.0

[U-Boot] [PATCH v3 7/8] Makefile: default to cc for host compiler

[Jeroen Hofstee]

Since the host compiler might not be gcc but e.g. clang
default to cc/c++ to invoke it.

cc: Masahiro Yamada <yamada.m@jp.panasonic.com>
cc: Tom Rini <trini@ti.com>
Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>
---
 Makefile | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index fdda3ec..42263e4 100644
--- a/Makefile
+++ b/Makefile
@@ -197,8 +197,8 @@ CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
 	  else if [ -x /bin/bash ]; then echo /bin/bash; \
 	  else echo sh; fi ; fi)
 
-HOSTCC       = gcc
-HOSTCXX      = g++
+HOSTCC       = cc
+HOSTCXX      = c++
 HOSTCFLAGS   = -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer
 HOSTCXXFLAGS = -O2
 
-- 
2.1.0

[U-Boot] [PATCH v3 8/8] README.clang: build command with clang

[Jeroen Hofstee]

Cc: Albert ARIBAUD <albert.u.boot@aribaud.net>
Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>
---
 doc/README.clang | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 56 insertions(+)
 create mode 100644 doc/README.clang

diff --git a/doc/README.clang b/doc/README.clang
new file mode 100644
index 0000000..9ad689f
--- /dev/null
+++ b/doc/README.clang
@@ -0,0 +1,56 @@
+The biggest problem when trying to compile U-boot with clang is that
+almost all archs rely on storing gd in a global register and clang user
+manual states: "clang does not support global register variables; this
+is unlikely to be implemented soon because it requires additional LLVM
+backend support."
+
+Since version 3.4 the ARM backend can be instructed to leave r9 alone.
+Global registers themselves are not supported so some inline assembly is
+used to get its value. This does lead to larger code then strictly
+necessary, but at least works.
+
+NOTE: target compilation only work for _some_ ARM boards at the moment.
+Also Aarch64 is not supported: Most notably boards which aren't using
+the generic board will fail to compile, but since those are expected
+to be converted this will solve itself. Boards which reassign gd in c
+will also fail to compile, but there is in no strict reason to do so
+in the ARM world, since crt0.S takes care of this. These assignments
+can be avoided by changing the init calls but this is not in mainline yet.
+
+NOTE: without the -mllvm -arm-use-movt=0 flags u-boot will compile
+fine, but llvm might hardcode addresses in movw / movt pairs, which
+cannot be relocated and u-boot will fail at runtime.
+
+Debian (based)
+--------------
+Binary packages can be installed as usual, e.g.:
+sudo apt-get install clang
+
+To compile U-Boot with clang on linux without IAS use e.g.:
+export TRIPLET=arm-linux-gnueabi && export CROSS_COMPILE="$TRIPLET-"
+make HOSTCC=clang CC="clang -target $TRIPLET -mllvm -arm-use-movt=0 -no-integrated-as" rpi_b_defconfig
+make HOSTCC=clang CC="clang -target $TRIPLET -mllvm -arm-use-movt=0 -no-integrated-as" all V=1 -j8
+
+FreeBSD 11 (Current):
+--------------------
+Since llvm 3.4 is currently in the base system, the integrated as is
+incapable of building U-Boot. Therefore gas from devel/arm-eabi-binutils
+is used instead. It needs a symlinks to be picked up correctly though:
+
+ln -s /usr/local/bin/arm-eabi-as /usr/bin/arm-freebsd-eabi-as
+
+# The following commands compile U-Boot using the clang xdev toolchain.
+# NOTE: CROSS_COMPILE and target differ on purpose!
+export CROSS_COMPILE=arm-eabi-
+gmake CC="clang -target arm-freebsd-eabi --sysroot /usr/arm-freebsd -no-integrated-as -mllvm -arm-use-movt=0" rpi_b_defconfig
+gmake CC="clang -target arm-freebsd-eabi --sysroot /usr/arm-freebsd -no-integrated-as -mllvm -arm-use-movt=0" -j8
+
+Given that u-boot will default to gcc, above commands can be
+simplified with a simple wrapper script, listed below.
+
+/usr/local/bin/arm-eabi-gcc
+---
+#!/bin/sh
+
+exec clang -target arm-freebsd-eabi --sysroot /usr/arm-freebsd -no-integrated-as -mllvm -arm-use-movt=0 "$@"
+
-- 
2.1.0

[U-Boot] [PATCH v2 7/8] Makefile: default to cc for host compiler

[Masahiro Yamada]

Hi Jeroen,


On Tue, 09 Sep 2014 19:34:44 +0200
Jeroen Hofstee <jeroen@myspectrum.nl> wrote:

> Hello Albert,
> 
> On 09-09-14 16:31, Albert ARIBAUD wrote:
> > On Thu, 31 Jul 2014 19:01:22 +0900, Masahiro Yamada
> > <yamada.m@jp.panasonic.com> wrote:
> >
> >>>   HOSTCXX      = g++
> >>>   HOSTCFLAGS   = -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer
> >> For consistency,
> >>
> >> HOSTCXX         = c++
> >>
> >> ?
> > So, Jeroen, what is your pick ? Will you send a v3 7/8, or are you
> > sticking with g++?
> >
> > (or if everyone agrees, I could to the change to v2 7/8 when applying
> > it, and add a comment about it in the commit message.)
> 
> I did check Masahiro's statement that cpp is actually used in u-boot
> and it is; make xconfig uses it, if I recall correctly. And as Masahiro
> suggested I sent it to linux-kbuild mailinglist, but I am in the impression
> it never arrived, perhaps I need to be subscribed or something...


I received it because you cced me.

But I am afraid it did not reach the kbuild ML
because I could not find it in the kbuild ML archive.


I recommend to subscribe to the ML and then
resend your patch.


To subscribe to it, visit the following and click 'subscribe'
http://vger.kernel.org/vger-lists.html#linux-kbuild

The kbuild ML does not have much volume.
I guess you won't be annoyed.


To attract the attention of key persons, I'd like to suggest:

 - add 'kbuild: ' prefix to the subject like:

     kbuild: default to cc/c++ for host compiler

 - you can cc linux-kernel at vger.kernel.org too.
   (scripts/get_maintainer.pl will do it automatically.
    But I am not sure if it can be reached from unsubscribers.
    this ML has a huge volume..)





Best Regards
Masahiro Yamada

[U-Boot] [PATCH v3 0/8] add clang support for some ARM boards

[Albert ARIBAUD]

Hi Jeroen,

On Wed, 10 Sep 2014 20:08:50 +0200, Jeroen Hofstee
<jeroen@myspectrum.nl> wrote:

> Changes since v2:
>    - As Albert pointed out the clang instructions don't work with
>      Debian based binary packages. While I was aware of that it is
>      for a different reason then I thought, it is not that ARM is not
>      enabled as a backend but older versions are a bit more picky on
>      the target argument and don't tolerate a trailing dash to it as
>      used for CROSS_COMPILE etc. The README is updated accordingly.
> 
>      As a side note clang3.5-svn as shipped in Ubuntu is not the 3.5
>      release but an snapshot of some svn commit and hence explain why
>      the recompiled 3.5 can behave different then the ubuntu clang-3.5.
>      Since it misses some patches, the clang3.5-svn can build less
>      boards then 3.4 or an actual 3.5 release.
> 
>    - While add it, include Masahiro suggestion to also use c++ instead
>      of g++.
>    - Drop dependencies from the cover-letter as they are merged.
>    - only patch 7/8 and 8/8 are reposted. 1..6 are the same as v2.

Thanks, tested building rpi_b, it works now.

The, tested on versatileqemu out of curiosity and got the following
results:

1.

clang warns about Unused static functions in common/console.c, namely
console_printdevs and console_doenv (1). Why gcc does not flag this?
We have -Wall set which is supposed to imply -Wunused-functions.

There is also an unused variable warning in disk/part.c28
(block_drvr). I haven't looked at why clang warns about it and not gcc,
but it could raise the same question as the functions above.

2.

clang errors on arch/arm/lib/cache.c:28 for this:
asm("0: mrc p15, 0, r15, c7, c10, 3\n\t" "bne 0b\n" : : : "memory");
and that is a clang mistake, as for ARM926EJS r15 is a valid (albeit
quite special semantically) Rd for Test and Clean DCache, see page 2-24.

Jeroen, do you feel like raising point 2 to the clang/LLVM folks?

(1) and BTW it's not like the functions are used in some configuration
other than versatileqemu; they're completely unused.

Other than that, the patch series seems to be good. I'll apply it
soonish.

Amicalement,
-- 
Albert.

[U-Boot] [PATCH v3 0/8] add clang support for some ARM boards

[Jeroen Hofstee]

Hello Albert,

On do, 2014-09-11 at 10:32 +0200, Albert ARIBAUD wrote:

> 
> On Wed, 10 Sep 2014 20:08:50 +0200, Jeroen Hofstee
> <jeroen@myspectrum.nl> wrote:
> 
> > Changes since v2:
> >    - As Albert pointed out the clang instructions don't work with
> >      Debian based binary packages. While I was aware of that it is
> >      for a different reason then I thought, it is not that ARM is not
> >      enabled as a backend but older versions are a bit more picky on
> >      the target argument and don't tolerate a trailing dash to it as
> >      used for CROSS_COMPILE etc. The README is updated accordingly.
> > 
> >      As a side note clang3.5-svn as shipped in Ubuntu is not the 3.5
> >      release but an snapshot of some svn commit and hence explain why
> >      the recompiled 3.5 can behave different then the ubuntu clang-3.5.
> >      Since it misses some patches, the clang3.5-svn can build less
> >      boards then 3.4 or an actual 3.5 release.
> > 
> >    - While add it, include Masahiro suggestion to also use c++ instead
> >      of g++.
> >    - Drop dependencies from the cover-letter as they are merged.
> >    - only patch 7/8 and 8/8 are reposted. 1..6 are the same as v2.
> 
> Thanks, tested building rpi_b, it works now.
> 
> The, tested on versatileqemu out of curiosity and got the following
> results:
> 
> 1.
> 
> clang warns about Unused static functions in common/console.c, namely
> console_printdevs and console_doenv (1). Why gcc does not flag this?
> We have -Wall set which is supposed to imply -Wunused-functions.

It is a gcc feature, see [1]: "Warn whenever a static function is
declared but not defined or a _non-inline static function_ is unused.
This warning is enabled by -Wall."

> 
> There is also an unused variable warning in disk/part.c28
> (block_drvr). I haven't looked at why clang warns about it and not gcc,
> but it could raise the same question as the functions above.
> 

Also a gcc feature, see [2]. The constant is indeed not used.

> 2.
> 
> clang errors on arch/arm/lib/cache.c:28 for this:
> asm("0: mrc p15, 0, r15, c7, c10, 3\n\t" "bne 0b\n" : : : "memory");
> and that is a clang mistake, as for ARM926EJS r15 is a valid (albeit
> quite special semantically) Rd for Test and Clean DCache, see page 2-24.
> 

This is the integrated-as complaining (the README tells you to disable
it for the moment). The clang folks push UAL hard, up to a point we need
to think about minimum gcc version etc. To avoid that, I just left out
such changes and just use gas instead, at least for the time being.
Below are some changes to compile versatileqemu with llvm integrated-as
and gcc/gas. No idea if it actually boots though.

> Jeroen, do you feel like raising point 2 to the clang/LLVM folks?

It is removed on purpose as far as I understood. I don't think they
regards it as a bug, see obfuscated patch below. 

> Other than that, the patch series seems to be good. I'll apply it
> soonish.
> 

Thanks,
Jeroen


[1] https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html
[2] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=13029


s/~/-/g

~~~

[U-Boot] [PATCH v3 0/8] add clang support for some ARM boards

[Albert ARIBAUD]

Hi Jeroen,

On Thu, 11 Sep 2014 13:17:20 +0200, Jeroen Hofstee
<jeroen@myspectrum.nl> wrote:

> Hello Albert,
> 
> On do, 2014-09-11 at 10:32 +0200, Albert ARIBAUD wrote:
> 
> > 
> > On Wed, 10 Sep 2014 20:08:50 +0200, Jeroen Hofstee
> > <jeroen@myspectrum.nl> wrote:
> > 
> > > Changes since v2:
> > >    - As Albert pointed out the clang instructions don't work with
> > >      Debian based binary packages. While I was aware of that it is
> > >      for a different reason then I thought, it is not that ARM is not
> > >      enabled as a backend but older versions are a bit more picky on
> > >      the target argument and don't tolerate a trailing dash to it as
> > >      used for CROSS_COMPILE etc. The README is updated accordingly.
> > > 
> > >      As a side note clang3.5-svn as shipped in Ubuntu is not the 3.5
> > >      release but an snapshot of some svn commit and hence explain why
> > >      the recompiled 3.5 can behave different then the ubuntu clang-3.5.
> > >      Since it misses some patches, the clang3.5-svn can build less
> > >      boards then 3.4 or an actual 3.5 release.
> > > 
> > >    - While add it, include Masahiro suggestion to also use c++ instead
> > >      of g++.
> > >    - Drop dependencies from the cover-letter as they are merged.
> > >    - only patch 7/8 and 8/8 are reposted. 1..6 are the same as v2.
> > 
> > Thanks, tested building rpi_b, it works now.
> > 
> > The, tested on versatileqemu out of curiosity and got the following
> > results:
> > 
> > 1.
> > 
> > clang warns about Unused static functions in common/console.c, namely
> > console_printdevs and console_doenv (1). Why gcc does not flag this?
> > We have -Wall set which is supposed to imply -Wunused-functions.
> 
> It is a gcc feature, see [1]: "Warn whenever a static function is
> declared but not defined or a _non-inline static function_ is unused.
> This warning is enabled by -Wall."

Ok, I'll assume there is some logic in there, but then, clang does not
follow that logic -- so which one is the 'good' one? Or maybe that's
the same as the second issue, where...

> > There is also an unused variable warning in disk/part.c28
> > (block_drvr). I haven't looked at why clang warns about it and not gcc,
> > but it could raise the same question as the functions above.
> 
> Also a gcc feature, see [2]. The constant is indeed not used.

... apparently, it's a case of trying to balance false positives and
missed true issue, and each team has its own view of where to set
the limit. :/

(anyway -- here clearly, clang is right in warning us and gcc is wrong
in not doing it)

> > 2.
> > 
> > clang errors on arch/arm/lib/cache.c:28 for this:
> > asm("0: mrc p15, 0, r15, c7, c10, 3\n\t" "bne 0b\n" : : : "memory");
> > and that is a clang mistake, as for ARM926EJS r15 is a valid (albeit
> > quite special semantically) Rd for Test and Clean DCache, see page 2-24.
> > 
> 
> This is the integrated-as complaining (the README tells you to disable
> it for the moment). The clang folks push UAL hard, up to a point we need
> to think about minimum gcc version etc. To avoid that, I just left out
> such changes and just use gas instead, at least for the time being.
> Below are some changes to compile versatileqemu with llvm integrated-as
> and gcc/gas. No idea if it actually boots though.
> 
> > Jeroen, do you feel like raising point 2 to the clang/LLVM folks?
> 
> It is removed on purpose as far as I understood. I don't think they
> regards it as a bug, see obfuscated patch below. 
> 
> > Other than that, the patch series seems to be good. I'll apply it
> > soonish.
> > 
> 
> Thanks,
> Jeroen

> ~       "mrc p15, 0, r15, c7, c14, 3\n"
> +       "mrc p15, 0, apsr_nzcv, c7, c14, 3\n"

Is this is a hack to set the Rd field of the mrc instruction to a value
equal to what "r15" would have given, but fooling clang by using an
unrelated and, in this context, meaningless, symbol instead of "r15"?

Amicalement,
-- 
Albert.

[U-Boot] [PATCH v3 0/8] add clang support for some ARM boards

[Albert ARIBAUD]

Hi Jeroen,

Correction on the asm stuff:

On Thu, 11 Sep 2014 13:17:20 +0200, Jeroen Hofstee
<jeroen@myspectrum.nl> wrote:

> > clang errors on arch/arm/lib/cache.c:28 for this:
> > asm("0: mrc p15, 0, r15, c7, c10, 3\n\t" "bne 0b\n" : : : "memory");
> > and that is a clang mistake, as for ARM926EJS r15 is a valid (albeit
> > quite special semantically) Rd for Test and Clean DCache, see page 2-24.
> > 
> 
> This is the integrated-as complaining (the README tells you to disable
> it for the moment). The clang folks push UAL hard, up to a point we need
> to think about minimum gcc version etc. To avoid that, I just left out
> such changes and just use gas instead, at least for the time being.
> Below are some changes to compile versatileqemu with llvm integrated-as
> and gcc/gas. No idea if it actually boots though.

Actually, I had the -no-integrated-as then and have just re-tested now,
making sure I have it and get the error above. For some reason, despite
the -no-integrated-as option, the internal assembler is invoked.

Amicalement,
-- 
Albert.

[U-Boot] [PATCH v3 0/8] add clang support for some ARM boards

[Albert ARIBAUD]

Hi Jeroen,

On Wed, 10 Sep 2014 20:08:50 +0200, Jeroen Hofstee
<jeroen@myspectrum.nl> wrote:

> Changes since v2:
>    - As Albert pointed out the clang instructions don't work with
>      Debian based binary packages. While I was aware of that it is
>      for a different reason then I thought, it is not that ARM is not
>      enabled as a backend but older versions are a bit more picky on
>      the target argument and don't tolerate a trailing dash to it as
>      used for CROSS_COMPILE etc. The README is updated accordingly.
> 
>      As a side note clang3.5-svn as shipped in Ubuntu is not the 3.5
>      release but an snapshot of some svn commit and hence explain why
>      the recompiled 3.5 can behave different then the ubuntu clang-3.5.
>      Since it misses some patches, the clang3.5-svn can build less
>      boards then 3.4 or an actual 3.5 release.
> 
>    - While add it, include Masahiro suggestion to also use c++ instead
>      of g++.
>    - Drop dependencies from the cover-letter as they are merged.
>    - only patch 7/8 and 8/8 are reposted. 1..6 are the same as v2.

Series (patches 1-6 of v2, 7 and 8 of v3) applied to u-boot-arm/master,
thanks!

(still 2 warnings and 5 errors at the top of u-boot-arm/master, but
this series does not make things any worse)

Amicalement,
-- 
Albert.

[U-Boot] [PATCH v3 0/8] add clang support for some ARM boards

[Jeroen Hofstee]

Hello Albert,

On 11-09-14 17:43, Albert ARIBAUD wrote:
> Hi Jeroen,
>
> Correction on the asm stuff:
>
> On Thu, 11 Sep 2014 13:17:20 +0200, Jeroen Hofstee
> <jeroen@myspectrum.nl> wrote:
>
>>> clang errors on arch/arm/lib/cache.c:28 for this:
>>> asm("0: mrc p15, 0, r15, c7, c10, 3\n\t" "bne 0b\n" : : : "memory");
>>> and that is a clang mistake, as for ARM926EJS r15 is a valid (albeit
>>> quite special semantically) Rd for Test and Clean DCache, see page 2-24.
>>>
>> This is the integrated-as complaining (the README tells you to disable
>> it for the moment). The clang folks push UAL hard, up to a point we need
>> to think about minimum gcc version etc. To avoid that, I just left out
>> such changes and just use gas instead, at least for the time being.
>> Below are some changes to compile versatileqemu with llvm integrated-as
>> and gcc/gas. No idea if it actually boots though.
> Actually, I had the -no-integrated-as then and have just re-tested now,
> making sure I have it and get the error above. For some reason, despite
> the -no-integrated-as option, the internal assembler is invoked.
>
>

You don't happen to be testing with the clang 3.5 minus a half /
non release (svn 201651) right? As I mentioned before, it will do
you more harm then good. I cannot reproduce this with an 3.4 nor
3.5 release.

Regards,
Jeroen

[U-Boot] [PATCH v3 0/8] add clang support for some ARM boards

[Jeroen Hofstee]

Hello Albert,

On 11-09-14 15:31, Albert ARIBAUD wrote:
>> Thanks, tested building rpi_b, it works now.
>>
>> The, tested on versatileqemu out of curiosity and got the following
>> results:
>>
>> 1.
>>
>> clang warns about Unused static functions in common/console.c, namely
>> console_printdevs and console_doenv (1). Why gcc does not flag this?
>> We have -Wall set which is supposed to imply -Wunused-functions.
>> It is a gcc feature, see [1]: "Warn whenever a static function is
>> declared but not defined or a _non-inline static function_ is unused.
>> This warning is enabled by -Wall."
> Ok, I'll assume there is some logic in there, but then, clang does not
> follow that logic -- so which one is the 'good' one? Or maybe that's
> the same as the second issue, where...

well I don't know the details, but the compiler should not emit a
warning if the static inline came from a header file, perhaps that
is motivation behind it. Anyway I have a branch with 60 patches
or so fixing warnings, don't bother too much about them for the
time being.

>>> 2.
>>>
>>> clang errors on arch/arm/lib/cache.c:28 for this:
>>> asm("0: mrc p15, 0, r15, c7, c10, 3\n\t" "bne 0b\n" : : : "memory");
>>> and that is a clang mistake, as for ARM926EJS r15 is a valid (albeit
>>> quite special semantically) Rd for Test and Clean DCache, see page 2-24.
>>>
>> This is the integrated-as complaining (the README tells you to disable
>> it for the moment). The clang folks push UAL hard, up to a point we need
>> to think about minimum gcc version etc. To avoid that, I just left out
>> such changes and just use gas instead, at least for the time being.
>> Below are some changes to compile versatileqemu with llvm integrated-as
>> and gcc/gas. No idea if it actually boots though.
>>
[..]

>> ~       "mrc p15, 0, r15, c7, c14, 3\n"
>> +       "mrc p15, 0, apsr_nzcv, c7, c14, 3\n"
> Is this is a hack to set the Rd field of the mrc instruction to a value
> equal to what "r15" would have given, but fooling clang by using an
> unrelated and, in this context, meaningless, symbol instead of "r15"?
>

Nope, it is UAL syntax, binutils agrees:

 > arm-linux-gnueabi-objdump -S u-boot

flush_dcache:
         mrc     p15, 0, r15, c7, c10, 3
    10320:       ee17ff7a        mrc     15, 0, APSR_nzcv, cr7, cr10, {3}


Clang is just pushing it a bit harder. I have a branch for that too,
but as said, I will let it bit-rot for a while, since that would require
about minimal gcc versions and other boring stuff.

Regards,
Jeroen