On 02/23/2015 10:05 PM, Masahiro Yamada wrote:
Hi Simon, Stephen,



On Mon, 23 Feb 2015 10:44:54 -0700
Simon Glass <s...@chromium.org> wrote:

Hi Stephen,

On 23 February 2015 at 10:33, Stephen Warren <swar...@wwwdotorg.org> wrote:
On 02/23/2015 07:02 AM, Simon Glass wrote:

Hi Masahiro,

On 20 February 2015 at 19:37, Masahiro YAMADA <yamad...@jp.panasonic.com>
wrote:

Hi Simon,


2015-02-21 11:28 GMT+09:00 Simon Glass <s...@chromium.org>:

Hi Masahiro,

On 20 February 2015 at 17:54, Masahiro YAMADA
<yamad...@jp.panasonic.com> wrote:

Hi Simon, Stephen,


2015-02-21 3:39 GMT+09:00 Simon Glass <s...@chromium.org>:

Hi,

On 20 February 2015 at 10:54, Stephen Warren <swar...@wwwdotorg.org>
wrote:

On 02/20/2015 10:06 AM, Simon Glass wrote:


+Stephen

Hi Masahiro,

On 19 February 2015 at 22:25, Masahiro Yamada
<yamad...@jp.panasonic.com>
wrote:


Now CONFIG_SPL_BUILD is not defined in Kconfig, so
"!depends on SPL_BUILD" and "if !SPL_BUILD" are redundant.



diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 41f3220..700e2a8 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -739,9 +739,8 @@ config TEGRA
           bool "NVIDIA Tegra"
           select SUPPORT_SPL
           select SPL
-       select OF_CONTROL if !SPL_BUILD
-       select CPU_ARM720T if SPL_BUILD
-       select CPU_V7 if !SPL_BUILD
+       select OF_CONTROL
+       select CPU_V7



Sorry if I have missed something here. On Tegra most unfortunately
the
SPL uses ARMv4t and U-Boot proper uses ARMv7. In fact that is the
only
reason that Tegra has SPL. Doesn't this change with this commit?



No.   I think behavior is still the same as before.

In a single .config, we cannot define two CPUs in Kconfig.

So, we only define CPU_V7, for the main processors.

For SPL, we override the "CPU" in config.mk

ifdef CONFIG_SPL_BUILD
ifdef CONFIG_TEGRA
CPU := arm720t
endif
endif

I know what you might be saying is, this is too ugly. Yes.

I think we can do a little better with further rafactoring,
but the basic idea is, SPL of Tegra is a special case.


Yes I saw that, I understand now. So SPL_BUILD is no longer available
in Kconfig, but is still available in Makefiles, right?


Yes, exactly!


This all works fine on Tegra for me. However I like to suggest
dropping a few patches in this series.

I don't think it is worth using ARCH_MALLOC_F_LEN. In fact for me the
Tegra defconfig looks OK and SPL is built correctly.

My remaining question is about that Tegra seems to want
USE_PRIVATE_LIBGCC for SPL but not for U-Boot. I'm not sure why, nor
whether it matters. It seems to work find using it for both.


Depending on the toolchain, we actively need USE_PRIVATE_LIBGCC for SPL, and
don't /need/ it for non-SPL. However, enabling USE_PRIVATE_LIBGCC for
non-SPL likely won't hurt.

The issue is that the libgcc bundled with most compilers is for ARMv7 (since
we tend to use ARMv7 compilers, since the main U-boot is built for ARMv7).
That bundled libgcc won't work on the ARMv4 that runs the SPL, so we need
USE_PRIVATE_LIBGCC there. The private libgcc bundled with U-Boot should work
fine when built for either CPU, so it is OK to always use it, rather than
only use it when strictly needed.

Ah yes, I think I knew that once. So in short Masahiro's patch here
should be fine.



Yes, Stephen explained all about my intention.

I think CONFIG_USE_PRIVATE_LIBGCC is also necessary for Raspberry Pi 1 for 
example.

I can't remember if it's already set for the Pi. If not, the toolchains I use happen not to need it:-)

Moreover, I had already posted this patch:
http://patchwork.ozlabs.org/patch/438360/

I'd like to expand the private library to all the ARM boards.


Linux Kernel includes the library in its source tree.

I think it is generally a good idea to reduce the depencendy on particular 
toolchains.
Agree?

I tend to agree. However, in the past, Wolfgang Denk has argued against (ever?) using that option, claiming people should just use the correct toolchain.
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